From the ABC 7 Weather team

Coastal Storm with Big Travel Impact Imminent for D.C. on Wednesday

November 24, 2014 - 08:15 AM
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Last week it looked unlikely, and now it is almost certain that D.C. will see a strong storm on Wednesday with the first snowfall of the season. And, on top of it all, the timing couldn't be worse for Thanksgiving travelers.  There are still many elements that have to come together.  Here is what we know right now. A cold front will pass our region tonight and stall just to our east in the Atlantic.  Low pressure will develop near the Carolinas Tuesday night into Wednesday  morning and head up the coast.  It will pull in colder air from the northwest and moisture from the Atlantic Ocean to make a travel headache for millions of Americans from DC to New England. All of the weather computer models have synced up that there will be a strong coastal storm, but they differ in the exact track.  This means that there is still uncertainty on where the rain/snow line is and how much snow could accumulate.

Possible Computer Model Storm Tracks

What can we expect in the D.C metro?  Right now, I am expecting temperatures to be in the 40s when we wake up on Wednesday, leading to the onset of precipitation as a cold rain.  As temperatures drop, it will transition to snow in the afternoon.  Because of the borderline temperatures at the surface and warm ground with today's record heat, it is going to be tough to get snow to accumulate on roads inside the beltway.  Minor accumulations are possible on grassy areas, but the snow rates will have to be very heavy for that to happen.

 

Potomac Highlands/Blue Ridge/Mountains:  Temperatures are key here too with upper 30s possible to start the day as moisture moves in.  Rain/snow mix possible to start with transition to snow by late morning or early afternoon.  With falling temperatures and elevation, snow will likely accumulate here.  It's too soon to put numbers on this, but we may need a whole hand to count the number of inches that accumulate.  As temperatures drop further after sunset, roads will become icy.

Computer models are showing a very wide range of possible accumulations. We will have a better idea Tuesday morning, so stay tuned for snow band maps. Here is a look though at a probability graphic of 1" of snow or more accumulating from Wednesday morning through Thursday morning.

Percentage of Probability of 1" of Snow or More- NOAA

The storm will exit late Wednesday or very early Thursday morning with wrap around snow showers in the mountains.  The rest of Thursday will be clear and cold with highs in the upper 30s to lower 40s.  A good day to turn on the oven and cook a bird and stay indoors.  The rest of the holiday weekend is looking calm and cool.

 

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Warming Up on Monday but Uncertainty Comes Mid-Next Week

November 21, 2014 - 02:33 PM
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Get ready for a warm up-and I believe that is something we can all latch on to given the bitterly cold air more normal for January that moved into our area of the last week. However, after some evening rain on Sunday, we will warm up nicely on Monday – into the lower 70s in some spots!

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Caption: Temperatures warm to around 70 degrees on Monday

However, a cold front will sweep on through on Monday night into Tuesday morning and that will gradually bring an end to our mini warm up. Tuesday should be a fairly quiet day as temperatures will still top out in the mid to upper 50s with sunshine however, as we head into Wednesday, we could see some changes.
Since this is several days away, the forecast confidence is low for mid next week but given it is one of the busiest travel days of the year, I want to go ahead and tell you what we’re looking it. Temperatures will continue to fall below normal on Wednesday and Thursday (Thanksgiving)-most likely topping out in the mid to upper 40s.
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The frontal system that passes through the area on Tuesday morning will stall out off the eastern seaboard. The models are hinting at an area of low pressure forming along the stalled frontal boundary and moving north along it. The question will remain: how close to the coast can that area of low pressure get? If we see a shift westward, then we could have some rain/snow along the eastern seaboard on Wednesday (D.C. area included). However, if it keeps veering out to sea, there is a good chance of not seeing anything expect a dry day here. Obviously this will be something we continue to watch as we head into next week.

As far as the rest of the U.S. is concerned for travel, there are no major storms across the region mid-next week. There could be a clipper system that dives southeast out of northwestern Canada that could bring some light snow showers to the Great Lakes region and Upper Plains (this could include any Chicago airports) – however, any snow associated with that looks to be light.

Until then, just enjoy the weekend and we’ll keep an eye on the weather!

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Voracious sunspot could impact us on Earth

November 20, 2014 - 10:22 AM
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When the sunspot faced Earth last month it was the largest one on record in nearly a quarter century. What impacts could it have on us and is there anything we can do to prepare for it? Check out my one-on-one interview with NASA Solar Astrophysicist Dr. Alex Young.

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Record cold across the D.C. area Wednesday morning

November 19, 2014 - 11:07 AM
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Record lows were broken at both Dulles and BWI Marshall last night. Dulles broke the record of 20F set back in 1990 by 7 degrees as the location plunged to 13F this morning. BWI Marshall broke its record of 20F set in 1936 as they dropped to 19F this morning. Reagan National, which hasn't broken any record lows between November and March since 1996 was close, but still failed to break the record of 18F this morning as it only fell to 22F.

Record Lows at Dulles and BWI Marshall Wednesday morning

 A number of other records were broken across the country this morning as well. Here are a few cities that also broke or tied low temperature records. You can find a bigger list of all kinds of records from the NWS here.

Elkins, WV: 12F (Old record 14F-1990)

Richmond, VA: 18F (Tied 1936)

Philadelphia, PA: 20F (Tied 1936)

Morgantown, WV: 16F (Old record 19F-1989)

Charleston, SC: 23F (Old record 27F-1949)

Savannah, GA: 26F (Old record 27F-2008)

Jacksonville, FL: 27F (Old record 28F-2008)

New Orleans, LA: 31F (Tied-1946)

While it was freezing in the central and eastern U.S., the opposite is happening in parts of Alaska, with record highs broken in both Anchorage and Nome yesterday.

Temperatures will begin to moderate tomorrow as they settle back into the mid 40s, but another brief cold push is expected Friday before a milder weekend ahead. Just to put this cold in perspective, today will be the earliest day with highs below 40 degrees at Reagan National since 1996. Basically, this is the coldest it's been this early in the season in 18 years. I don't think anyone I've spoken to has missed the cold!

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Arctic Blast Brings Record Challenging Temperatures Tonight and Wednesday

November 18, 2014 - 08:49 AM
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Today's bitter arctic blast brought us the coldest air of the season so far and beats last week's cold by about ten degrees. D.C. dropped down into the 20s for the first time and wind chill temperatures were down in the the teens and even single digits in a few spots.

Lows this Morning

Believe it or not, our high temperature actually happened at midnight with 42 degrees and then plummeting temperatures through sunrise. This afternoon will recover a bit, but temperatures only warm a few notches in the low to mid 30s. That is more typical of January temperatures! And it isn't just the temperatures making it feel unreasonably cold. Gusty winds will keep our wind chill factor in the 20s all day long. Wind gusts will reach 25 to 30mph at times. Here's a look at ABC7's computer model forecast wind chill temperatures this afternoon.

Forecast Wind Chill this Afternoon

The wind will diminish after sunset, so that will help, but clear skies means a cold night ahead. Record lows are in jeopardy tonight. The record low for Dulles is 20. I'm expecting to meet or just break that record. Reagan National's record low is 18, and I think we'll miss that by just a few.

Lows Wednesday Morning

Additional records may be set Wednesday afternoon. Highs will only reach the low to mid 30s. We could have the coldest high temperature on record for the date. Here at the stats for that.

Record Cold Highs Wednesday?

By Thursday, we start a slow recovery with temperatures back in the 40s. A dry cold front will pass our area, but won't bring the temperatures down too much more on Friday. For those of you hating on the cold, we'll reach near average temps in the mid 50s late this weekend and should easily top 60 on Monday. The warmer temperatures won't stop there.

 

6-10 Day Temperature Probability

The 6-10 day outlook has much above average temperatures for the Mid-Atlantic and that should last into the first part of December. Hang in there!

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Chilly Rain Monday Then Bitter Blast Tuesday

November 16, 2014 - 04:47 PM
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Grab the umbrella and rain coat Monday morning and allow for some extra time for the AM commute.  Rain, and even some sleet, started falling Sunday evening and rain will continue, on and off, through late Monday afternoon.  Even though there were reports of sleet at the onset of precipitation, temperatures will remain above freezing for the duration of the wet weather, so it will be an all rain event.

Here's a radar simulation at 7 AM Monday.  Notice the wide shield of rain overhead.  Expect extra delays for the morning rush, so be prepared.

The rain is coming from an area of low pressure currently over the deep south.  This low will track northeastward overnight and tomorrow bringing ample moisture.  Between .75-1.00" of rain is expected.  Here's a larger view of our weather story.

The bulk of the moisture should be out of the region by the evening commute.  Winds will begin to shift out of the NW drawing in another very cold airmass.  Temperatures will tumble quickly Monday night into the lower 30s.  The gusty winds should help dry the roads, but icy spots are possible Tuesday morning.  Even during the afternoon, highs will struggle to reach the freezing marks in spots.

Temperatures will be nearly 20° colder than average for this time of year.  And it's not just us dealing with the bitter cold.  The map below shows the temperature departure from average.  The blue and purple colors indicate temperatures 20-30° below average. 

WxBell GFS Output

If the cold wasn't enough, winds will be howling between 25-35 mph Tuesday.  That means wind chills will be in teens and 20s during the day.  Here's an hourly forecast of the "feels like" temperature on Tuesday.

Winds will gradually diminish late Tuesday night, but the cold air sticks around Wednesday with highs, again, in the mid 30s.  Temperatures will rebound slightly by the end of the week and into next week, but will still be well below our average of 58°.

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Fun Weather Facts: Just How Cold & Snowy Has It Been?

November 15, 2014 - 06:35 PM
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*A total of 28.5% of the U.S. is currently covered by snow compared to 5.8% last year at this time.

Current Snow Depth
Current Snow Depth

*In the last 11 years, only November 2012 comes closest to snow coverage seen so far this month when 20.1% of the Lower 48 was covered by snow.

Current Snow Depth
Current Snow Depth
*Snowfall coverage (snow extent in thousands of square kilometers) across North America in September was the highest since records began in 1966 and eighth highest in October.
Current Snow Depth *Snowfall coverage (snow extent in thousands of square kilometers) in northern Asia (Eurasia) last month was the second highest since records began in 1966.
Current Snow Depth *In the last 24-hours, there was a 103 degree temperature spread across the U.S. The high Friday hit 84 at Death Valley, CA and today’s morning low was -19 in Jordan, MT & Dunn Center, ND..

*There have been more cold record highs set this month in the U.S. than warm record highs.

Current Snow Depth *Lake Superior (largest of the Great Lakes) and Lake Michigan’s water temperatures are below average; the remainder of the Great Lakes currently are seeing near average water temperatures.

Be sure to get the latest forecast for the Washington area by clicking here.

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A Cold Wet Rain Could End as Snow on Monday

November 14, 2014 - 12:46 PM
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If you didn’t think the cold weather was here with yesterday’s daytime high temperatures topping out in the 40s, I am sure you were reminded how winter has paid us an early visit with the first flakes of the season Thursday evening. Not everybody saw the light flurries; some people experienced some sleet as well! Any precipitation last night quickly changed to rain but it was a reminder that this forecast is more reminiscent of a December or January forecast as opposed to a mid-November forecast. Either way, we will have yet another reminder of winter paying us an early visit as we start off the next work week.

Winds will continue to die down through the evening so we are expecting light winds during the overnight. Light winds and clear skies means those temperatures are going to drop.

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Caption: Overnight lows Friday overnight

We will start off on the chilly side on Saturday as arctic high pressure builds right overhead. Temperatures will manage to make it into the low to mid 40s. So if you are headed to College Park on Saturday night, watch for temperatures falling through the lower 30s during the Maryland/Michigan State game. Clouds will increase on Sunday ahead of our next system with temperatures warming to around 50 degrees! That means we are looking good for the Redskins vs. Tampa Bay game at Fed Ex – just some clouds but remaining dry.

After midnight on Sunday, all bets are off. An area of low pressure will move out of the Gulf of Mexico and to the northeast along a cold front. It will gain some energy from a few disturbances moving out of the Great Lakes region as well as the Midwest.

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We could see a little wintry mix at the onset after midnight on Sunday well north and west of D.C. but this is mainly going to be a cold rain event for the WJLA viewing area all day on Monday with the influence of warm air at all levels of the atmosphere. And FYI, it will most likely rain both during the morning AND evening commutes.

 

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Caption: Monday afternoon, snow stays well west with rain (green) around the region.

As that low moves off the coast into the evening hours, there is a chance the rain could quickly change to some light snow as cold air surges in from the west. Not expecting any accumulation around the D.C. area as that low will quickly move to the north and east, taking the precipitation with it.
After the precip moves out Monday night, another arctic high pressure will move in advancing even colder air into the region. Daytime highs on Tuesday and Wednesday may not make it out of the 30s!

Good news is, the Climate Prediction Center has our temperatures moving back towards normal (mid to upper 50s) by Thanksgiving week so there is an end in sight!

 

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The 1987 Veterans Day Snowstorm remembered

November 11, 2014 - 11:20 AM
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Above is some footage from Fox 5 during the 1987 Veterans Day Snowstorm. Thanks to Capital Weather Gang for finding this and I hope you all enjoy watching my friend Sue Palka discuss the storm. Notice that it reached the 60s the day before and the forecast was for highs in the 50s with scattered light rain. Let's just go ahead and hope this scenario doesn't repeat itself any time this Winter!

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Arctic cold front moves through D.C. midweek

November 10, 2014 - 12:23 PM
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Enjoy the mild temperatures while they last this afternoon through Wednesday, as unfortunately they won't hang around much longer. Conditions will remain very quiet and mild through Tuesday.

Wednesday will continue to be mild but a strong cold front is expected to enter the region, with gusty winds up to 20-25 mph and cooling temperatures through the afternoon and evening. After highs in the mid 60s Wednesday, morning low temperatures should be in the 20s and 30s by this Thursday.

Comparison of forecast 850mb temperatures this evening (left) and Thursday evening (Right) Courtesy: College of Dupage Models

For the tail end of the work week into the weekend, temperatures should hang in the 40s. The current forecast depicts highs in the upper 40s Thursday, low to mid 40s Friday and mid to upper 40s for the weekend. There is a chance the 50 degree mark may be reached on Sunday ahead of another cold push returning temperatures in the 40s possibly Monday through Friday of next week.

ECMWF Forecast Temperature Anomaly Friday afternoon (Courtesy: WeatherBell Models)

While this isn't statistically qualifying as extreme cold, it will be unseasonably cold for this time of year with highs forecast to be on the order of 10 to 15 degrees below average. In addition, Reagan National is yet to record a high temperature below 50 degrees this fall, and hasn't experienced a prolonged period of sub 50 degree days since March 24-26 when highs topped out at 43, 36 and 39 degrees and 1.7" of snow fell during the time period.

Speaking of snow, there has been talk about the potential for some flakes in the forecast over the past few days. As of our current forecast, the best possibility will be Thursday night into Friday morning mainly south and east of the city as a weak area of low pressure develops off the Virginia/North Carolina coastline. The best possibility to see any flakes would be closer to the Middle Peninsula of Virginia and points south and east. This system looks moisture-starved and too far east to affect the D.C. Metro at this time.

500mb heights and vorticity forecast for Sunday showing the next trough and energy allowing for the next better chance for precipitation (Courtesy: College of Dupage Models)

A stronger area of low pressure looks to develop for the latter part of the weekend on Sunday bringing with it an additional chance for precipitation, but at the moment it appears to be in the wet variety rather than white. We will of course keep you informed throughout the week of any forecast changes.

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Cold Air Headed Our Way after Remnants of Nuri Hits Alaska

November 7, 2014 - 12:01 PM
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After a windy Friday, we will settle nicely through the 50s for the weekend. The weekend forecast looking great! We may have a few clouds and a sprinkle here or there Saturday evening into Sunday morning, but for the most part, we are looking at sunshine!

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Nice weather will continue into the beginning of next week as a weak area of high pressure moves into the region. Temperatures will rebound back into the low 60s for a period of time before another cold front pushes through the region by mid next week. After that, big changes are on the way to our area.


Remember that Super Typhoon Nuri that I was harping about in my last blog? Well it is barreling down on the western coast of Alaska and the Bering Sea as it has now formed into a cold core low that is a very powerful storm. Most likely, one of the most powerful storms we have seen in 2014 and one of the most powerful storms to hit Alaska in decades. This storm could actually be a record breaker in that it could break the lowest atmospheric pressure recorded in Alaska. The old record was 925mb (millibars) that was measured in October of 1977 in the Dutch Harbor (off the southern coast of Alaska).

 

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Alaska will take a brutal hit from this storm this weekend with hurricane force winds, very high seas and heavy precipitation. As it stalls out during the end of the weekend and into early next week in the central Bering Sea, it will weaken significantly knocking down the odds of a large coastal flood event of the mainland of Alaska. However, this storm will have an effect on our weather around the continental United States as it causes a ripple effect for the jet stream.


Okay, let’s all calm down about a polar vortex (yes, I am talking about my friends around the country in the media). THE POLAR VORTEX IS ALWAYS THERE! I want to face palm myself every time I hear that (which has been about 40 times on social media and on TV in about 30 mins on this Friday morning). Here is a simple reminder:

 

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With that being said, yes we are going to get chilly towards the end of next week. Why? Well in simplest terms – behind a cold front that will cross through mid-week, a strong arctic high will build across the region and this little blast of chilly air is most likely due from the remnants of Super Typhoon Nuri as that storm will continue to pump warm air into the atmosphere in the western North America, surging cold air down across the United States.

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Cold air will filter out of the northern plains and continue to trek into the Midwest at the beginning of next week. As we head into the end of the work we and once that frontal system moves through and high pressure slides eastward across the United States, we are looking at temperatures around the D.C. area below average for this time of year.

 

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Caption: Cold air filters out of the Northern Plains on Tuesday afternoon.

 

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Caption: Cold air slides to the east coast by Friday as an Arctic High travels eastward across the United States.

Our average temperature towards the end of next week will top out in the upper 50s; however, we will most likely fall into the 40s by the end of next week. So we are not too chilly but chilly enough to take notice! And just a note, we have generally already fallen into the 40s in the D.C. area by this time so we have some work to do to catch up!

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Super Typhoon Nuri and How It Can Effect D.C. Weather

November 5, 2014 - 04:15 PM
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How much are you enjoying this taste of spring in November? Or would you rather like to keep your winter jackets on with cold air over us? Well, this is the first time I can honestly say we can make everyone happy with the weather forecast. For at least the next 10 days as we get a taste of both mild air and cool air thanks to the remnants of an incredible storm that will reshape near the western coast of Alaska by Friday.

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Caption: NASA’s Aqua satellite captured a visible picture of Typhoon Nuri on November 4th at 11:10p.m. EST as clouds (newly developed thunderstorms) replace the original eyewall.

In the short term, expect rain to roll across the region Wednesday night continuing through the first part of Thursday as a cold front finally works its way through the region. There will be another cold front that will swing through Thursday evening that could produce a few more isolated showers but for the most part, we will just be concerned with the winds and the cool air that will follow the front on Thursday night.


By Friday, temperatures will only rise into the 50s for daytime highs after only topping out in the upper 60s/lower 70s for the last few days.

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We look to stay in the 50s before another warm up into the 60s by the middle of next week followed by another cool down by the end of next week: a rollercoaster of temperatures if you will. And of course, this sounds like something we speak of almost every single month, no matter the season. However, for this forecast – there is an interesting addition to the puzzle. That piece of the puzzle is about 805 miles south of Tokyo, Japan today.

Super Typhoon Nuri is one heck of a storm. This is one of the most impressive and most powerful cyclones that has developed in the western Pacific in 2014. Not only did this storm reach the equivalent of a category 5 hurricane but it kept winds going at 180 mph for at least 24 hours with a minimum pressure recorded of 910mb!

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Wednesday afternoon, Typhoon Nuri moved to the northeast at 12 mph weakening as it migrates to the east of Japan entering into an area with pretty high vertical wind shear, ripping it apart as it travels. It is also moving into colder water, cutting off its moisture and supply feed. However, with that being said, the eventual remnants of Nuri will continue to move through open waters and towards the western coast of Alaska and the Bering Sea, reintensifiying as it navigates to the north and east becoming a storm-force cold core area of low pressure.

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Caption: The European Model shows the strong area of low pressure off the coast of Alaska with a forecast barometric pressure of 920mb.

By the time it reaches the Bering Sea and the western Alaska, the pressure is forecast to drop from about 970mb on Thursday night to between 918mb and 922mb on Friday night (the lower the pressure means the more intense the storm). In fact, the lowest pressure storm (obviously we are not talking about a tropical storm here) observed in the Bering Sea was on October 25th, 1977 where a storm by the Dutch Harbor (the islands the roll southwest off the southern part of Alaska) dropped to 925mb in pressure! *To give you a little comparison: the minimum barometric pressure of Hurricane Katrina’s second landfall was 920mb – which is the third strongest to make landfall*


(For all the weather nerds out there *I am obviously one so I welcome you with open arms*: The extreme drop in pressure will be due to the very cold air at the surface interacting with the warm air from Nuri aloft. This will make for a fast-moving wind surrounded by slower moving air that will eventually create a bombing out or an extreme deepening of that low-dropping the pressure rapidly).


Since this is such a powerful and impressive storm, we are talking about hurricane force winds for Alaska on both Friday and Saturday as well as seas that could reach more than 45 feet with abundant precipitation! Good news is that this low will weaken steadily through the end of the weekend and the middle of next week as it drifts slowly to the east.


However, all this energy has to go somewhere and generally when we see these types of situation, we can see effects across portions of North America as that energy gets pulled into the North Pacific jet stream. All in all, as the storm moved through the open waters of the Pacific, on its way to Alaska, it was already doing its deed and amplifying the longwave pattern downstream across North America. And what does that mean exactly? Well the remnants of Nuri will impact our weather forecast across the continental United States


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Caption: As the remnants of Nuri effects Alaska, we cool down quite a bit on the eastern seaboard with heavy snow and much cooler temperatures expected in the northern plains.

And back to our rollercoaster temperatures here on the east coast. While we are warming up here over the last few days with high pressure pumping in some nice southerly air, we will be cooling down as a front dives our way for Thursday. We look to stay cool through the weekend before yet another frontal system comes through on Saturday into Sunday. Warming up into mid next week, we cool down once again by the end of next week.


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Caption: A look a daytime highs possible next Friday are significantly cooler around the D.C. area.

While I think we will see minimal effects here in Washington D.C. that anybody will just chalk up to “regular weather changes,” it is very interesting to think that everything is connected in the weather world. A storm in the western Pacific could eventually impact our weather no more than 10 days later.

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November weather in the D.C. area

November 4, 2014 - 12:23 PM
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The sunset is around 5pm, our average high temperatures are only in the 60s to start the month and in the low 50s to end the month, and the duration of daylight sinks below 10 hours. Typically, I do not look forward to any of those statistics. And after last winter with over 30 inches of snow reported at Reagan National, I am not hoping for more of the white stuff any time soon. 

If November continues like today and tomorrow with highs around the 70 degree mark you wouldn't hear any complaints for me. Statistically speaking, however, that is entirely unlikely, as the average high temperature drops to 59 degrees by November 12th. The first and second of the month started out below average in the 50s, but we are still waiting for our first day with highs below 50 degrees at Reagan National. That day has already come in four of the past five years.

Earliest days below 50 degrees at Reagan National over the past 5 years

Daylight continues to diminish from ten hours and thirty-two minutes on the first of the month to nine hours and forty minutes by November 30. The sunrise on November 30 is at 7:07am and the sunset is at 4:47pm. We will only lose one more minute of daylight at night into December, with the earliest sunset at 4:46pm from December 2 through December 12.

Veterans Day Snowfall in 1987

As far as snowfall is concerned, Reagan National has not recorded more than a trace of snow since November 14, 1996 when 0.2" fell. In fact, the month only averages 0.5". This doesn't mean we can't have a big snow, as on Veteran's Day in 1987, D.C. recorded 11.5". That is not only a daily snow record for November, but also the record snow for the month.

8-14 day temperature outlook from the Climate Prediction Center

Current 6-10 and 8-14 day outlooks from the Climate Prediction Center are showing temperatures forecast to be below normal, but at this time it does not appear that snow will be in the 7-day through the middle of the month. I guess only time will tell how the rest of the month pans out!

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First Freeze of the Season Possible Sunday Night

November 1, 2014 - 05:12 PM
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A deep trough over the eastern U.S. has brought colder than average temperatures for the first of November.  In fact, some folks in the Carolina's had their first snow of the season!  Check out this view in South Carolina earlier today:

 

No snow for us, but gusty winds will be the main story. The deepening low off the Carolina coast will ride north increasing our winds speeds.  Winds may gust between 30 and 40 mph through tomorrow late morning.  Air temperatures overnight will remain above freezing, but wind chill values will be at or below freezing, especially west of the city.  Here are simulated wind chills tomorrow morning:

As the low pulls farther northeast tomorrow, sunshine will return, but temperatures will only reach the upper 40s.  Keep in mind, winds will still be gusting to around 30mph through the afternoon keeping wind chills in the upper 30s to low 40s.

Winds will subside late Sunday and temperatures will tumble.  Here is a look at the forecast low temperatures by Monday morning.

D.C. will likely remain a few degrees above freezing; however, the growing season will likely end for folks west of the city with below freezing temperatures.

Fortunately, the cold snap will be short lived.  Highs by Monday afternoon will rebound to 60 degrees.

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A Treat For the Halloween Forecast but we will be Tricked for the Weekend

October 31, 2014 - 07:28 AM
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We have experienced quite a rollercoaster week in terms of temperatures. On Tuesday, temperatures made it to 80 degrees. By the weekend, some portions of our area may not make it out of the 40s. We have quite an atmospheric set-up as we head into the end of this work week and weekend so hold on to your hats folks, because we are in for a windy ride. 

For Halloween, we are just watching that initial area of low pressure and its attendant cold front move closer to the Washington D.C. region. I do have a feeling that some showers will get going through the late evening hours (after 8p.m.) in the Shenandoah Valley and west- but only a small chance. Eventually, by Saturday, showers will spread east past the Blue Ridge Mountains. So expect increasing clouds on Friday afternoon ahead of the cold front with showers to the west after about 8p.m. Trick or Treating around the D.C. area should be dry (that is until after midnight when rain chances increase).
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A deep upper level area of low pressure (a “Manitoba Mauler” if you will –since it is originating from the Canadian province of Manitoba) and its attendant cold front will shoot down from the Great Lakes region Friday and continue to trek through the Appalachian Mountains. Canadian high pressure will aid in the movement of the upper level low. Through Saturday, that area of low pressure will transfer its energy off the coast of North Carolina to a developing coastal low.

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Saturday is a different story. If you are headed to any area college football games (Maryland at Penn State, TCU at WVU, Boston College at Virginia Tech or the night game at Fed EX as Navy hosts Notre Dame) – it is going to be cold! Temperatures on Saturday with on and off spotty rain showers will only top out in the upper 40s to lower 50s. However, winds will increase after 10a.m. on Saturday to around 10 – 15 mph. As we head through the early afternoon and into the evening hours, winds will increase 15-25 mph with gusts up to 30 mph. By the evening hours (after around 7p.m.), wind chills will end up in the 30s.
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Caption: This is a look at wind speeds off the eastern seaboard after midnight on Saturday. (Courtesy: WeatherBell Models)

Winds will continue to be strong over the course of Sunday. However, we will get some sunshine back on Sunday as high pressure builds in. Temperatures on Sunday will only top out in the upper 40s for most spots and with the wind, it will feel much cooler!

However, this cold spell won’t last too long. As we head into the next work week, we will gradually warm up into the lower to mid 60s by Wednesday.

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Partial solar eclipse arrives Thursday

October 22, 2014 - 04:16 PM
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A partial eclipse happens when the moon passes in front of the sun, partially obscuring the disk of the sun with some of it left uncovered. This will occur late today just before sunset at 6:19PM.

Live coverage of the eclipse can be viewed online from NASA here starting at 5pm!

While the window of opportunity to catch the partial eclipse on the east coast is limited (26 minutes in the metro D.C. area) the farther west you head the longer that window take in the celestial splendor.

Courtesy: NASA

Viewing is expected to be best for people in the Central Time Zone because of the timing and the weather, which is mainly clear in those locations. Locally, it may be a different story, as the low pressure system riding along the east coast is expected to continue to spread clouds over the region. The hope is that while the region will start mostly cloudy we should break into some sunshine by this afternoon.

One thing is for certain, if you can see the sun, do not attempt to view the partial eclipse without special viewing tools as you can damage your eyes. From NASA, "Direct viewing should only be attempted with the aid of a safe solar filter."

Check out this great tutorial on how to make a solar eclipse viewer from the great folks at space .com!

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Weak tornadoes last week confirmed by National Weather Service

October 20, 2014 - 08:30 PM
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Big tree went right into this Honda in Alexandria during the storm last week. (Photo: Jeff Goldberg/WJLA)

The National Weather Service confirmed Monday an EF-0 tornado touched down in eastern Fairfax County and the City of Alexandria. The storm hit during the noontime hour on October 15th. Estimated wind speeds are said to have been between 55 and 60 miles per hour. Skipping a path about one and one-half miles long, it first touched ground near Belle Haven in eastern Fairfax County and quickly moved north into the City of Alexandria. Within three minutes, rotation was no longer detected.

Damage was limited to a few downed trees and snapped limbs. No injuries were reported.

Another tornado was confirmed near Savage, Maryland in eastern Howard County. This storm also had winds clocked around 60 miles per hours and uprooted a large tree.

Some scrutiny had been placed on the National Weather Service for issuing a Tornado Warning that included a large and heavily populated area in the middle of the workday. The warned areas included parts of Fairfax, Arlington and Prince Georges counties along with Alexandria and the District.

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Frost Season: When Will Washington Have Its First One?

October 19, 2014 - 06:31 PM
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A Frost Advisory is posted when temperatures are expected to be 33 to 36 degrees on clear, calm nights during the growing season. An even colder night that brings temperatures to or below freezing requires the weather service to issue a Freeze Warning.

Both of these cold weather alerts are only posted until the end of the growing season. When defines the conclusion to the growing season? A widespread freeze (temperatures at or below freezing) that kills off outside vegetation left uncovered.

The Allegheny mountains far west of Washington are first to see the end of the growing season. As time goes on during the fall, the temperatures eventually get cold enough to end the growing season from the Allegheny Foothills to the Blue Ridge.

First Frost

The Washington area has its first frost usually around this time; mid-October. In an average fall then, by November 1, temperatures likely have dipped below freezing to end the entire Mid-Atlantic’s growing season.

Frost Advisories and Freeze Warnings cease to be posted then during the winter but are warranted when a late-spring freeze is expected to cause damage to plants and crops.

Below is a table that lists the typical first fall frost and last spring frost dates. If temperatures are expected to be near or below freezing after the typical last spring frost dates, Frost Advisories and/or Freeze Warnings will be posted.

First Frost

Stay with ABC7 and WTOP for the latest forecasts and cold weather alerts as Autumn continues.

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Weak El Nino? What could that mean for D.C. Winter - Comparing the past

October 17, 2014 - 03:15 PM
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Now that we have established that in the D.C. region, the summer of 2014 wasn’t quite as cool as we had perceived it to be, we can now move on to the winter of 2014-2015. Does a cool summer mean a harsh winter? I have been getting this question a lot, especially as we head into the end of October.

I decided to go back to ALL of the harsh winter’s Washington D.C. has recorded since 1899 and tried to find exactly what the summer preceding that harsh winter was exactly like and if we were experiencing a La Nina year, an El Nino year or a neutral year since that gives us an idea of our winter long range forecast. Again, these are all from Washington, D.C. National Weather Service forecast office (it had moved a couple times throughout this history but was always within the District of Columbia). 

1899: The Great Eastern Blizzard of ’99.
The Winter: This storm moved into the Washington D.C. region on Valentine’s Day, a Tuesday in 1899. Snow was reported as far south as Florida with around 21.0” of snow falling on the Washington D.C. and Baltimore area and up to 16.0” as far as New York. Pretty gusty winds that accompanied the Blizzard caused serious snow drifts that blocked transportation lines into Washington D.C causing a coal shortage. The Washington area had a snow depth of 34.0”. This was also the winter of The Great Arctic Outbreak in winch temperatures were so cold all across a good portion of the United States that the National Weather Service reports that ice flowed from the Mississippi River into the Gulf of Mexico.

The Summer of 1898:  With an average summer temperature of 75.0 degrees and an observed temperature of 76.0 degrees, the meteorological summer of 1898 (June – August) was 1.0 degrees WARMER than average.

January 28, 1922 “Knickerbocker Storm”:

The Winter: This storm was a crushing blow to the Washington D.C. area. A heavy snow of 28.0” was measured in Washington D.C. with higher amounts around the regions. This was the infamous “Knickerbocker Storm” where around 100 people were crushed to death as the roof at the Knickerbocker Theater on 18th and Columbia in NW Washington succumbed to heavy snow.

Summer of 1921: The summer preceding the “Knickerbocker Storm” was 0.83 degrees WARMER than average, but just by a very thin margin. The average temperature was 74.6 degrees for the summer and the summer of 1921.

April 1st, 1924 “Aprils Fools Day Storm”:

While this storm was mild in comparison with other storms of the past, this was the latest snowfall of the season of this amount. (This was considered a major snow storm because it accumulated more than 4.00”). Actually 5.00” of snow fell on the Washington area (a trace of snow fell on May 10th, 1906 but again, this was the most snow recorded this late in the season). Baltimore received 9.00” of snow with this storm.

The summer of 1923 was once again just a touch on the warmer side with the average temperature for the summer at 74.6 degrees and an observed temperature for the three summer months was 75.2 degrees. This means that D.C. was 0.63 degrees WARMER the summer before the April’s Fools Day Storm.

February 7th, 1936:

While this storm does not have a name, the Spring following this Winter helped set up for “The Great Spring Flood of March 1936” which was recorded as one of the worst floods for the Potomac River and Washington D.C. More than 14.0” of snow fall around Washington D.C. with more amounts through the Eastern Shore, Southern Maryland and south. All that snow helped lend to the massive flooding of the Potomac River through the spring.

Temperatures for the summer of 1935 were at 74.6 degrees for an average. The summer was very warm with temperatures topping out at 1.95 degrees ABOVE the normal temperature!

March 29th-30th 1942

This was a big storm that is actually still spoken about to this day! The “Palm Sunday Snowstorm” was a late bloomer, moving in at the end of March. However, it was a big snow producer dropping a foot of snow on Washington D.C. That was a minimal total compared to Baltimore, which received the greatest snow accumulated with one storm in 20 years! Baltimore recorded 22.0” of snow and Hagerstown measured 22.0” of snow as well in about 24 hours!

Chalk it up as another warm summer around Washington D.C. with temperatures 1.0 degrees WARMER than average. The average temperature for the summer of 1941 was 74.6 degrees with the observed temperature at 75.6 degrees.

January 30th-31st 1966

Strong El Nino Year. A pretty bad winter was upon the D.C. region during 1965-1966. With already snow on the ground, a blizzard came whisking through the region dropping one to two feet of snow through Virginia and Maryland. Washington D.C. recorded 14.0” of snow while Baltimore received just around a foot. There of course were some higher totals through Fredericksburg and Manassas.

The summer leading up to the fairly bad winter was almost near normal. The average temperature for the summer of 1965 was 76.3 with a recorded temperature of 76.0 degrees. That means the summer of 1965 was 0.3 degrees BELOW average, slightly just still below.

January of 1977 “The Bicentennial Winter”

Weak El Nino Year: This was a harsh one to say the least. This was one of the coldest winters recorded on the East Coast. The average temperature in Washington for January was 25.4 degrees which was the coldest since 1856 when the average temperature was 21.4 degrees (the normal temperature for January was 34.6 degrees)! The Carter Administration was getting settled into Washington and starting on January 4th, snow kept falling every few days. It was just a few inches here and a few inches there. Believe it or not, the Tidal Potomac (which is salt water) was frozen solid with the cold temperatures! People could actually skate across it to the Memorial Bridge! This winter was terrible for everybody – in fact, snow was even seen in Miami, Florida on January 19th. (Courtesy of NWS-Sterling)

Looking back at the summer of 1976, the average temperature was just slightly above normal for the meteorological summer, only 0.8 degrees warmer. The average temperature for those months was 76.8 degrees and the D.C. area measured a summer with an average temperatures of 77.6 degrees.

February 18th-19th 1979


Neutral Year: “The President’s Day Storm” was a one that a lot of people around the region remember as well considering it was thought to be the worst storm to hit the Washington, D.C. region in 57 years. Snow was recorded as falling 2”-3” per hour during the storm! One of the most interesting facts about this storm is that there was a protest on the National Mall with tractor trailers and other large farm machinery to protest for higher agricultural pricing. The protestors on the mall ended up using their equipment to help people dig out of the depths of snow that were around 2 feet!


With another bad winter upon the D.C. area in 1979, the summer of 1978 was a hot one. Temperatures were 2.1 degrees ABOVE normal! The average summer temperature for that summer was 78.7 degrees and the Washington D.C. area observed a warm average temperature of 78.9 degrees.

February 11th-12th 1983


Strong El Nino Year: Up to this point in history, the February storm of 1983 was the 2nd greatest snowfall on record for the Washington D.C. region as 24-hour snowfall records were set in some of the surrounding areas and D.C. received 17.0” of snow with this storm. There was more snow if you traveled outside the city, snowfall totals were up to 2 feet in some areas. Not only was the region dealing with large snowfall totals but gusty winds also caused large snow drifts around the Mid Atlantic.


The summer preceding the snowstorm that beat out the President’s Day Snowstorm was actually slightly cooler than average. The average temperature for the summer of 1982 was 76.8 degrees and D.C. observed a temperature of 76.2 degrees. That means D.C was 0.6 degrees BELOW normal for that summer.

November 11th, 1987 “The Veteran’s Day Storm”


Moderate transitioning into Strong El Nino Year:
Who can remember this storm? I actually do because my mom had to learn how to drive stick in a snowstorm to get me to an emergency dentist for a screaming 5 year old-oh memories. The snow came down fast a furious and right and took people by surprise considering these were the days before Doppler radar. By the time the snow moved through Fredericksburg, dropping heavy amounts, it was too late and meteorologists didn’t even really grasp what was happening until snow reached the forecast office in Camp Springs. Around a foot of snow fell across the region as motorists were still out and about. Stranded cars decorated area roadways.


This was actually a very warm summer in 1987 and an early massive snowstorm that followed. Temperatures in the summertime were 2.2 degrees ABOVE normal. The average temperature for that summer was 77.0 degrees and D.C. topped out at 79.2 degrees!

March 13th – 14th 1993 “The Superstorm of March ‘93”

Coming out of Moderate El Nino this was a Neutral Year: Yet another memory because I was pretty sure, growing up in Winchester, VA, I was never going back to school after this one (which was fine by me at that point in my life). This was a massive storm, with the lowest pressure ever recorded at the storm’s center, that affected the entire east coast. Not only did it cause huge storm surge through the Florida panhandle and several tornadoes (several deaths resulted in those weather events as well), it dropped more than a foot of snow across multiple states. Although this was an incredible storm, D.C. has seen worse. D.C. recorded 13.0” of snow with almost a foot right outside the city; in the suburbs and in extreme southwest VA some totals were around 40.0”. There were plenty of strong winds accompanying the storm as well as this was a true blizzard. Snow drifts were over 12 feet, the National Guard was called in and there were several deaths not only from hypothermia and collapsed roofs but more commonly from overexertion leading to heart attacks while shoveling snow.

I wouldn’t exactly call the summer of 1992 a warm summer as temperatures in the Washington D.C. area were 1.9 degrees BELOW average. The average temperature for that summer was 77.0 degrees and D.C. measured a temperature of only 75.1. June and August were particularly cooler.

The Winter of 1994

Neutral Year: Several ice storms pelleted the D.C. area early in 1994 and temperatures plummeted below zero several mornings. This is thought to be the iciest winter on record for the D.C. area. During January and February, there were multiple storms that not only dropped sleet but snow a freezing rain as well. One storm in particular on February 10th left a coating of ice that was 1.00” to 3.00” thick across the region! Due to the thick coating of ice, there were several power outages as falling trees and power lines due to heavy ice were to blame. There was a disaster declaration given in our area and several injuries as a direct result of the heavy ice coatings.

The summer of 1993 was a warm one with temperatures 1.3 degrees ABOVE average. The average temperature was 78.0 degrees with the D.C. area observed a warm temperature of 79.3 degrees.

January 7-13, 1996: The Blizzard of '96

Weak La Nina Year: Another one for the record books, another one in recent memory. If you were north and west of the District, you were dealing with almost 40.0” of snow in some areas while D.C. was climbing out of around 20.0” of snow. Just as the roads started to clear, an infamous “Alberta Clipper” came diving into our area out of the northwest bringing another shot of several inches of fresh snowfall. And then, just when we thought it was over, a third storm moved into the area piling on another 4.0” to 6.0” of snow in the District with more north and west of D.C. All in all, around 2 to 3 feet of snow accumulated after these series of storms.

Another warm summer preceded a nasty and snowy winter with temperatures in the summer of 1995 1.1 degrees above normal. The average temperature was 78.03 degrees and we measure a temperature of 79.13 degrees bringing us a summer that was 1.1 degrees ABOVE average.


February 15-17, 2003
Moderate El Nino Year: Moving into the 21st century, another strong storm was moving up the eastern seaboard in mid-February while temperatures were measuring in the teens. As this Nor’easter was developing, heavy snow began to fall into the overnight and early morning hours on February 16th. The snow continued through Presidents Day morning, February 17th with totals in D.C. topping out at 26.8” of accumulation.

Another very warm summer on tap for the region as temperatures were 2.3 degrees ABOVE normal for the meteorological summer! The average temperature for that summer was 77.03 degrees in D.C. while temperatures warmed up to 79.36 degrees!

Winter of 2009-2010
Moderate El Nino Year: Here we go. The winter that never quit and the first time I had to get on air and say “yeah, we are going to see 30.0” - 35.0” of snow in spots (with only 2 years under my belt as a Chief Meteorologist at my first station, I was almost in tears to know that I could completely bust this forecast and never work again if this prediction didn’t come to fruition, fortunate for me, it did – unfortunately for everybody else, it did as well). This was one of many weekend storms we saw that winter with snow rates at 2.00” per hour at times. That was the first storm that came through on December 18th and 19th. By January, we had our fair show of “little” storms –dropping over 5.00” in spots at times and then came a blizzard on February 5th and 6th. That storm dropped 17.8” in D.C. with over 3 feet of snow north and west of town. Then just when we thought we had enough, we got another blizzard on February 9th and 10th. DC received an additional 10.8” of snow with up to 2 more feet recorded in areas. That winter, DC saw 56.1” of snow fall. That is the number one winter for snowfall in the Washington D.C. area as long as records have been kept (since the late 1800s)!

The summer of 2009 was pretty much on average. Yes, temperatures were just slightly cooler but only by 0.2 degrees. The average temperature for the summer of 2009 was 77.0 and we reached 76.8 degrees with a pretty warm August on tap to help close the deficit from a cooler than average June and July. Therefore, we were 0.2 degrees BELOW average for the summer of 2009.

Winter of 2013/2014

Neutral Year: And yes, another winter that never ended! I couldn’t believe that we were seeing St. Patrick’s Day snow. It was the middle of March and we had been dealing with minor snowstorms since December! We had a least 9 snow events last winter around the region where several inches of snow were reported. Eventually, DCA totaled 32.0” of snow for the season. 32.0” of snow does not even fall into the top 5 snowiest winters for D.C.

The summer last year was just slightly warmer than our average summer. The average summer temperature for June to August is 77.7 degrees and DC warmed up to 78.3 degrees for all three months combined. That is 0.6 degrees ABOVE average.

El Nino vs La Nina vs Neutral

 

 

ZZZZZ

 

Wow. There is so much I can write on this subject. However, without turning into a very lengthy term paper with lots of graphics and images; let me just give you the short and skinny of it because these events strongly and often dictate the patterns of precip and temperatures globally. It is a very interesting meteorological phenomenon: the correlation between the sea surface temperatures and the atmosphere in the eastern Pacific. According to NASA’s definition of these events, “the development of El Niño events is linked to the trade winds. El Niño occurs when the trade winds are weaker than normal, and La Niña occurs when they are stronger than normal.”

El Niño: Unusually warm temperatures in the eastern Pacific when warm water builds up and migrates along the equator in the eastern Pacific. Of course, this warms the atmosphere creating thunder and rain storms.

 

ZZZZZ

 

La Nina: Unusually cool temperatures in the eastern Pacific when cool water builds and migrates along the equator. This event cools the atmosphere and less water evaporates creating fewer rainstorms in response to the cooler and drier dense air.

ZZZZZ

 

 

Neutral: This is the period (like we were in 2013-2014) when neither La Nina nor El Nino is present. This can be chalked up as a likely transition period to either a La Nina or El Nino event. Pretty much everything (ocean temps, tropical rainfall patterns and atmospheric winds) is right around average.

With that being said and according to the NWS, during El Nino years (and depending on the strength) “there appears to be some historical correlation between the strength of the El Nino and the warming in the Pacific Ocean and seasonable temperatures, precip and snowfall. Weak El Niño winters averaged below normal temperatures and precipitation, while strong El Niño episodes averaged above normal temperatures and precipitation. On average, the stronger the El Niño episode, the warmer and wetter the winters have been. These findings can partly be linked to a stronger than normal sub-tropical jet that typically occurs during moderate to strong El Niño winters, which would favor more active storm systems from the south that draw warm, moist air northward as opposed to the drier Alberta clippers from the northwest. Seasonal snowfall averaged above normal for weak, moderate and strong El Niño.” –credit www.erh.noaa.gov

 

 

ZZZZZ

As for La Nina years (in the winter’s that I analyzed, I only recorded one – which was a weak La Nina from 1995-1996 and approximately 20 winters were influenced by La Nina episodes since 1950) and according to the NWS “there appears to be some historical correlation between the strength of the La Niña episode and seasonal temperatures locally at Washington D.C. and Baltimore: the stronger the La Niña, the warmer the temperatures averaged. Winter precipitation averaged slightly drier than normal during all La Niña intensities. Seasonal snowfall during La Niña winters averaged below normal during moderate and strong episodes. However, while almost all of the La Niña episodes are linked to near or below normal snowfall at Washington D.C. and Baltimore, the weak La Niña episode during the 1995-96 winter was an outlier in the dataset with well above normal snowfall for the season. In this case, the above normal snowfall was weighted heavily by the 6–8 January 1996 blizzard, when 17.1 (22.5) inches of snow fell at Washington D.C. (Baltimore). –credit www.erh.noaa.gov

 

ZZZZZ

So what do we have in store for the end of 2013 through the spring of 2014 in terms of El Nino/La Nina?

The Climate Prediction Center has issued a statement that they expect (67% chance) of a WEAK El Nino to develop from October 2014 through December 2014 and continue through early 2015. Right now, observations in the Pacific are consistent with neutral conditions (same as last year) but there is a 67% chance of transitioning to most likely a weak El Nino event or a slight chance of a low-end moderate El Nino. Check our Alex Liggitt's blog for an in-depth look on the CPC's predition.

So there is the information and honestly we are just touching the surface as to what goes into a seasonal forecast: historic trends in both the winter and the summer, the Pacific Ocean temperature, wind movement, contrast and comparison. So if we happen to see a weak El Nino develop, maybe check back and see how that compares to the winter of 1977. Hopefully it WON’T be like that year.

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NOAA issues Winter Weather Outlook

October 16, 2014 - 03:44 PM
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NOAA issued its winter weather outlook today which features a temperature and precipitation outlook for the entire United States. The Mid Atlantic has typically been an extremely difficult place for seasonal forecasting, and last year was no different.

The outlook showed equal chances of above, below or near average conditions for both precipitation and temperatures for the 2013-14 winter. We all know that it was actually colder and wetter than average, with 32 inches of snow recorded at Reagan National Airport.

This winter, NOAA is predicting equal chances of near, above or below average temperatures.

NOAA Winter Temperature Outlook

They are also predicting a 30% chance of above average precipitation for the D.C. area and points east. The outlook did specifically state, "Last year’s winter was exceptionally cold and snowy across most of the United States, east of the Rockies. A repeat of this extreme pattern is unlikely this year, although the Outlook does favor below-average temperatures in the south-central and southeastern states."

NOAA Winter Precipitation Outlook

There is still a chance that El Nino will develop this winter, and the Climate Prediction Center has a 67% chance that it will develop by the end of the year. Strong El Nino patterns can affect the weather on a global scale.

Read much more about NOAA's Winter Outlook here.

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