From the ABC 7 Weather team

Archive for December 2013

Still a chance for snow into Friday; Cold may be bigger story

December 31, 2013 - 10:13 AM
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After looking at some of the latest guidance, the east coast still looks like it will see the chance for some light snow, though little is expected for the D.C. area. At this time, Thursday looks cloudy and cool with temperatures in the low 40s.

Precipitation is expected to move in from the west and southwest as a disturbance (which will move into the Pacific Northwest today) digs into the Tennessee Valley and pulls some Gulf and Atlantic moisture over the Mid Atlantic.

Thursday evening MSLP, 3hr Precip and 850mb temp forecast via GFS Model (Courtesy: WeatherBell Models)

Precipitation appears like it will fall mainly in the form of snow, though accumulations still appear light. The latest guess would be anywhere from a few flurries to the potential of an inch or two.

The main low develops so far out in the Atlantic and progresses east quickly which gives little time for snow to fall in the D.C. area. Typically the bigger snowstorms will feature low pressure tracking in a more north-northeasterly course, which would pull in more moisture from the Atlantic into the D.C. area. This just doesn't seem to be the case with this system.

Regardless, with the potential for snow late Thursday into early Friday morning, there will be the possibility of delays come Friday morning. Again, we'll be sure to update you over the possibilities again tomorrow and Thursday, no need to fret just yet!

Friday afternoon temperatures per the ECMWF Model (Courtesy: WeatherBell Models)

Gusty winds and cold temperatures may be a bigger story on Friday, with winds up to 30 mph or higher at times and temperatures only in the 20s throughout the day on Friday.

Friday night into Saturday looks like it may be the coldest night of the season, with lows in the teens throughout the D.C. area and the possibility of a few locations in the far northwestern suburbs dipping into the single digits.

High pressure appears like it will regain hold of the region Saturday before the next area of low pressure moves into the region Sunday into Monday.

This system may also bear watching but is far enough out that we're not putting too much stock in it just yet. Another strong cold push is possible next week behind that disturbance.

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New chance for snow in the New Year

December 30, 2013 - 02:59 PM
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This year ended with a roller coaster ride in the temperature department, hitting record highs on the Saturday and Sunday prior to Christmas before plummeting back into the 30s for Christmas Day. It was actually the coldest Christmas Day since 2004 and coldest high temperature recorded since last February!

Temperatures as of late have been seasonable or slightly milder than average, but the New Year looks to bring with it another active pattern reminiscent of mid-December. A weak cold front will bring nothing more than a wind shift for New Year's Eve, but winds will become breezy tomorrow afternoon and evening out of the northwest around 10 to 20 mph.

This will help bring in slightly cooler air for New Year's Day, with highs around the lower 40s. A disturbance that has been hanging around the Gulf Coast will get caught up in a trough of low pressure and get steered towards the East Coast on Thursday. Ample moisture will be available as the system moves into the D.C. area Thursday afternoon and intensifies off the East Coast.

GFS Forecast MSLP and 6=hr Precipitation for Thursday Evening

As usual, there isn't a lot of consensus in the forecast just yet, but latest trends are beginning to show signs for the potential of snow in parts of the region as an area of low pressure develops along the East Coast. Literally as of Monday's afternoon model guidance, the snowfall confidence is extremely low. There are more questions than answers. Current guidance shows everything from moderate snow to flurries. Location of where the surface low will develop also hasn't been pinned down and this will be a huge factor in determining where or IF snow will fall.

This blog is merely to inform you there is a possibility of snow Thursday night into Friday. We will definitely be updating this throughout the week, so any changes that arise in the forecast will be forwarded to your attention. Our current best guess is for precipitation to move into the region Thursday afternoon and exit the area Friday morning. Light snow appears possible, but at this point, that's as much as we can say. We'll be able to hone in on this system a little better as we head later into the week.

Here's to hoping for a better chance for snow in the New Year!

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Coldest Christmas... In How Long?

December 26, 2013 - 07:53 AM
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Did Santa bring you a new winter coat, gloves, and/or mittens?  If so, I'm sure you were able to put it to good use Christmas Day.  The high at Reagan National reached 33 degrees.  That's 11 degrees below average!  And it tied as the coldest Christmas since 2004. 

Reagan National Statistic

Most locations, in our area, barely made it to the freezing mark yesterday.

Looking at past Christmases, back to 2000, the lowest temperature (at Reagan National) was 28 degrees!  The highest -- nearly 60 degrees -- in 2008.  Thanks to the folks at Sterling's National Weather Service for this data.  Click here for a lot more information on Christmas weather history.

National Weather Service - Baltimore/Washington

Looking ahead to the end of 2013 and start of the New Year, it will be cold!  A strong cold front will slide through Monday and will drop highs New Year's Eve and New Year's Day into the mid and upper 30s. 

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Holiday Lights and Decorations

December 24, 2013 - 11:35 AM
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Festive lights are one of my favorite things around the holidays. I think the main reason I enjoy Christmas lights is because we lose so much daylight approaching the winter solstice.

I wanted to share some of the homes I was able to showcase on Good Morning Washington. Each of the families graciously welcomed me to their homes and were delighted to show off their hard work. To all of you who put the time, effort, energy, and money (I don't even want to guess how high the electric bill is!), thank you for the holiday memories you create. And the light you bring to your neighborhoods.

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Record challenging warmth to start winter

December 20, 2013 - 11:01 AM
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Technically, the Winter Solstice occurs this Saturday at 12:11 p.m., but temperatures will be anything but winter like!

Highs across the region on the first day of astronomical winter will be more in line with late October or early April than late December. (Of note: temperatures have been running slightly below average for 12 of the past 19 days this month)

ZZZZZ

A big Bermuda high off the coast and a developing low across the south central US will funnel a strong southerly flow into the region through the weekend. This push of warm air will thrust temperatures well into the 60s Saturday and may even crest 70° on Sunday.

We will have an abundance of clouds that will make tying or beating the records close, but it definitely looks doable. Cooler, more seasonable air moves in behind a late Sunday cold front returning the region to more seasonable conditions, low to mid 40s, for Christmas.

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Least amount of daylight for D.C. Friday-Sunday

December 18, 2013 - 12:04 PM
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With the Winter Solstice comes the least amount of daylight in the northern hemisphere. This is because the earth is at its maximum tilt away from the sun. As we progress into January, the tilt of the earth starts to go the opposite direction bringing more daylight back to the cold, dark north. During the winter solstice, the suns rays are located directly over the Tropic of Capricorn as shown in the picture below.

Washington D.C. experiences its least amount of daylight between December 20th and 22nd (Friday through Sunday). Even though temperatures will still be in the upper 50s to upper 60s through the time period making it feel more like spring, those days are in line with the Winter Solstice which occurs Saturday at 12:11pm. Only 9 hours and 26 minutes of daylight occurs during that period. That is 5 hours and 28 minutes less daylight than the region experiences during the Summer Solstice!

By December 31st, D.C. gains 4 minutes of daylight. By January 31st, we gain 43 more minutes, getting up to 10 hours and 13 minutes of daylight. The region finally eclipses the 12 hour mark just prior to the Spring Equinox when we see 12 hours and 1 minute of daylight on the 17th of March. This is just prior to the equinox which is on the 20th. The longest days are in June between the 18th and 23rd when D.C. has 14 hours and 54 minutes of daylight. That's what I love!

If you're looking for later sunsets, you only need to wait until the 4th of January to watch the sun set at 5pm in D.C. It sets at 6pm by the last day of February, and we spring forward on March 9th in 2014, which will push the sunset to 7:09pm. The latest the sun sets is 8:38pm, which occurs on the 27th and 28th. Here's looking forward to more daylight to start the new year!

 

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Winter Solstice won't be too wintry

December 17, 2013 - 02:38 PM
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The Solstice occurs Saturday at 12:11pm EST, marking the beginning of astronomical winter. Meteorological Winter began on December 1st and continues through the end of February. Astronomical winter will run through March 20th, when Spring begins. Thus far, temperatures have been running slightly below average this month, with 10 of 16 days recording below average temperatures.

7 Day Outlook

This appears likely to change by the end of this week and into the weekend. High temperatures Friday should make it into the upper 50s before jumping into the 60s both Saturday and Sunday.

There is an outside chance that temperatures may actually reach the 70 degree mark ahead of a strong cold front Sunday. This would only be the first time since November 18th that Reagan National would hit 70°F if it occurs. Two of the past five December months recorded temperatures hitting 70, including twice last year. The record high Sunday is 72°F which is a record that goes all the way back to 1889.

A strong low-level jet stream will help temperatures bump into the 60s this weekend as a cold front approaches from the west. Above is a look at the 12z GFS forecast valid Sunday around lunch time. Winds are screaming out of the southwest around 75mph only 5,000 feet above the ground helping usher in the much warmer air mass to the region. There is some indication of severe weather being possible in the Deep South and Southeast this weekend with the cold front, but none is expected in the D.C. area.

The cold front is forecast to bring precipitation in the form of rain to the area Saturday and Sunday, and the front should pass through the region Sunday night into Monday morning. This may allow for precipitation to hang around for Monday morning. Much colder air is expected to settle back into the area Tuesday through Christmas week with highs back in the 40s. A White Christmas does not appear likely at this time, but we'll continue to keep you well informed!

 

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More Snow Brushes DC Suburbs

December 14, 2013 - 09:37 PM
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The third winter storm in less than a week is coming to a close across the Mid-Atlantic. For many locations west of the Metro area, today's storm was yet another measureable snow. The eastern West Virginia Panhandle, Shenandoah Valley and northern Maryland top the list with the most snow (see table below) with only trace amounts near the major Interstate 95 corridor.

snow_totals

In Washington, Reagan National Airport reported no accumulation but the total for the month stands at 1.5 inches. That amount exceeds last December’s 0.2 inches but is below the average December snow of 2.3 inches. Meanwhile, Dulles International has seen 4.3 inches since December 1. This exceeds the average of 3.5 inches for the last month of the year.

What’s next? The storm will continue to roar through New England, producing more than one foot of snow in the interior and close to a foot for places like Boston. In the wake of the low pressure, gusty northwest winds will pivot into the DC Metro area on Sunday. A few weak cold fronts will cross the Great Lakes into the Mid-Atlantic and Northeast Monday and Tuesday, keeping temperatures below average for Washington.

current jet stream

The pattern will flip-flop Thursday into Friday. The jet stream will retreat north, allowing a surge of above-average temperatures to move into Washington. Highs will warm to at least 50 degrees by Friday.

forecast jet stream

Click here for the latest forecast for the Washington area.

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Another wintry mix for parts of the D.C. area

December 14, 2013 - 06:43 AM
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9:15am: Here are some of the snowfall reports coming from parts of the region. Up to an inch to an inch and a half has been reported in Winchester, VA, 2 inches have been reported in Woodstock, VA along I-81.

8:53am: A few conversational flakes coming down in Leesburg, VA.

8:51am: Check out the live cameras in Western MD this morning. Nice snow falling!

Live Traffic Cams

8:35am: Snow is falling as close to D.C. as Sterling, VA at the National Weather Service office.

8:21am: Light snow is falling in the Blue Ridge just west of Front Royal, VA.

8:15am:

7:54am:

7:51am: Take a look at some of the latest model forecast snowfall totals from the HRRR. This gives a great idea of where to see moderate snow, with highest amounts along the Blue Ridge, Catoctins, and points north and west.

(Courtesy: WeatherBELL Models)

7:34am: Light snow is now being reported in Culpeper and Remington, VA. Temperatures are near freezing in those locations (33°F in Culpeper, just dropped to 32°F in Remington) but little to no accumulation is expected.

7:12am: I want to explain these Winter Weather Advisories a bit more and as the entire counties of Loudoun and Montgomery are not expecting to see 1-3 inches of snow. There is a much better chance for accumulating snows in the higher elevations of the counties, such as northern Montgomery where it's up to 600ft in elevation, and in the higher elevations in western Loudoun closer to the Blue RIdge.

This also goes for Frederick and Washington Counties in MD, which should have big snow ranges from south to north. Expect more snow closer to the Mason-Dixon line as the highest snowfall potential in this storm appears to be in Pennsylvania. Feel free to ask me any questions through our Facebook page or through Twitter at @alexliggitt

7:05am: Light snow is falling in Berryville, VA this morning. Here's a look at our HD WeatherBug camera there. Hard to tell, but it's definitely snowing.

6:56am: Light snow is beginning to be reported south and west of D.C. Already up to a half inch of snow has been reported in Fort Ashby, WV per the NWS Sterling office. Winter Storm Warnings and Winter Weather Advisories begin at 8am.

 

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Winter Weather Advisories, Warnings Saturday for the D.C. area

December 13, 2013 - 04:27 PM
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An area of low pressure is approaching the D.C. area tonight from the southwest and should begin to affect parts of the region by Saturday morning. Precipitation is expected to start as a period of light snow across the majority of the region with light accumulations possible in the immediate D.C. area.

Timing:

Precipitation should begin in the morning hours between 7am-10am across the region. Rain should begin to overspread the region by Noon in the D.C. Metro and points to the south and east. The system will exit the region by midnight Saturday.

Dependency on Area:

Big differences will be likely tomorrow in snow amounts in the D.C. area and places closer to the Mason-Dixon line such as northern Frederick County (MD), Carroll and Washington Counties as well. Areas farther north will have substantially more snowfall from this storm, and regions throughout Pennsylvania are expecting up to 8 inches of snow across much of the state.

Once again, the D.C. area itself isn't expected to see much of anything. A few snowflakes are possible at the onset of precipitation but snow should change to rain by the late morning hours in D.C. and points east. This appears like it will be another situation where even if it's snowing, accumulations on the roads won't be likely as temperatures should be at or above freezing and roadways should be above freezing.

Areas in higher elevations such as northern Loudoun, northern Montgomery and west into Frederick County, MD will have a better chance for light accumulations, even on the roadways.

We will be reporting live tomorrow morning on Newschannel 8 and will have a live blog going throughout the morning with the latest on where the snow is, where it's changing, and if there are any changes to the forecast. Be sure to stay tuned to ABC 7 News at 6pm and 11pm tonight for any recent changes to the forecast.

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Another wintry mix possible this Saturday in the D.C. area

December 12, 2013 - 11:54 AM
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As cold air continues to hang around the Continental U.S., any system that  develops has had the potential to bring snow.

This weekend will be no different, as enough cold air will be in place for the potential of another wintery mix in the D.C. area. Once again, the hot spots are anticipated to be in the common locations north and west of D.C.

GFS Model MSLP and Precip Type for Saturday evening (Courtesy: WeatherBELL)

Low pressure is expected to move into the region from the southwest. High pressure over Canada will help ensure a supply of cold air at the surface, but it shouldn't be as strong of a cold air damming situation that brought the icing to the region last weekend.

At this time, it appears light snow may develop in the late morning hours Saturday, changing to rain by the afternoon in the D.C. Metro and points southeast. As surface temperatures in those locations are expected to be above freezing, it should turn out a lot like Tuesday, with little to no snow expected.

4km NAM Temperature forecast for Saturday around lunch (Courtesy: WeatherBELL)

Farther north and west, however, temperatures may hang at or below freezing for much of the day, resulting in light accumulations on par with the snow that accumulated in those areas Tuesday.

Everyone in the D.C. Metro saw what can happen when temperatures are only a degree or two above freezing, as snow is again may melt on contact with little disruptions to the city.

Northwest into western Fauquier, Loudoun, northern Montgomery and points west, light snow may again be possible. Pinpointing accumulations at this point isn't very smart as accuracy would be exceptionally low, but the possibility for a few inches of snow is possible through Saturday evening. We'll be sure to keep you updated when we learn more!

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D.C. Area Snow Coverage

December 10, 2013 - 06:00 AM
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11:50am: All Warnings and Advisories have been allowed to expire. Through the rest of the afternoon expect snow to come to an end and temperatures to hang in the low 30s. Tonight will be cold with lows in the mid 20s around town and mid teens in the western suburbs. Be ready for icy spots tomorrow morning!

11:29am: Low temperatures tonight will be in the teens in the western suburbs to lower 20s in D.C. and points southeast. Roads will be icy throughout the region and areas that don't have snow removal may see this wet snow become a big icy problem by the morning. I think delays will be likely and cancellations will again be possible.

Low temperatures Wednesday morning per the 4km NAM model Courtesy WeatherBELL Models

10:46am: Conversational snow continues to fall in the D.C. area but that's about it. It should continue to exit the region closer to lunch time. Here is our latest snow map (as of 9am). We'll have an update this afternoon.

10:04am: Here is the National Weather Service's latest update.

9:48am: There's a giant snowman warning in effect for Howard County, MD :)

9:15am: The Winter Storm Warning has been cancelled for D.C. and Fairfax but continues for Montgomery and Loudoun Counties and points west.

Latest Warnings and Advisories

9:10am: Latest radar trends are depicting the heaviest of the snow now beginning to leave D.C. There are breaks showing up on radar so snow will be tapering off in the next few hours. Expect light snow through 11am and then a few flurries through lunch time.

9:00am: Snowfall totals are beginning to come in to the National Weather Service office, with 4.3" the high spot in Berryville, VA (Clarke County), 4" in Frederick, MD and 4" in Hamilton, VA (Loudoun County).

Latest Snowfall Reports

8:23am: Cancellations are beginning to pile up at Reagan National Airport. The problem is this storm is affecting much of the northeast including Philadelphia, New York and Boston. This will have an impact through the afternoon.

8:16am: Roads are still wet for much of the immediate D.C. Metro, though snow has been sticking on roads in the western part of the Beltway.

7:50am: Check out this video from Leesburg, VA of the snow coming down and accumulating on the roadways. Currently in D.C. it's snowing but temperatures are at 34°F, so it's not sticking to the roads and I've only seen a dusting so far outside.

This is shaping up to be your typical snow situation in the D.C. area with more the farther north and west of D.C. you are.

7:42am: This car has become stuck off Greensboro Dr. in Tysons Corner, VA. It's that easy to do, very slick!

7:33am: Snow is making for a very quiet morning in the Tysons Corner, VA area! Roadways are covered so be sure to take it slow if you need to head out this morning.

7:19am: This is one of the things I'm worrying about today, as snow is falling on trees that are already covered with ice. This could lead to more tree branches (or entire trees) coming down with the added weight of the snow. Luckily winds shouldn't be that high. Be safe out there today!

7:14am: Plenty of snow is falling across the region with light accumulations of 1-3 inches becoming common west of D.C. Currently in Arlington we are seeing wet roads, still waiting for the moderate snow to start accumulating.

7:00am: We have some unofficial reports of a few inches (possibly up to 4" in Winchester, VA) of snow across the western parts of the area. Snow is expected to continue through the the morning before ending by the early afternoon.

For those of you that made it to work today, this should give plenty of time for road crews to treat the roads through the afternoon prior to the PM rush hour, though slick spots and side roads may be tricky.

4km NAM Model depicting composite reflectivity and surface temperatures early this afternoon (Courtesy: WeatherBELL Models)

6:50am: Here is the latest look at our Doppler Radar. Snow and sleet has been coming down in the D.C. Metro, snow to the west and a mix to rain south of town. Conditions will deteriorate quickly with roads becoming hazardous. Looks like a good day to stay home and enjoy it!

6:46am: Roads are beginning to get very slick across the D.C. area so be very careful out there this morning!

6:29am: Snow is beginning to cover the roads in Winchester already. Heavy snow was being reported there over the past hour.

6:27am: Eileen is already noticing the roads (at least this parking lot) are being covered with snow in a very short period of time.

6:21am: Our very own Eileen Whelan is out live with the Stormchaser this morning and is now reporting sleet mixing in with some snow in Fairfax, VA.

6:11am: Snow is beginning to fall in parts of the area with moderate to even heavy snow being reported west of the Blue Ridge and now some light snow as far east as Leesburg, VA.

A few areas of sleet and rain are being reported in the southern portions of the area such as Quantico, VA and points southeast but they will eventually change over to snow over the next few hours.

 

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More winter precipitation heading to D.C. Tuesday

December 9, 2013 - 11:37 AM
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As one winter storm exits, another is forecast to enter by early Tuesday morning, making for the possibility of more delays, cancellations and additional travel complications.

A Winter Storm Watch is in effect everywhere besides Southern Maryland as well as Stafford and Spotsylvania Counties in Virginia.

Areas to the southeast are expected to mix in a bit more of the way of rain and sleet so accumulations will be limited in those locations, thus not hitting the 5" or greater Winter Storm Watch criteria.

At this point, our team is thinking a more general 2" to 5" will be possible tomorrow, with the highest amounts just to the west of D.C. where snow should be the primary precipitation type with colder air available.

I like the graphic from the National Weather Service below showing the probability of greater than 4" of snow in a given area. For the D.C. Metro it only stands at 40-50%.

Timing

At this point it appears that snow will begin in the morning hours during the rush hour and continue through the early afternoon. Precipitation may start as a mix in the D.C. Metro and points east but should change over to snow the rest of the day. This will of course create more travel headaches, and delays and cancellations will be likely.

Other thoughts

The National Weather Service is discussing the potential for a banding feature to set up somewhere just west of the D.C. area that could bring the potential for heavier snow in isolated locations. At this point, I think it's a little difficult to say exactly if this feature will happen or where exactly it will be.

Heavy snow band northwest of D.C. Sunday

We saw the same kind of feature yesterday north and west of D.C. where very heavy snow fell from Winchester north to Hagerstown and east to north of Baltimore. We'll be monitoring radar trends tomorrow to try and stay on top of it. With that being said, there's an outlying chance of some locations seeing 5" or more.

Another note is most of the roadways are wet right now and will continue to be wet through tomorrow morning.

Area roadways are currently above freezing and should be tomorrow morning, leading to the majority of snow in the morning to melt on contact. Snow will need to become moderate or heavy to overcome the warm roads in order to pile up.

Snowfall totals may be reached but you might not notice it if the roads aren't as bad!

We'll of course be on air and online all day so tune in tonight at 5, 6 and 11 p.m. and tomorrow starting at 4 a.m. (if you happen to be up that early!) to see if there are any changes to the forecast!

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D.C. Area Winter Storm Live Blog

December 8, 2013 - 04:05 AM
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Photo: Mike Jaffe

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7:36pm:  Very wet in D.C. along Columbus Circle in front of Union Station.  Bands of moderate rain have caused standing water.  Fortunately, temperatures are above freezing, so it's just wet.  Farther north and west, ice is a major concern. 

7:25am:  The rain train continues, but will gradually taper off over the next several hours.  Any freezing rain will transition to rain, as temperatures slowly climb above freezing. 

Intellicast

6:45am:  Moderate rain falling in the District.  West of I-95 freezing rain is still being reported.  Here's a radar image depicting the mixed precipitation across the metro area. 

RadarScope

5:10am:  Numerous schools are closed across the area.  The federal government is on a 2 hour delay with unscheduled leave.  Click here for the latest closings and delays.

4:25am:  Temperatures downtown are now above freezing (34 degrees), but freezing rain is still an issue west of the District.   The moisture train continues with precipitation possible through early afternoon.

 

 

11:25 pm:  Last blog post tonight. It will rain most of the night, across most of the area. BUT the temperature trend is encouraging especially south and east of DC. As soon as temperatures reach 33 degrees, no more ice will form. The problem is it may take until after sunrise tomorrow for that to occur across the entire region. Don't be surpised to hear some sleet and a clap of thunder overnight. The highest ice accumulations willoccur north and west of DC where temperatures will stay below freezing the longest. Jacqui and Eileen will start our coverage on ABC 7 at 4:30 Monday morning...just 5 hours from now. And by the way. model guidance suggest we may see more snow on Tuesday with the next system moving in. Be safe out there!

10:40 pm: As the heavier rain returns, we have noticed icicles forming on the branches of the sycamore trees along Lynn Street just outside our studio windows here in Rosslyn. This rainfall rate does not accrete as quickly as steady very light rain or drizzle does. As long as temps stay below  32 ice will build up. And rain will continue all night long. We expect a slow rise in temepratures but many areas north and west of DC may stay below freezing for most of the overnight hours. That is not good.

9:50 pm:  The leading edge of the next precipitation area has arrived here in Arlington. There have been reports of lightning and thunder along with some sleet. The rain will get heavier in places at times for the rest of the night. Additional icing likely and significant icing in those areas that remain more than a degree below freezing. In time, we expect to see some rise in surface temperatures. But it will be a long, icy and nasty night.

9:05 pm:  The 9 pm observation at Reagan Nat'l Airport rose 1 degree to 32 degrees. The temperature at BWI rose by 1 degree to 30 degrees. At least some temperatures are trending upwards. More icing as the next batch of rain arrives. Improvement only when temps go up to 33 degrees. Could happen overnight if some heavier downpours bring some warmer air down to the surface. This will take longer the farther north and west you are from DC.

8:06pm:  The leading edge of the next batch of freezing rain is moving rapidly from southwest to northeast. It has now reached Harrionsburg. The rain stretchessouthwestward to North Georgia, Alabama and Mississippi.Icing will develop quickly and continue until temperatures rise above freezing. And in many areas that may not happen until after sinrise Monday morning.

6:43pm:

6:19pm:

5:32pm: The Winter Storm Warning has been extended to include D.C., Arlington and Alexandria in VA, Prince Georges Co. and Anne Arundel Co. in MD. The National Weather Service is anticipating the next round of precipitation to be a period of moderate to at times heavy freezing rain.

Up to a quarter of freezing rain is possible, which would make for major icing on trees, power lines and roadways. Major travel disruptions would be possible tonight and into Monday morning.

5:06pm: Be very careful out there tonight, quite slippery!

4:30pm: Light sleet and freezing rain is expected to end over the next few hours, with a large break expected until closer to bedtime. When the next batch of precipitation enters, it should either be in the form of rain or freezing rain and rain. Temperatures are still hanging in the upper 20s to lower 30s and we will be monitoring them closely.

Doppler here

3:24pm: Here's a video of sleet in Manassas sent in by @3Mile on twitter.

2:54pm: Accidents have been common this afternoon and roadways will continue to be very treacherous this evening and tonight. Be safe out there!

2:48pm: Ice is now beginning to accumulate on elevated surfaces and may soon begin (if it hasn't already) to accumulate on trees, bridges and overpasses and even the road surfaces. Snow is still clinging to life in Loudoun and Frederick Counties and points northwest into the Shenandoah Valley.

2:07pm: Snow has changed over to sleet now in Arlington, VA and has also changed over south and east of D.C. Here is the current surface observations as of 2pm. Dulles Airport is now reporting sleet mixing in as well as Fort Belvoir and Quantico in VA. Areas will continue to change over to sleet and freezing rain through the afternoon and evening.

2:03pm:

1:14pm: Here are some of the latest snowfall totals from Jacqui Jeras. Way more than expected northwest of D.C. with the very intense snow band earlier. Less than an inch in D.C. and points east.

1:04pm: Snow has been reported mainly north and west of the red line (though coverage is spotty in Southern Maryland, any reports are welcome!). Snow has been continuing through the D.C. Metro and heavy snowfall continues to be reported in the western suburbs including Martinsburg, Leesburg as well as places just to the north of Baltimore along I-95.

A few areas south of D.C. such as Culpeper and Orange are reporting light sleet as well. A transition to sleet and freezing rain should occur during the next few hours from southeast to northwest. Some locations in Southern Maryland may change over to rain but not until later this afternoon and evening.

Surface Observations as of 1pm

12:47pm: Mike Stinneford west of Front Royal is now reporting close to 4" of snow.

12:01pm: Here is the latest snowfall report as of Noon. Over 4 inches so far in Winchester, VA! Other area snowfall reports can be found in the latest Public Information Statement here.

11:54am: Frederick, MD has been reporting very heavy snowfall, but our very own Ron Riley just reported a change to sleet in southeastern Frederick County. This is a picture from Bryan Schuerman along I-70 in Frederick. Very poor conditions on the roadways.

11:42am: Very heavy snowfall is falling in the Shenandoah Valley north and east to Frederick County, MD. We have reports of 3 inches or more in various locations, along with very poor visibility and covered roadways along I-81 and I-70. I've circled the area with the heaviest snow band in yellow.

Heavy snow band

11:08 a.m.: We held a quick Google Hangout to update everyone on the current situation. Check out a replay of Alex Liggitt's forecast.

10:50am: Mike Stinneford near Front Royal, VA sent in this nice snow video. About 2 inches has fallen there so far.

 

10:37am:

10:11am: Here are the first snow reports coming in across the region to the National Weather Service. In addition, we have seen many reports of over an inch along and west of the Blue Ridge and upwards of a half inch in the western suburbs of D.C.

LWX Public Information Statement (Snow/ice reports)

10:05am:

9:54am: Snow has been sticking to the roadways west of D.C. This was a look at Reston Parkway around 9am. Please tweet me any pictures or share them to our Stormwatch 7 Facebook page wall so we can share them.

9:48am: Dulles Airport has just taken over on the Flight Misery map for most delays in the U.S. right now. See the map here.

9:38am: Ryan Miller just tweeted a picture of the road temperatures in Arlington pegged at 28°F. Other area road temperatures in Maryland can be found here. Many are hanging near freezing.

9:27am: Here is the latest storm timeline from Jacqui Jeras. Snow will change over to sleet and freezing rain closer to lunch time. Icing may be up to a quarter of an inch west of D.C. with lesser amounts for the Metro and points east to the Chesapeake Bay.

9:23am: Mike Stinneford has some sound advice for those of you living west of D.C. and also those of you who have well water.

9:18am: Adam Caskey is now reporting snow grains in Arlington. This could be part of the first signs of a changeover as it means there is a warmer layer somewhere aloft. Snow is still being reported west of D.C. and freezing rain is now being reported in St. Mary's County, MD.

9:06am: Check out the "Misery Map" from flightaware.com. Already reporting massive delays at Dulles Airport and delays still common in Dallas and have spread to New York City. Not a great day to be traveling!

Flight Delay Map

9:00am: Be sure to send pictures in to the station and our facebook page. We started a photo gallery and you could also see your pictures on air!

8:30am: Here is the atmospheric sounding from this morning at Dulles Airport, showing cold air extending from the surface and no warm layers aloft just yet signaling all snow to start the day. Once warm air gets into the region aloft, precipitation will begin changing to sleet and freezing rain.

8:27am: Snow is now being reported at the National Weather Service office in Sterling too!

8:19am: Snow is now being reported in many locations across Virginia. A dusting has already been seen in Ashburn and moderate snow has accumulated up to an inch in areas in the mountains and west.

8:14am:

8:10am: Up to an inch of snow being reported in the Blue Ridge and west towards parts of the Shenandoah Valley.

7:40am: Here's a look at the storm total ice forecast from the National Weather Service. Ice is worse than snow or sleet as it can cause massive traffic problems and can also cause trees to fall and possible power outages due to the weight of the ice on the surfaces.

7:32am:

7:22am: A few reports are already coming in, with some sleet starting in Fredericksburg and some light snow being reported in the Shenandoah Valley. Mike Stinneford took this picture from his mountain home in the Blue Ridge where a dusting has already fallen.

7:06am:

6:59am: Here's the current look at Doppler radar. Here's a link to the bigger picture of the storm taking shape and moving towards the D.C. area.

6:47am: The stage is being set with dry air at the surface (dew points in the teens) and temperature currently at or below freezing. Precipitation is beginning to move into the region (per Doppler radar) but is falling as virga and not reaching the ground just yet with surface moisture levels so low. We'll have to wait until later this morning (8am-11am) for enough moisture to get into the region for snow to begin to fall.

Oddly enough, Reagan National Airport is reporting flurries right now, but looking out the window I don't see anything just yet and don't expect to until another couple of hours.

 

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D.C. Weather Sunday: Wintry mix still expected

December 7, 2013 - 11:53 AM
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Here I am sitting at work on a nice December Saturday afternoon, seeing sunshine out the window and thinking how different it will be in 24 hours. Taking a look at the current surface map, high pressure to the west is helping push cool and dry air into the region, with dew points now falling into the 20s and high temperatures only in the low to mid 40s.

Tonight, winds will subside, temperatures will fall into the upper 20s to lower 30s, and clouds will begin to increase from the southwest as a disturbance moves into the region.

Futurecast for 2pm Sunday showing a mix of snow, sleet, freezing rain and rain

Precipitation is still expected to start as snow in the D.C. area. It will move in from the southwest and spread to the north and east through the morning hours. At this time light accumulations are still possible, with the highest likelihood of only 1 to 2 inches of snow by lunch time or the early afternoon.

Chances for Accumulating snow in the D.C. area (Highest totals West)
Futurecast Snowfall Predictions (Probably a little overdone)

Here is a look at snowfall accumulations from our in-house model simulation. I think it is a little on the high end, so please take this with a grain of salt. Also, once precipitation changes over to sleet and freezing rain, these accumulations won't mean much as the snow will get compacted and eventually melted by rain Sunday night into Monday morning.

Timeline from 6am to 2pm Sunday (Sorry the title is off!)

Snow is expected to change to sleet and freezing rain by the early afternoon hours. The timing is anywhere from Noon-3pm with snow hanging on a little longer in the western portions of the area.

Timeline from 4pm to Midnight Sunday

Sleet and freezing rain should then be the predominant precipitation type through the late afternoon and evening hours. Areas to the east may see a change to plain rain in the afternoon, with the highest likelihood closest to the Chesapeake Bay. Locations west of D.C. may hold on to freezing rain a bit longer into Sunday night.

Icing Chances (Highest likelihood west of D.C.)

Some locations west of the Blue Ridge in the Shenandoah Valley have the highest threat for freezing rain and icing accumulations. Some locations may stay at or below freezing into early Monday morning west of the Blue Ridge and at this time we think cancellations will be likely in those areas.

East of the Blue Ridge, enough warm air should enter the region Sunday night into Monday morning to change precipitation to plain rain, and temperatures should be above freezing Monday morning for the morning commute.

The chance is still there for cancellations and delays Monday morning east of the Blue Ridge, but minor changes in just one degree in temperatures could make the difference between more or less ice.

Our team will be starting on Newschannel 8 at 7am Sunday and will continue to be live throughout the day with updates on everything from where the precipitation is to how the roads are faring. Be sure to tune in during the day and charge your iPads and Laptops as if you lose power, you can always tune in online as well.

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Snow, sleet, freezing rain and rain all expected Sunday in D.C.

December 6, 2013 - 04:00 PM
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A strong cold front pushed through the region this morning, with temperatures in the 60s overnight pushed back into the 50s by sunrise and into the 40s through the afternoon.

Scattered showers will continue through the afternoon and end later tonight. High pressure will move over the D.C. area Saturday making for partly cloudy skies and cooler temperatures in the low to mid 40s.

3pm Friday Temperatures (WeatherBELL Models)

Saturday night will be cold and dry, with low temperatures in the 20s and 30s in the region and dewpoints back into the teens to low 20s. This is all setting the stage for a disturbance to move into the region Sunday, with warm, moist air moving over the cold, dry air at the surface beginning Sunday morning.

Winter Storm Watch from the National Weather Service

A Winter Storm Watch has been issued for the majority of the D.C. area Sunday morning through Monday morning. Southern Maryland and the Northern Neck isn't included in the Watch, but they still may have a little frozen precipitation before changing over to rain earlier in the afternoon Sunday.

4km NAM forecast for Sunday morning (Courtesy: WeatherBELL Models)

Precipitation is expected to start Sunday morning in the form of snow before changing over to sleet and freezing rain in the afternoon hours. At some point, enough warm air will get into the region to change precipitation to rain, but the question is how late in the day or into Sunday night it will take place.

If it happens earlier, much less of an impact can be expected, but if it happens later, there could be major complications in the region due to icing. Below is a look at one forecast model depiction for Sunday evening, still showing the blue 32 degree line south and east of the D.C. Metro.

At this point, we expect areas of precipitation to begin changing to rain come Sunday evening southeast of D.C. and it will be on the edge of changing in the D.C. Metro. Travel looks poor Sunday evening.

4km NAM Sunday Evening (Courtesy: WeatherBELL Models)

Here is Chief Meteorologist Doug Hill's discussion which I thought summed up the forecast perfectly,

"At this point we can tell you what is possible on Sunday…what we expect to happen on Sunday. Because temperature profiles will be so important, we cannot yet tell you for certain, what WILL happen.

More rain with slowly falling temperatures WILL continue tonight and perhaps into the morning hours Saturday. Breezy and chilly weather WILL tomorrow with skies becoming partly sunny. Even colder air WILL settle into the region Saturday night.

On Sunday, moisture WILL rapidly increase over the area and precipitation WILL begin to fall.. It WILL begin as snow in many areas and then mix with or change to sleet for a period and then change to Freezing Rain.

Eventually, when surface temperatures rise above 32 degrees, the precipitation will become just plain rain. This IS NOT a one size fits all forecast.

Different precipitation types with different effects WILL be the story all day Sunday. Adverse to dangerous driving conditions WILL DEVELOP. The most likely areas for this to occur will be along and west of the I-95 corridor.

The longer it takes for temperatures to rise above freezing, the greater the chances for these conditions. And in general, the farther north and west you are from D.C, the greater the chances of this happening."

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Mix of sleet and heavy icing from Texas to Tennessee

December 6, 2013 - 09:45 AM
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A winter storm continues to wreak havoc from Texas and Oklahoma east to the Mississippi and Tennessee Valleys.

Take a look at what people have been posting on social media highlighting the storm over the past few days. We'll start in the middle of it in Arkansas, where ice build up as accumulated on trees making for a mess.

And another from Arkansas. Not something you like to see!

Transitioning to the Dallas area in Texas, icing seems to be a bit of an issue there as well. This is exactly what we do not want to see in the D.C. area come Sunday.

The National Weather Service is reporting 1-2 inches of snow and sleet in the Dallas-Fort Worth area with even higher amounts to the northwest of the city.

And another from the Dallas area.

Moving into Indianapolis, cold air wasn't just at the surface, allowing for all snow to develop rather than the icing seen south. One person sent in a picture of their snow measurement which was up to 3.25".

As far as the D.C. area is concerned, we started in the 60s this morning, but have quickly dropped into the 50s and 40s and will continue to move into the 40s through the remainder of the day.

Areas of rain will be likely late this morning and into the afternoon hours. Rain may be heavy at times, but it is expected to be rain, no snow, no sleet, no freezing rain. We can deal with that!

Doppler Radar  |  Stormwatch 7 Facebook Page

Our chances for wintry precipitation will increase on Sunday. You can read about it here in our blog from last night. I'll be working on a new blog which I'll post this afternoon on the latest updates on Sunday's storm. I really don't think anyone is hoping for what is going on out west!

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Wintry weather still a likelihood Sunday in the D.C. area

December 5, 2013 - 03:10 PM
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Winter storm warnings and ice storm warnings are posted for parts of the Deep South east into the Mississippi and Tennessee Valleys today and tomorrow and reports of icing and major traffic complications are already beginning to pile in through social media.

Above is a look at just one of the highways in Oklahoma where reports of up to a quarter of an inch of ice has built up causing multiple accidents.

Here's a look at all of the watches and warnings across the U.S. from the National Weather Service. They stretch from Texas all the way to Ohio, with the shade in pink Winter Storm Warnings and in deep purple Ice Storm Warnings.

Take a look at this tweet below showing the difference in temperature across Texas.

It gives you an idea of just how much cold air is involved with this system. The cold air is undercutting the warmer air aloft, and with precipitation falling through the warm layer above it melts precipitation to rain which will then either refreeze into sleet before hitting the ground or freezing on contact with the surface in the form of freezing rain.

Below is a nice graphic showing this type of scenario.

Courtesy NWS

One of the biggest questions for the D.C. area will be how cold it is at the surface, how deep that cold layer is, and how big is the warm layer aloft. This will all determine the precipitation type at the surface.

When there is a warm layer aloft, often times if that layer is greater than 600 ft deep or if it exceeds 3-4°C, then complete melting will occur. The next problem is figuring out how deep the cold layer is at the surface, as even if the precipitation melts aloft, it may refreeze into sleet if there is a cold layer greater than 800 ft deep at the surface.

Little nuances like that make it fun for us forecasting such a delicate process. A matter of 1 to 2 degrees are all that it takes to differentiate snow, from sleet, to freezing rain and plain rain. And you say meteorologists have it easy!

What we can give is our best guess this far out. Right now, we think hazardous conditions will be likely through the day on Sunday. Here's our current thoughts as to the timing.

Start Time Frame: 7am - 11am

-Taking a look at some of the guidance, the starting time has been delayed just a bit to the mid-morning hours on Sunday. This could be bad news for people headed to the Redskins or Ravens games as it may be quiet when you wake up but treacherous by the time you exit the game. Keep that in mind for now and stay tuned to the latest updates.

850 Temperatures Sunday Evening

Changeover to Rain: 5pm (East) - Overnight (West)

-A changeover from snow and sleet early on to plain rain is still expected, but it appears like it will be a slow progression from east to west with some western areas hanging on to freezing rain through the overnight on Sunday. This will be the toughest part of the forecast and has the least confidence at this point.

Our thoughts are that D.C. and points east will change to rain after sunset and points north and west will hang on to freezing rain overnight. This may lead to delays or possible closings Monday morning.

System Exits

-The system won't exit the region until Monday or Tuesday as the cold front moves off the east coast. Rain will fall during the day on Monday and temperatures will rebound into the mid and upper 40s. Much colder air will filter into the region Tuesday and Wednesday with highs in the mid 30s each day and lows into the teens possibly by Tuesday night!

Impacts

-Areas of light snow are expected to develop in the morning hours, changing to sleet and eventually freezing rain later into the afternoon and evening. Light accumulations may be possible, though they are too difficult to pinpoint at the moment. Regardless, we think it will be enough to cause slick road surfaces and enough of a travel issue that you might want to stay home Sunday afternoon and evening.

Depending on the amounts of snow, sleet and icing, power may be lost, so be sure to just keep that in the back of your mind in the case of the worst scenario.

We will have full updates tonight on ABC 7 at 5, 6 and 11pm and will continue to update you on each live newscast. In addition, we'll be updating our website around the clock tonight and tomorrow and will continue to substantial updates through the weekend.

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Major winter storm organizes across the country

December 4, 2013 - 11:27 AM
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Numerous weather alerts are posted through the country, with heavy snow falling in the Rockies to the Midwest, and the potential for a dangerous ice storm shaping up for parts of the Central Plains and Mississippi Valley.

This will be a high impact system with numerous travel complications likely through the weekend.

Watches and Warnings as of 11am Wednesday

Flight Aware Misery Map

Heavy snow has already been reported across parts of the U.S., with some of the heaviest totals so far seen in Minnesota. Below is a tweet from Susie Martin.

For those of you that are looking forward to ski season, it's already looking good in the Rockies, with reports of over 10" of snow so far in locations and the possibility of 1 to 2 feet more. Here's a look at the Vail Mountain Cameras. I wish I was out there with them today!

Snow isn't the only issue in the forecast, as freezing rain will become a big problem from Texas and Oklahoma, east to the Ohio Valley.

Below is a look at the probability of more than 0.1" of freezing rain across the U.S. from a 48-hour period Wednesday night through Friday night.

Graphic from the WPC

This shows a 80-90 percent likelihood of greater than 0.1" of freezing rain accumulating across parts of southeast OK, much of AR and points northeast through the Mississippi and Ohio Valleys. This storm will affect those regions through Friday night into Saturday morning.

The next threat will move in behind this system and will bring an additional chance for frozen precipitation into the weekend for the D.C. area.

This has been a relatively consistent forecast since the beginning of the week and the chance for a wintry mix at the onset of precipitation and possibly a good amount of Sunday is increasing.

(Courtesy: WeatherBell)

Above is a look at the forecast MSLP, 3-hr precipitation and 850mb temperatures for Sunday around lunch time per the GFS model. If you take a look at the northeast, you see the blue H over Canada representing a large area of high pressure.

You also see the black lines which are constant lines of pressure (called isobars) dipping on the east side of the Appalachians. This is showing cold air damming, as the cool, dry air from the high over Canada is pushing air into the D.C. area from the NE and trapping it against the mountains.

As warmer air and precipitation moves over the cold pool at the surface, the air will begin to saturate and temperatures will more than likely be below or near freezing through much of the D.C. area.

Depending on the depth of the warm air layer above the surface, precipitation may either fall as snow, melt some and refreeze in the cold pool to sleet, or possibly melt aloft and fall onto a frozen ground in the form of freezing rain.

This could cause travel complications across the D.C. area Sunday, but don't expect to have Monday off, as warmer air is expected to move into the region late Sunday into Monday morning changing everything over to rain.

Places that will hang on longest to the wintry precipitation will be in areas to the northwest such as the Shenandoah Valley. We will have further updates on this developing situation in the D.C. area over the next few days.

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Earliest sunset of the year; shortest day of the year is soon

December 3, 2013 - 03:34 PM
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The sun sets at 4:46pm this evening and will continue to do so for the next week and a half. In fact, the earliest sunset of the year spans between December 1st and December 12th, all coming at 4:46pm. By December 13th, the sun begins to set later, but days continue to get shorter through the winter solstice, which lies on December 21st. The shortest days of the year are December 20th-22nd, which all have 9 hours and 26 minutes of daylight.

Above is a look at the sunrise and sunset times over the next few months. The sunrise continues to get later through the end of the month, with the latest sunrise at 7:27am from December 30th through January 10th. The first sunset at 5:00pm in 2014 will be on January 4th, and you can see how much daylight we gain by the 31st, with the sunrise at 7:15am and the sunset all the way to 5:28pm.

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