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%.
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.
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!
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.
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.
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.
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.
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.
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.
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.
10:11am: 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.
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.
9:27am: 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.
Here is an updated timeline of today's weather for the D.C. Metro.Freezing rain holds on West of I-95 into the a.m. pic.twitter.com/AYIXVFXaA4
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!
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!
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.
A half inch of snow already just west of Front Royal.
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.
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.
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.
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
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."
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.
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".
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!
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.
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.
-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!
-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.
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.
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.
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.
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.
Back to work and all of a sudden it's December! Seems like November flew by. November ended up to be a cooler than average month by three degrees. It might be hard for you to believe that, if you recall, we hit 70 degree temperatures the first two days of that month! Winter is officially here, now. Meteorological winter is recorded as December, January and February. However, the winter solstice is on Saturday, December 21st at 12:11p.m. EST.
Now that we've turned the page to December, we are starting with near average temperatures. We begin the month with an average high of 52 degrees on the 1st. By the end of the month, our average high at Reagan National drops to 44 degrees.
With less daylight and colder temperatures, we typically see our first measurable snowfall at Reagan National. December gets 2.3" of snow on average for the month. The snowiest day on record was December 19th, 2009 when we had 15" of snow in 24 hours. There have also been plenty of Decembers with zero snowfall.
The coldest December day bottomed out with -13 degrees on the 31st back in 1880. And, the hottest December day featured a high of 79 on December 7th, 1998. Our forecast for the first week of the month has highs and low points. We should hit 60 degrees on Thursday, but by Sunday, it will be cold and back in the 30s with a chance for some snow.