The Return of Snow
Accumulating snow likely today; Maybe more Saturday
Winter weather advisory in effect for the metro area, winter storm warning in Loudoun, Fauquier and Frederick counties.
Here we go. After more than a month since our last accumulating snowfall, chances are good some measurable amounts of the white stuff will fall today. An area of low pressure moving up the Southeast coast will spread snow into the metro area. However, with only a shallow level of cold air over the region, it is likely that frozen precipitation will mix with and change to rain (from southeast to northwest) sometime during the late afternoon and evening hours. Light accumulations are likely in the metro area (1-3"), with some moderate accumulation (2-4") north and west of town.
ACCUMULATION MAP AND TIMELINE
Snow develops from south to north. Little or no accumulation. Temps 28-35.
10 AM to 3 PM THU
Snow, moderate at times. Accumulations to around 1" downtown and S&E suburbs, especially on grassy areas. Up to 1-2" N&W. Temps 30-34.
3 PM to 7 PM THU
Sleet and rain mixes in with snow from SE to NW. Additional 1" possible downtown and 1-2" N&W. Changeover to all rain possible downtown and S&E. Temps 31-36.
7 PM to Midnight THU
Precipitation tapers from SW to NE. Temps 30-35.
IMPACT FORECASTS
STORM FAQ
How confident are you in your forecast? We're fairly confident that precipitation will start as snow over much of the area, and that the precipitation will eventually change to rain or a wintry mix over the immediate DC metro area. We are less confident about what time this will happen and whether most of the heavy precipitation will have fallen as snow before the changeover.
Keep reading for answers to more FAQs about the storm ...
When/where will the heaviest frozen precipitation fall? In general, the heaviest precipitation will likely fall south and southwest of the immediate DC metro area. However, these areas will also likely change over to a mix or rain, cutting into the accumulation potential in those spots. The heaviest snow amounts will probably be in spots like Frederick and western Loudoun county, where 3-6" is possible.
Will the frozen precipitation stick? As with most winter storms, the further north and west you get from DC, the colder the temperatures will be and the more likely the snow will stick. In downtown DC, snow will have a difficult time sticking to the roads except when it snows hard since temperatures will be hovering right around freezing and the ground surfaces are not that cold. Most heavily traveled roadways in the metro area should tend toward wet as opposed to snowy except during moderate to heavy snow bursts -- probably around midday.
Where is the precipitation now? Track the precipitation's progress using regional and local radar. Note that parts of the leading edge of the precipitation seen on radar may be virga -- precipitation that's in the air but not yet reaching the ground.
When will travel be most difficult? Most likely during the morning rush hour in locations south and west of town, and during the mid-morning to mid afternoon hours everywhere. It's possible that snow will be moderate to heavy at times during this time period. By the PM rush, the precipitation may be letting up a bit in intensity and changing to sleet or rain -- although the evening commute does have the potential to be a little nasty, particularly north of town.
What about precipitation type? When precipitation first falls, most areas will get snow. As the day wears on, precipitation will mix with and changeover to sleet and rain from SE to NW by the late afternoon and early evening hours.
When will conditions improve? By early to mid evening, when the precipitation changes from snow to sleet or rain and the intensity of the precipitation diminishes.
Could it fizzle out? The storm itself is unlikely to fizzle out since it has already developed and there is good model agreement on the potential effects for our area. Snowfall amounts may be less than forecast if the precipitation is lighter and/or temperatures warmer than expected. Please note that in many storms downtown DC and parts of Alexandria get considerably less snow accumulation than surrounding areas because of the warming influences of the city and river. This may well be one of those cases.
Could the storm bring more ice/snow expected? Possibly. If the precipitation moves in a bit earlier than anticipated and falls heavily, it will allow for the snow to pile up more before the warmer air arrives later in the day.
What will conditions be like after the storm? We expect most of the precipitation (in the form of rain by the time the storm ends) will exit the area by late tonight or early Friday morning. Thereafter, we may experience some partial clearing during the afternoon hours as temperatures climb into the low 40s. It will turn considerably colder once again on Saturday and particularly Sunday, with a chance of a second shot of snow by later in the day on Saturday.
What are other forecast outlets calling for? ...
NWS: Same as us. 1-3" DC and close in, 2-4" N&W
NBC4: Also same us. 1-3" DC and close in, 2-4" N&W
WUSA-9: 1" Metro Area, 1-3" N&W
WJLA-7: 1-2" Metro area. 4"+ out toward Loudoun.
WTTG-5: 1-3" Metro area. 4-6" Loudoun and Frederick counties and points N&W
By Josh Larson |
January 17, 2008; 5:00 AM ET
Forecasts
, Winter Storms
Previous: Forecast: How Much Snow? |
Next: Alert: Here Comes the Snow
Posted by: Snowlover | January 17, 2008 05:21 AM
Looks reasonable to me, good work to the C' Dub Team....I mean Gang! ;)
Posted by: Mike from the Blue Ridge | January 17, 2008 05:35 AM
what is the max amount of sno for moco. Early dismissal/delay fri?
Posted by: sam | January 17, 2008 06:29 AM
Sam- You kidding me? I'm at 32.4 degrees here in Rockville. If the temps climb any higher the only reason moco'd have to delay would be wet roads.
Luckily, I've got a 5 day weekend.
:-D
I love exam week.
Posted by: Havoc | January 17, 2008 06:38 AM
New visitors -- Welcome!
Visitors from our old site -- Welcome Back!
It's still the same old crew, just some new, snazzier surroundings. To head off a couple questions that are sure to arise:
How do I get to this site? ... There are various paths and URLs that get you here, but one of the easiest to remember is simply www.capitalweathergang.com.
What happened to the 7-day? ... We are working hard on a 7-day graphical forecast. The format will likely be a little different than on our old site, and will probably take a couple of weeks to complete. But we know the importance of having this snapshot information as a complement to our own detailed written forecasts.
Posted by: Dan, Capital Weather Gang | January 17, 2008 06:43 AM
Temps should start to drop as the precip gets here right?
Posted by: | January 17, 2008 07:11 AM
Hah, I've got a 5 day weekend too. :-D
Exam week is the best. (besides exams of course!).
Posted by: Peter | January 17, 2008 07:13 AM
I realize the focus is on today's weather, but your headline mentions again the prospect of snow on Saturday. Could you elaborate? (Sorry if I missed it)
Posted by: jeffc | January 17, 2008 07:19 AM
jeffc -- the Saturday chance gets a brief mention in our 2nd-to-last Storm FAQ. We'll try to look into it more later today, but for now our focus is the here and now.
Posted by: Dan, Capital Weather Gang | January 17, 2008 07:27 AM
As always, the team will be around, monitoring conditions and radar, so if the dynamic is changing, we will let you know. For those of you that haven't been around a while, here's what we can expect.
The Many phases of snowfall at capitalweather, and it's comments:
Commenter 1 (10:05 am): Where's the snow? I'm in Mclean, and I don't see any snow. BUST!
Commenter 2 (11:30 am): It's been snowing for over an hour, I still don't have any snow on the ground, and the temperature is 35. Another storm will under perform here in Moco
Commenter 3 (1:30 pm): Guys, I think you missed this one, the storm looks to be HUGE! I already have an inch, and that radar looks great. Looks like I going to be getting the more than high end of your range in Alexandria
Commenter 4 (6:30 pm): The snow is changing to rain just north of the city, and it seems like your forecast was spot on for me. Thanks CWG.
Hopefully, this storm brings us ALL above the range and a winter wonderland
Posted by: Jamie Jones, Capital Weather Gang | January 17, 2008 07:32 AM
My drive home from D.C. to PAX River is going to suck.
Posted by: PAXR | January 17, 2008 07:35 AM
SNOW BEGINNING to fall in my area at 7:15 am.
32 degrees, se breeze at 4-8. NWS says 4-6 inches for my area. I will go with 3-5 for my area and 1-3 for the general D.C. area. This is based on model interpretation, but confidence level is not high, because high pressure is offshore that is feeding this storm. This is too far east to lock in cold air.
The NAM is very bullish on the potential for Sat. GFS still holds significant precip. s.e. of us on Sat.
Posted by: Augusta Jim | January 17, 2008 07:35 AM
My drive home from D.C. to the Blue Ridge is going to suck.
Posted by: Mike from the Blue Ridge | January 17, 2008 07:37 AM
my drive anywhere in the DC area will always suck ;)
Posted by: Jamie Jones, Capital Weather Gang | January 17, 2008 07:38 AM
Good stuff Jamie and Jim...speaking of Jim, check out I-81 in Roanoke, where are ya Jim from B'Burg?
http://www.trafficland.com/#city/ROA/camera/8113
Posted by: Mike from the Blue Ridge | January 17, 2008 07:40 AM
Uggh. Nice timing on this one. Begrudgingly hopped the LoCo Bus into Foggy Bottom this morning and am praying for a special weather bus around lunchtime. We Loudouners have a fantastic commuting option to get to DC, but are typically stuck here until at least 4pm since there are no scheduled mid-day buses back to LoCo outside of Fridays...temp was 30 as of 6am in Southern LoCo. NWS bumped my area from "up to an inch" to 3-7 inches since I went to bed last night. 7 inches? Thats a top 20 storm here in the past 15 years...I may have a fun time on the bus sitting on the Toll Road later today...timing of this one is AWFUL! But hey - sounds like I have a shot to get Baby ARC her first pictures with a snowman...
Posted by: ARC Dulles | January 17, 2008 07:43 AM
Well, that all just sucks.
Posted by: PAXR | January 17, 2008 07:52 AM
Lordy, it's 30 degrees, not a flake of snow and they've already called schools in fauquier! So an early release would be more problematic with the changeover to rain and ice? After last night's upgrade from advisory to storm,I expected to see some white stuff by now. In any case, my boy's snow dance rituals worked ... he's a happy camper!
Posted by: weathergrrl | January 17, 2008 07:59 AM
did I mention the drive will suck? :)
Posted by: PAXR | January 17, 2008 08:01 AM
Temps are scary right now! Are we expecting some cooling during the initial stages of the precip?
Posted by: Snowlover | January 17, 2008 08:11 AM
Folks, it aint the temps at the ground with this system...it's what is happening aloft.
This storm has been a snow to rain event from Atlanta northward. Temps will fall some with the advent of the snow. Doesn't look like much of an event for Eastern and Southern Maryland...and I'm thinking the accumulations will be low even in the District.
Posted by: Curmudgeon | January 17, 2008 08:20 AM
Looks Like Loudoun County has finally grown up when it comes to calling school. They didn't do anything for the clipper in December and I don't think they will be doing anything today.
Posted by: Big Goob | January 17, 2008 08:22 AM
Capital Weather Gang...maybe a discussion about wet bulbs and cold air thicknesses would be appropriate to explain why snow is on the way, even though some surface temps are well above freezing.
Posted by: Curmudgeon | January 17, 2008 08:24 AM
Heavy snow now falling, visibility down to a quarter mile, temp. has dropped 2 degrees since 7:15, down to 30. The highway is 100% covered with snow.
It's rapidly turning into a winter wonderland, but I don't like the wind direction from the south. I would be much more confident of overall potential, if the wind was east to north.
Posted by: Augusta Jim | January 17, 2008 08:27 AM
Folks--temps that are aboving freezing now will cool when the precip starts, probably closer to 10am or just a bit after in the metro area. Currently snowing in Richmond and Charlottesville.
Posted by: Jason, Capital Weather Gang | January 17, 2008 08:38 AM
So...the drive sucking part; if someone is coming from Lynchburg either through Charlottesville or up 1-81, would it be smarter to wait until say 8 or 9 this evening to travel or are temps dropping west that would actually make it icier there in spite of the changeover to rain here about then...
Posted by: missy | January 17, 2008 08:38 AM
Jamie,
Love the comment predictions. I think you might have nailed it :)
Posted by: Anne | January 17, 2008 08:39 AM
Does anyone know about PGCPS? I thought I saw an early dismissal announcement on NBC 4 this morning, but didn't see it a second time. And, nothing posted on their website.
Posted by: jerry | January 17, 2008 08:45 AM
Margusity is predicting Saturday's storm will be the biggest of the season thus far for the east coast. He says all the models are on board. Dare we hope??
Posted by: | January 17, 2008 08:49 AM
Ooops. The above comment was mine. I am used to my name automatically coming up. Sorry!
Posted by: science teacher | January 17, 2008 08:50 AM
Missy, by 8 or 9pm tonight, the precip will be over to the south and southwest (and probably in the metro area as well, for the most part). Now would definitely not be a good time to be driving up I-81 from Lynchburg/Cville...
Posted by: Jason, Capital Weather Gang | January 17, 2008 08:51 AM
The radar on the left column shows some intense precip right over DC...clearly none of it is making it to the ground, though
Posted by: SnowBound | January 17, 2008 08:52 AM
First flakes out of my 8th story window overlooing 21st St NW at E St...here we go!
Posted by: ARC Dulles | January 17, 2008 08:55 AM
As a sign of things to come, check out the webcam at the University of Virginia in Charlottesville
Posted by: Jason, Capital Weather Gang | January 17, 2008 08:56 AM
I just finished measuring a solid one inch of snow on my deck and still coming down. One down and two to go, to get into the lower range of my 3-5 thoughts. 29 degrees.
Posted by: Augusta Jim | January 17, 2008 08:58 AM
Flurries in NW DC
Posted by: Jason, Capital Weather Gang | January 17, 2008 09:00 AM
no flakes yet in oakton :(
Posted by: mandarb77 | January 17, 2008 09:04 AM
Speaking of things I miss from the old site set up, I really miss the graphs with % likeliness of various scenarios. Any way to bring that back?
Posted by: mandarb77 | January 17, 2008 09:07 AM
Sitting here at the Hyundai dealership in Manassas and I see....nothing.
Jeeze, hurry up already! if it is snowing in DC, it ought to be out here! LOL
Posted by: Kim in Manassas | January 17, 2008 09:11 AM
Kim -
Muhahahahahaha!!!!
Posted by: Dulles ARC | January 17, 2008 09:15 AM
mandarb: We ran a graph with different scenarios (i.e. probability of different amounts of snow) yesterday and will continue to provide that sort of thing. Admittedly, maybe should've done an update for today and will remember that next time.
I'm outta here for a while but other folks from the Gang will weigh in from time to time and there will be some new posts periodically
Posted by: Jason, Capital Weather Gang | January 17, 2008 09:16 AM
Light snow in Gaithersburg for the past 10 minutes
Posted by: mark | January 17, 2008 09:17 AM
Looked at the UVA cam. Sure looks like they have at least an inch already.
Posted by: winchester | January 17, 2008 09:17 AM
Heavy snow near Richmond. starting to stick on grass but seems very, very wet. It's heading north...
Posted by: fab | January 17, 2008 09:18 AM
Flurries in downtown DC, near The Mall
mandarb77, thanks for the feedback. We will take that into consideration, when storms look more and more probable on the horizon. Glad you liked the scenario graphs!
Posted by: Camden, CapitalWeather.com | January 17, 2008 09:20 AM
Finally broke through - flurries in Purcellville (western Loudoun County)!
Posted by: vatchr | January 17, 2008 09:25 AM
Was snowing when I got up at 7:30 this morning, with 2-3" already on the ground. Probably 3-4" on the ground now. Temps in the upper 20s. Snow has ranged from very light to moderate/heavy, but there have been no total stoppages. Seems like light snow, with heavier bands moving through.
Doesn't look like this will change over anytime soon either. I really wonder if we will see much mix at all, I am beginning to think the back edge of the precip gets here prior to a changeover. Maybe a bit of freezing drizzle at the end.. but beyond that.
Posted by: Jim in Blacksburg | January 17, 2008 09:27 AM
Snowing in Lake Ridge - PWC.
Posted by: | January 17, 2008 09:28 AM
Wtop traffic cams are showing snow out in Front Royal... looks like it is just starting.
Posted by: Anne | January 17, 2008 09:31 AM
flurries in frederick
Posted by: Alan | January 17, 2008 09:32 AM
NWS Blacksburg just upgraded us to a Winter Storm Warning and is now calling for a total of 4-8" of snow :D.
I love it when a storm overperforms.. so rare in these parts!
Posted by: Jim in Blacksburg | January 17, 2008 09:33 AM
no snow yet in capitol hill...
Posted by: madison | January 17, 2008 09:35 AM
LT snow in Chantilly.
Posted by: Jake DeNardo | January 17, 2008 09:36 AM
Light snow just began in NW Montgomery County.
Posted by: JT | January 17, 2008 09:36 AM
Heavy snow in Fredericksburg. Starting to stick on driveways and roads.
Posted by: Glenn in the burg | January 17, 2008 09:40 AM
nice steady snow started in New Baltimore about 9:15. Vindication at last!
Posted by: weathergrrl | January 17, 2008 09:40 AM
I'm sorry, I can't let that go . . . view the Virginia Tech webcam!
Posted by: Uncle Dak | January 17, 2008 09:42 AM
just started snowing in columbia, md
Posted by: mickb | January 17, 2008 09:44 AM
38.5 in Mt Pleasant...occasional flurry
Posted by: Matt Ross, Capital Weather Gang | January 17, 2008 09:47 AM
Light snow in Beltsville
Posted by: Ryan | January 17, 2008 09:49 AM
Saw at least 22 flakes on the way in from Chevy Chase to downtown. Well, it might have been 21... I think I saw one flake twice. ;-)
Posted by: SoMoCo | January 17, 2008 09:54 AM
starting to stick to grass, cars and sidewalk here in oakton
Posted by: mandarb77 | January 17, 2008 10:01 AM
snowing in falls church! small flakes, not sticking yet.
Posted by: walter | January 17, 2008 10:03 AM
Moderate snow in Woodbridge, sticking nicely. temp dropped to 32.0 from an earlier high of 34.5.
Posted by: PC | January 17, 2008 10:03 AM
No snow yet here on the SE Waterfront at the Navy Yard. @1005
Posted by: Andrew | January 17, 2008 10:05 AM
Snow very hard in North Stafford, sticking to the roads...
Posted by: TJ | January 17, 2008 10:05 AM
The lightest of snow in Bowie, I wouldn't even call it flurries, but still snow! Temps warm, though, at 35.
Posted by: jtf | January 17, 2008 10:06 AM
Finally...snow in S.W....i hope it never ends..
Posted by: J from A | January 17, 2008 10:07 AM
2 inches and still coming down. 29 degrees
Highways are terrible with many accidents in my area. Police are asking folks to stay off the highways unless absolutely necessary and will charge people that don't have their vehicles properly equipped.
12z Nam is intensfying the Sat. potential.
4-8 inches possible Sat. afternoon and night if the 12z run verifies!
Posted by: Augusta Jim | January 17, 2008 10:09 AM
OK Jamie here we go (and this is true)(10:09 am): Where's the snow? I'm in College Park, and I don't see any snow. BUST!
Posted by: | January 17, 2008 10:09 AM
HA it worked (10:12) AM. Light snow here in College Park! (I swear it just started in the last 3 minutes).
Posted by: | January 17, 2008 10:11 AM
haha...ask and you shall receive!
Posted by: J from A | January 17, 2008 10:15 AM
finally... flurries in capitol hill :)
Posted by: madison | January 17, 2008 10:22 AM
light snow in Frederick now
Posted by: Alan | January 17, 2008 10:26 AM
heavy, wet snow in arlington... not sticking yet.
Posted by: | January 17, 2008 10:31 AM
heavy snow in Foggy Bottom
Posted by: | January 17, 2008 10:33 AM
picking up a bit in Laurel
Posted by: jerry | January 17, 2008 10:38 AM
snowing hard in howard county now.
Posted by: mickb | January 17, 2008 10:40 AM
For those who missed it, Dan posted a new post above with our latest thoughts, check it out! Newest thoughts
Posted by: Jamie Jones, Capital Weather Gang | January 17, 2008 10:41 AM
Heavy, fat flakes falling here in Alexandria!!! SNOW BABY SNOW!!!!!!!
Posted by: Jamie | January 17, 2008 10:43 AM
Here in Glover Park, it started as graupel about an hour ago and quickly transitioned to traditional snow as the intensity picked up. It's now coming down at a decent clip and is accumulating pretty quickly on everything but pavement.
How did I ever manage on days like this before telecommuting was an option?!
Posted by: Parker | January 17, 2008 10:50 AM
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