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Posted at 5:00 AM ET, 01/17/2011

Forecast: Snow, ice, and rain tonight

By Jason Samenow

Another cold week

Today's Daily Digit
 
A somewhat subjective rating of the
day's weather, on a scale of 0 to 10.

 

Cold & raw with a wintry mess tonight. At least it's a holiday.
 
Get the 'Digit' on Twitter

EXPRESS FORECAST

Today: Increasing clouds. 32-36. | Tonight: Snow to ice to rain. 30-32. | Tomorrow: Morning rain, remaining cloudy. 36-41. | A Look Ahead | Get Express Forecast by E-mail

FORECAST IN DETAIL

For most of the winter storms in 2010-2011, the question has been snow or no snow. This time around, we entertain the possibility of multiple precipitation types which evolve from snow to sleet to freezing rain and then rain, starting this evening and continuing through Tuesday morning. Another batch of precipitation, likely rain, arrives Tuesday night. Then we get a couple dry days while we await the next (slight) chance of precipitation Friday.

Snow Potential Index: 5 (↑) - Decent chance of a brief period of snow tonight before ice & rain. Slight chance of late week snow.

 
The SPI is a daily assessment of the potential for accumulating snow for the next week on a 0-10 scale. Get the 'SPI' on Twitter
 

Temperatures: Latest D.C. area temperature map powered by iMapWeather (base map by Google). Click and hold on map to pan. Double-click to zoom. Refresh page to update. See larger map on our Weather Wall.

Today (Monday): Clouds lower and thicken as low pressure organizes to the south. A snow flurry or two is possible, but most precipitation holds until after dark. Highs are in the low-to-mid 30s. Winds are light, from the east at 5 to 10 mph.Confidence: Medium-High

Tonight: Snow is likely (60% chance) to develop from southwest to northeast between 5 and 9 p.m. The snow quickly mixes with and changes to sleet southeast of D.C. with just a coating of snow accumulation. However, several hours of snow are possible in the northwest suburbs, where an inch or so of snow is possible. By 1 to 2 a.m., most locations change to sleet and/or freezing rain. And between 3 and 6 a.m., the frozen precipitation transitions to plain rain from southeast to northwest (in most spots) as temperatures slowly rise.

By the a.m. commute, most spots are above freezing. However, the normally colder outlying north and west suburbs from central Loudoun county to Frederick county may still have ice - especially on elevated surfaces. There is some uncertainty as to how fast temperature rise overnight, so stay tuned for updates later today. If temperatures stay at or below freezing longer than anticipated, serious icing could occur. Confidence: Low-Medium

Keep reading for the forecast through next weekend...

Tomorrow (Tuesday): Rain is likely in the morning except for some isolated pockets of freezing rain early in the outlying north and west suburbs (changing to rain by 10 a.m.). By midday, the rain should taper off. For the afternoon, it remains cloudy with raw temps in the upper 30s to near 40. Winds are from the north around 10 mph. Confidence: Medium

Tomorrow Night: Another disturbance swings through, but this time less frozen precipitation is expected. Light rain is good bet (60% chance) after around 7 p.m. Toward morning, the light rain could briefly mix with and change to snow mainly north and west of the District, but little or no accumulation is expected. Lows are in the mid-30s. Confidence: Medium

A LOOK AHEAD

Weak high pressure builds into the region for Wednesday and Thursday. Cold flow from the northwest means highs in the 30s with Wednesday's overnight low from the upper teens in the colder suburbs to the mid-20s downtown. Confidence: Medium-High

Thursday night and Friday, a cold front passes through the region, providing a chance of some light snow, especially Friday morning. Behind the front, it's breezy and cold with highs only near freezing Friday. Confidence: Medium

The weekend is probably dry and cold but we'll have to watch and see if low pressure develops along a cold front stalled our south, which might bring back the chance of some storminess. Weekend highs are cold, only in the low 30s. Overnight lows are in teens to low 20s. Confidence: Low-Medium

By Jason Samenow  | January 17, 2011; 5:00 AM ET
Categories:  Forecasts  
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Next: Wintry mess expected tonight

Comments

The trend this winter sure is hard-to-forecast events.

Is there potential for a 2 hr delay if the temps are slow to warm up in the night?

Thanks!

Posted by: kirom | January 17, 2011 5:42 AM | Report abuse

I dunno... I wish I had bob Miller's knowledge but I think there will be 4 feet of snow 5 weeks from now!!!!

Posted by: PlowKing1 | January 17, 2011 6:40 AM | Report abuse

Actually it probably will only be 4.7899877 inches but I'll chase the dream!!!

Posted by: PlowKing1 | January 17, 2011 6:47 AM | Report abuse

Yeah, but I'm hoping for 44.7899877"!

Posted by: BobMiller2 | January 17, 2011 6:57 AM | Report abuse

Yeah, but I'm hoping for 44.7899877"!

Posted by: BobMiller2 | January 17, 2011 6:57 AM | Report abuse

---------------------------------

That is a bit on the low side if you've seen my models! I hear global warming is heading for a recession... We might be getting two feet in May if my model verifies!!!

Posted by: PlowKing1 | January 17, 2011 7:05 AM | Report abuse

looks like im in for a long night, to salt or not to salt, that is the question?

Posted by: KRUZ | January 17, 2011 7:12 AM | Report abuse

Ah, I see. Do your models predict a white Christmas 5 years from now?? Mine do!!

Posted by: BobMiller2 | January 17, 2011 7:51 AM | Report abuse

Ah, I see. Do your models predict a white Christmas 5 years from now?? Mine do!!

Posted by: BobMiller2 | January 17, 2011 7:51 AM | Report abuse

-------------------------

No mine only go out 4 years... But i know it will snow... If enough people comment on it must be true!!!!!!

Posted by: PlowKing1 | January 17, 2011 7:56 AM | Report abuse

Oh, well the Bob Miller models go out 7 years! ;)

Posted by: BobMiller2 | January 17, 2011 8:07 AM | Report abuse

While this storm will probably bring mostly rain to most of the area, I do think it needs to be watched closely as some of the models have DC as very close to significant icing.

Posted by: Dylan0513 | January 17, 2011 8:26 AM | Report abuse

This is going to be a very tricky one and must schools in the northern and western suburbs will just close rather than take a chance with a one or two delay. It will turn out they overreacted (nothing new there) leading to the classic "schools closed today for rain" scenario we see every couple years when the freezing rain is short lived and turns to rain by 9am.

Posted by: rwalker66 | January 17, 2011 8:40 AM | Report abuse

This sure is a gross forecast, but the area urgently needs moisture.
No winter weather advisories posted yet. Are we likely to see any?
WILL IT REALLY SNOW & WILL I SEE IT BEFORE NIGHTFALL?
Be prepared for power outages. And if the ice is thick enough you will be stuck for a while until it melts. Is everybody prepared to be stuck inside for a minimum of 24 hours should things go badly?
No, I'll bet not.

Posted by: FIREDRAGON47 | January 17, 2011 8:44 AM | Report abuse

I live in Frederick and work in MoCo. I'm usually on the road by 6:30am. Should I make tomorrow a work-from-home day, or would that be overreacting?

Posted by: lily2905 | January 17, 2011 8:47 AM | Report abuse

ummm 24 hours is not a real long time to be stuck inside...

Posted by: mandarb77 | January 17, 2011 8:57 AM | Report abuse

Hmmm. I'm supposed to drive up to Baltimore from Silver Spring tonight, arriving at 6, usually stay for dinner with friends until about 8 - Is there enough snow accumulation planned for that time to make my commute back home dangerous/should I reschedule, or is that being jumpy? Opinions very welcome!

I'm not too afraid of myself in the snow, it's the other drivers that terrify me!

Posted by: noelblue | January 17, 2011 9:06 AM | Report abuse

You're right mandarb 24 hours isn't a long time at all, but you would be surprised at the number of folks who don't keep much food in the house & don't have an extra roll of TP in the closet. There is a reason for those big grocery store runs before predicted snowstorms.
We stock our house much like a bunker in the winter months. Last year taught us a few things.

Posted by: FIREDRAGON47 | January 17, 2011 9:07 AM | Report abuse

There's really just zero chance of being stuck inside for 24 hours with this one...

Posted by: bbirnbau | January 17, 2011 9:09 AM | Report abuse

this storm is gonna be another bust. everyone stop freaking out about this. by 9 am tomorrow the everything will be wet like a rainy day. 2 hour delay for moco schools most likely.

Posted by: SNOWLUVER | January 17, 2011 9:44 AM | Report abuse

how is it a bust when that's exactly what they are saying is going to happen?

Posted by: bbirnbau | January 17, 2011 9:47 AM | Report abuse

@FIREDRAGON47

You're right. 24 hrs can be a long time if you don't have the necessities.

@bbirnbau

True, but if the storm changes even the slightest bit, you could get stuck at home.

@rwalker66

Most school systems hit the panic button before precip even starts falling. I'll bet you several will anounce closures and/or delays this evening.

@kirom

I think you're gonna have to wait and see.

@noelblue

Well, that's gonna be a close call. I think that by 8 pm there could be a few problems.

Posted by: BobMiller2 | January 17, 2011 9:47 AM | Report abuse

@lily2905

Working at home might be a good option.

@noelblue

We can't pin down the exact start time, but your trip home would be around the time we might expect some snow and/or sleet to begin. I'd keep my eye on the radar starting late this afternoon.

Posted by: Jason-CapitalWeatherGang | January 17, 2011 10:23 AM | Report abuse

CWG,

Do you think we will get a Winter Weather Advisory?

Posted by: icecubedownthetoilet | January 17, 2011 10:39 AM | Report abuse

Given the early closes and snow days Fauquier has already had this season, I predict nothing less than a 2-hour delay, if not a snow day (called the night before(!)

For kids at the end of a three-day weekend, it's a big deal.

Posted by: weathergrrl | January 17, 2011 10:45 AM | Report abuse

How much ice accumulation could be expected? Will it be like the ice storms we got in the mid '90s that coated the trees so heavily that they made tinkling noises in the wind? Those storms were horrible.

Posted by: SubRosa2 | January 17, 2011 10:49 AM | Report abuse

@SubRosa2

This isn't going to be like the mid-1990s (1994, specifically) ice storms which were widespread and crippling - temps were in the teens in 20s. This is a much more marginal event, but still could cause some problems, especially N&W.

Posted by: Jason-CapitalWeatherGang | January 17, 2011 10:59 AM | Report abuse

@icecubedownthetoilet

I think we will get a Winter Weather Advisory.

Posted by: Jason-CapitalWeatherGang | January 17, 2011 11:00 AM | Report abuse

Thank you so much for the reply, Jason. (And you also, Bob!) I will definitely be watching radars closely. Not worth the risk, I'm thinking.

Man, and I could have really used a drink tonight, too.

But thank you for this wonderful blog; I never thought of myself as a weather geek before finding you guys during the Snowpocoli, and now I'm always on here. A friend and I had a ridiculously girly "OMG best weather source ever!" moment recently when we discovered we both read you.

Posted by: noelblue | January 17, 2011 11:05 AM | Report abuse

Latest Euro isn't looking so good for a weekend snow event. It looks like the low will go OTS.

Still hoping the next GFS will show something.

PS Current reading on my deck in Sterling, VA: 30.2°F and cloudy.

Posted by: BobMiller2 | January 17, 2011 11:06 AM | Report abuse

noelblue - always appreciate you reading and commenting - thanks for following us and for your kind comment. Also really keen on your vocabulary: "Snowpocoli" is super word.

Posted by: Camden-CapitalWeatherGang | January 17, 2011 11:10 AM | Report abuse

@noelblue

You're welcome. Always happy to help!

Posted by: BobMiller2 | January 17, 2011 11:10 AM | Report abuse

@BobMiller
We are in a typical DC winter. Awfully hard to predict these things -- like this weekend.

Funny - Accuweather App just notes that there is a chance for rain on Tuesday!! Totally useless!!

Posted by: moo1 | January 17, 2011 11:26 AM | Report abuse

heres an acuwx hi res map for tonights storm....

http://vortex.accuweather.com/adc2004/pub/includes/columns/community/2011/wrf117anim.gif

According to that map its not gonna be very much mix around DC metro and east. Whats anyone elses thoughts on that map?

Posted by: KRUZ | January 17, 2011 11:33 AM | Report abuse

You guys should talk to your IT people about making your website more smartphone friendly.

Posted by: bryankellogg1 | January 17, 2011 11:34 AM | Report abuse

@BobMiller2

Still several days of model runs to get through in terms of a Friday storm. Right now, the Canadian supports a big storm while the Euro and GFS support a lesser storm. I'm sure that will change, as it has over the last couple of days.

Posted by: DLO1975 | January 17, 2011 11:38 AM | Report abuse

Kruz, thanks for posting that simulation... a little hard to see all the details, but the NAM and RUC simulations appear to bring more snow/mix into DC...

Posted by: spgass1 | January 17, 2011 11:53 AM | Report abuse

KRUZ - I don't believe the accuweather map takes enough into account how difficult the cold air will pool and not scour out easily (until perhaps morning, especially N&W of DC)

Posted by: Camden-CapitalWeatherGang | January 17, 2011 11:58 AM | Report abuse

The Canadian model shows a massive storm on Friday:

http://www.meteo.psu.edu/~gadomski/CMC_0z/f108.gif

Posted by: BobMiller2 | January 17, 2011 11:59 AM | Report abuse

What do you think about the Baltimore area? We are north and east (as opposed to north and west) of DC?

Posted by: marcm2 | January 17, 2011 12:13 PM | Report abuse

What do you think about the Baltimore area? We are north and east (as opposed to north and west) of DC?

Posted by: marcm2 | January 17, 2011 12:14 PM | Report abuse

CWG -- headed to VT Wed PM, how is the 95 corridor shaping up? Should I be concerned with this snow/rain event or will it clear out as I head north?

Also think you all do the best job possible given the multitude of variables taken into consideration when formulating forecasts.

Posted by: Garret_in_VA | January 17, 2011 12:31 PM | Report abuse

Differing opinions...righty talker WMAL [which gets its weather forecasts from TWC] says everything will be liquid by daybreak.

Channel 9 [Mt. Holly, NJ] says we could have an extended period of wintry mix overnight, but precipitation may taper off around or just after daybreak with temps still near freezing.

NOAA Weather Radio seems to trend towards a change to rain during the early morning.

Not heard yet...Accuweather...maybe Joe Bastardi is considering the great half-inch icing event.

One question out there...How long might it take for PEPCO to restore any power in their service area which goes out???

Posted by: Bombo47jea | January 17, 2011 12:42 PM | Report abuse

In terms of North and West I would assume that includes Fairfax (centreville), The latest new casts both 9 and 7 say 1 inch of snow and a teth to quarter inch of ice accum. looks like a mess! And 9 had the Coastal Storm? logo above Fri-Sat time frame :)

Posted by: teebyrd86 | January 17, 2011 12:54 PM | Report abuse

Supposed to report for jury duty in Leesburg tomorrow at 8 a.m. but the words "serious icing" connected with Loudoun terrify me. I know schools will probably have a delayed opening, but anyone have any guesses about Loudoun County government?

Posted by: panamanancy | January 17, 2011 1:08 PM | Report abuse

We have a new post up. Click here

@panamanancy

No ideas about Loudoun gov. I think it could be kind of icy out there in the morning, so be careful.

@marc2m

You're in about the same boat as D.C. -- probably just wet on the east side in the morning, but better chance of some iciness on the west side.

@Garret_in_VA

I think the I-95 corridor should be ok Wed PM- storm mostly gone by then and it will be a snow to rain storm for the big cities up north anyways.

Posted by: Jason-CapitalWeatherGang | January 17, 2011 1:25 PM | Report abuse

boy, the site is extra slow to load this morning....

Posted by: walter-in-fallschurch | January 17, 2011 1:45 PM | Report abuse

...and afternoon...

Posted by: walter-in-fallschurch | January 17, 2011 1:46 PM | Report abuse

So the forecast for ice kinda scared me a bit - nobody likes that. But then I checked out the Weather wall and realized all was going to be fine as I gazed upon the picture under the DC Webcam title which shows what looks like a summer day...partly cloudy...nice green trees/grass...no ice on the tidal basin... Must be global warming! Drats...upon further review, the NPS camera is undergoing maintenance.

Posted by: amaranthpa | January 17, 2011 3:28 PM | Report abuse

In my profession (law) we say that difficult cases make bad law - by analogy to CWG's chosen profession, I'd say difficult forecasts make for crappy storms...

Posted by: prickles1009 | January 17, 2011 5:44 PM | Report abuse

The comments to this entry are closed.

 
 
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