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Posted at 11:00 AM ET, 12/ 4/2009

Forecast: Season's first snow likely Saturday

By Camden Walker

Chance for minor accumulations; chilly weekend

* China tinkers with weather, again | Expect anything in December *
* Photo contest winners | 2010 calendar | The Fed readies for winter *

Updated @ 11 a.m.

EXPRESS FORECAST

Today: Partly to mostly cloudy. Near 50. | Tonight: Mostly cloudy. Mid-30s to near 40. | Tomorrow: Cold with periods of snow/rain. 30s. | Sunday: Partly to mostly sunny. Low-to-mid 40s. | A Look Ahead | Get Express Forecast by E-mail

FORECAST IN DETAIL

Let's get the easy part of the next three days out of the way first: No precipitation today or on Sunday. That leaves Saturday, which is likely to bring our first snowflakes of the season. We're not expecting a major snowfall. Still, it may look and feel quite wintry for a time. Just how much snow, and when?...

Temperatures: Current area temperatures. Powered by Weather Bonk. Map by Google. Hover over and click icons for more info. Click and hold on map to pan. Refresh page to update. See map bigger on our Weather Wall.

Today (Friday): We're partly to mostly cloudy today, and yesterday's mild temperatures are history. Highs only make the upper 40s to low 50s. On the plus side, winds will be light after yesterday's gusty breezes. Confidence: Medium-High

Tonight: Mostly cloudy and not too chilly for December, with lows in the upper 30s to near 40 downtown and mid-30s in the colder suburbs. Winds remain light and start to come out of the northeast. Confidence: High

Keep reading for the latest on Saturday's snow chances, and for the forecast into early next week...

Saturday Morning: Periods of light snow or a rain/snow mix are possible during the morning, probably with little or no accumulation as temperatures stay mostly steady in the mid-to-upper 30s. Confidence: Medium

Saturday Afternoon & Evening: Precipitation is likely to change to all snow. Accumulations of around an inch or two are possible on grassy areas. Any moderate bursts of snow could whiten the pavement and make untreated roads, bridges, overpasses and ramps slick, especially once the sun starts to go down. With temperatures in the mid-and-low 30s and winds around 10-20 mph, wind chills should be in the 20s. Confidence: Low-Medium

Saturday Night: Snow tapers during the evening as the storm pulls away, with clearing skies overnight. Low temperatures by dawn should be below freezing area-wide, in the 20s in the suburbs to near 30 downtown. Be on the look out for patches of black ice if out and about during the early-morning hours. Confidence: Medium

Sunday: Partly to mostly sunny skies and light winds make for a much improved Sunday. Highs in the low-to-mid 40s will still be chilly. But they should be high enough to melt down any accumulated snow. Confidence: Medium-High

A LOOK AHEAD

Partly cloudy on Sunday night with lows in the 20s (suburbs) to near 30 downtown. Confidence: Medium

Partly sunny and cool on Monday & Tuesday with highs in the 40s to near 50. No precipitation threats as of now. Confidence: Medium

CWG's Dan Stillman contributed to this forecast.

Tell a friend about CWG: E-mail this forecast

By Camden Walker  | December 4, 2009; 11:00 AM ET
Categories:  Forecasts  
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Comments

why are we getting snow while Boston, Hartford, and NYC are expecting rain? Usually other way around, why are temps going to be cooler here?

Posted by: TGT11 | December 4, 2009 8:26 AM | Report abuse

Conversational only. Air temps will be too warm and ground/road temps are well above freezing.

Ch 9 seems to have watered down their forecast this morning.

Posted by: ThinkSpring | December 4, 2009 9:51 AM | Report abuse

Think it will be more than conversational given time of yr if nothing else. Roads may not be a major issue, true. Midday models are juicy, beautiful almost..

Posted by: Ian-CapitalWeatherGang | December 4, 2009 10:49 AM | Report abuse

@Ian-CWG-If we are lucky enough to have the snow stick to the grass, are we looking at a potential 2-3 inches in the DC metro area, or am I being delusional?

Posted by: snowlover | December 4, 2009 10:53 AM | Report abuse

Hi snowlover, I don't think the temperatures before the storm (today) and during the storm (tomorrow) will allow for accumulations above 1" in the DC area. A wildcard typical of DC storms, would be heavy bursts of precipitation cooling the atmosphere in order to allow higher accumulations. But the shield of preipitation simply is not forecast to be heavy enough tomorrow. Thus NOT inducing colder temperatures from higher in the atmosphere (which can be "dragged down" with heavy precipitation)

Posted by: Camden-CapitalWeatherGang | December 4, 2009 11:02 AM | Report abuse

I sort of disagree with Camden, especially if today's trends continue. I think there's potential for a decent little event. But potential does not always win out and I've been bullish all week so maybe I'm sticking with that.

Posted by: Ian-CapitalWeatherGang | December 4, 2009 11:08 AM | Report abuse

Camden and Ian - It pains us readers to see you disagree. We want compromise. So if one of you is saying 1' and the other thinks 3' is possible, can we settle on 2'? That would make your readers happy.

Posted by: authorofpoetry | December 4, 2009 11:25 AM | Report abuse

The spread is a bit wider than the difference between 1 and 3 inches.

Posted by: jpl1019 | December 4, 2009 11:32 AM | Report abuse

The clear trend today is for heavier precipitation. I agree with Camden's thoughts that we need that to get good accumulation, but I think it's becoming more likely to happen. I still have to fall back on seasonal trends for coastal systems -- many have produced very well in this area. All along in my mind it's been an issue of cold air (will we have enough etc). Now that the "west trend" has begun we -- snow lovers -- need to hope it does not go too much further.

Posted by: Ian-CapitalWeatherGang | December 4, 2009 11:36 AM | Report abuse

JPL - What is the spread? I have a dinner tomorrow that I am trying to get out of...

Posted by: authorofpoetry | December 4, 2009 11:36 AM | Report abuse

Forecast above has been updated... tweaked accumulation forecast from "around an inch or less" to "around an inch or two," still with the various caveats as outlined above as to when and on what surfaces snow will accumulate. Forecast confidence is still "Low-Medium," so stay tuned for the afternoon update.

Posted by: CapitalWeatherGang | December 4, 2009 11:38 AM | Report abuse

Ian - What is your current prediction on grassy areas?

Posted by: snowlover | December 4, 2009 11:39 AM | Report abuse

Well up until this morning there was much disagreement in many of the models. Some called for rain, some called for an inch of snow, and some called for almost nothing but flurries. What Ian is speaking of is that some of the last few model runs from the American models have come closer to a consensus in terms of timing, temperature, and precipitation amount. So at this point a conservative estimate would be an inch or two just based on those model runs alone.

I would wait until at least the afternoon (18z) models come out to see if the trend continues. We are less than 24hrs until the event takes places so there really isn't that much more time to forecast until we need to nowcast.

Posted by: jpl1019 | December 4, 2009 11:43 AM | Report abuse

snowlover, as noted we will update this afternoon. It does look like some watches might go up today based on trends though.

Posted by: Ian-CapitalWeatherGang | December 4, 2009 11:47 AM | Report abuse

Where's the crystal ball???

Posted by: Etch | December 4, 2009 12:18 PM | Report abuse

Come on snow! I can't wait to get back out in my Jeep in some snow!

Posted by: Havoc737 | December 4, 2009 12:25 PM | Report abuse

This has all the makings of a major winter event. My modules show 5"-8" across the Washington region AND WITH SIGNIFICANT DRIFTING that could make it into the feet in some areas! Though it'll happen on Saturday, you can bet there'll be some school closings Monday. Get ready.

Posted by: shoveit | December 4, 2009 12:33 PM | Report abuse

CWG Folks -- In the future, I would appreciate it if you highlighted a bit better when you change your forecast and where as you did above moving from less than an inch to an inch or two? Even an "UPDATED" in your post title would let us know that we should rescan the post.

Thanks!

Posted by: Registration1982 | December 4, 2009 12:35 PM | Report abuse

@Etch

No Crystal Ball once within 24-36 hours of an event. The Ball needs to rest up for when it's summoned next.

Posted by: CapitalWeatherGang | December 4, 2009 12:37 PM | Report abuse

Any thoughts on the 12z GFS gents? Seems to be increasing the likelihood we'll see more than 2 inches, no?

Posted by: worldtraveler | December 4, 2009 12:39 PM | Report abuse

@Registration1982

Good idea... added updated to the top of the post

Posted by: CapitalWeatherGang | December 4, 2009 12:41 PM | Report abuse

No way we hit 53 today. And that's a pro-snow comment, not a criticism of the CWG forecast :)

Posted by: fleeciewool | December 4, 2009 1:11 PM | Report abuse

12Z Euro looks mighty fine for DCA, I believe. WSW can't be too far off now. Will LWX issue in their next package?

Posted by: Holt1 | December 4, 2009 1:17 PM | Report abuse

I'm never one for models - I just check the short-term trends in the various forecasts. Interesting that weather.com is now calling for 3-6 inches in Richmond. That's a tad bullish but I like the trend.

Posted by: fleeciewool | December 4, 2009 1:24 PM | Report abuse

holt: I think they'll put up watches at the next update and warnings/advisories this evening.

Posted by: jpl1019 | December 4, 2009 1:30 PM | Report abuse

Finally as my lunch hour comes to a close: Winter Storm Warning now issued for metropolitan Houston, Texas.

Posted by: fleeciewool | December 4, 2009 1:33 PM | Report abuse

Fleeciewool where are you seeing 3-6" for RIC on Weather.com?

Posted by: Registration1982 | December 4, 2009 1:38 PM | Report abuse

Reg82 - go to their accumulation map. It's called "rain/snow forecast" or 24-hour rain snow or something like that.

Posted by: fleeciewool | December 4, 2009 1:42 PM | Report abuse

After the last few years, the last thing the crystal ball needs is rest. The swirling clouds within are are nothing more than the empty yearnings of unrequited snow falls. Reset the pathetic orb by hauling it out for a sure thing, so it gets the scent of actual snow again. Poor thing probably thinks 34 degrees and a steady rain is what we refer to as a snow storm in this area.

Posted by: Etch | December 4, 2009 1:59 PM | Report abuse

Here is a little tip people who only show up when snow is in the forecast. DO NOT depend on or quote weather.com. It is a weenie site and is rarely accurate.

Posted by: MKadyman | December 4, 2009 2:23 PM | Report abuse

Looks to me like a Winter Weather Advisory situation from noon to 10 PM tomorrow.

One caveat in favor of snow: This resembles how Veterans Day, 1987 started out. We were supposed to get cold rain or one to three inches of snow at most. We ended up with ten to sixteen inches from Arlington eastwards, & good thundersnow at the outset.

BTW, authorofpoetry: 1' to 3' means one to three FEET of snow, not one to three inches [depicted as 1" to 3"]. If we get that much, we snow lovers will be VERY HAPPY, but that doesn't look likely, though we do have the shining example of Veterans Day, 1987!

Posted by: Bombo47jea | December 4, 2009 2:23 PM | Report abuse

Great discussion, yet again! Thanks to all, and especially to Registration1982 for the update idea. Liking the trend of the forecast!

My guesstimate is a 3"-4" grassy-area accumulation NW of I-95, tapering off as you go SE. Roads should stay wet in most areas.

This event should be just enough to get out of those things we don't want to do tomorrow, but allow us to get the essentials done and play with the kids in the yard (without having to shovel the driveway). In other words, SNOW-TOPIA!!!.

Can't wait to see what really happens.

Posted by: dprats21 | December 4, 2009 2:24 PM | Report abuse

WWA for DC/Arlington/PG for 1" to 2".
WWA for Fairfax/MoCo/Prince William and NW for 2" to 4".

Posted by: jpl1019 | December 4, 2009 2:29 PM | Report abuse

MKadyman - if you think I'm shilling for weather.com you're out of your mind.

Posted by: fleeciewool | December 4, 2009 2:30 PM | Report abuse

Bombo - Ha! You are right! It was wishful thinking on my part of course...

Posted by: authorofpoetry | December 4, 2009 2:31 PM | Report abuse

The comments to this entry are closed.

 
 
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