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Posted at 04:00 PM ET, 03/17/2013

D.C. area forecast: Colder today with more gray than green; wintry mix/snow possible tonight

* Winter weather advisory N and W of D.C. midnight to 2 p.m. Monday | Winter storm warning western Va., mountains (map) *

4 p.m. update: Winter weather advisories have been posted north and west of the District, including Fairfax and Montgomery counties from midnight to 2 p.m. Monday for up to 1-2 inches of snow accumulation. Inside the beltway and south and east of town, 1 inch or less is likely, mainly on grassy areas. Most snow should fall between 1 a.m. and 7 a.m. Between 7 a.m. and noon, snow will gradually change to rain and/or drizzle with temperatures climbing above freezing from southeast to northwest. We’ll have a more detailed update and SchoolCast by 9 p.m. this evening.

Link: Snow accumulation map from National Weather Service (we concur with this)

1:15 p.m. update: Showers, mixed with snow at times, are primarily focused on the southern half of the area this afternoon — I-66 is a good marker for now, though some activity may extend north of that at times. With temperatures ranging from the mid-30s to low 40s, this precip won’t amount to much other than wetting the ground a bit. For the most part, any consistent showers should stay across the southern half of the area through the afternoon, and there may be a lull before things pick up again tonight. Precip should start lifting north a bit more as we get into evening. Any risk of accumulation (as noted in the forecast below) should hold off till after dark.

EXPRESS FORECAST

Today: Mostly cloudy. 30% chance of p.m. showers. Low-to-mid 40s. | Tonight: 60% chance of wintry mix. Near 30 to low 30s. | Tomorrow: Wintry mix possible early, then chance of rain. Upper 30s to low 40s. | A Look Ahead | Get Express Forecast by E-mail

TODAY'S DAILY DIGIT

A somewhat subjective rating of the day’s weather, on a scale of 0 to 10


Middle of the road kind of day - mostly dry, but cloudy and about 15 deg colder than yesterday. Get the Digit on Twitter | Discuss on Facebook

SNOW POTENTIAL INDEX

A daily assessment of the potential for *accumulating* snow for the next week on a 0-10 scale. More info


SPI: 4 (↑) - And you thought we were done for this winter. Sunday night-Monday brings a 0-1” type storm for the metro area. Get the SPI on Twitter | Discuss on Facebook

FORECAST IN DETAIL


It may look similar outside today as it did yesterday, but it’s a good deal colder once you get out there thanks to a chilly wind from the north. That northerly wind plays a big part in the forecast, combining with an approaching storm to threaten a wintry mix tonight into early Monday. A bit of accumulation is possible especially north and west of D.C., before changing to intermittent rain showers during the day tomorrow into early Tuesday.

Today (St. Patrick’s Day): Looking outside today will feature a lot more gray than green, but fortunately, it looks to stay dry for a while. Clouds remain entrenched overhead but lucky for us a storm system to our west should be slow to approach, which means a rain-free morning and then a 30% chance of afternoon showers. Temperatures struggle to highs in the low-to-mid 40s thanks to a cold breeze from the north. Confidence: Medium-High

Tonight: Snow? Sleet? Rain? A clash of warmer air from the south with cold air sinking in from the north has the potential to produce a bit of all three. Precipitation (60% chance) looks to be light to moderate, which may not be heavy enough to threaten more than a late-night dusting or so in the city. The risk of something more impactful is greater for the usually colder spots north and west (e.g., northern Montgomery, Frederick, Loudoun, western Fairfax, northern Fauquier counties) where a couple inches of snow and slippery roads are possible by day-break. Lows dip to near 30 to the low 30s. Confidence:Low-Medium

Will March warm up again? Keep reading for the forecast through midweek...

Tomorrow (Monday): An early-to-mid morning wintry mix (60% chance) threatens that dusting in the city to a couple inches far north and west, and a generally lousy Monday morning commute. The late morning and afternoon favors mainly rain or possibly a lull as cloudy skies cap highs in the upper 30s to low 40s. Confidence: Medium

Tomorrow night: Intermittent rain showers are a decent bet (60-70% chance) during the evening and into the overnight hours as a cold front closes in. Temperatures don’t do a whole lot, mainly hovering in the upper 30s to mid-40s. Confidence: Medium-High

A LOOK AHEAD

Showers could linger through around mid-morning Tuesday (50% chance) before the cold front clears them out from west to east. By afternoon we should see clearing skies, highs in the 50s, and eventually a pretty nice sunset. One constant through the day though is the wind, likely gusting near or past 30 mph. It’s clear and blustery Tuesday night with lows reaching right around the freezing mark. Confidence: Medium

Wednesday features partly to mostly sunny skies, but we’ll still be dealing with that pesky breeze. So while highs should max out in the mid-40s to low 50s, it will feel colder than that. Confidence: Medium

By  |  04:00 PM ET, 03/17/2013

Categories:  Forecasts | Tags:  forecast, latest

 
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