Winter weather advisory until 2 p.m. for much of the north and west part of the area.
10:45 a.m. update: With snow lightening up across most of the area, this will be our last update on this post. Temperatures are on the rise, so the rain-snow line will continue to march north. We expect light snow in the northern suburbs and around Baltimore through around 12 p.m. with little to no additional accumulation. Points south will be transitioning to rain if they haven’t already. Scattered rain showers could continue through the afternoon through 5 or 6 p.m. Read on for the full forecast through the weekend.
TODAY’S DAILY DIGIT
A somewhat subjective rating of the day’s weather, on a scale of 0 to 10.
3/10: Very low marks for a.m. commute headaches. But snow wanes and conditions improve during the afternoon.
Today: Snow to rain/mix before ending. Highs: 35-43.
Tonight: Clearing. Lows: 28-36.
Tomorrow: Sun and springtime. Highs: Mid-50s to low 60s.
Sunday: Mostly cloudy. Highs: Upper 40s to low 50s.
FORECAST IN DETAIL
After today’s snow snarls the morning commute, we should be able to thaw out. And then some. But first, we deal with the risk of moderate to occasionally heavy snow moving through at the exact wrong time for those looking to get to work hassle free. Fortunately, it’s late in the season and temperatures are not super cold. And whatever falls won’t last long. Tomorrow, our sun and warmth line up perfectly with the first full day of astronomical spring.
Today (Friday): Most rain should change to wet snow by sunrise if not sooner, except for the southeast suburbs, where it may be more of a rain-snow mix to all rain well south and east. Even with temperatures only right near freezing, or maybe several degrees above around downtown and other typically milder spots, the commute could be rough. Periods of moderate-to-heavy snow are possible through about 10 a.m. locally. Slush is more likely than solid snow pack on heavily impacted roads, while conditions may be worse in elevated areas to the north and west.
By late morning, we should see more places changing back to rain or even a tapering of the heaviest activity. Through the afternoon, precipitation should be mostly periodic lighter rain except for the coolest areas well north and west, which may hold onto snow into mid-afternoon. Even they eventually go over if precipitation continues long enough, but it should be exiting before we head home for the weekend. Temperatures struggle given the conditions, perhaps only making the mid-30s in the coldest spots to about the low 40s in the warmest. Confidence: Medium
Tonight: A shower could linger into evening, but let’s favor drying overall. Note our local spring equinox time of 6:45 p.m. It’s astronomical spring! Clouds hang tough and only slowly decrease. Northerly breezes should remain light around 5 mph, though it still could be chilly. Around 30 is possible well outside the Beltway, with mid-to-upper 30s likely downtown and points south. Confidence: Medium-High
For related traffic news, check out Dr. Gridlock. Keep reading for the forecast into next week…
Tomorrow (Saturday): Yeah, spring! Show us what you’ve got. High temperatures in the mid-50s to low 60s are probable along with mostly sunny skies. Breezes should remain mostly calm in the morning, turning toward the southwest around 5 mph in the afternoon. That should reinforce our more mild, spring-like air. Melting will be quick and painless. Confidence: Medium-High
Tomorrow night: Springtime warmth gets denied a long stay. We’ve got another cold front moving in, keeping us mostly cloudy. At least the front should pass through dry. If you are out late, past midnight, you might notice winds picking up a bit (to perhaps 10 mph) out of the west and then northwest. A few gusts are possible near dawn, as low temperatures bottom out in the upper 30s to mid-40s. Cold air trickles in slowly. Confidence: Medium
Sunday: It’s chillier but perhaps salvageable with high temperatures still managing the upper 40s to low 50s. Consider that light jacket, since this air mass will be cooler and drier. Not too spring-like, maybe, but we could see some peeks of sunshine through the clouds. Hopefully. Outdoor plans shouldn’t have any rain threat either. Neither a great nor terrible way to end the weekend, eh? Let’s just hope we keep a tame northwest breeze around 5 mph. That should help… Confidence: Medium
A LOOK AHEAD
Sunday night: We may have periodic cloudiness stick around so that very few stars are visible, at least for long periods. If you do get some momentary cloud breaks at your house, you might be able to spot our new crescent moon in the west during the evening. It should be very near the usually-bright Venus. If we remain lucky, winds should stay mostly calm, so that we don’t have to dawn the scarves and gloves. By just before dawn, we should bottom out in the mid-to-upper 30s for most of us. Confidence: Medium
It’s less breezy on Monday. Hopefully that means we don’t bundle up but so much for mid-to-upper 40s highs. With decent amounts of sunshine, we might be just fine without too many layers, actually. Winter just trying to keep its foothold a bit longer, but spring is slowly gaining the upper hand. Confidence: Medium
With prospects for even more sun Tuesday, we probably can’t complain to much about temperatures around 50 to perhaps mid-50s. Arguably we warm enough to feel more like an early springtime state of mind, rather than late winter? Fingers crossed. Confidence: Medium
SNOW POTENTIAL INDEX
A daily assessment of the potential for at least 1 inch of snow in the next week, on a 0-10 scale.
Earlier snow updates:
10:00 a.m. update: The HRRR model, which we typically check out for short-term forecasts, is really sticking to its guns about the snow being over in the Beltway by 12 p.m. Looks like some snowy precipitation could still be pushing through the northern suburbs and Baltimore between 12 and 2 p.m., though.
After that, looks like we’ll get dry slots interspersed with areas of rain, but all is gone in this model by 5 or 6 p.m.
The difference between reports from the southern half and the northern half of the Beltway are dramatic. People in NW D.C. were talking about “heavy snow” in the 9 o’clock hour, while in Alexandria there has been little to no accumulation!
@capitalweather Here in Carlyle, Alexandria (Holland Lane) – Zilch as of 9:56 am
— RBM (@akai1969) March 20, 2015
Meanwhile, Frederick, northern Montgomery and western Loudoun are of course seeing the largest snowfall totals — up to 3.5 inches so far in those locations.
9:30 a.m. update: A few snow totals from around the region, and the time at which they were reported:
Reagan National — Trace (7 a.m.)
Dulles International — 0.3 inches (7 a.m.)
Baltimore-Washington Int’l — 0.1 inches (7 a.m.)
Columbia, Md. — 1.3 inches (8 a.m.)
Frederick, Md. — 3 inches (9:25 a.m., via Twitter)
Ballenger Creek, Md. — 1.3 inches (7:43 a.m.)
Damascus, Md. — 2.1 inches (7 a.m.)
Germantown, Md. — 1.5 inches (7 a.m.)
Gaithersburg, Md. — 1.3 inches (7 a.m.)
Barcroft, Va. — 0.2 inches (7:56 a .m.)
Leesburg, Va. — 1 inch (8 a.m.)
Purcellville, Va. — 1 inch (8:27 a.m.)
The big-picture view of our vernal equinox storm. The rain/snow line runs through the D.C. region, and snow stretches through most of Pennsylvania, New Jersey and western New York.
Temperatures in our area are holding steady anywhere from 32 to 36 — the cooler areas are north and west and in the higher elevations, and the warmest is Reagan National. Lots of personal weather stations in the Beltway are at 33 degrees right now
— Tara (@midwifewitch) March 20, 2015
— Charles Crum (@chascrum) March 20, 2015
— Mike Armogida (@armogida) March 20, 2015
9:00 a.m. update: Snow bursts are still roaming the area. It appears the rain/snow line has slowed its southward movement and may begin to reverse in the time ahead.
Temperatures ranging from about 33-37 (a little colder in higher elevations) across the immediate area continue to keep most roadways just wet, with much of the new accumulating snow occurring during heavier activity. Some melting is also going on concurrently, as the strong March sun makes itself known even through clouds.
— Perfect Liars Club (@PerfectLiarsDC) March 20, 2015
— Jani (@jad4812) March 20, 2015
— maggielmcg (@maggielmcg) March 20, 2015
8:35 a.m. update: How long is this going to last? The newest model run of the short-term HRRR says it mostly winds down between 10 a.m. and noon across the region. Here’s a snap for 11 a.m.:
Radar seems to agree that we’ve still got at least a few more hours of this batch, including periodically moderate-to-heavy snow. It should wind down late morning, but an additional area of precipitation may develop or move in during the afternoon. That should be more in the liquid form.
8:05 a.m. update: Our current bout of snow and rain/snow mix is not departing to the east for a while yet. Periods of lighter activity intermixed with moderate activity are likely though.
Accumulation is growing where snow is sticking, especially on grassy and elevated objects. A good chunk of the area has now seen a dusting to about 1.5 inches of snow, with elevation north and west seeing the most. (see the latest totals from NWS). Some higher numbers across the region include 2.1 inches in Damascus, 1.8 inches in Westminster, and 1.5 inches in Winchester as well as Germantown.
7:30 a.m. update: The rain/snow line continues to head south. The city has gone over to snow, and temperatures are bottoming out near freezing to a few degrees above locally. With sunrise, it will eventually become even harder to get snow to stay on roads well, but that may still be an hour or two off in spots that have seen some slushy pavement accumulation. In places with wet roads at present, they are likely to mainly remain that way.
Even with the sun rising, grass accumulation can occur in heavier snow where it has not yet stuck, though we continue to favor the lower end of the forecast in the I-95 area and east.
Some more pics as the sun comes up, heading into the final hours of winter:
— Brian DiNunno (@BDiNunno) March 20, 2015
— Kara (@KJPGS) March 20, 2015
— Linda (@lindainleesburg) March 20, 2015
— Doug Clark (@stormes44) March 20, 2015
6:55 a.m. update: Like many late-season snow events, every foot further inland and higher in elevation helps when it comes to getting snow to fall and getting snow to stick. So far, it’s a tale of two sub-regions:
North and West
— Hilary O'Brien (@GWHilary) March 20, 2015
— Matt Jackson (@jacks5917) March 20, 2015
— Patrick Steward (@famhistrybuff) March 20, 2015
South and East
Change from rain to snow Rt. 7 E and Rt. 123 N in Tysons on the ramp. Went from noisy to quiet almost instantly @capitalweather
— Matt Ohlson (@mattohlsonusa) March 20, 2015
— Erikson Young (@EriksonYoung) March 20, 2015
@capitalweather Just drove to Huntington Metro from Mt Vernon. Just rain, but it's not all water. Slushy drops on the windshield.
— Sparkle Girl (@halosparkle) March 20, 2015
As the sun rises, temperatures do continue to drop, with even the city into the mid-30s and snowflakes beginning to mix in. Readings across the region are now generally in the 32-38 range — most spots remain above freezing.
Radar continues to indicate the potential for periodic moderate-to-heavy precipitation over the next few hours, and the snow line is drooping south.
6:25 a.m. update: The changeover to snow is occurring on the slow side in and right around D.C., as well as to the south and east. The short-range HRRR model’s radar simulation shows this idea below:
It suggests a snow push through the city, and surrounds that are still seeing rain, between about 7 a.m. and 9 a.m. Given current conditions, it’s hard to argue with the slow progression. That seemingly suggests the lower end of totals in parts of the coating to 2 inch band, particularly I-95 and east. Where it has already been snowing and sticking, things are more on track.
5:55 a.m. update: Reports from social media tend to back up the radar depiction posted below. Rain changed to snow during the past hour or so in places like Leesburg, while locations nearer Frederick are picking up grass accumulation, and elevated spots like Damascus are even getting a little pavement snow.
Road temperatures — like air temperatures — remain above freezing many spots, but they’ve cooled to around freezing in some of our high-spot north and west suburbs, indicating the risk for at least slushy accumulation during heavier snowfall.
5:15 a.m. update: Rain and snow spread across the area over the past few hours. It started as rain many spots locally, but locations like Germantown have been seeing snow since the start. Right now, temperatures are mostly ranging from the mid-30s to near 40 locally, but dropping. Areas like D.C. that are still seeing rain should witness a change over to snow shortly.
— Mark Ellinwood (@markellinwood) March 20, 2015
6/10 (↑): Is Friday’s snow the last of the winter season? Possibly, but we’ll keep watching a while longer.