- After its arrival, 1 to 6 inches of snow fell across the region Wednesday morning, heaviest west and northwest. 2.5 to 4 inches was most common in the immediate area before the change to a wintry mix.
- Icing around a trace to as much as a tenth or two tenths of an inch occurred. The most significant ice accumulation is across northern Maryland and into Pennsylvania. Much of the local area saw minor icing. A little more is possible before the storm ends.
- While precipitation tapers off around midnight, slushy and ice spots are likely to linger into early Thursday morning, resulting in some delays. By Thursday afternoon, sunshine returns with highs near and above 50.
9:00 p.m. - Main ice risk waning; some slick spots remain likely
After falling near sunset, temperatures have mostly edged up slightly into the night. That seems likely to continue, which means fewer and fewer places are below freezing and others are just barely below. The winter weather advisory has been extended again, until 1 a.m., for the risk of some minor icing continuing.
At least one more organized batch of showers — potentially even a few rumbles of thunder — is likely to move through as we head into the overnight. A little additional ice accumulation can’t be ruled out, particularly in the coldest spots north and west. With temperatures continuing to slowly rise, and any precipitation likely to be quick-hitting, new icing issues should be minor. Do continue to plan on some slick spots in the region, especially north and west of Interstate-95. This may be a risk into early morning in at least a few spots.
For Thursday, some iciness could still be around early, but temperatures are relatively quickly headed upward after sunrise. Under partly to mostly sunny skies, and along with a breeze from the northwest, highs should head toward 50 or into the low 50s. Good enough for lots of melting!
6:50 p.m. - New batch of freezing rain and rain moving through
While the heaviest precipitation is still to our south, a new batch of light to moderate freezing rain is headed into and through the area from the west. The NWS Storm Prediction Center recently issued an outlook for this area of rain that will fall into freezing or subfreezing temperatures in many spots. The local NWS has also extended the winter weather advisory for D.C. and counties south/east until 10 p.m.
The Storm Prediction Center is calling for up to around 0.25 inches of ice accretion this evening, mainly to our north in Pennsylvania. Places near Interstate-95 remain near or just below freezing as well, with temperatures generally a few degrees colder than that to the north and west. Icing on the order of about a tenth of an inch seems possible in our region, mainly to the north and west of Interstate-95. Some spots could see a bit more.
Temperatures remain rather steady, although it is likely that they will continue to come up somewhat into the night. Much of that rise may hold off until after the heavier precipitation winds down. Caution is advised if out and about this evening, especially along and northwest of the Interstate-95 corridor.
5:35 p.m. - Precipitation remains light but temperatures holding steady near freezing
Heavy rain is moving through Central Virginia while mostly just light rain and drizzle resides over the D.C. area. Some of it is freezing, mainly on cold, untreated surfaces, where temperatures are below 32.
The areas of particular concern for icy spots are north of the yellow line on this map - note this area has expanded some since mid-afternoon as some areas have cooled by a degree or so:
There is still potential for a steadier period of freezing rain between 7 and 10 p.m. but models have generally backed off on the overall coverage and duration of freezing rain tonight. Irrespective of how much freezing rain falls, be careful on untreated surfaces, including neighborhood roads and sidewalks.
4:30 p.m. - Freezing rain could become more of an issue as night falls and precipitation increases in our colder areas
Precipitation coverage this afternoon, since the snow changed to a wintry mix, has been rather spotty, which has allowed conditions to improve - especially on treated roads.
But radar and short-term modeling suggest precipitation may increase from southwest to northeast early this evening, before mostly exiting by midnight. In this window, between about 5:30 and 11 p.m., our colder areas may see some ice build-up. In addition to temperatures holding steady between 30 and 32, the loss of daylight will make it easier for ice to adhere to cold surfaces like tree limbs and untreated pavement. This is something we’ll monitor.
3:00 p.m. - Patchy freezing rain continues, as temperatures linger near freezing
Reports are that treated roads are passable but untreated roads and sidewalks are a slushy mess. That will be the general trend into this evening.
Radar shows patchy areas of freezing rain and rain with temperatures generally right around freezing, ranging from 30 to 34 degrees. The real concern for icy spots on roads and sidewalks are where it’s just below 32 and such areas are mostly confined well north and west of the Beltway, as shown in the map below. That said, most areas are just 32 and 33 which means any slushy surfaces aren’t going to meaningfully improve until they are treated.
Temperatures may very slowly rise into the evening, but we don’t expect a whole lot to change
2:30 p.m. - Precipitation changing to freezing rain in many areas; winter storm warning changed to advisory for immediate area
As precipitation changes from snow and sleet to freezing rain, the National Weather Service has made some changes to warnings and advisories:
- Along and east of Interstate 95, the winter storm warning has been changed to a winter weather advisory until 7 p.m. A light glaze of freezing rain (up to 0.1 inches) is possible in this zone before precipitation changes to plain rain.
- In Montgomery, Howard, and eastern Loudoun counties, a winter storm warning has been extended until 10 p.m. as freezing rain is expected to continue in this zone into the evening, with a heavier glaze of 0.1 to 0.25 inches possible.
- In northern Fauquier, western Loudoun, and Frederick counties, and to the west and north, a winter storm warning is in effect until 1 a.m. Thursday for up to 0.25 inches of freezing rain.
- A winter weather advisory remains in effect for Southern Maryland and Stafford County until 4 p.m. when freezing rain should change to rain.
1:30 p.m. - Snowfall total summary: 2.5 to 4 inches most common in immediate area
As precipitation has changed to a wintry mix, the accumulating snow portion of this event is mostly over. Inside the Beltway, 2.5 to 4 inches were most common, with 3-6 inches to the north and west, and only around an inch in our southeast areas.
The 2.6 inches that fell at Reagan National Airport pushes the season total to 16.6 inches, ensuring an above normal winter for snowfall (normal is 15.4 inches).
Here are some select totals:
- Dunkirk: 1.0 inches
- Annapolis: 2.0 inches
- Reagan National Airport: 2.6 inches
- Gainesville: 3 inches
- Falls Church: 3.2 inches
- Manassas: 3.4 inches
- Chantilly: 4.0 inches
- Chevy Chase: 4.0 inches
- Herndon: 4.5 inches
- BWI Marshall Airport: 4.5 inches
- Dulles Airport: 4.7 inches
- Columbia: 4.8 inches
- Germantown: 5 inches
- Ashburn: 5.3 inches
- Leesburg: 5.4 inches
- Frederick: 5.5 inches
- Germantown: 6.1 inches
- Lovettsville: 6.2 inches
12:55 p.m. - Precipitation transitioning to sleet in most areas
Most areas inside the Beltway and to the west and south have changed over to sleet after a closing burst of snow with big flakes in the last hour. But some areas, especially north and northeast of town still have snow, including around Columbia and Laurel, and farther to northwest, around Winchester.
We’re now entering the wintry mix phase of the storm and areas with snow should see a transition to sleet over the next hour or so. And freezing rain is likely also to enter the mix.
Radar shows the steadiest precipitation has shifted to the region from the Beltway south, with just light, spotty precipitation to the north. As the afternoon wears on, we do expect mixed precipitation to spread back into our northern areas but it may be intermittent rather than continuous.
Snow accumulation is mostly completed across the area. Here are some pretty pictures of the snow, before it starts to turn into a slushy mess by the sleet and freezing rain:
11:40 a.m. - Heavy burst of snow with huge flakes passing through Beltway
Per the previous update, a heavy batch of precipitation passing through has cooled the air enough to change sleet back to snow. Radar shows heavy snow entering the Beltway and pushing east. This snow will lower visibility and cause more slush build-up on roads. It probably won’t last more than 30 to 45 minutes, but will add a bit more accumulation.
After this heavy burst passes, expect snow to transition back to sleet.
Here are some pictures:
11:15 a.m. - Mix of sleet and snow continues; heavier activity building west of Beltway
As precipitation eased in intensity over the last hour, many areas switched from snow to sleet. But, now, a heavier area of precipitation is building to the west and some areas, which had switched to sleet, are changing back to snow. The heavier precipitation is helping to cool the column of air enough for snowflakes not to melt. That said, while an additional burst of snow is possible - mainly from the Beltway and to the north and west - the entire region is still expected to shift to sleet by early afternoon. This batch of snow and sleet could add a little more accumulation.
Amounts (list) so far have mostly concentrated around 2 to 5 inches, with the heaviest totals in our northwest and west areas. But some locations east and southeast have seen just an inch or so.
10:15 a.m. - Sleet moving into southwest areas, but some thundersnow well to northwest
As precipitation intensity eases some west and southwest of Washington, we’re seeing some reports of sleet mixing with the snow - in Fauquier, southern Fairfax, and even into Loudoun counties. But snow, mostly light, continues from the Beltway north. The heaviest snowfall is in northern Maryland and, in western Maryland, we even received reports of thundersnow in the past hour!
For the next hour, we expect sleet reports to increase and to migrate northeast, as a milder zone of air pushes in aloft. But north of the Beltway, the predominant accumulation type should remain snow for another hour or so. Short-term models suggest much of region should transition to sleet by 1 p.m. It may take until around 2 p.m. in northern Maryland.
Roads remain messy out there...passable with care, but slushy. Allow extra time if you’re venturing out in this.
9:10 a.m. - Heaviest snow band lifting north, sleet line advancing north
Snow continues in varying intensity across the area. We are also watching the mix line, where snow transitions to sleet, head this way from the south. The precipitation intensity also eases near this changeover line. We expect this will move north over the next several hours, eventually into and through the immediate area.
However, around midday, precipitation may increase in intensity with mostly sleet in the immediate area and south, and snow and sleet in our northern areas.
Snow totals now vary from about 1.5 inches to 4 inches across the area, with less to the east of Interstate 95. Some places have picked up an inch or more per hour over the last few hours.
The highest totals are generally out west near the Blue Ridge, with Woodstock, Va coming in at 5.2 inches already. Closer in on our region, totals of 3 or 4 inches are common across Loudoun and Montgomery counties in particular. Olney and Leesburg have checked in with 3.5 inches. Dulles was up to 3.3 inches as of 8:35 a.m.
8:25 a.m. - Occasionally heavy snow before midday transition to sleet
As the snow continues to accumulate, with a report of “hamster-sized flakes” under one particularly heavy snow band, we’re looking ahead to that expected transition from snow to sleet. The modeling has been pretty consistent on this happening late morning into the early afternoon, around 10 a.m. to 1 p.m. from south to north, as shown in the model simulation below. It’s difficult to pinpoint within that window, but we seem to be on our way to reaching the forecast snow accumulations however early or late that changeover occurs.
7:35 a.m. - Remember, this is a multi-phase storm, so enjoy the snowy phase
This is the fun snowy phase, with the D.C. area now turning into a pretty winter wonderland. Some spots are already closing in on a half-inch to an inch, with Dulles Airport reporting 1.5 inches. Enjoy this phase. Because the snow should turn to sleet late this morning into the early afternoon, with a possible period of freezing rain after that, and then plain rain. That does not sound as fun. Here are some snowy pictures we can look back on when this turns into a slopfest later today...
6:45 a.m. - Snow starting to coat roads, heaviest expected north and west of D.C.
While a check of traffic cameras show most highways to be just wet so far, the snow has started to coat side roads and many main roads across the area, especially south and west of the Beltway where snow started the earliest. We expect road conditions to continue to deteriorate area-wide over the next couple of hours as the snow continues and temperatures drop another degree or two. The National Weather Service’s Storm Prediction Center (SPC) expects the heaviest snow through around noon to occur west and northwest of D.C., as outlined below. “Snow rates are expected to increase into the 1-2”/hr range through mid-morning with an eventual changeover to sleet from south to north," says the SPC.
5:55 a.m. - Snow moving in, gradually starting to stick
The snow has arrived from the south and west on time over the last hour or so. Some of it is melting on pavement initially with temperatures starting out around 32-34. But as the snow starts to pick up, temperatures should drop a couple of degrees, helping to increase accumulation on all surfaces. Thus far, the forecast below seems on track. In additional updates this morning, take a closer look at forecast snow accumulations, and the timing of the changeover to sleet later this morning and midday.
TODAY’S DAILY DIGIT
A somewhat subjective rating of the day’s weather, on a scale of 0 to 10.
5/10: Enjoy the snow this morning, before it turns into a sloppy mess of sleet and rain this afternoon.
Today: Accumulating snow, then ice to rain. Highs: Low 30s.
Tonight: Evening rain, freezing rain north and west. Lows: Low-to-mid-30s.
Tomorrow: Early shower? Becoming partly sunny. Highs: Upper 40s to mid-50s.
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FORECAST IN DETAIL
Despite some uncertainty about exact snow accumulations — and exactly when this morning’s snow will change to sleet, and then possibly freezing rain, and then rain — the overall impact of this storm is not really in doubt. Hazardous road conditions are likely through the morning hours, with gradual improvement from south to north later this afternoon into the evening. But that’s only after a period of sleet and freezing rain covers parts of the area, mainly north and west of D.C., with a glaze of ice in time for what’s left of an afternoon commute. The worst icing and potential for scattered power outages is north and west of the Beltway.
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Today (Wednesday): Snow comes down in moderate to heavy amounts at times, possibly mixing with sleet, with at least a few inches accumulating through the morning hours (see snowfall forecast map below). The snow should be heavy enough to cause hazardous road conditions, with temperatures in the mid-20s to low 30s (from northwest to southeast). We expect the snow to change to sleet from south to north around 10 a.m. to 1 p.m., with the precipitation perhaps letting up a bit during that time. A period of freezing rain is then possible midafternoon into early evening, mainly from around the Beltway toward points north and west, with plain rain to the south and east. Confidence: Medium-High
Tonight: Freezing rain and sleet should change to plain rain from south to north during the late afternoon into evening as road conditions gradually improve, with areas north and west of the Beltway holding on to icy conditions the longest (see ice potential map above). Everyone should be above freezing before midnight, except our far northern and western suburbs, which may hover right around freezing. The rain ends overnight with temperatures in the mid-30s. Confidence: Medium
Tomorrow (Thursday): Some residual school delays and closings are possible. But overall, it’s not bad for the day after a winter storm. After a cloudy start and maybe a lingering early-morning shower, skies turn partly sunny by afternoon as highs reach the upper 40s to mid-50s. Just a bit of a breeze from the west-northwest. Confidence: Medium-High
Tomorrow night: High pressure builds in from the west, although a passing shower is possible. We should stay partly cloudy, with lows in the 30s and light winds. Confidence: Medium-High
A LOOK AHEAD
Just a slight chance of a shower during the day on Friday, with partly cloudy skies and highs near 50, as high pressure should hold off a system lurking to our southwest. Shower chances increase Friday night as lows fall back to the 30s. Confidence: Medium-High
Rain is likely Saturday into Saturday night, with highs in the 40s and temperatures remaining fairly steady through the night. Still a chance of showers Sunday morning, but then milder and breezy by afternoon as highs aim for the milder 60s. Confidence: Low-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.
9/10 (→): At least a few inches of snow are expected across much of the area this morning. Next chance of anything wintry looks like at least a week from now.