* Winter weather advisory from 2 p.m. to midnight Saturday, north and northwest suburbs *
A fast-moving storm system will drop a mixture of snow, sleet and rain across the area through this evening. Some snow accumulation is possible, especially in colder areas north and west of the city, where slick conditions are most likely to develop, especially once it starts getting dark.
We’ve got more details below and will be updating this forecast as the night progresses. This is a complicated and complex precipitation forecast that is bound to give us a surprise in some areas, so please check back.
3:52 p.m. update: Not much has changed since we last checked in. Temperatures are still above freezing across the D.C. region which is (thankfully) preventing snow from sticking to the roads. In NW D.C. and areas north of the Beltway, the grass has a decent coating already. On the other hand, in Arlington, snow has been falling at a decent clip but warmer surface temperatures are preventing it from accumulating on the grass beyond a little slush here and there.
The Storm Prediction Center issued a statement earlier this afternoon, noting that their area for highest concern was up in Pennsylvania, where the temperature is at or below freezing. Here in D.C., it looks like the air will stay warm enough to prevent this from being more than a nuisance event:
Southeastward across the piedmont toward the Greater Baltimore and Washington D.C. metropolitan areas, even with boundary layer evaporative cooling of initial precipitation [translation: it got colder when it started to rain], surface temperatures may generally not fall below the mid 30s. This seems likely to result in lower potential for sustained and/or accumulating snow.
Big picture radar shows us how this storm is progressing outside the D.C.area. Those red lines indicate temperature. You can see D.C. metro is still above freezing. 32-degree line is well up into PA still. pic.twitter.com/0uIJmqimRg
— Capital Weather Gang (@capitalweather) February 17, 2018
3:08 p.m. update: Fat snowflakes are falling in the northern suburbs, but warm temperatures are keeping accumulation at bay. It’s above freezing up into Frederick County, which is hovering around 33-34 degrees this afternoon. Father south, temperatures are more like 34-46 degrees.
Grassy accumulation is happening up in Montgomery, Loudoun and Frederick. Snow and sleet are mixed in with rain in the District, Arlington and southern Prince George’s and has only just started to appear on the grass.
Roads are still in good shape, albeit wet. As temperatures drop this afternoon and evening, we’ll be watching roads for slushy — potentially slippery — conditions.
— Exhaustipated (@ImExhaustipated) February 17, 2018
Through tonight: Snow and sleet is overspreading the region this afternoon but should mostly melt with temperatures above freezing. From there, we will be on the temperature watch.
Heavier precipitation will move into the D.C. area rather quickly, especially between about 5 and 8 p.m., and the increase in precipitation intensity and nightfall will drag surface temperatures down to around 30 to 34 degrees; 1 or 2 degrees will make a huge difference in what falls from the sky and on how many surfaces it accumulates on. We still think our forecast map (below) from this morning holds true, with the bulk of the precipitation falling in the early evening hours in the form of a sleet/snow to rain (in that order) in and around the Beltway.
Areas that have the potential to see more snow are perfectly outlined in the county map below. For the rest of us, some snow/sleet will accumulate on grassy surfaces, but in general, main roads will just be wet. That said, there may be some slushy accumulations on secondary roadways near the District during the heavier bursts of precipitation after dark. All of the precipitation will be out of here by 10 p.m., leaving us with mostly cloudy skies and temperatures ranging from 29 to 33 degrees. Some icy spots are likely to develop, especially to the north and west of D.C. where any standing liquid should be able to refreeze.
View the current weather at The Washington Post.
Tomorrow (Sunday): High pressure slides quickly into the region behind the departing storm system, setting the stage for very comfortable and seasonable day. Partly cloudy skies in the morning will give way to mostly sunny skies by the afternoon. Temperatures will be mild despite a light (5 to 10 mph) northwest wind. Afternoon highs will range from 47 to 51 degrees. Clouds thicken overnight with lows in the mid 30s.
Activate the blowtorch next week: Don’t worry, within a few days, you will have long forgotten about the wintry mess of this weekend. Next week, a ridiculously strong ridge of high pressure will park itself over the East Coast for a few days, pumping in some record-breaking warmth pretty much everywhere east of the Mississippi.
Forecast high temperatures for Tuesday (top) and Wednesday (bottom) feature back to back 70 degree days in February.
Here in the DMV, we should hit break the 70 degree mark easily on both Tuesday and Wednesday, which would mark the first time we’ve had back to back 70-plus degree days in February since — 2017. However, if we look at the daily temperature data for Reagan National Airport, which dates back to 1942, I can only find 10 years in which we hit 70-plus degrees on back-to-back days in the month of February. In any case, feel free to break out the shorts and T-shirts for a few days next week.
Want our 5 a.m. forecast delivered to your email inbox? Subscribe here.
This news collected from :Source link