|Dew Point:||24.0°F (-4.4°C)|
|Wind:||From the SSW at 7.0 MPH|
|Wind Chill:||17°F (-9°C)|
|Sea Level Pressure:||26.85" (909.1 mb)|
Light Snow LikelyHigh: 28 Low: 28
Patchy Fog then Mostly SunnyHigh: 39 Low: 28
SleetHigh: 45 Low: 34
Chance SleetHigh: 38 Low: 8
M.L. King Jr. Day
SunnyHigh: 19 Low: 10
Snow likely. Cloudy, with a high near 28. South wind around 10 mph. Chance of precipitation is 60%. New snow accumulation of less than half an inch possible.
Periods of snow before 1am, then a chance of snow and patchy freezing fog between 1am and 3am, then patchy fog and a slight chance of snow and a slight chance of sleet and a slight chance of freezing rain. Cloudy. Low around 28, with temperatures rising to around 34 overnight. Southwest wind around 13 mph. Chance of precipitation is 90%. New snow accumulation of around one inch possible.
Patchy fog before 10am. Mostly sunny, with a high near 39. West wind 10 to 14 mph.
Partly cloudy, with a low around 28. East wind around 9 mph.
Sleet between 7am and 4pm, then freezing rain and rain. Cloudy, with a high near 45. Southeast wind 9 to 14 mph. Chance of precipitation is 90%. New snow accumulation of less than half an inch possible. Little or no ice accumulation expected.
Freezing rain and rain. Cloudy, with a low around 34. Chance of precipitation is 100%. Little or no ice accumulation expected.
Rain before 10am, then a chance of sleet and a chance of rain and snow between 10am and 4pm. Partly sunny, with a high near 38. Chance of precipitation is 100%.
Partly cloudy, with a low around 8.
Sunny, with a high near 19.
... Low pressure will slide by to our west through tonight, bringing light snow to the region. A cold front will move through on Friday, with a brief warm up ahead of it. High pressure builds in Friday night into early Saturday. Stronger low pressure will track through the Tennessee Valley Saturday, before passing through our area Saturday night into Sunday. Arctic high pressure will build overhead later Sunday through Monday, ushering in very cold air into the region. High pressure moves offshore Tuesday
NEAR TERM /THROUGH TONIGHT/... Low pressure will track up the Ohio Valley this afternoon and into the lower Great Lakes tonight. Snow should begin in the next couple of hours along the Allegheny Front, then move east throughout the afternoon/evening hours. So, a Winter Weather Advisory is in effect for the Allegheny Front starting at 3 PM and going through tonight. Snow spreads east into the DC/Baltimore metropolitan areas by early evening, right around the evening rush hour. So, Winter Weather Advisories spread east into northern VA and central MD at 4PM, then to the DC/Baltimore metropolitan area starting at 6PM and going through tonight. Given the timing of the onset of precipitation, and temperatures dipping below freezing at roughly the same time, roads could become slippery this evening.
Widespread totals of 1-2 inches are expected across the advisory area through tonight, with the onset occurring right around the evening rush hour. Amounts generally around an inch or less will be found for southern portions of the CWA in this modest QPF event. Along the Allegheny Front, expecting higher totals of 2-4 inches due to upslope influence.
Temperatures will drop through the evening as sunset occurs, but then temperatures in most areas will either hold steady or rise a few degrees through the night as low level flow becomes southeasterly. For the most part, the column will rise above freezing from warm air advection aloft nearly coincident with where surface temperatures will be above freezing. So while some sleet pellets or drizzle/freezing drizzle could occur as precipitation tapers off, it will largely be a snow (with some rain in the southeast) event. All precipitation east of the Allegheny Front will likely have ended by daybreak.
SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/... The cold front associated with the aforementioned surface low pressure system will swing through the area early tomorrow. Warmer temperatures are expected tomorrow as a result, as the front is fairly weak, and has no real push of cold air advection to come along with it. Accordingly, low-level moisture will be slow to leave the area, as flow is very weak behind the front. So, could see some clouds linger tomorrow across the area. In fact, recent guidance seems to like this solution more than previous runs. This will be the difference between high temps into the upper 40s/low 50s, or high temps barely reaching 40 again. So, a bit of uncertainty in that aspect of the forecast tomorrow, but if things are able clear out, it should be a seasonably mild day. The once certainty is that it will remain dry east of the Allegheny Front tomorrow, so at least it will be dry.
LONG TERM /SATURDAY THROUGH WEDNESDAY/... A strong area of low pressure will approach the region from the Tennessee Valley on Saturday. Warm advection aloft will overspread the area late Saturday morning through early Saturday afternoon allowing precipitation to breakout. There is the potential for precipitation to briefly start out as snow or a wintry mix anywhere except far southeastern portions of the forecast area, but most locations are expected to quickly transition over to rain by Saturday evening. With high pressure situated to the north, and model guidance indicating a small wedge of higher pressure holding strong to the west of the Blue Ridge/East of the Allegheny Front, there is some concern that cold air may remain locked in at the surface much longer across portions of West Virginia Panhandle, Western Maryland and the far northern Shenandoah Valley. All model guidance has a strong southerly low-level jet (on the order of 50 kts) blasting warm air in aloft Saturday evening across the entire CWA. If cold air remains locked in at the surface for the aforementioned areas, a prolonged period of freezing rain or sleet could ensue. The Euro is currently most aggressive in keeping the cold air locked in at the surface, and the NAM keeps temperatures near freezing in those areas for much of the event. A majority of EPS members keep temperatures near or below freezing through much of the event as well. The 12z GFS erodes the cold air very quickly, but is often way too fast in eroding cold air at the surface in these types of situations. As a result we're currently leaning toward the Euro/NAM temps and resultant precipitation types.
The remainder of the area, including the immediate I-95 corridor, will receive a dose of heavy rainfall Saturday Night into early Sunday. In excess of an inch of rainfall is expected to fall area- wide. All of that rain falling on top of remnant snow pack from last weekend's storm could lead to instances of flooding Saturday Night (smaller stem streams/rivers) through Monday (main-stem rivers). Precipitation should come to an end from west to east late Sunday morning through early Sunday afternoon as a cold front pushes through the area.
Behind the front, conditions will become very windy and turn much colder Sunday afternoon. Temperatures will drop from the 40s to the low 20s by evening. As a result, any leftover standing water will freeze over Sunday afternoon and could result in hazardous travel conditions. Wind advisories may be needed Sunday afternoon as gusty winds move in behind the front. Those gusty winds combined with cold temperatures will lead to bitterly cold wind chills Sunday Night. Wind chill headlines will likely be needed Sunday Night as wind chill values drop well below zero everywhere. Wind chill values may bottom out below minus 10 in the metro areas and below minus 20 in the mountains. Monday will be bitterly cold as well, with high temperatures in the teens to low 20s and wind chills remaining below zero for much if not all of the day.
High pressure will build in from the Ohio Valley for Monday Night into Tuesday, allowing winds to gradually relax. Temperatures will remain well below normal (lows in the single digits/teens, highs in the 30s), but it will feel much warmer with light winds. Dry weather conditions are expected Monday Night through Tuesday Night.
The next system will approach the area from the west by Wednesday afternoon. Currently it appears as though any precipitation would fall in the form of rain, but forecast uncertainty is still rather high that far out.