... A strong cold front crosses this morning. High pressure Friday and Saturday. Low pressure crosses Sunday night, with a cold front Monday morning. Cooler with weaker systems next week.
NEAR TERM /THROUGH TONIGHT/... As of 1202 PM Thursday...
Have made some minor tweaks to POPS and temperatures. Otherwise...no real changes made.
As of 645 AM Thursday...
Cold front entering southeast OH and northeast KY at this hour. Expect gusty winds to ensue following frontal passage. Some afternoon showers will pivot down into northeast WV, which could produced sporadic gusts to 40 kts.
As of 230 AM Thursday...
Back end of the strong to sever QLCS is exiting our mountains at this hour with a few hours of trailing stratiform rain to contend with. The true cold front will cross in the 09Z to 12Z time frame with perhaps some gusty showers. CAA will ensue in earnest this morning and into the afternoon on a gusty west to west northwest wind. Any morning stratus should mix out later this morning. Model soundings show the mixing layer getting up about about H7 this afternoon which should allow for efficient momentum transfer, though speeds at that level aren't particularly high. As such, expect gusts 25 to 35 mph in the Lowlands and up to 50 mph on the highest elevation ridges in the mountains. This necessitated a wind advisory for those locales. Temperatures will run about 5 degrees below normal today.
The mean longwave trof becomes established in earnest across the northeastern third of the country tonight with a secondary front and s/w trof axis swinging thru overnight. This will allow scattered showers with perhaps some graupel to break out with a change to wet snow across the mountains and perhaps even portions of the lowlands by morning as H85 temperatures drop to -5 to -7C. A general 1 to 3 inches is forecast on the highest ridges of Pocahontas/Randolph Counties with nothing elsewhere.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 410 AM Thursday...
Upper level short wave trough exits first thing Friday morning, but with deep layer west to northwest flow in its wake, upslope showers, snow across the higher mountainous windward terrain, diminish only gradually on Friday, with upslope clouds persisting into Friday night. There could be a small additional accumulation of snow across the higher terrain Friday morning, before we start to lose the better dendritic growth.
High pressure builds toward the area Friday night, but not quite over the area, so some boundary layer flow remains. Nonetheless, the air mass will still be cold enough for temperatures near freezing by dawn across the northern tier of the lowlands, and valley decoupling may still allow frost under a clear sky.
The high will then move east of the area Saturday, and clouds will increase, lower and thicken in developing warm advection, ahead of the next low pressure system approaching from the west.
The increasing chance for precipitation Saturday night will depend upon the persistence of dry low level air beneath the mid level warm advection moisture and lift, an initial surge of which lifts through Saturday evening.
Central guidance temperatures and dew points looked good, with below normal temperatures through Friday night, including highs Friday mainly in the 40s lowlands, 30s across the higher terrain, before getting back to normal for Saturday.
The humidity will also be low Friday afternoon amid gusty winds and drier fuels. Interestingly, wind chills will be low, 20s rising into the 30s across the lowlands, teens and 20s in the mountains.
LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 410 AM Thursday...
Deepening low pressure approaches Sunday, and then swings north of the area Sunday night into Monday, pivoting a cold front across the area first thing Monday morning, driven by a negatively tilted upper level short wave trough rotating about the east side of an upper level low digging into the upper midwest and Great Lakes.
The resulting good southerly fetch of moisture will bring widespread rain showers to the area Sunday afternoon and night, with thunderstorms also possible given the strengthening, negatively tilted system. Narrow CAPE should keep the severe threat low despite strong bulk shear.
Showers and possible thunderstorms will end from west to east overnight Sunday night and Monday morning. A dry respite is then possible late Monday and Monday night, but the timing of any light precipitation after that next week then depends upon the timing of short wave troughs rotating about a large upper level low over eastern Canada, and even whether the long wave trough establishing itself over the eastern U.S. hangs back far enough to the west long enough to allow an east coast system to affect portions of the central Appalachians.
Nonetheless, there is little doubt that, after near normal temperatures to start the week, temperatures fall back below normal heading into midweek, with another frosty night possible if we could sneak in a night between systems.