Wintergreen Resort

Summary

SYNOPSIS

... A stalled frontal boundary will remain draped to the south of the forecast area through tonight before returning north as a warm front late this weekend. This system will bring on and off showers and possible thunderstorms. A secondary cold front will move through the area on Monday before lifting northward as a warm front on Tuesday. This boundary eventually stalls to the north by the middle of the week. This will bring a prolonged period of unsettled weather through much of the week.

NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... The Mid-Atlantic remains firmly in the grasp of a CAD wedge. Shortwave energy lifting out of the Tennessee Valley will carry a more organized batch of showers through the region overnight (seen on regional mosaic imagery near the VA/NC border east of the Blue Ridge as of 8 PM). Another quarter to half inch of rain is possible with this next batch, locally a bit higher in the Blue Ridge Mountains or in areas that receive repeated heavier downpours. Forecast low temperatures stay fairly close to the readings reported right now. Widespread low to mid 50s are likely with a few upper 40s possible across northeastern Maryland. Easterly winds persist which helps maintain a thick area of marine stratus clouds.

SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... Expect warmer temperatures for Sunday as the mentioned boundary returns northeastward as a warm front. Model guidance is notoriously too quick in lifting these boundaries poleward. Thus, there may be some north-south temperature gradient over the forecast area where locations near the Mason-Dixon Line stay much cooler. The current forecast package calls for mid/upper 60s across northern Maryland and the local mountains. Meanwhile, low/mid 70s are more commonplace elsewhere. There may be some breaks in the cloud cover as winds shift from easterly to south-southeasterly. Where these breaks occur will dictate where any convective threat resides. For now, have placed a bulk of the area with a slight chance for afternoon/evening thunderstorms. Gradually taper off this threat into the overnight hours as any instability is lost after dark. Some patchy fog is possible given recent rainfall, decreasing winds, and a moist boundary layer. Nighttime lows remain mild, generally staying in the upper 50s to mid 60s.

An approaching cold front ends up on the door step of the local area on Monday. This system eventually stalls in the vicinity by late Monday night. Its close proximity to the area will maintain shower and thunderstorm chances to start off the work week. However, temperatures should warm up rather markedly with the Mid-Atlantic fully into the warm sector. Forecast highs are in the upper 70s to low 80s, locally in the upper 60s to low 70s across mountain locales. Expect yet another mild night with lows in the upper 50s to mid 60s. Compared to typical early May nights, this is around 10 to 15 degrees above normal.

LONG TERM /TUESDAY THROUGH SATURDAY/... The unsettled and active weather pattern is likely to continue through the rest of the week, then possibly dry out next weekend. Aloft, nearly zonal flow continues as several shortwave troughs traverse the region. At the surface, a stalled frontal boundary is likely to be located north of the area, over central to southern PA, through mid week as a few waves of low pressure move across it. Moisture and instability are likely to be plentiful each day, leading to scattered to widespread showers and thunderstorms each afternoon. Most of the daytime activity dissipates by late evening, though a few showers could linger through the overnight. There is some model agreement for drier conditions next weekend as surface high pressure builds into the region.

The most active period looks to be Wednesday night through Thursday evening. This is when the strongest mid-level trough of the week and an associated surface cold front cross the Mid-Atlantic. Our area should be squarely in the warm sector, with plenty of instability and moisture available (PWATs over 1.5-1.6" possible). Some strong to severe storms are possible Thursday as a line of storms develop along the passing cold front. The better chances for severe storms look to be east of the Blue Ridge where ample instability and shear (model soundings indicate 40-50kt of bulk shear) are more likely to be present. The biggest question mark is whether early morning cloud cover dissipates in time to allow for better instability to develop. Moderate to heavy rainfall is also possible areawide, which could lead to some instances of flooding (though it is also highly dependent on how much rain falls in the prior days).

Temperatures continue to warm through mid week as highs in the low 80s Tuesday reach the mid to upper 80s Wednesday and Thursday. Slightly cooler temperatures in the 70s behind the cold front Friday into Saturday. Very mild overnight lows in the 60s, then cooling a bit to the 50s Friday night.