Appalachian Ski Mountain

Summary

SYNOPSIS

... High pressure passing overhead to the east will provide dry weather for most locations through tonight. Increasing moisture pooling ahead of an approaching cold front will bring widely scattered showers and thunderstorms for Wednesday and Thursday. This activity will increase in coverage through the weekend as the low pressure system tracks toward the eastern United States.

NEAR TERM /THROUGH WEDNESDAY/... As of 215 PM EDT Tuesday...

Key messages:

- Confidence moderate for isolated thunderstorms this afternoon - Confidence high for above normal temperatures today and tonight

Satellite imagery depicts scattered fair weather clouds across the region this afternoon, with more pronounced development along the higher ridges west of the Blue Ridge. Still, abundant sunshine has allowed temperatures to warm into the upper 70s and low 80s for the region as we approach maximum heating.

Rapid update weather models still hinting at the development of a few showers and isolated thunderstorms developing across the mountains after 4 pm. This activity is expected to remain progressive, resulting in relatively brief periods of rainfall, with mainly a tenth of an inch or less in accumulation where it does manage to develop.

For tonight, any showers and storms will fade quickly with the loss of daytime heating as sunset approaches. With light winds and mostly clear skies overtop moist soils from recent rainfall, patchy fog will redevelop after midnight, particularly in the river valleys. Overnight lows will bottom out in the mid 50s to around 60 degrees.

For Wednesday, winds will shift more from the south as high pressure moves away and a cold front approaches from the west. Will start the day with fog burning off quickly and otherwise abundant sunshine. By mid afternoon, expect another round of widely scattered showers and thunderstorms to develop, mainly for the mountains. Afternoon highs will be a few degrees warmer than todays, reaching into the upper 70s to the mid 80s areawide.

SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... As of 130 PM EDT Tuesday...

Key Messages:

1. Daily chances of showers and storms through the period. 2. Locally heavy rain possible Thursday and Friday. 3. Temperatures near to just above normal.

A cold front approaches the Mid Atlantic from the west by late Wednesday into Thursday, and will bring unsettled weather to the area through the end of the work week. This front stalls over the eastern US, resulting in near daily chances of showers and thunderstorms, highest chances along and west of the Blue Ridge on Thursday and Friday as mid level shortwaves track across the area. Precipitable water values will increase as the front continues to move closer to the area, with forecast values near or exceeding the 90th percentile relative to climatology. With these above normal PWATs, there is potential for locally heavy rainfall. There is a marginal risk for flooding by the end of the week with the multiple rounds of rain expected, especially over areas with saturated ground from recent rainfall.

Widespread cloud cover and rain Thursday will limit potential for severe thunderstorms, but instability is forecast to be higher on Friday, so there are higher probabilities for thunderstorms by Friday. However, it is too far out to determine mesoscale details at this time, so confidence at this time is lower on convective development by the end of the work week.

Temperatures will be above normal, but clouds and rain will moderate daytime temperatures through the period. Overnight lows will be mild.

LONG TERM /SATURDAY THROUGH TUESDAY/... As of 130 PM EDT Tuesday...

Key Messages:

1. Continued chances for rain and possible storms. 2. Slightly cooler temperatures over the weekend, cooling to below normal by midweek.

Through the Memorial Day weekend, a frontal boundary will meander and stall over the eastern US, and an upper shortwave tracks eastward from the central US, which will continue the chances of unsettled weather through the period. While the weekend doesn't look to be a total washout, there are daily chances of showers and thunderstorms each afternoon and evening. However, differing model solutions on the progression, or lack thereof, of the front, brings uncertainty and thus lower confidence in the details on timing of the precipitation.

A 500mb trough moves towards the region during the first half of the work week, and looks to deepen as the surface low moves over the Great Lakes. As the upper flow transitions to more northwesterly behind this system, temperatures will cool to near to below normal by the middle of next week.