... High and dry through Wednesday. Cold front Thursday into Friday. High pressure returns Friday. Active weather returns for the weekend.
NEAR TERM /THROUGH WEDNESDAY/... As of 846 PM Tuesday...
Forecast appears to be on track. Only real question is when and where will the dense valley fog form.
As of 145 PM Tuesday... A hot and dry day is underway across the Central Appalachians amid building high pressure. This dry airmass will be in place through much of the period, prompting an abundance of sunshine and fair weather cumulus each afternoon. Temperatures will soar into the low 90s outside of the mountains both today and Wednesday, but should feel less humid in response to dewpoints remaining down in the 60s. Efficient radiational cooling may impose another round of river valley fog Wednesday morning.
A minuscule opportunity for precipitation will be in the cards this afternoon along the mountains as a frontal boundary parks itself south of the Appalachians. A better, but still weak chance for showers arrives late Wednesday afternoon and evening along a mid-level shortwave dropping down from the Great Lakes. Forecast models suggest the bulk of moisture will remain north of the forecast area, but we may still need to monitor decaying convection moving into the Ohio Valley from the Midwest late in the period.
SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... As of 230 PM Tuesday...
For the start of this period, chances of showers/storms may increase slightly around the northern periphery of the CWA across the northern panhandle for Wednesday night. Model consensus is that a weak upper level disturbance may promote some activity for the northern half of the area through the evening as it quickly moves across the region. Just about every model agrees with this solution except for the NAM 4K Nest who keeps us dry. Consequently, cannot rule out a rogue shower or storm to our north before Thursday morning when the aforementioned disturbance abruptly leaves the region. The area will only endure a short break from semi-active weather as POPs increase out ahead of a cold front prog to move into the area by midday Thursday. Models are not in good agreement with timing of this feature, therefore accepted the blended model guidance which did bring in some likely POPs by the late afternoon for our northern sections of the CWA hinting on a later passage than previous runs.
Most of the severe storm potential will be dependent on if the cold front moves through during the afternoon/evening rather than the nighttime. Right now SPC has us in a marginal threat for severe and WPC has us in marginal threat for excessive rainfall. This will support the idea of heavy downpours in stronger convection promoting possible damaging winds and flash flooding, especially to areas that may repeatedly get hit. Instability, shear and anomalously high moisture will all be ripe through the day and effective lifting from the front will easily support severe storms throughout frontal passage, especially if an early arrival comes to fruition. However, If some of the other models are correct, the passage will be much later in the day and offer little in the way of severe storms by sun down, likely being more isolated in nature, at best. The front should kick out to the south late Friday morning leaving fairly settled weather in the wake.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... As of 100 PM Tuesday...
High pressure fills in behind a cold front late Friday and will help to dry out the area and maintain dry weather potentially into Saturday evening. Chances do come into play late Saturday into Sunday, however just slight chances for mainly the southern half of the area due to a disturbance forecast to develop to the southwest. According to long range models this feature will just graze the area as it traverses east through Sunday. Thereafter, long rang models spin up an upper low over Canada which could affect the area with a possible frontal band for the rest of Sunday and into Monday, therefore accepted central guidance who kept POPs and storm potential slightly elevated to support this solution for the rest of the long term. Did however make one alteration and capped shower/storm probability off to less than slight chances for the very end of this period and beyond (Tuesday) due to the inconsistency between models. Daytime highs will remain slightly below average and nighttime lows will be much more lower than average through this period.