Area Forecast Discussion

WHAT HAS CHANGED

Severe Thunderstorm Watch until 6pm tonight for a large portion of our region.

KEY MESSAGES

1) Strong to severe thunderstorms expect this afternoon and evening, damaging wind gusts will be the main threat

2) Daily shower/thunderstorm chances return later next week

DISCUSSION

KEY MESSAGE 1... A passing mesoscale convective system (MCS) will continue to track into eastern Ohio, western Pennsylvania, and northern West Virginia over the next 4 to 6 hours. Damaging wind gusts along the leading edge of the MCS are expected for areas south of I-80 and north of Morgantown, WV; a Severe Thunderstorm Watch is in effect until 6pm. Wind gusts will likely range between 50 to 65 mph; down trees and power lines are likely. Rainfall amounts will likely range from a half to one inch, flooding isn't likely due to the progressive advancement of the MCS.

In the wake of the passing MCS, there could be redevelopment of isolated strong to severe storms near the northern and southern flank of the remnant convection. There is a question of whether if there is enough time for the environment to recovery, cooling aloft, to prompt new updrafts. The Watch may need to be extended or expanded if that occurs. A special weather balloon may be released in the wake of the MCS to capture what the temperature profile looks like aloft.

The probability of severe storms decreases between 8pm to 11pm tonight. There may be training showers and storms that could create isolated swaths of 1 inch of rain or higher. Urban flooding would be the main concern given it has been dry for a number of days.

KEY MESSAGE 2... Ridging is progged to build back in early next week among all ensemble guidance with some uncertainty in temperatures for Monday and Tuesday as the departing trough to the east exhibits some timing differences as does the orientation and strength of the building ridge. Lingering troughing could hold temperatures in the upper 70s while quicker ridging could point to 80s for the majority of the week. Either way, a return of drier and warmer weather is anticipated for at least the first half of next week. Ridging then may break down some and allow for some summertime-like afternoon showers and storms, though with surface high pressure in the vicinity, coverage shouldn't be widespread or bring a notable severe weather risk. High temperatures will be highly dependent on coverage of convection.

AVIATION /18Z SATURDAY THROUGH THURSDAY/

Medium confidence forecast with slightly lower confidence overnight into the early morning hours Sunday depending when and if low clouds and or fog develops.

Showers and storms will impact most of the airports this afternoon with a brief drop to MVFR and perhaps IFR in moderate to heavy rainfall. After this moves through, there will be a lull in the activity until more develops around 22Z and could last as late as 4Z. It doesn't appear to be widespread unless cells congeal into a line.

After the storms pass this evening, attention shifts to fog development. HREF mean has high probs for sub IFR VIS at DUJ and LBE. Still low confidence on how much develops. Sunday VFR weather returns.

Southwest wind around 10 kts with occasional gusts into the 20 kt range during day becomes nearly calm this evening into Sunday.

Outlook... Daily thunderstorm and associated restriction chances begin Tuesday after a dry Monday.

PBZ WATCHES / WARNINGS / ADVISORIES

PA...None. OH...None. WV...None.