... An approaching weak front returns rain chances on Tuesday followed by warm and humid weather the rest of the week. There will be a chance of showers and thunderstorms each day, mainly during the afternoon and early evening.
NEAR TERM /THROUGH TONIGHT/... Dry conditions continue the remainder of the afternoon and into the evening as warm air aloft keeps a lid on convection. There is a possibility a MCV associated with convection currently over the Midwest initiates some showers and possibly a thunderstorm south and east of Pittsburgh early this morning.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... Shower/thunderstorm chances return Tuesday with the passage of an upper level disturbance and a weak cold front crossing the region late afternoon and into the evening. During the afternoon we could see development ahead of the front with daytime heating and increasing low level moisture, however, models are not in very good agreement on whether warm air aloft will be overcome. Nearly all CAMs at this time fail to initialize any convection so have cut back on PoPs during the afternoon considerably leaving only slight chances. The front then stalls in the vicinity of the Mason-Dixon line and remains through the period maintaining shower/thunderstorm chances with the best chances south and east of Pittsburgh during the afternoon and early evening. Above normal temperatures will continue.
LONG TERM /THURSDAY THROUGH MONDAY/...
Broken record forecast in the extended with little change to the longwave pattern. The main belt of westerlies will remain to our north with ridging across the southeast CONUS. As a result, the frontal boundary is expected to remain in the general vicinity of the middle Ohio Valley into next weekend. This will keep daily chances of showers and thunderstorms in the forecast with coverage best during the afternoon and early evening thanks to diurnal influences. Temperatures will remain above normal, although 90 degree readings should be few and far between thanks to the front and precipitation.