... Hot and dry high pressure will prevail until Friday when a cold front drops south across our region. Heat indices near or in the triple digits are likely outside the mountains in the afternoon. The cold front will become stationary just south of our area this weekend. Expect scattered afternoon and evening showers and thunderstorms through the weekend. Another cold front is expected to arrive from the north on Monday.
NEAR TERM /THROUGH TODAY/... As of 140 am: A relatively dry boundary layer is expected to yield quiet conditions through the period. While mountain valley fog and/or low stratus is expected to develop through daybreak, it is expected to be much less widespread than in previous days Temperatures will be right around normal.
Profiles remain inhospitable to convection later today, and heights and temps continue to increase from the west. With plenty of mid to upper 90s, expect heat index values to rise to 100 to 105 east of the mountains. Mainly the southern Piedmont will flirt with the 105 degree threshold for a Heat Advisory, but some measure of dewpoint mixing is likely again with the dry air aloft. Will keep the heat mention in the HWO and cap PoPs sub-slight chance throughout with the warm profiles.
SHORT TERM /TONIGHT THROUGH SATURDAY/... As of 240 PM EDT Wednesday: the short-term fcst picks up at 00z on Friday with broad upper trofing centered over the Northeast and steep upper ridging still in place over the rest of the CONUS. This pattern is expected to persist thru the period and into the extended. At the sfc, another weak cold front will track out of the Ohio Valley on Thursday and drop into our CWA late Thurs/into early Friday as the period begins. The front will be slow to move thru the fcst area, with most of the latest guidance placing the bndy to our south as the period ends late Saturday. As for the sensible forecast, we can expect more typical summertime PoPs returning for both Friday and Saturday. The severe potential continues to look minimal both days. Temps will remain well-above climo thru the period with triple digit heat indices likely across most of the lower terrain on Friday, but likely relegated to our southern-most zones for Saturday.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... As of 235 PM EDT Wednesday: the extended forecast picks up at 00z on Sunday with broad upper trofing centered over the NE CONUS and steep upper ridging still in place over the west. This pattern is expected to persist thru the period with the upper trof amplifying again early next week and shifting at least slightly west. At the sfc, a weak frontal bndy and associated lee trof will be lingering somewhere to our south as the period begins. Most of the long-range guidance has the bndy lifting slowly back to the north over the weekend. By early next week, broad high pressure from Canada will push southward and move over the Great Lakes as the period ends. This may provide some brief drying across our northern zones, however the above-mentioned moist bndy will likely persist just to our south and then lift back northward towards the end of the period. Temps will start out near normal on Sunday, and cool to well-below normal by Tuesday.