671 FXUS62 KRAH 070137 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 937 PM EDT Thu Oct 6 2022 .SYNOPSIS... A lee trough and warm southwesterly flow will prevail ahead of a strong, but moisture-starved cold front that will cross the region Friday night. Canadian high pressure will follow and extend from the mid MS Valley to the mid-Atlantic through the weekend. && .NEAR TERM /THROUGH TONIGHT/... As of 935 PM Thursday... In the wake of a shortwave trough lifting across the mid-Atlantic, rising heights, and wly/quasi-zonal flow at the base of a broad trough centered across the Great Lakes, will extend across the srn Appalachians and Carolinas. Beneath that wly flow aloft, an Appalachian-lee trough will continue to extend swwd across the srn mid-Atlantic Foothills and wrn Piedmont. While occasional light swly stirring may result in the presence of the lee trough, a weak MSL pressure gradient surrounding it, and the development/maintenance of a strong nocturnal inversion, will favor more calm than stirring. When combined with mostly clear conditions, with fleeting patches of 5-6 thousand ft stratocumulus, strong radiational cooling will result in low temperatures in the upr 40s to mid 50s, or a couple of degrees on average above those of Thu morning. && .SHORT TERM /FRIDAY AND FRIDAY NIGHT/... As of 140 PM Thursday... Embedded within the long wave trough in place across the central and eastern CONUS, a positive-tilted shortwave trough centered over the upper MS Valley will swing eastward across the Ohio Valley and Lower Great Lakes region during the day on Friday and then into the NE US and northern mid-Atlantic states Friday night. The pre-frontal trough in place over western NC Friday morning will get displaced eastward ahead of the attendant strong but moisture starved cold front that will move into the area during the evening and overnight hours. Temperatures will warm up nicely ahead of the front. Under sunny skies, afternoon highs ranging from upper 70s/near 80 NW to lower/mid 80s across the south. Expect an increase in mid and high clouds Friday evening/night as the front moves into the area. Otherwise, it will remain dry with strong post-frontal cold dry air advection during the second half of the night and into Saturday. Lows ranging from upper 40s north to mid 50s south. && .LONG TERM /SATURDAY THROUGH THURSDAY/... As of 140 PM Thursday... By Saturday morning, a surface cold front will have pushed through central NC. Behind the departing cold front, considerably drier air will spill into our area with PWAT dropping as low as ~0.5 to 0.8 inches (~40 to 60 % of normal for this time of year) Saturday through Wednesday. Chilly high pressure will migrate just north of our area through middle of next week. Low-level thicknesses are forecast to dip into the 1340s to 1350s Sunday and Monday mornings, supportive of min temperatures in the lower to mid 40s area-wide, with perhaps some upper 30s possible in our traditionally cooler spots. Temps will then moderate back to near normal with highs in the lower to mid 70s and lows in the lower 50s Tuesday through Thursday. Our next chance for rain appears to be sometime late next week as the next upper trough and associated sfc cold front approach our area. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... As of 700 PM Thursday... 24 hour TAF period: High confidence VFR conditions will prevail through the TAF period. Winds will generally be light, 5 kts or less and variable between southerly and northwesterly. A few lingering mid and high clouds will give way to largely clear skies overnight. Late Friday a cold front will approach, coupled with increasing clouds and winds between 18Z Fri and 00Z Sat. Looking ahead: VFR conditions should prevail through Tuesday. A dry cold front will move through the area Fri night, with the primary impact of increased cloud cover and winds becoming northwesterly then northerly and breezy in the wake of the front late Fri night/Sat. Cloud cover should decrease and winds should relax a bit Sat night/Sun. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...MWS NEAR TERM...MWS SHORT TERM...CBL LONG TERM...Luchetti AVIATION...KC