Area Forecast Discussion
Issued by NWS Greer, SC

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000 FXUS62 KGSP 040747 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 347 AM EDT Sat Apr 4 2020 .SYNOPSIS... High pressure will move north of the region today, then to our east on Sunday. A weak cold front will push in from the northwest by Sunday evening, stalling over the area Monday, before lifting back north as a warm front on Tuesday. A stronger cold front will cross the region on Wednesday. && .NEAR TERM /THROUGH TONIGHT/... As of 213 AM EDT: More mid-level clouds sooner than expected...and now upstream radars are picking up some light precip over the Cumberland Plateau. Some of the guidance brings the light precip down over the NC mountains in the pre-dawn hours. Have some doubts that any of this is reaching the ground, though. Will not rule out a few sprinkles, but will not include any precip chance for now. Temps were running warmer than fcst with the increasing cloud cover. Otherwise, fair weather will continue for the next 24 hours as an upper ridge moves overhead and dampens out, supporting weak high pressure to the north. A chunk of the high eventually breaks off over the Carolinas tonight. High temps should be similar to Friday, although with more high cloud cover, it won`t be as pretty of a day. Model guidance has thicker high cloud cover moving in tonight, so min temps will be above normal. If there is a concern for the near term, once again it will be minimum RH this afternoon, but it should not be as low as Friday. See the Fire Weather Discussion for more info. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... As of 315 AM EDT Saturday: the short-term fcst begins at 12z on Sunday with broad upper ridging over the area. The upper ridge is expected to remain over the region thru the period and into the extended period. At the surface, a weak cold front will move thru the CWFA from the NW on Sunday. The models push the front offshore on Monday and move relatively dry high pressure back over the area. By early Tuesday, the high shifts SE which puts our area back under warming SLY flow as a broad plume of deeper moisture spreads over the CWFA from the west. As for the sensible fcst, PoPs will follow a diurnal pattern on both Sunday and Monday with the best chances over the higher terrain. Temps will remain above normal thru the period. && .LONG TERM /TUESDAY THROUGH FRIDAY/... As of 255 AM EDT Saturday: the extended forecast picks up at 12z on Tuesday with broad upper ridging still over the Southeast and a vigorous closed h5 low developing over Southern California. On Wednesday, the upper ridge will flatten over our region and on Thursday, another broad upper trof digs down across the Great Lakes. Beyond this point, the long-range models diverge considerably wrt the large-scale upper pattern. The GFS, and to a lesser extent the CMC, develop a massive upper trof and move it across the the entire Eastern CONUS on Fri/Sat. The ECMWF, however, maintains flat upper ridging over the Southeast and keeps the upper trof relegated to our north. At the sfc, a broad plume of deep-layer moisture associated with a weak cold front will be moving into the fcst area from the SW as the period begins early Tuesday. By early Wednesday, the front is expected to be east of the CWFA with the deeper moisture pushed offshore. Beyond this point, the operational models diverge considerably. The GFS develops a deep low over the Southern Plains and quickly moves it NE pushing a strong cold front thru our area early Fri. In the front`s wake, it spreads drying high pressure over the CWFA for the remainder of the period. The ECMWF on the other hand, moves a dry cold front quickly thru the fcst area on Thursday with Canadian high pressure spreading back over the area in the front`s wake. I didn`t change PoPs much early in the period but I did increase them for Fri and Sat, although if the ECMWF pans out, we`ll likely stay dry during that period. Otherwise, temps will run well above climatology thru Thursday, before cooling back down closer to normal, if not below, for Fri and Sat. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... At KCLT and Elsewhere: VFR conditions will persist through the period. A bit more mid-level clouds thru daybreak, at least over the west. Wind should be light from the NW or N. The clouds should thin during the day, but will return in greater number late Saturday afternoon. As high pressure moves past, wind will come around to NE for awhile in the afternoon, but should continue to veer to ESE in the early part of the evening. Outlook: Expect VFR conditions to persist into early next week. Flight restrictions may return on Tuesday as moisture increases ahead of a weak front. Confidence Table... 07-13Z 13-19Z 19-01Z 01-06Z KCLT High 100% High 100% High 100% High 100% KGSP High 100% High 100% High 100% High 100% KAVL High 100% High 100% High 100% High 100% KHKY High 100% High 100% High 100% High 100% KGMU High 100% High 100% High 100% High 100% KAND High 100% High 100% High 100% High 100% The percentage reflects the number of guidance members agreeing with the scheduled TAF issuance flight rule category. Complete hourly experimental aviation forecast consistency tables are available at the following link: www.weather.gov/gsp/aviation && .FIRE WEATHER... A Fire Danger Statement will remain in effect for Upstate SC through today. The South Carolina Forestry Commission has opted to issue a "Red Flag Fire Alert" for the entire state. We usually let that speak for itself, but since the FDS has already been issued, we`ll let it ride out to avoid confusion. Weaker winds as well as increasing dewpoints (yielding min RH in the 25-35% range) are expected Saturday, thus no additional products are expected at this time for GA or NC. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...Fire Danger Statement from noon EDT today through this evening for SCZ001>014-019. && $$ SYNOPSIS...PM NEAR TERM...PM SHORT TERM...JPT LONG TERM...JPT AVIATION...PM FIRE WEATHER...JPT

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