Area Forecast Discussion
Issued by NWS Greer, SC

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000 FXUS62 KGSP 281804 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 104 PM EST Sun Feb 28 2021 .SYNOPSIS...
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A cold front will cross Tennessee tonight then cross our area by mid day Monday. Dry high pressure will build over from the north as the high center moves from the Great Lakes to the Mid- Atlantic coast Monday night into Tuesday. Unsettled weather returns from the west Tuesday night into Wednesday morning. Another low pressure system may affect the Gulf Coast region Friday into Saturday.
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&& .NEAR TERM /THROUGH TONIGHT/...
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As of 1250 pm: Low clouds and fog finally are giving way to incr gusty SW winds this afternoon. Although hourly temps are running way behind forecast maxes, we`re hesitant to make any radical changes to this afternoon`s highs, as temps have been warming by as much as 10 degrees in an hour where surface winds and insolation have increased. Thus, only made minor tweaks for now. Weakly forced warm sector regime will yield only spotty-at-best shower coverage through the evening, with the best chances occurring in response to mech lift across the srn NC mtns/Blue Ridge escarpment. The latest short term guidance continues to depict some modest instability... generally 500-1000 J/kg of sbCAPE developing in the 75-80 degree air over southern Piedmont areas this afternoon, with some convection- allowing models continuing to respond with some spotty showers... mainly across the eastern SC Piedmont this afternoon, where slight chance pops are advertised. The front will take it/s time reaching the NC mtns, likely aft 08z, when stronger sfc forcing and a llvl jet begin to generate higher precip rates over the wrn NC mtns. Not anticipating any hydro threats thru the near term period, but the lingering rainfall into the short range may create isol and minor flooding over the far srn NC mtns, mainly in wrn Graham Co thru late morning Mon. Min temps tonight will also remain well abv normal with readings likely ranging from the l50s over the mtn valleys to the u50s south of the I-85 corridor.
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&& .SHORT TERM /MONDAY THROUGH WEDNESDAY/...
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As of 1205 pm EST Sunday: As sfc ridging rolls over into the region Monday night, the llvls will continue to dry, but model cross sections depict varying degrees of mid and upper level moisture lingering within the west to wsw flow aloft. Gridded model sky cover solutions are all over the place, and at this point, the generic partly cloudy should cover it. Downstream of developing southern stream low pressure, clouds should thicken again as Tuesday wears on and within the cool NE llvl flow, maximum temperatures will be back to below climo values. From late day Tuesday into Wednesday morning, as forcing and better moisture associated with the encroaching southern stream system overspreads the region, pcpn will be become widespread. Vertical temperature/moisture fcst profiles over the NC mtns still suggest that a period of snow developing into a wintry mix remains possible during this time. Fast moving s/wv passage is expected on Wednesday, the axis of which is timed to be near the coast by the afternoon. Whatever the orientation and cvrg of pcpn shield is in the morning should be replaced by dry slotting by Wed afternoon.
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&& .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
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As of 1215 pm EST Sunday: No change to the going dry and mild fcst for Thursday as extended range guidance remains in good agreement in progging deep layered dry air within the cyclonic flow aloft and a dry northerly llvl flow. Within the lingering llvl northerly flow, a dry cold front is progged drop south through the region on Friday ushering in another period of below climo temperatures. The mean pattern does not change very much for next weekend, featuring a lingering eastern CONUS trough. Forcing rounding the base of upper trough is progged to activate baroclinic zone, but way off to our south and into the offshore Atlantic on Saturday into Sunday. The dry conditions will continue with temperatures around 5 deg F below the early March climo each day.
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&& .AVIATION /18Z SUNDAY THROUGH FRIDAY/...
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At KCLT and elsewhere: Lingering low cloud cover is scattering/ clearing early this afternoon and visby is (finally) improving quickly in the KCLT area. VFR conditions should be seen at all sites no later than 20Z. Most terminals will see gusty S/SW winds this afternoon that will likely diminish a bit this evening. However, SW winds should begin to pick up again after midnight as surface gradient increases in advance of an approaching cold front. Can`t rule out a brief return of fog btw roughly 03-06Z. However, fog chances will decrease once winds pick up late tonight. Cigs should lower to MVFR after midnight as rain chances also increase. Most sites will see categorical SHRA for several hours from around daybreak through the morning. Improving conditions are expected at KCLT during the 18Z-00Z Monday outlook period, with NW winds developing in the wake of the front. Outlook: Drier high pressure building back into the area late Monday will result in improving flt conditions through early Tuesday. Moisture will then surge back into the area by the end of the day Tuesday, with restrictions and precipitation chances returning Tue night into early Wed. Another round of drying is expected by late Wed, likely continuing through the end of the work week. Confidence Table... 18-24Z 00-06Z 06-12Z 12-18Z KCLT High 89% High 100% High 91% High 97% KGSP High 90% High 99% High 95% High 96% KAVL High 99% High 95% High 86% High 94% KHKY High 89% High 95% Med 74% High 88% KGMU High 91% High 97% High 95% High 95% KAND High 91% High 100% High 95% High 95% 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
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&& .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...DEO NEAR TERM...JDL/SBK SHORT TERM...CSH LONG TERM...CSH AVIATION...JDL

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