Area Forecast Discussion
Issued by NWS Greer, SC
Issued by NWS Greer, SC
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792 FXUS62 KGSP 300610 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 210 AM EDT Sun Jun 30 2024 .SYNOPSIS... Warming temperatures as shower and thunderstorm chances increase ahead of a robust cold front arriving Sunday. Drier and cooler conditions return Monday and Tuesday behind the front, before summer heat returns on Wednesday and beyond. && .NEAR TERM /THROUGH TODAY/... As of 200 AM Sunday...Seeing the requisite shower activity once again early this morning in the continued light southerly moist upslope flow across the region. Like last night, this should continue on toward daybreak with scattered coverage mainly close to the higher terrain. Cloud cover will help to keep temps above normal and dewpoints relatively high even for this time of year. Otherwise...a cold front will be just to our NW on Sunday, helping trigger convection across eastern TN and in the NC mountains. There will also be a pronounced lee trough setting up across the Piedmont, providing convergence for convection. Guidance is in good agreement the approaching upper trough and the aforementioned front and trough should support decent coverage of showers and tstms across the area. SBCAPE will range from 1500-2500 J/kg and 0-6 km bulk shear around 20-25 kt will be enough for quasi-organized clusters of storms drifting toward the east. A few storms may produce damaging wind gusts, and the Day 2 SPC outlook of marginal severe for our area looks good. Convection will likely get going late enough to allow peak heating to get temps into the mid 90s, while dewpts remain in the mid 70s across much of the Piedmont Sunday aftn. This results in heat indices getting into the 100-107 range across the I-85 corridor and southeast. Have issued a Heat Advisory for the NE GA Piedmont, the Upstate, and SW NC Piedmont for Sunday aftn into early evening. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... As of 150 PM Saturday: By Sunday night, what is left of a frontal boundary clears the CWA and dissipates to the south. Synoptically, high pressure builds in from the west with an amplifying high over the southern CONUS. To the north, a trough attempts to dive southward and turns flow aloft form the NW. High pressure at the sfc will also keep sfc winds out of the N/NW, maintaining a stream of drier and somewhat cooler air for the short term. Modeled upper air guidance shows a stout subsidence aloft with a mid-level inversion at the top of the BL, snuffing out rain chances Monday afternoon and into Tuesday. A break in the heat will occur Monday and into Tuesday, before a snap back to summertime reality. As far as fire concerns with drier air during this time, it will drop RH values into the 40 percent range, but critical thresholds are not anticipated. Winds could have some low-end gusts Monday afternoon. Fuel moisture is dry, especially east of the mountains meaning vegetation is more prone to ignition. Otherwise, temperatures look to be a few degrees below climo until the next period. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... As of 200 PM Saturday: The summertime pattern continues into the extended. Tuesday night and into Wednesday, the trough off to the north starts to deamplify as the ridge axis slides over the eastern CONUS. A strong area of high pressure also grows over the southeast and Mid-Atlantic regions. As the heights rise, so do the temperatures. Guidance from the GFS and EURO depicts moisture returning toward the end of the week as sfc flow remains light and starts to veer more E/SE. The slow advection of moisture from previous model runs, does keep dewpoints more reasonable and in the low 70s by end of week. This will have a direct impact on heat indices, especially those locations east of the mountains. 90s should return by Thursday and beyond. Once the high pressure starts to weaken on Thursday and Friday, a return to more diurnally driven convection is possible across the mountains, though confidence is low. All in all, the extended looks relatively dry, temps ramp up through next weekend, and qpf response is minimal. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... At KCLT and elsewhere: For the third night in a row we are seeing widely scattered showers developing in a light moist southerly flow across the region. Will be handling the restrictions with amendments, as confidence in showers impacting any of the terminals is sketchy through daybreak. Wind will be light S or calm. On Sunday, expect with minimal heating we should develop a low cloud deck, followed by the development of deep convection in the early afternoon. The CAMs show some decent agreement, so confidence is high enough to present a TEMPO for the mid/late afternoon hours at most terminals. Convection should persist well into the evening ahead of an approaching cold front, so a PROB30 will be employed. Restrictions should be contained to the TEMPO/PROB30 groups. Wind should be light S to SW. The cold front should move southeast across the region in the late night hours with wind coming around to NW after the front moves through. Outlook: The cold front will push thru and stall just south of the area, resulting in quieter weather for Monday thru mid-week. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...Heat Advisory from noon today to 8 PM EDT this evening for GAZ018-026-028-029. NC...Heat Advisory from noon today to 8 PM EDT this evening for NCZ070>072-082. SC...Heat Advisory from noon today to 8 PM EDT this evening for SCZ008>014-019-104>109. && $$ SYNOPSIS...CP NEAR TERM...ARK/PM/SBK SHORT TERM...CP LONG TERM...CP AVIATION...PM