Area Forecast Discussion
Issued by NWS Greer, SC
Issued by NWS Greer, SC
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234 FXUS62 KGSP 011101 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 701 AM EDT Wed May 1 2024 .SYNOPSIS... Dry and warm high pressure will build across the through Thursday, before an active frontal system moves in Friday and lingers through the weekend. The atmosphere remains unsettled with afternoon storms possible early next week. && .NEAR TERM /THROUGH TONIGHT/... As of 6:15 AM EDT Wednesday: The isolated showers have pretty much fizzled out just east of the I-77 corridor, but we`re still left with patchy fog across a good portion of our area. Most of the locations reporting the denser fog (ie, 1/2 sm or less) are relegated to the fog-prone NC mtn valleys, but we are still seeing a few sites in the eastern Upstate and southern NC piedmont reporting less than 1 sm. Thus, the current SPS for patchy dense fog still looks sufficient for our area. If the dense fog becomes more widespread, a Dense Fog Advisory may still be needed. Otherwise, a well-defined upper shortwave will move off the Atlantic Coast today. In its wake, heights rebound as upper ridging amplifies over our area again. At the sfc, what`s left of the weak frontal bndy will also move offshore as weak high pressure spreads back over our area and keeps us dry thru the near-term period. Despite weak low-lvl winds from the north, temperatures this afternoon should rebound a decent amount under mostly clear skies and increasing thicknesses. Most of the guidance has highs topping-out 1 to 2 categories above climatology. Although dewpts are expected to mix out some this aftn, it`s unlikely that min RH values will reach critical thresholds. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 155 AM Wednesday...Upper level heights remain in a definite ridge config Thu and expect deep layered drying to continue for another day. This will lead to abv normal temps while sfc td/s remain in the l50s making for a rather pleasant day with afternoon fair-wx Cu. On Fri, the pattern begins to break down as a srn stream s/w approaches from the west and crosses during max heating while llvl moisture increases destabilization. However, this system will only generate a weak sfc reflection as it fights neg forcing and rather warm temps aloft. Also, the dynamic fields remain meager as the upper s/w attenuates interacting with the departing ridge. So, with low-end shear and only modest sbCAPE, the llvl convg zone wont have much to work with and an organized or severe tstm threat is not expected. Will anticipate mainly outflow driven cells or multicells, a few of which may become quite strong, through the afternoon/evening with reduced convec activity after sunset as the mlvl energy traverses east. && .LONG TERM /SATURDAY THROUGH TUESDAY/... As of 230 AM Wednesday...The ext range continues to look active and will likely be transitioning into more of a summertime pattern. Upper heights become loosely divergent yet moreso zonal each day as rounds of mlvl srn stream vort energy traverse the flow. Large scale high pressure centers remain well north and east of the fcst area, which leaves general low pressure at the sfc maintaining ill-defined areas of sfc convg over the FA. Hard to pinpoint the best chance and locations of afternoon convec in this setup as the models continue to indicate modest sbCAPE developing over most areas while shear levels remain quite weak. This will set the stage for afternoon heat driven activity or modified pulse tstms into the evening hours each day. Some of these cells will have the potential to become rather strong and precip rates could become high enuf for minor hydro issues with any given area of anchoring or training. Saturday looks to have the best chance for any possible localized hydro concerns as the column becomes deeply saturated, while mid-level dry air mixes in Sun-Tue. Max temps will lower a bit to near normal Sat due to widespread cloud cover, but the other days shud see temps pushing 5- 7 degrees abv normal. With the enhanced warm afternoon temps and no airmass change, mins will only be able to drop off into the 60s each morning or abt 8-10 degrees abv normal over all areas. && .AVIATION /11Z WEDNESDAY THROUGH SUNDAY/... At KCLT and elsewhere: Other than some lingering visby restrictions for the first hour or two of the taf, we can expect VFR conditions thru the 12z taf period. At present, the only taf sites that are still reporting reduced visby are KCLT (at 4sm) and KAND (at 6sm). The other terminals are >6sm. Still expect any lingering visby re- strictions to dissipate by 13z or so, leaving mostly clear skies with just a few passing cirrus for the rest of the period. Winds will pick up from the N to NE by the early afternoon, and then go light and vrb again later tonight. Outlook: VFR conditions are expected Thursday and much of Friday. More numerous showers and thunderstorms and their associated res- trictions are likely on Saturday and possibly into Sunday with the passage of another cold front. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...SBK NEAR TERM...JPT SHORT TERM...SBK LONG TERM...SBK AVIATION...JPT