666 FXUS62 KGSP 070222 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 1022 PM EDT Sat Nov 6 2021 .SYNOPSIS... A low pressure system will move along the southeast coast through the weekend, bringing rain chances to the Carolina Piedmont through tonight. Dry and warming high pressure develops for the first half of the upcoming week before a significant storm system begins impacting the eastern states late in the week. && .NEAR TERM /THROUGH SUNDAY/... As of 1010 PM EDT: An 1003 mb surface low pressure system continued to spin with little movement off of the northern Florida coastline. Weak mid-level frontogenesis continued to support an influx of mid- level clouds near the I-77 corridor with a few sprinkles or light showers observed with associated isolated rain bands just east of the forecast area. It now appears any light showers or drizzle will stop just short of the forecast area. So in this update will trim back slight chance showers to at least to eastern Union NC county, if not removed altogether. The lastest observations showed dewpoints hovering around 30 deg F with temperatures still in the 40s for areas where frost may be a concern tonight in active zones north of I-85 from Franklin county northeast to Rutherford (mostly excluding Greenville county). With mid to high clouds gradually thinning overhead, think we continue to be on track for at least patchy frost for these areas. Otherwise, high pressure builds in behind the departing low pressure area Sunday. Clouds should scatter out with mostly sunny skies for much of the day. Expect low end gusts to redevelop with mixing during the morning then tapering off through the afternoon. With sunshine returning and increasing thickness values, highs should end up near normal. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... As of 1230 PM Saturday: An upper-level low and a coastal low laying underneath will continue to meander off the Southeast coast through much of the short-term. Ridging aloft will nudge over the region from the southwest, while a deep upper anticyclone sets up shop over the west-central Atlantic. This will keep the coastal low from moving much, but will gradually push eastward as upper ridge deepens from the southwest and takes control of the large-scale pattern. With a surface high in place over the southeastern CONUS, expect dry and mostly sunny skies through the forecast period. Rising heights from the upper ridge will raise our daily max temperatures to above normal values by Monday and Tuesday. Good radiational cooling conditions during the nighttime period will cause overnight lows Sunday night to dip into the mid to upper 30s across the piedmont and lower 30s for the high country. Expect areas of frost to develop or most locations. Monday night will be a slightly different story due to the rise in thicknesses, which in turn will raise overnight lows to near normal values. Either way, expect a large diurnal cycle for the new work week. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... As of 200 PM Saturday: By the middle part of next week, the aforementioned upper ridge begins to flatten out in response to a potent shortwave trough that quickly pushes across the northeastern CONUS. Surface high will still be in control, but the warming trend will likely plateau Wednesday and beyond. Max temperatures will remain a few degrees above normal through much of the upcoming work week, while lows gradually increase as an uptick in cloud cover develops and a better moisture flux enters the CFWA from the southwest. Changes begin to take place by late Thursday into the day Friday as global models continue to spit out a vigorous storm system over the eastern CONUS. The overall consensus has a similar synoptic setup with a potent upper trough swinging in from the west. The timing and location of the frontal system are a bit different with the GFS sending the attendant front through the CFWA by early Friday, with little to no QPF response besides the TN border. On the other hand, the ECMWF has a wetter solution, with a good frontal zone and QPF response ahead and along the boundary. Also, the ECMWF has the attendant front entering the CFWA 6-12 hours later compared to the GFS. Highest PoPs will be late Thursday into Friday to account for all global model solutions. The GFS and ECWMF QPF response is unimpressive, but the outlier that is the Canadian, produces very high QPF amounts, which could lead to an excessive rainfall threat in this scenario. The overall severe threat is nonzero at this time, but continues a downward trend as the GFS and ECMWF come to better terms. Temperatures will likely remain above normal for both highs and lows through the rest of the period, with the exception of day 7 as we favor a post-frontal regime. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... At KCLT and elsewhere: MVFR to VFR cigs will prevail through 08Z to 12Z mainly east of the mountains and especially near the I-77 corridor including KCLT. Low end gusts will likely return for many terminals between 13-16Z. High confidence in VFR conds prevailing all sites after 14Z. Outlook: No significant flight restrictions are anticipated through at least Wednesday with high pressure over the area. However, morning mountain valley fog will be possible. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...DEO NEAR TERM...Munroe/RWH SHORT TERM...CAC LONG TERM...CAC AVIATION...RWH