textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

Precip chances generally increased through the period as unsettled weather looks more likely.

The aviation discussion was updated to reflect the recent 00Z TAF issuance.

KEY MESSAGES

1. Summer like weather with hot conditions and afternoon showers and thunderstorms continue through Monday. Precipitation chances continue Tuesday and Wednesday with temperatures dropping to near or even below normal.

DISCUSSION

Key message 1: Summer like weather with hot conditions and afternoon showers and thunderstorms continue through Monday. Precipitation chances continue Tuesday and Wednesday with temperatures dropping to near or even below normal.

Mostly clear conditions across the area as broad, ~598dm upper anticyclone remains entrenched across the Southeast US. Mostly clear and dry conditions still expected this evening and tonight, other than some mountain valley stratus again Thursday morning.

Otherwise...the upper anticyclone over the area retrogrades to the lower MS Valley through the weekend. Despite some ridging over the area extending eastward from the anticyclone, this doesn't prevent shortwaves from rounding the ridge and crossing the area from the north. In addition, an upper low undercuts the ridge and moves west across Florida through the weekend. The northern stream waves push a backdoor cold front into the area Friday, which stalls on Saturday, then dissipates on Sunday. The upper low helps produce a fetch of moisture from the Atlantic into the area as well. After scattered diurnal mountain convection Thursday, all these features will combine to produce more widespread convection Friday and Saturday. With the dissipating front, convection could again be more limited to the mountains. Highs rise into the low to mid 90s for all but the higher elevations by Friday. They cool a little Saturday but warm back to around 90 for Sunday.

More shortwaves cross the area in the developing more zonal flow Monday through Wednesday. These help push another backdoor cold front into the area Monday with a cold air damming-like high setting up into Wednesday keeping the unsettled weather and precip chances in place. After another day with highs around 90 on Monday, good cooling takes place with highs dropping to around normal for Tuesday and a few degrees below normal for Wednesday.

AVIATION /00Z THURSDAY THROUGH MONDAY/

At KCLT and elsewhere: VFR on tap for the 00Z TAF period, with most sites expected to see calm winds and SKC most or all of tonight, with only the usual exception of KAVL, which is likely to see another round of valley stratus develop before dawn Thursday. Little has changed with the large-scale pattern, so went with a forecast similar to persistence, bringing in restrictions at 08Z and keeping them in the TAF through morning. Mostly quiet conditions then expected on Thursday, with a FEW/SCT cu field likely to develop again across much of the area. Some widely scattered showers and embedded storms may develop across the NC mountains Thursday afternoon (and perhaps even parts of the I-40 corridor in the NC Piedmont) but for now, confidence was only great enough for a token VCSH in the KAVL TAF, and no mention at KHKY or KCLT. Light SE wind expected at most locations through the period, except at KAVL where it'll be predominantly NNW...but still light.

Outlook: Increased shower and thunderstorm chances with associated restrictions through Monday. Mountain valley fog and low stratus will be possible each morning.

GSP WATCHES/WARNINGS/ADVISORIES

GA...None. NC...None. SC...None.