textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

Tapered off showers faster overnight, with fog possibly dense.

Dry Friday.

KEY MESSAGES

1. Showers taper off from NW to SE this evening as a cold front crosses the area. Low clouds and patchy fog, some possibly dense overnight. Clouds slowly lift through the day Friday. 2. Dry and warm through the weekend with cooler and wetter conditions to start next week.

DISCUSSION

Key message 1: Showers taper off from NW to SE this evening as a cold front crosses the area. Low clouds and patchy fog, some possibly dense overnight. Clouds slowly lift through the day Friday.

Widespread showers over the are this afternoon taper off from NW to SE through the evening as a cold front crosses the area. The showers may possibly linger south of I-85 into early Friday morning. Can't rule out an isolated rumble of thunder south of I-85 this afternoon, but chance is very low. Moderate to possibly brief, heavy rainfall this afternoon should remain in the beneficial range with little flood threat given the drought conditions. Gusty SW winds have only been spotty today as the precip has lead to a weak in situ CAD across portions of the area. Still, some locations south of I-85, and locations where heavier showers can mix down the stronger winds aloft, could see some gusts.

Expect the low level flow to weaken and turn northeasterly behind the front overnight. Copious low level moisture lingers and a low level inversion develops. This will keep low clouds across the area with patchy fog, some possibly dense by morning. Expect the fog to dissipate by noon Friday, but low clouds could linger through the day, especially outside of the mountains, but the bulk of the day should be dry. Right now, have highs around 5 degrees above normal across the mountains and near normal elsewhere. That said, highs could be lower, especially outside of the mountains depending on how long the fog and low clouds last.

Key message 2: Dry and warm through the weekend with cooler and wetter conditions to start next week.

By this weekend, a mean longwave trough will be draped from the Canadian Rockies across the Northern Plains and into New England. Weak flow will extend across the southeast states in the far southern portion of the base of the trough. The trough axis will shift east of the region through the weekend with rising heights and quasi-zonal westerly flow. This will allow for temperatures to warm back to above seasonal average for late February with mid 60s to mid 70s common, especially by Sunday. A notable pattern change occurs by the start of the new week, however. A sprawling 1040mb surface high will shift from out of the Midwest into the Mid-Atlantic/New England with a resulting Cold Air Damming wedge setting up shop over the Carolinas and northeast Georgia. At the same time, a belt of weak, but perturbed, southern stream flow will reside from the Southern Plains into the Southern Appalachians. A weak lead wave will translate across the region on Monday with a return of precipitation chances. Subsequent waves may bring additional rounds of precipitation Tuesday into Wednesday, but forecast confidence rapidly wanes as global model guidance diverges with respect to the synoptic evolution. Thermal profiles may support a wintry mix across the highest mountain elevations/northern mountains, but confidence is too low to warrant much more than a brief mention in the forecast. Otherwise, temperatures elsewhere are currently forecast to be too warm for any wintry mischief. Speaking of temperatures, Monday will be a rude awakening with chilly highs in the CAD wedge that may be upwards of 20-25 degrees colder compared to Sunday.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

At KCLT and elsewhere: Widespread showers moving across the area at this time with generally IFR cigs and MVFR vsby, but with some lower and higher variability. Gusty winds have been much more spotty than expected, at least at the TAF sites as weak in situ damming has developed with the increased shower coverage. This has lead to LLWS where winds are light with a southwesterly low level jet in place. Brief gusty winds may mix down in the heavier showers, so included that in the TEMPOs. Can't completely rule out a TSRA for the SC sites, but chance too low for the TAFs. Expect the SHRA, and any gusts, to diminish from NW to SE through the afternoon and end during the evening. Vsby will improve as the showers end, but IFR to possibly MVFR cigs will linger. Conditions then deteriorate overnight with lingering low level moisture, northeasterly winds, and a developing low level inversion. Expect IFR cigs and vsby to develop, with LIFR and even VLIFR possible. Expect later forecasts to fine tune those lower values. Vsby improves by noon but IFR to MVFR cigs will linger into the afternoon. NE winds expected through the day.

Outlook: Dry and VFR conditions should return by Saturday. Another front may bring showers and associated restrictions Monday into Tuesday.

GSP WATCHES/WARNINGS/ADVISORIES

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