textproduct: Columbia

WHAT HAS CHANGED

Introduced Slight Chance PoPs in the far southeastern forecast area based on satellite and radar trends. Decreased PoPs slightly on Sunday afternoon based on the latest model guidance. Aviation discussion updated for 18z TAFs.

KEY MESSAGES

- 1. A few showers or thunderstorms possible today in the southeastern Midlands with hot and dry conditions elsewhere.

- 2. Rain chances increase this weekend with a more typical summertime pattern returning next week.

DISCUSSION

- 1. A few showers or thunderstorms possible today in the southeastern Midlands with hot and dry conditions elsewhere.

There is a gradient in the PWATs across the region this afternoon with values ranging from 0.8 inches in the Charlotte Metro to 1.1 inches in the southeastern Midlands and CSRA. This shows up well on recent satellite imagery with only a few fair weather clouds across the north and west and more aggressive cumulus across the southeast. A few light showers are starting to develop in this area as well, with more convection firing across the Low Country along the seabreeze. Based on these trends and hi-res guidance, Slight Chance PoPs were introduced to portions of Bamberg, Clarendon, and Orangeburg counties to account for a few pop up showers or thunderstorms. Dry conditions are expected across the remainder of the CWA today with temperatures on track to reach the lower to mid 90s.

- 2. Rain chances increase this weekend with a more typical summertime pattern returning next week.

An upper trough over the Upper Midwest and associated surface front are expected to move toward the area for the weekend into next week. As they do, moisture increases significantly, especially Saturday night into Sunday as PWATs are forecast to top the 2" mark. However, guidance keeps the frontal boundary to the west, keeping a main trigger for focused precipitation to our west as well. Ensemble probabilities keep relatively low (~10-20% depending on model suite) chances of greater than 2" of rain through Wednesday. With this in mind, PoPs were dropped by 10-20 percent across the forecast area Sunday afternoon as hi-res model guidance is suggesting more scattered convection as opposed to a widespread rainfall. However, given the expected atmospheric conditions it would not be surprising to see localized amounts over 2" as any activity that develops should be efficient rain makers. This is supported by modeled soundings that show a long skinny CAPE profile. There is also an inverted-V indicated suggesting a threat for strong winds from any robust convection. This is echoed by the SPC Day 3 SWO which shows a Marginal (1/5) risk for severe weather on Sunday across the Midlands and CSRA.

After the weekend, more typical diurnally driven activity is anticipated through mid-week as residual moisture hangs around the area.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

VFR conditions expected through the TAF period.

Some fair weather cumulus across the area will continue through the afternoon hours. Satellite does show some enhanced cu along the sea-breeze along the coast, with an isolated light shower or two being indicated on radar. These will remain off to the east of all taf locations. VFR conditions will prevail with the cumulus this afternoon, then mostly clear conditions overnight. With the airmass still on the drier side, do not anticipate any visibility issues tonight, but can not rule out some shallow steam rising on area rivers and lakes Saturday morning. Winds mostly variable through tonight, then turning more out of the southeast Saturday late morning.

EXTENDED AVIATION OUTLOOK...Rain and restrictions become increasingly likely later this weekend and into early next week.

CAE WATCHES/WARNINGS/ADVISORIES

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