textproduct: Columbia

WHAT HAS CHANGED

Aviation discussion updated.

KEY MESSAGES

- 1. Daily chances for showers and storms continue through Tuesday, with locally heavy rain possible tonight.

- 2. Relatively cool temps today and Tuesday, followed by a warming trend.

DISCUSSION

Key Message 1: Daily chances for showers and storms continue through Tuesday, with locally heavy rain possible tonight.

Radar shows on-going isentropic showers in the southeastern Midlands this evening as the cold front remains southwest of the CSRA, but PWAT's have already rebounded toward 1.90-2.0" along a line extending from Augusta to Orangeburg toward Manning. This comes in response to as shortwave currently dropping into the southern Tennessee Valley. PWAT's north of the aforementioned line should continue to raise toward 1.75-1.90" and lingering 300-305K isentropic lift coupled with PVA from the shortwave are expected to yield additional shower/weak storm activity tonight into early Monday. With the FA being north of the front, instability is forecast to be fairly meager (MUCAPE under 700 J/kg), but deep moisture/warm cloud layer depths should yield efficient warm rain processes in any activity overnight tonight. This efficient rainfall could yield isolated spots of flash flooding once again. CAM guidance has been wobbling a bit in terms of where the highest chance for isolated spots of flash flooding is, but currently favor areas in between the I-20 and I-95 corridor. This axis may still wobble a bit more heading into tonight.

The frontal boundary is then expected to waver some tomorrow and Tuesday before a sharper trough digs through the eastern US, aiding in pushing the front out of the area. With this front in place, rain chances continue through Tuesday, but PWATs are expected to be lower than they have been, so the flooding threat decreases after today. Then, mainly dry weather is forecast for the rest of the week.

Key Message 2: Relatively cool temps today and Tuesday, followed by a warming trend.

Temperatures today remain well below normal for much of the area, with most locations in the mid to upper 60s at this time. Only a few locations have reached the 70s so far. Therefore, have lowered high temps for today to generally the mid 70s. As the frontal boundary wavers north tomorrow, then south again for tomorrow night into Tuesday, temps rebound for tomorrow to near normal before dropping again on Tuesday. After Tuesday, a gradual warming trend is anticipated the rest of the week.

AVIATION /02Z MONDAY THROUGH FRIDAY/

Low Ceilings and Scattered Showers Tonight....

MVFR ceilings continue at the terminals this evening, with scattered showers passing through the region. With lingering low level moisture and a front remaining in the area, rain showers will continue into the overnight hours, perhaps increasing in coverage towards daybreak. Ceilings are expected to lower further tonight, especially at AGS/DNL, with some improvement Monday morning. Showers and thunderstorms are possible Monday afternoon and evening and VCTS has been added to the TAFs from 21-23Z to account for this potential, though exact timing and location of the convection remains unclear.

EXTENDED AVIATION OUTLOOK...Restrictions possible into Tuesday, then drier air could begin to move into the region mid-week.

CAE WATCHES/WARNINGS/ADVISORIES

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