textproduct: Columbia

WHAT HAS CHANGED

Increased rain chances this morning while decreasing them this afternoon based on recent guidance. Updated aviation discussion for 12z TAFs.

KEY MESSAGES

- 1. Rain chances decrease this afternoon.

- 2. Confidence increasing in moderate rainfall for portions of the forecast area Friday night and Saturday.

DISCUSSION

Key Message 1: Rain chances decrease this afternoon.

Early morning convection continues to weaken and move out of the forecast area this morning. Much needed rainfall occurred across much of the area with many locations receiving a quarter to a half inch of rain. A shortwave that was driving this convection is crossing the region now and subsidence in the wake of this should keep things relatively quiet this afternoon with only isolated showers or a thunderstorm.

Key Message 2: Confidence increasing in moderate rainfall for portions of the forecast area Friday night and Saturday.

Chances of the most significant rainfall we have seen in a while continue to look pretty good for Friday night into Saturday. Northern stream energy digging into the upper Midwest is expected to phase with southern stream energy moving across the southern Plains into the MS Valley on Friday before swinging through the Carolinas and off the Mid-Atlantic coast Saturday night. This will induce low pressure development along the Gulf Coast which then lifts northeastward off the Carolina coast on Saturday. While it appears the heaviest rainfall and highest totals likely remain south of our area, there should be reasonable chances for much needed rainfall with NAEFS IVT above the 97th percentile. The CSRA and southeast Midlands are more favored for highest rainfall given a gradient in PWATs with higher values from north to south. There is little instability available with this system as it looks like an overrunning event with the surface low to our southeast. LREF Probabilities for 24hr rainfall amounts greater than 0.5 inches are in the 50-75 percent range for Friday night through Saturday and probabilities of greater than 1 inch are near 50 percent in the southeast Midlands. 48hr QPF from the NBM is a bit more bullish with precipitation with the 50th percentile showing much of the forecast area receiving at least one inch of rainfall.

AVIATION /13Z THURSDAY THROUGH MONDAY/

Mix of restrictions expected this morning and early this afternoon before VFR conditions are likely into Friday.

Any lingering thunderstorms or notable heavy rain has pushed east of the terminals as of 14z. Some lingering showers continue along with some lower MVFR or IFR cigs over the next couple hours. Cigs lift to VFR by early afternoon for all TAF sites along with some northerly surface winds 5-10 knots. A few isolated showers or storms are possible this afternoon but widespread coverage is not expected. Low level moisture should yield some stratus early Friday morning, primarily MVFR but IFR for a period is possible.

EXTENDED AVIATION OUTLOOK...Periods of restrictions will be possible again early Friday morning, but higher confidence comes Friday night into Saturday as widespread rain is expected to overspread the region. Drier conditions then are expected Sunday and into the early week.

CAE WATCHES/WARNINGS/ADVISORIES

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