textproduct: Columbia

WHAT HAS CHANGED

Updated current conditions. Aviation discussion updated for 00Z TAF issuance.

KEY MESSAGES

- 1. Daily shower and thunderstorm chances continue into the upcoming week, with localized flash flooding possible through Tuesday.

DISCUSSION

Key Message 1: Daily shower and thunderstorm chances continue into the upcoming week, with localized flash flooding possible through Tuesday.

Tonight: Additional showers and a few thunderstorms remain possible through midnight. There then looks to be a bit of a break in the action through the remainder of the overnight period. The main hazard with these evening storms remains the potential for bouts of heavy rainfall that may lead to isolated flash flooding.

The overall forecast hasn't changed too much. Southwest flow is expected to persist at least through the first half of the week with the synoptic pattern favoring ridging offshore and an upper low over the lower Mississippi Valley. NAEFS mean indicates PWATs remain around or above the 99th percentile through Tuesday, generally around 2". Heavy rain and isolated flash flooding will be possible with afternoon convection today and Tuesday. However, a strong trough digging south from the Pacific Northwest strengthens the ridging over our area which would limit forcing, particularly on Tuesday, limiting the flash flood threat for that day compared to previous forecasts. With moisture so high and moderate destabilization each afternoon, scattered storms are anticipated to develop. Storm coverage Wednesday through the end of the week may be a bit more limited as southwest flow weakens but isolated diurnal showers and storms remain possible. A front will approach the area next weekend with EC EFI signaling below average temperatures for the weekend with precipitation chances increasing.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

Isolated showers and thunderstorms continue through this evening with restrictions developing tonight.

Storm coverage should continue to diminish this evening and through the overnight period. However, any showers or storms at the terminals over the next several hours may produce heavy rainfall leading to reduced VSBYs and lower CIGs. Outside of periodic restrictions in precipitation, low level moisture will support lowering ceilings tonight with highest confidence in MVFR but possible IFR conditions as well. Scattered showers and storms likely once again tomorrow, although the most likely timing will be after 18z, though some earlier convection may occur near AGS/DNL. Outside of some gusty thunderstorm winds, surface windspeeds will remain less than 10 kts our of the south and southeast.

EXTENDED AVIATION OUTLOOK...Abundant low level moisture will bring morning restrictions from fog and/or low clouds. Scattered afternoon/evening showers and thunderstorms are possible each day.

CAE WATCHES/WARNINGS/ADVISORIES

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