textproduct: Columbia

WHAT HAS CHANGED

Aviation discussion updated for 12z TAF issuance.

KEY MESSAGES

- 1. Gradually warming temperatures through Friday. Rain chances increase Thursday and into the weekend.

DISCUSSION

KEY MESSAGE 1: Gradually warming temperatures through Friday. Rain chances increase Thursday and into the weekend.

Surface high pressure continues moving offshore today, which will combine with strengthening upper ridging to produce gradually warming temperatures through Friday. Fortunately it looks like most, if not all, of our CWA should see another dry day with forecast highs in the upper 80s to lower 90s. Temperatures Thursday and Friday should warm into the lower to mid 90s. Increasing heat and humidity will likely push heat index values above 100 degrees during peak heating but still below Heat Advisory criteria. Moisture will slowly return to the region, increasing rain chances during the late week period. Scattered showers and thunderstorms will be possible Thursday, although forecast soundings indicate continued capping aloft which may restrict convection to the Coastal Plain, sparing much of our FA. This changes Friday and into the weekend when a weakness in the ridge and higher PWATs favor more widespread convection, though the severe threat appears low at this time.

AVIATION /10Z WEDNESDAY THROUGH SUNDAY/

VFR conditions generally expected through the 24hr forecast period although predawn fog/stratus possible Thursday.

Upper ridge continues to expand east into the southeastern states with a drier air mass in place. Satellite imagery showing only some thin high clouds across the area although some stratus has developed across southeast GA. The surface ridge axis will shift more offshore today allowing for easterly flow off the Atlantic which should support SCT-BKN stratocumulus favoring OGB/AGS/DNL, although cigs expected to remain VFR. Cannot rule out an isolated shower late afternoon but confidence is low at this time so will not include in this forecast. Light and variable winds should pick up from the east around 7 to 10 knots by 15z then diminish again around sunset. Some mixed signals in hi-res guidance for the end of the forecast period hinting at some fog/stratus development after 08z. Did not include restrictions with this forecast but if the trends continue later forecasts may need to include restrictions early Thursday morning.

EXTENDED AVIATION OUTLOOK...Diurnal storm chances return in the later part of the week and increasing chances of morning fog/stratus concerns with increasing atmospheric moisture.

CAE WATCHES/WARNINGS/ADVISORIES

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