textproduct: Columbia

WHAT HAS CHANGED

Aviation discussion updated for 12z TAFs.

KEY MESSAGES

- 1. Dry conditions with above normal temperatures are expected through Friday.

- 2. Rain chances may enter late in the week through this weekend.

DISCUSSION

KEY MESSAGE 1: Dry conditions with above normal temperatures are expected through Friday.

Upper-level ridging will continue to build over the next few days. At the surface, high pressure is expected to shift offshore through the middle of the week, allowing for a gradual return of southerly flow and increasing moisture across the Carolinas by Thursday and Friday. Overall, this pattern will support daily high temperatures in the upper 80s to low 90s through at least Friday, with mostly dry conditions continuing. Dewpoints previously in the 50s will build into the mid 60s through Friday and may approach the upper 60s to low 70s by the weekend.

KEY MESSAGE 2: Rain chances may enter late in the week through this weekend.

There remains some uncertainty regarding how quickly a broad trough shifts into the Northeast later this week. At the surface, a cold front will approach the region and could stall nearby before a shortwave eventually pushes the front through by early next week. This is evident in a wide spread of high temperatures Sunday into Monday. Long range guidance has continued to trend toward a slower arrival of the front, with the global deterministic models continuing to hold off on widespread rainfall until Saturday evening into Sunday. In the meantime, isolated to scattered showers and storms will be possible starting Friday and into the weekend as LREF probabilities for PWATs greater than 2" reach 50-70% amid subtle forcing. Trends are showing rain of at least an inch are likely (40-60%). Exact totals are uncertain due to inconsistent model trends. The heaviest rain appears to be Sunday evening into Monday when the shortwave moves through. However, the exact timing this weekend still remains uncertain regarding the trough, but increasing rain chances should bring temperatures back closer to normal. Ensemble guidance also hints at additional rain chances continuing into early next week, potentially brining another period of damp, cloudy, and cool conditions to the FA. Otherwise, with a strong area of high- pressure building over New England next week, more fall-like weather returns behind the cold front.

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/

VFR conditions expected through the forecast period except for morning fog/stratus the next few days.

High pressure continues to provide quiet weather under mostly clear skies. Light to calm winds combined with some increase in low level moisture and light southeasterly flow off the Atlantic has resulted in a large area of stratus clouds across the eastern Midlands and across eastern GA. This resulted in periodic LIFR cigs at AGS/DNL/OGB and may linger through 13z or so. Winds should pick up by 15z to around 5 knots or so from the southeast with only a few fair weather cumulus clouds and possible afternoon cirrus. As the surface high shifts offshore, more southeasterly flow expected overnight above the surface and guidance is suggesting another round of stratus and possible fog developing after 08z along the Coastal Plain and spreading inland favoring the CSRA and eastern Midlands.

EXTENDED AVIATION OUTLOOK...Restrictions in stratus/fog appear more likely Thursday morning with increasing low level moisture. Increasing chances of precipitation this weekend may lead to additional restrictions.

CAE WATCHES/WARNINGS/ADVISORIES

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