textproduct: Columbia

WHAT HAS CHANGED

Minimal change to Key Messages. Aviation discussion updated for 00z TAFs.

KEY MESSAGES

- 1. High pressure and drier air builds in tonight followed by cool temps into mid-week before a warming and wetter pattern develops into the weekend.

DISCUSSION

Key Message 1: High pressure and drier air builds in tonight followed by cool temps into mid-week before a warming and wetter pattern develops into the weekend.

Surface ridging builds into the region Tuesday with PWAT's dropping to around 0.50 inches as this drier surface high pressure builds into the Mid Atlantic. Persistent northeasterly low level flow into the mid week should keep temperatures near to just below normal with lower humidity and dry weather expected. Weak surface ridging is expected to continue into the late week along with some building heights and temps returning to near-above average.

The weekend is looking more active as moisture returns across the region as deep southwesterly develops. There could end up being some tropical connection within this flow with NHC now outlooking the southern gulf with a 70% chance of development. This will be the key component to whether we see appreciable rain with this setup. Without any tropical component, a broad surface ridge will build and allow for widespread but weak overrunning with no notable synoptic forcing (not dissimilar to last weekend) and therefore a generally low QPF setup. With a tropical-synoptic shortwave to help drive both enhancement of PWAT's and omega, then we could see a notable rain event given the frontal boundary & overrunning favorability in place. Guidance is a mess of solutions at this point and until a steady state surface low develops in the gulf, uncertainty will remain very high.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

VFR conditions prevail through the TAF period.

With rain ended and well east of the terminals, low clouds have generally diminished and mainly high clouds remain over the area. Clearing of these high clouds from west to east is expected over the next several hours as drier air continues to move into the region. Winds should remain light out of the northeast the remainder of the night before increasing Tuesday morning to around 10 kts. A few higher gusts nearing 18-20 kts are also possible through the day Tuesday as a bit more of an easterly component develops. Cannot rule out some brief stratus or patchy fog around sunrise Tuesday as guidance has been inconsistent, but it will depend on how fast the drier air moves in compared to clearing of high clouds. For now, have left the TAFs VFR but trends will be monitored.

EXTENDED AVIATION OUTLOOK...VFR conditions are expected into the mid to late week with drier air in place.

CAE WATCHES/WARNINGS/ADVISORIES

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