textproduct: Columbia

WHAT HAS CHANGED

Minimal changes to latest forecasting trends. Aviation discussion updated for 18z TAFs.

KEY MESSAGES

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

Upper ridging will strengthen across the area as the low off the northeastern coast tracks further away from the region. At the surface, high pressure will slowly move off the coast through mid- week. The surface wind pattern shifts to more southerly as the surface high moves east. This pattern will bring temperatures back up above normal through Friday, with afternoon highs back up into the upper 80s to around 90. Moisture will slowly increase through the end of the week. However with the upper ridge across the area, and the moisture still somewhat shallow, conditions should remain dry for the work week.

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

As we get into the weekend, an approaching upper trough will weaken the upper ridge. As this occurs, moisture will continue to increase, and should eventually be deep enough to begin bringing rain chances back across the region this weekend. Pwat values appear to rise to over 1.75 inches into Saturday. Shortwave energy moving through the approaching upper tough is expected to spark diurnal rain/storms along an approaching surface front through the weekend. Behind the front for early next week, temperatures drop back down below normal.

AVIATION /18Z MONDAY THROUGH FRIDAY/

VFR conditions will continue through the valid TAF period. A dry airmass with high pressure located to the north will continue to keep VFR conditions through the next 24 hours at all TAF sites. Only a few passing cirrus overhead are expected, otherwise SKC. Winds will generally be light and variable through this evening, then fall calm tonight at all sites except DNL, where light winds have persisted the past couple of nights. Although MOS and LAMP guidance hint at some patchy ground fog possible at fog-prone AGS around sunrise, dew point depressions of 3-5 C will largely prevent formation, and any fog that does form will be shallow and patchy enough to not result in vis restrictions. Expect light and variable winds to return by Tuesday mid to late morning.

EXTENDED AVIATION OUTLOOK...Mostly VFR in the extended with increasing moisture by the end of the week.

CAE WATCHES/WARNINGS/ADVISORIES

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