textproduct: Columbia

WHAT HAS CHANGED

Key Messages 1 and 2 updated and Key Message 3 added. Aviation discussion updated for 18z TAF.

KEY MESSAGES

- 1) Breezy and very warm through Friday.

- 2) Chance of rain on Friday with higher chances on Saturday.

- 3) Cold and dry conditions develop early next week.

DISCUSSION

KEY MESSAGE #1: Breezy and very warm through Friday.

Partial sunshine has developed across much of the forecast area this afternoon allowing temperatures, aided by breezy southwesterly flow, to climb into the 60s and lower 70s. Breezy and anomalously warm conditions are expected to continue through the remainder of the work week with today expected to have the strongest winds. A Lake Wind Advisory remains in effect until 7pm this evening to account for gusts up to 30 mph on area lakes, which has been confirmed by area webcams and surface observations. Winds appear to be lower on Thursday but the pressure gradient will increase once again on Friday as the next storm system moves into the region. The warming trend peaks on Friday, despite partly to mostly cloudy skies and a chance for rain, with highs in the upper 70s to lower 80s.

KEY MESSAGE #2: Chance of rain on Friday with higher chances on Saturday.

Latest guidance continues to support several periods of rain moving through the region Friday and Saturday, with improving conditions on Sunday. The first chance for rain comes on Friday as a cold front moves in from the north and west but should stall near/over the FA. The NBM continues to be aggressive with precipitation chances, so opted to cap PoPs in the Chance category since the best dynamic support passes to the north. The upper pattern diverges significantly this weekend but it appears that Saturday will be the best day for significant rainfall as an area of low pressure develops along the stalled frontal boundary. The deterministic guidance differs on the timing of the heaviest rainfall with the Euro favoring late Saturday into Saturday evening and the GFS suggesting Saturday night into Sunday morning. A few thunderstorms cannot be ruled out this weekend, but the chance for severe weather is low at this time. The rain should end from west to east on Sunday with improving conditions possible Sunday afternoon and evening.

KEY MESSAGE #3: Cold and dry conditions develop early next week.

A potent upper trough is expected to dominate the weather across the Eastern CONUS early next week. At the surface, a cold and dry air mass will move in behind the departing weekend system with below normal temperatures favored. Monday looks to be the coldest day of the next seven follow by a gradual warm up towards the middle of next week. Monday may also be breezy due to a tight pressure gradient but winds should be lighter Tuesday and Wednesday as surface high pressure moves in from the west.

CAE WATCHES/WARNINGS/ADVISORIES

SC...Lake Wind Advisory until 7 PM EST this evening for SCZ016-018- 020>022-025>031-035-037-038-041-115-116-135>137. GA...Lake Wind Advisory until 7 PM EST this evening for GAZ040- 063>065-077.