textproduct: Columbia

WHAT HAS CHANGED

Aviation Discussion updated for 12z TAF issuance.

KEY MESSAGES

- 1. Frost Advisory in effect this morning before a Freeze Warning will be in effect late tonight into Sunday morning.

- 2. Below normal temperatures are expected to persist through early next week, moderating by mid next week.

DISCUSSION

Key Message 1: Frost Advisory in effect this morning before a Freeze Warning will be in effect late tonight into Sunday morning.

Temperatures across the area are dipping into the upper 30s to low 40s as skies clear and CAA pushes in. Winds remain around 4-7 kts, but a relaxing pressure gradient may allow winds to weaken slightly, aiding in bringing morning lows in the mid to upper 30s. Conditions into the morning hours should be conducive for patchy to scattered frost development, especially north of I-20, thus the Frost Advisory remains in effect until 8am this morning.

The main change in this forecast package was upgrading the Freeze Watch to a Freeze Warning tonight. Confidence is fairly high that widespread sub-freezing temperatures will be seen early Sunday as NBM probabilities reach above 70%. Strong radiational cooling conditions and persistent CAA set the stage for overnight lows that fall into the low 30s, but spots in the upper 20s will be possible. The Freeze Warning goes into effect 1 AM Sunday, continuing until 9 AM. Remember to protect the three P's in these conditions: People, Pets, Plants, and Pipes.

Key Message 2: Below normal temperatures are expected to persist through early next week, moderating by mid next week.

A chilly airmass likely remains over the region through early next week as surface high pressure centers just northwest of the CWA. This should keep afternoon high temperatures in the upper 50s to low 60s, and multiple nights with low temperatures dipping into the 30s. There is increasing confidence across global models that upper ridging should slowly glide overhead into the mid to late week, moderate temperatures a bit closer to normal. Unfortunately, there is little signal across guidance that meaningful rainfall will be possible through next week.

AVIATION /12Z SATURDAY THROUGH WEDNESDAY/

VFR conditions expected through the period with NW winds.

Dry air behind a cold front will continue to lead to VFR conditions with mostly clear skies at all terminals. Winds will remain out of the northwest through the period leading to one line TAFs for all sites. Winds generally remain between 5 to 10 knots through the period, a bit lighter early in the period and likely decreasing tonight, becoming light and variable.

EXTENDED AVIATION OUTLOOK...Dry air will likely prevent widespread restrictions through the extended.

CAE WATCHES/WARNINGS/ADVISORIES

SC...Frost Advisory until 8 AM EST this morning for SCZ016-018- 020>022-025>031-035-037-038-041-115-116-135>137. Freeze Warning from 1 AM to 9 AM EST Sunday for SCZ016-018- 020>022-025>031-035-037-038-041-115-116-135>137. GA...Frost Advisory until 8 AM EST this morning for GAZ040-063>065- 077. Freeze Warning from 1 AM to 9 AM EST Sunday for GAZ040-063>065- 077.