textproduct: Columbia

WHAT HAS CHANGED

Rain chances tonight into Thursday remain very low. Aviation discussion updated for the 06z TAF issuance.

KEY MESSAGES

- 1. A front will bring breezy winds Thursday and frost/freeze potential late this week into the weekend.

DISCUSSION

Key Message 1: A front will bring breezy winds Thursday and frost/freeze potential late this week into the weekend

The forecast the remainder of the week remains on track. The southern stream shortwave is noted in WV imagery across the Ark- La-Tex region with the northern wave further off to the northwest, in the Northern Plains. These waves are expected to remain out of phase with the southern most shortwave moving in later this evening and overnight before the deepening northern one shifts through the region Thursday and Friday. This offset in forcing brings limited moisture advection (PWAT's under 1") ahead of a cold front tonight into Thursday morning despite a 35-40 kt LLJ. Due to this, deterministic CAMs and LREF Cluster Analysis keeps chances for measurable precip quite low with the latter showing less than 20% PoP's in each cluster. Overall, cannot rule out a stray shower developing, but chances are quite low. As the front moves through early Thursday, a tightening pressure gradient develops with a surface low shifting into the Mid-Atlantic. As mentioned above, a robust 35-40 kt LLJ is expected to develop overnight tonight into Thursday, but soundings indicate a strong inversion should prevent this from mixing down until late Thursday morning. Once the inversion breaks, BUFKIT soundings indicate westerly gusts to 25-35 mph should begin mixing down, possibly necessitating a Lake Wind Advisory through the day before conditions improve overnight into Friday.

A secondary front is expected to move in late Thursday into early Friday morning, bringing much drier air and a push of CAA that is expected to influence temperatures through early next week. In general, the two frontal passages are expected to yield temperatures that cool the remainder of the week with temperatures Thursday remaining in the low to mid 70s before dropping into the upper 50s to low 60s Friday and finally the mid to upper 50s this weekend into early next week. As has been advertised, this northwesterly flow regime and the associated CAA favors frost potential Saturday and Monday mornings and a possible freeze Sunday morning. NBM probabilities for low temperatures less than 32F Sunday morning remain around 25-50% across the area, highest in the northern Midlands while probabilities for low temperatures less than 35F are up to 50-70% Saturday, Sunday, and Monday mornings. The need for frost/freeze products this weekend and early next week will continue to be monitored.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/

Generally VFR conditions expected through the period.

Mostly clear this evening with some passing high clouds, which is currently moving in from the west. A slight increase in coverage to SCT by the afternoon and evening. Much like the past few mornings, some fog near rivers is possible again around daybreak Wednesday morning where AGS is most likely to be affected. Have maintained the TEMPO for brief VSBY IFR restrictions. Otherwise, light and variable to calm winds overnight becoming WLY/SWLY late Wednesday morning around 5-10 kts.

Near the end of the period, a low-level jet is expected with increasing winds a mile above the surface over a low-level inversion. A wind shear group may be needed in the 12Z TAF update to account for LLWS between 06-12Z.

EXTENDED AVIATION OUTLOOK...Dry air will likely prevent widespread restrictions through the extended with moisture increasing ahead of an approaching frontal boundary on Thursday.

CAE WATCHES/WARNINGS/ADVISORIES

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