textproduct: Columbia

WHAT HAS CHANGED

Guidance showing increasing potential for spotty showers with the cold front this weekend. Aviation discussion updated for 12z TAFs.

KEY MESSAGES

- 1. Near-record warmth through Friday.

- 2. A strong cold front is forecast to push through the region Friday night, ushering in cooler weather this weekend.

DISCUSSION

Key Message 1: Near-record warmth through Friday.

Southerly to southwesterly flow will continue to promote warm air transport into the region through Friday. An upper-level ridge sits over the southeast with the LREF and NAEFS both showing 500mb heights at the 99th percentile. Highs are expected to climb into the upper 80s to near 90 degrees through Friday, potentially approaching record levels each day. Clear skies will promote efficient radiational cooling each night, allowing lows to drop into the mid-50s to low 60s. PWATs are generally around average for this time of year as dry conditions persist leading to minimal humidity and no heat indices.

Key Message 2: A strong cold front is forecast to push through the region Friday night, ushering in cooler weather this weekend.

Guidance remains in good agreement that a strong cold front will sweep across the Southeast this weekend, ushering in a much cooler and drier airmass. A developing trough currently over the Canadian Prairies will dig southeastward and deepen across the central US over the next 2 days, pushing the front eastward along with it. Latest models have started to trend to a solution showing more energy and activity impacting the Eastern US, rather than a dry frontal passage previously discussed. In particular, guidance hints at the trough popping off a potential coastal storm later this weekend. With this in mind, rain chances could increase as trends have shifted toward a more robust area of energy closer to the Carolinas. However, significant cold air advection could still limit the shower development across the FA. Enhanced winds are possible behind the front, with decent mixing potentially supporting peak gusts of 25-35 mph.

Following several days of near-record highs, a dramatic temperature drop of 20-25F is expected behind the front. Well- below normal highs in the 60s are anticipated Saturday and Sunday, with temperatures rebounding a bit into the low to mid-70s by next week. However, if this system continues to linger offshore, any significant warmup could be delayed as cooler air will continue to funnel into the region. Chilly overnight temps are also expected this weekend as lower dew points promote efficient cooling, allowing lows to drop into the 40s. A few sheltered locations across the northern counties near the North Carolina border could dip into the upper 30s, though confidence at this time is too low to mention any potential frost.

AVIATION /12Z THURSDAY THROUGH MONDAY/

VFR expected outside of potential early morning patchy fog.

High pressure and upper ridging will continue to promote VFR conditions at the terminals over the next twenty-four hours. However, similar to previous days, some brief sunrise morning fog at our fog-prone sites of AGS/OGB is possible and along the rivers. A TEMPO group has been added between 9-12z for potential mifg and lowered vsby. More of the same continues on Thursday as light winds and clear/dry conditions continue with winds generally out of the southwest, but varying from south to west.

EXTENDED AVIATION OUTLOOK...A front will move across the area late Friday into Saturday. Although precipitation is unlikely, breezy W/SW winds are expected Friday shifting to a northerly direction on Saturday.

CAE WATCHES/WARNINGS/ADVISORIES

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