textproduct: Columbia

WHAT HAS CHANGED

Updated Key Message 1 to remove mention of daytime current conditions. Otherwise no changes to Key Messages. Aviation discussion updated for 00z TAFs.

KEY MESSAGES

- 1. Dry, warm weather favored through the week.

- 2. A strong cold front is forecast to push through the region Friday night, ushering in cooler Autumnal 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 should reach the upper-80s to near 90 degrees through Friday with lows in the mid-50s to low-60s. High temperatures will be near record territory as normal highs are in the upper-70s. 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 Autumnal weather this weekend.

Guidance remains in good agreement that a strong cold front will sweep across the Southeast heading into this weekend, ushering in a much cooler and drier Autumn 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. This will occur in conjunction with a strong, anomalous surface high pressure pushing out of the upper Midwest and into the Mid- Atlantic by this weekend. With a stout cap and practically no CAPE present, this will a relatively dry front with little to no deep convection and only sprinkles possible late Friday and into Saturday morning. Spread in timing of the guidance continues to narrow down to arrival on Friday night. Breezy northwesterly winds are expected following the frontal passage Friday night into Saturday. Decent mixing should allow max gusts of 25-35 mph behind the front, which may pose future advisories for local lakes.

Guidance is tightly clustered for highs and lows this weekend into early next week. After several days of near-record highs, a dramatic 20-25 F temperature drop is expected behind the front. Well-below normal high temps in the 60s F are on tap for Saturday and Sunday, bumping back up into the low to mid 70s F by early next week. Chilly overnight lows due to lower dew points will allow for lows to fall into 40s F this weekend. A few protected areas in northern counties closer to the NC border may fall into the upper 30s F, but confidence is too low to note any potential for frost in these areas quite just yet.

AVIATION /00Z THURSDAY THROUGH MONDAY/

VFR 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 low visibilities. 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.