textproduct: Columbia

WHAT HAS CHANGED

Refreshed Key Message 1 and added more details on the potential for hazardous weather on Monday. Aviation discussion updated for 18z TAFs.

KEY MESSAGES

- 1. A more typical summer-like pattern expected this week.

DISCUSSION

Key Message 1: A more typical summer-like pattern expected this week.

Midday temperatures are in the 80s across the FA, on track to reach the lower 90s in most locations this afternoon. The increase in moisture is evident with higher dewpoints and widespread scattered cumulus. While showers have been focused in the Coastal Plain thus far today, isolated showers and thunderstorms are possible, mainly across the Southern Midlands and CSRA.

Rain chances are higher on Monday as a cold front approaches the region. The latest Day 2 SPC SWO places much of the CWA in a Marginal (1/5) risk for severe weather, with a Slight (2/5) risk grazing the northern part of the FA. Should thunderstorms become severe, damaging wind gusts will be the primary severe hazard. With anomalously high PWATs and long skinny CAPE profiles appearing in modeled soundings there will also be the potential for localized flash flooding from any thunderstorms that develop.

A series of weak, mid-level disturbances will move across through much of the upcoming week. At the surface, high pressure settles over the eastern Gulf and western Atlantic with weak boundaries passing just north of our area. This pattern is typical for June, with fronts struggling to reach the region. As a result, expect summerlike weather to dominate with hot and humid conditions accompanied by isolated afternoon and evening showers and thunderstorms.

Late next week, a stronger upper-level ridge is forecast to build over the Four Corners, promoting broader troughing across the eastern CONUS. This pattern may support a more organized weather system affecting the area, though confidence remains low regarding timing and evolution.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

VFR conditions still expected through the TAF period.

Some thin cirrus along with afternoon mid-level vfr scattered cumulus field should be the primary clouds through the early evening hours at all sites. Visible satellite imagery this afternoon does show an area of low pressure spinning in the cumulus fields across west-central Georgia, and this will continue to track off to the east through this evening. Although most areas will remain dry as this low moves east, a few convective models do show there remains the potential for an isolated shower or thunderstorm to develop, especially across ags/dnl/aik/ogb where moisture is a little deeper. Confidence is not high enough to place in the taf at this time, but it will be monitored. Towards sunset, expecting the cumulus field to dissipate along with any rainfall, with only the cirrus overnight. Additional rainfall may become possible near the end of the taf period ahead of the next upper low and surface trough.

Southerly winds at most sites this afternoon turning light and variable by sunset. By 13z Monday morning, winds are expected to begin increasing to between 5-10 knots. By late morning sustained winds will top 10 knots, with wind gusts upwards of 20 knots possible at all sites as the pressure gradient tightens and winds aloft begin to strengthen.

EXTENDED AVIATION OUTLOOK...A strong line of thunderstorms could move through the forecast area late Monday afternoon or evening. For the remainder of the week, diurnally-driven widely scattered convection is expected.

CAE WATCHES/WARNINGS/ADVISORIES

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