textproduct: Columbia

WHAT HAS CHANGED

Aviation discussion updated for 12z 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.

Shower and thunderstorm chances increase this afternoon and evening as a cold front approaches the region. The latest SPC Outlook for today places much of the area in a Marginal (1/5) risk for severe weather, with a Slight (2/5) risk extending into the northern portions of the FA. Damaging wind gusts would be the primary hazard in stronger storms, although locally heavy rainfall and isolated flooding will also be possible given anomalously high PWATs and long skinny CAPE profiles.

CAM guidance continues to show uncertainty regarding the timing and coverage of convection ahead of the front. Confidence in the severe threat east of the Appalachians remains somewhat low, as storms may not arrive until after peak heating and could weaken through the evening hours. Highest probabilities remain along and north of I-20, with the greatest threat across the Pee Dee and far northmen Midlands Breezy conditions are expected ahead of the front as the pressure gradient tightens and stronger winds aloft mix down to the surface. The greatest potential for showers and thunderstorms appears to be from late afternoon until around midnight.

Typical summertime conditions persist through much of the week, featuring hot and humid weather with isolated afternoon and evening convection. Brief ridging develops Wednesday before another shortwave weakness it. A surge of moisture increases on Thursday and Friday leading to higher rain chances. Ridging returns and strengthens into the upcoming weekend pushing temperatures well into the 90s, with some global models suggesting upper 90s possible early next week.

AVIATION /12Z MONDAY THROUGH FRIDAY/

Early morning restrictions from fog and stratus possible with a chance of thunderstorms this afternoon.

Winds will pick up out of the SW shortly after sunrise with speeds between 5 to 8 kts, then strengthen to around 10 kts with gusts to 20 kts after 16Z. As a front moves into the Southeast, showers and thunderstorms are expected to develop to our west. It is possible that we see these storms move into the forecast area in the late afternoon and overnight hours. PROB30 added for potential thunderstorms late in the TAF period. Gusts will subside by 03Z this evening but remaining mixing and potential convective debris clouds tonight should limit the threat of fog.

EXTENDED AVIATION OUTLOOK...For the remainder of the week, diurnally-driven widely scattered convection is expected.

CAE WATCHES/WARNINGS/ADVISORIES

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