textproduct: Columbia

WHAT HAS CHANGED

Minimal change to Key Message 1. Aviation discussion updated for 18z TAFs.

KEY MESSAGES

- 1. After a cold front moves through today, a more typical summer-like pattern returns this weekend into next week.

DISCUSSION

Key Message 1: After a cold front moves through today, a more typical summer-like pattern returns this weekend into next week.

The remnant low level circulation that once was Arthur can be seen on satellite imagery this afternoon pushing off the NC coast with its upper wave also departing. Latest surface analysis shows a cold front pushing into the Upstate and toward the Pee Dee with the air mass ahead of it maintaining deep moisture and surface dewpoints in the low to mid 70s. This is yielding MLCAPE values between 1000-1500 J/kg, but with the departing surface low and upper wave deep layer shear is down to around 20-25kts. As heating of the airmass continues ahead of the front, isolated to scattered convection is expected to develop this afternoon into the early evening hours. An isolated storm on the stronger side cannot be ruled out with DCAPE values approaching 700-900 J/kg, but widespread severe weather is not anticipated. Slightly drier air moves in behind the front into Saturday with mostly dry conditions expected. Low level moisture is expected to recover Sunday as a weak upper disturbance moves through, bringing diurnal rain chances back. Temperatures this weekend are expected to remain near normal in the upper 80s to low 90s.

There is decent agreement amongst global models that multiple weak disturbances are progged to move through mainly zonal flow into the mid week, bringing diurnal shower/storm chances each day and temperatures in the low to mid 90s. A robust upper ridge is expected to build across the Four Corners region late this week, bringing a troughing pattern toward eastern CONUS where a more amplified system may be able to sneak into the FA, but there remains considerable spread on timing.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

VFR conditions expected through the TAF period.

Low pressure is departing the area with widespread showers and storms well to the south of the terminals early this afternoon. A front will move into the area later this afternoon into evening and while isolated storms will be possible along it, storm coverage will likely be east of all the terminals. Winds remain generally out of the west with gusts into the teens subsiding later this afternoon, becoming mostly light and variable tonight. With low level drier air filtering into the area, expect VFR conditions to continue tonight.

EXTENDED AVIATION OUTLOOK...Diurnally driven convection to return Sunday, although coverage will be isolated with higher coverage expected next week.

CAE WATCHES/WARNINGS/ADVISORIES

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