textproduct: Columbia

WHAT HAS CHANGED

A few stronger storms possible late tonight into early tomorrow morning. Aviation discussion updated for the 06z TAF issuance.

KEY MESSAGES

- 1. Showers are expected through Friday with a few thunderstorms also possible today and Friday.

DISCUSSION

Key Message 1: Showers are expected through Friday with a few thunderstorms also possible today and Friday.

An upper trough over the Great Plains is beginning to phase with an upper low and trough currently over the central CONUS. The leading edge of this trough is inching its way over the Southeast early this morning. An embedded shortwave is sparking a few showers and storms in the CSRA and western Midlands. Expect this activity to decrease through the early morning hours as the shortwave moves through and away from the area.

A nearly stationary surface front is draped over the Blue Ridge this morning. The front is expected to inch eastward for much of the day today until the aforementioned upper troughs fully phase and help to push the front eastward later today and through the area late tonight into Friday morning. As the front approaches later today, some scattered showers and storms are anticipated to redevelop during the afternoon. Overnight as the front begins to move through the forecast area, additional development of showers and storms are expected. The HRRR deterministic model and REFS ensemble both show some instability exceeding 500 J/kg and 0-6 km shear in the 20-30 kt range. This could lead to a stronger storm or two overnight tonight into the early morning hours Friday, with gusty winds being the main threat with any stronger storms. Activity is forecast to push east of the area by midday or so as the front moves through. Dry, cool air then filters into the area Friday afternoon and remains in place through the weekend.

Latest rainfall amounts continue to remain relatively steady this morning. NBM QMD probabilities of one half an inch through Friday morning continue to be around 40 to 60 percent for areas north and west of I-20. Some locally higher amounts are possible with thunderstorms.

AVIATION /06Z THURSDAY THROUGH MONDAY/

Mix of MVFR/IFR conditions expected through Thursday morning with some possible showers as well throughout the TAF period

Some scattered showers continue across the area with notable moisture in place across the region. MVFR/IFR cigs expected after 09z through around 16z with fairly high confidence in periods of IFR or LIFR between 11-14z. There could be some vsby restrictions also within scattered showers and potential drizzle. Winds overnight should be around 5 knots or less from the east to southeast then pick up to around 7 to 9 knots and shift more southerly after 15z as the front moves toward the region. A few showers are possible again Thursday afternoon into overnight, but confidence is low for a TAF mention yet.

EXTENDED AVIATION OUTLOOK...Increasing chances for rain particularly again Friday may lead to some lower CIGS or VSBY restrictions. Conditions should improve over the weekend.

CAE WATCHES/WARNINGS/ADVISORIES

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