textproduct: Charleston

WHAT HAS CHANGED

KEY MESSAGE 1 has been updated for latest trends. The Aviation Section has been updated for the 00Z TAF issuance.

KEY MESSAGES

- 1) Isolated strong thunderstorm possible early evening.

- 2) Unsettled weather is expected from Wednesday into the weekend, with daily chances for showers and thunderstorms and the potential for locally heavy rainfall.

DISCUSSION

KEY MESSAGE 1: Isolated strong thunderstorm possible early evening.

Deep moisture remains while a stationary front is draped over the Southeast. Best chances for storms continue to be across inland Georgia during early evening hours, where boundary collisions and cell mergers occur. An isolated strong thunderstorm remains possible with damaging wind gusts. However, this concern will continue to lower with the loss of diurnal heating. PWATS remain high (1.7 to 2.0 inches) across inland Georgia, and could continue to support minor flooding concerns through early evening, before convection wanes by mid-late evening.

KEY MESSAGE 2: Unsettled weather is expected from Wednesday into the weekend, with daily chances for showers and thunderstorms and the potential for locally heavy rainfall.

An upper-level trough will remain positioned across the Ohio River Valley with a series of shortwaves moving through the region through the end of the week. At the surface, a stationary front will linger across the Southeast before a cold front approaches this weekend. This pattern will provide repeated sources of lift, while abundant atmospheric moisture, with PWAT values near or slightly above 2 inches, well above normal for late August, will support efficient rainfall production. As a result, showers and thunderstorms will be possible each day, with most guidance suggesting convection will be scattered to numerous in coverage. However, confidence in the exact location and timing of storms remains relatively low.

An isolated storm could become strong to severe, with damaging wind gusts possible. The primary concern, however, will be locally heavy rainfall. The stationary front draped over the area could result in slow-moving storms or repeatedly track over the same areas. These processes can produce locally high rainfall totals in a short period of time, increasing the potential for localized flooding or flash flooding, particularly in urban and low-lying areas.

AVIATION /00Z WEDNESDAY THROUGH SUNDAY/

VFR conditions should prevail at CHS/JZI/SAV through at least 16Z Wednesday, although TEMPO MVFR cigs are possible at JZI between 00-02Z this evening. PROB30 groups have been introduced at all terminals Wednesday afternoon for thunderstorm and MVFR potential, between 17-21Z at JZI, and 18-23Z at CHS/SAV.

Extended Aviation Outlook: Daily chances for showers and thunderstorms will continue through the weekend, with storms potentially producing temporary flight restrictions, reduced visibility, gusty winds, and brief periods of heavier rainfall each afternoon.

MARINE

Through Tonight: Easterly winds will shift southerly later this evening. Wave heights are forecast to remain between 2 to 3 ft.

Wednesday through Sunday: South/southwesterly winds will continue through the period, with winds averaging 15 knots or less. Small Craft Advisories are not expected during the period at this time. However, any showers or thunderstorms that develop over or move across the waters could produce locally strong wind gusts, frequent lightning, and/or briefly higher seas.

CHS WATCHES/WARNINGS/ADVISORIES

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