textproduct: Charleston

WHAT HAS CHANGED

The Aviation section was updated for the 00z TAF issuance.

KEY MESSAGES

- 1) Daily scattered showers and thunderstorms are expected through Thursday, with locally heavy rainfall possible. A wetter pattern may develop Friday into the weekend, increasing the potential for heavy rainfall and localized flooding.

DISCUSSION

KEY MESSAGE 1: Daily scattered showers and thunderstorms are expected through Thursday, with locally heavy rainfall possible. A wetter pattern may develop Friday into the weekend, increasing the potential for heavy rainfall and localized flooding.

A warm and moist airmass will remain in place through Thursday as deep moisture continues to advect northward along the western periphery of Atlantic high pressure. With PWATs generally around 2 inches and daily sea breeze development, scattered to numerous showers and thunderstorms are expected each afternoon and evening. While severe potential should remain limited, deeper convection could produce heavy downpours dropping a quick inch or two, and isolated minor flooding. However, impacts are expected to remain localized, with much of the rainfall beneficial given the ongoing drought conditions.

Rain chances will increase Friday through the weekend as a weak cold front drops south into Central South Carolina and Georgia Thursday night/Friday morning. It is then expected to stall in the vicinity through the majority of the weekend, with the potential for a weak surface low to develop along the front. This set up will yield a widespread pattern of showers and thunderstorms. Moisture convergence along the front will increase PWATS to around 2.0-2.2 inches Friday into Sunday morning. Several rounds of rainfall, which could be heavy at times, could lead to localized minor flooding, especially in areas that see repeated storms. Additionally, slow-moving storms could be common with speeds around 10-15 kt, especially Friday.

Current forecast guidance suggests widespread rainfall totals Friday through the weekend around 2 to 4 inches, with locally higher amounts. Latest NBM shows a 15-30% probability of 3 inches of rain or greater falling over a 72-hour period between Friday and Monday morning, with the highest chances located across southeast Georgia and along the immediate coast. While confidence is increasing in a wetter pattern later this week and weekend, details on exact rainfall totals and where the heaviest rain sets up will likely change over the coming days.

AVIATION /00Z WEDNESDAY THROUGH SUNDAY/

The 00z TAF period begins with VFR conditions at KCHS, KJZI, and KSAV. Overnight, there will once again be potential for isolated showers to develop at just about any time, but the likelihood of direct impacts at the terminals is low. After sunrise, we should again see cumulus and stratocumulus develop and it's possible there could again be periods of MVFR ceilings. In the afternoon, it again looks as though the best chance for showers and thunderstorms will remain inland of the TAF sites. Therefore, there is no mention of any showers or storms in the TAF's.

Extended Aviation Outlook: Brief flight restrictions possible within showers and thunderstorms at CHS/JZI/SAV terminals during the afternoon hours into the later half of the week. More periodic flight restrictions are possible Friday into the weekend as the potential for widespread showers/thunderstorms increases. In addition, patchy overnight fog and/or stratus cannot be ruled out after recent rains.

MARINE

Through tonight: The marine zones will remain under the influence of broad high pressure. South winds should remain between 10-15 kt with some gusts into the low 20s. Wave heights will favor values between 4-5 ft.

Wednesday through Sunday: Conditions are forecast to remain below Small Craft Advisory criteria through the end of the week, with daily chances for showers and thunderstorms. There is potential for a weak surface low to form along a stalled front across Central SC/GA, which would bring an increase in wind speeds along with wave heights nearing Small Craft Criteria on Sunday.

Rip Currents: An elevated rip current risk will remain through the week with a modest easterly swell around 3 to 4 feet every 8 seconds and sea breeze influences. A moderate risk of rip currents is in place for all area beaches through Thursday.

CHS WATCHES/WARNINGS/ADVISORIES

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