textproduct: Charleston

WHAT HAS CHANGED

All sections have been updated.

KEY MESSAGES

- 1) Periods of showers and thunderstorms this week through the weekend could bring locally heavy rainfall. The threat for organized severe weather is low at this time.

DISCUSSION

KEY MESSAGE 1: Periods of showers and thunderstorms this week through the weekend could bring locally heavy rainfall. The threat for organized severe weather is low at this time.

The region will remain on the western periphery of high pressure at the surface and aloft through tonight. Atmosphere remains juicy with PWats near or just over 2 inches, which is above the 95th percentile of climo. Radar thus far has remained fairly active, with showers and thunderstorms largely moving inland with time with the sea breeze. For the remainder of the afternoon, the focus should be along and west of I-95. Convection should largely remain sub-severe, though there is potential for gusty winds and locally heavy downpours. 12z HREF continues to indicate a 10-30% chance of 3"/3 hr with a 50-70% of 1"/3 hr over interior southeast Georgia. The bulk of activity should wane this evening, but enough moisture and instability will exist to allow for some shower activity to percolate at times overnight, especially near the coast.

This general trend will continue daily through Thursday. Again, some storms could produce heavy downpours and minor flooding issues, but much of the rainfall will help ease ongoing dry conditions.

Rain chances will increase Friday through the weekend as a weak front meanders in the vicinity, bringing a more widespread pattern of showers and thunderstorms. Moisture convergence along the front will increase PWATS to around 2.0 - 2.2 inches Friday and through the weekend. Several rounds of rainfall which could be heavy at times, could lead to localized minor flooding, especially in areas that see repeated storms. Current forecast guidance suggests widespread rainfall totals through the weekend around 2 to 4 inches. The NBM currently shows a 20-35% probability of 3 inches of rain or greater falling over a 72-hour period between Friday morning and Monday morning, with the highest chances located along the 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 /18Z MONDAY THROUGH SATURDAY/

The bulk of shower/thunderstorm activity and associated impacts should remain west of the terminals for the rest of the afternoon and into the evening. Guidance hints at some MVFR ceilings briefly developing Tuesday morning, but probability is too low to include in the TAF at this time. Otherwise, convection will be possible again late Tuesday morning into early afternoon, before it shifts inland with the sea breeze.

Extended Aviation Outlook: TEMPO flight restrictions possible with showers and thunderstorms at CHS/JZI/SAV terminals mainly during the afternoon hours through the week. In addition, patchy overnight fog and/or stratus cannot be ruled out after recent rains.

MARINE

Through tonight: High pressure centered over the western Atlantic will remain remain over the marine zones. As a result, winds will generally remain from the SSE through the period, favoring speeds between 10 to 15 kts. Wave heights are expected to range between 3 to 5 ft.

Tuesday through Saturday: Generally no marine concerns as conditions are forecast to remain below Small Craft Advisory criteria through the end of the week, with daily chances for showers and thunderstorms.

Rip Currents: An elevated rip current risk will remain through the week with a modest easterly swell around 3 to 4 feet every 7 seconds and sea breeze influences. A moderate risk of rip currents is in place for all area beaches through at least Wednesday.

CHS WATCHES/WARNINGS/ADVISORIES

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