textproduct: Charleston

WHAT HAS CHANGED

Dew points have been lowered this afternoon to reflect current observations. The Aviation Section has been updated to reflect the 18Z TAFs.

KEY MESSAGES

- 1) An impactful system arrives during the later half of this weekend, resulting in renewed precipitation chances and perhaps a few thunderstorms.

DISCUSSION

KEY MESSAGE 1: An impactful system arrives during the later half of this weekend, resulting in renewed precipitation chances and perhaps a few thunderstorms.

Sunday into Sunday night will feature the most impactful weather for the next week. A potent shortwave will track across the Southeast U.S., with an associated surface reflection taking a similar track. Southeast South Carolina and southeast Georgia should become positioned within the warm sector through the day on Sunday, before the cold front pushes through as the low pulls off the coast Monday morning. Given the forcing and deep moisture in place, noted by PWats near or even exceeding 1.3 inches (well above normal for this time of year), showers with a few embedded thunderstorms are expected to overspread the area. Rainfall amounts are currently forecast to average in the 0.50-1 inch range. The chance for precip totals to exceed 1" in 24 hours ending 7 AM Monday is only 10-20% per ensemble means, however it is certainly possible in spots especially where convective pockets occur. These values should not pose much of a flooding threat given ongoing drought conditions with widespread D2 (severe drought) and portions of southeast Georgia even in a D3 (extreme drought). Severe threat looks pretty minimal given instability of a couple hundred joules at best and poor lapse rates. Precip coverage should be highest Sunday afternoon and evening, with rain chances decreasing after midnight and into Monday morning.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

VFR will prevail at KCHS/KJZI/KSAV through the 18Z TAF period.

Extended Aviation Outlook: The potential for flight restrictions will increase into Sunday as an area of low pressure moves into the region.

MARINE

High pressure will dominate over the marine waters through Saturday. An area of low pressure will approach from the west on Sunday, creating a pinched gradient across the local waters between the approaching low and the offshore high pressure. Wind gusts could approach 25 knots on Sunday along with seas building to 6-8 ft across the 20 to 60 nm offshore GA waters, likely necessitating Small Craft Advisories for portions of the waters. The low is then forecast to push through Monday, however the NBM probability of gusts >25 knots are only around 20% on Monday.

CHS WATCHES/WARNINGS/ADVISORIES

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