textproduct: Charleston

WHAT HAS CHANGED

The previous Key Message 1 was removed and the old Key Message 2 detailing the late weekend system became the new Key Message 1. The Aviation section was updated for the 06z TAF issuance.

KEY MESSAGES

- 1) An impactful system arrives late this weekend, resulting in renewed precipitation chances and perhaps a few thunderstorms.

DISCUSSION

KEY MESSAGE 1: An impactful system arrives late this weekend, resulting in renewed precipitation chances and perhaps a few thunderstorms.

Heading into the weekend, will see a substantial southern stream shortwave track into the southeast as a surface low tries to develop off the Mid-Atlantic coastline. While model variability still exist concerning the overall track and strength of the aforementioned low, latest trends suggest a slightly slower onset time. Thus, should see largely dry conditions prevail Saturday, before the region becomes warm- sectored early Sunday morning.

Light showers will likely be ongoing across much of the area by daybreak Sunday, as broad WAA builds overhead. These showers then look to become more widespread (70-90%) heading into the afternoon hours as the front nudges closer to the region. Regarding rainfall amounts, there continues to be a 80-90% chance of rainfall > 0.5" and a 60-70% chance of rainfall > 1" within a 24-hr period. WPC seems to agree with this sentiment, as the region has been placed in a Marginal Risk of Excessive Rainfall. With a bit of instability also present, can't rule out seeing a few thunderstorms, which may result in localized pockets of higher accumulations. Certainly something to keep an eye on in the coming days. Outside of a few lingering post- frontal showers Monday morning, should see largely dry conditions return to the region Monday evening as sfc high pressure builds across the eastern CONUS.

AVIATION /06Z THURSDAY THROUGH MONDAY/

VFR conditions are expected to prevail at KCHS, KJZI, and KSAV through 06z Friday.

Extended Aviation Outlook: VFR expected to prevail through Saturday. The potential for flight restrictions will increase into Sunday as an area of low pressure moves into the region.

MARINE

Through tonight: Winds will be strongest across the local waters this morning as the gradient is enhanced for a short period of time with high pressure building in. Speeds will top out in the 15-20 knot range, with a few gusts approaching 25 knots in the outer GA waters. The gradient will weaken later in the day and into the overnight and speeds will come down accordingly.

Friday through Monday: High pressure will prevail Friday through Saturday, though the high will become centered to the east on Saturday allowing for winds to turn more easterly and southeasterly with time. The main time period of concern for the coastal waters will come from Sunday onward. An area of low pressure will approach from the west on Sunday and southerly flow will increase between the low and the offshore high. Winds could increase into the Small Craft Advisory range on Sunday as a result. The low will move through into Monday and another period of stronger winds could occur on the backside of the low. There remains considerable uncertainty regarding the low and its track, so the confidence in this period is low confidence. But, the potential for needing Small Craft Advisories remains.

CHS WATCHES/WARNINGS/ADVISORIES

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