Marine Weather and Tide Forecast for Folly Beach, SC

NEAR TERM /UNTIL 6 AM THIS MORNING/
Tonight: Aloft, a primarily zonal flow sets up across the Southeast United States between weak mid-lvl ridging shifting further offshore and a trough progressing eastward across the Mid-west and Ohio River Valley regions. At the sfc, winds will remain calm and/or light from the south-southwest, maintaining mild conditions locally well in advance of an approaching cold front. Low temps should only dip into the low-mid 70s, warmest along the beaches. Approaching daybreak, ongoing convection across northern Georgia will progress eastward across the Carolinas and could reach far western zones, but activity will encounter drier air while advancing east, likely eroding most precip completely and/or to limited precip coverage (isolated showers).

SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/
Wednesday: A broken line of showers/tstms ahead of an approaching cold front will be in a weakening phase as it approaches the far interior areas prior to daybreak. Some remnant shower/tstm activity could push into interior Southeast Georgia just after daybreak, but confidence in anything meaningful happening is low. Guidance still shows little in the way of significant forcing ahead of the front with model cross sections showing the corridor of strongest UVVs displaced to the north where a passing shortwave/vorticity lobe will traverse North Carolina. Some low-level forcing is noted, likely along/near the frontal surface itself, but the best 850 hPa theta-e pooling will occur south of I-16 during peak heating and this is where the best overlap of instability and theta-e will occur. Given the westerly low-level flow ahead of the front within an environment without any strong forcing mechanisms, it is unclear exactly how much coverage of showers/tstms will occur during the afternoon hours and its very possible convection will remain largely absent through FROPA. A blend of the latest HRRR and 13z NBM was favored to construct pops, which yields rain chances of 10-30%, highest across the Georgia coastal counties. The front should clear the coast during the evening hours which will end any chance for measurable rain. Modified soundings do show modest to locally strong mixed- based instability within a belt of around 30 kt of 0-6km bulk shear.
This could support an isolated severe tstm with damaging winds and large hail, but an organized severe weather event seems highly unlikely at this time. Highs will warm into the lower-mid 90s, a bit cooler at the beaches where a pinned sea breeze will be late to form.

Thursday and Friday: A modest cyclonic flow aloft will prevail through the period as high pressure tries to be build into the region. A weak, secondary cold front will push offshore Thursday evening which will help to reinforce the relatively cooler and drier airmass that will filter in on Thursday. The front will pass through dry with no meaningful moisture return occurring prior to is passage. Highs will warm into the upper 80s/lower 90s Thursday with 80s for Friday (maybe even a few upper 70s across the far interior adjacent to the CSRA). Lows Friday morning will drop into the lower 60s well inland to around 70 at the beaches and Downtown Charleston.

LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/
Mostly quiet conditions will prevail for much of the extended period. Rain chances will increase slightly Sunday into Monday as a weak warm front lifts north through the area ahead of a developing storm system to the west. Temperatures will start out near to slightly below normal over the upcoming weekend, then begin to recover back to levels slightly above normal.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
VFR conditions will prevail at CHS/JZI/SAV terminals through 06Z Thursday. However, a cold front arriving to the area could produce a isolated showers/thunderstorms that impact any terminal, producing brief periods of flight restrictions. At this time, probabilities remain too low to include SHRA/TSRA at the terminals. However, warm conditions will create a well-mixed layer Wednesday, resulting in gusty westerly winds upwards to around 20-25 kt at times prior to and post fropa late Wednesday morning through Wednesday afternoon.

Extended Aviation Outlook: There are no concerns with a >50% confidence level.

MARINE
Tonight: The pressure gradient will gradially strengthen across local waters for the remainder of the night between high pressure shifting further offshore and a cold front approaching the region from the west-northwest. South winds will gradually veer to more south-southwest late, with wind speeds generally between 15-20 kt across most waters, and perhaps slightly higher gusts off the Charleston County Coast just prior to daybreak.
Seas will range between 2-3 ft, but could build up to 4 ft across outer Georgia waters approaching daybreak.

Wednesday: Southwest winds will increase ahead of an approaching cold front. Winds could get as high as 15-20 kt over the South Santee-Edisto Beach nearshore leg and Charleston Harbor during the afternoon hours. Gusts could get close to 25 kt, but its duration is somewhat uncertain. For this reason, a Small Craft Advisory has not been issued. The need for an advisory will be reevaluated overnight.
Winds will shift offshore during the evening hours as a cold front shifts offshore. Seas will build 2-3 ft, except 4-5 ft over the South Santee-Edisto Beach nearshore leg.

Thursday through Sunday: There are no major concerns. Offshore winds will turn back more southwesterly Thursday before returning offshore Thursday night as a reinforcing cold front shifts offshore. Offshore winds will persist through Friday before turning northerly Saturday ahead of a developing warm front. Winds will then veer southerly Sunday as the warm front lifts north.

CLIMATE
Record High Minimum Temperatures: May 20: KCHS: 72/2022 KCXM: 76/2022 KSAV: 73/1896

May 21: KCHS: 74/2022 KCXM: 78/1998 KSAV: 74/2017

CHS WATCHES/WARNINGS/ADVISORIES
GA...None.
SC...None.
MARINE...None.