Marine Weather and Tide Forecast for Seabrook Island, SC

NEAR TERM /UNTIL 6 AM SUNDAY MORNING/

Tonight: Expect any remaining isolated to scattered convection to die down by or shortly after sunset. Mostly cloudy expected to continue with light west-southwest winds all night, which will help to keep temperatures very mild for this time of year, generally in the upper 60s to lower 70s.

SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/
Sunday: The mid-levels will consist of zonal flow over our region in the morning. By the afternoon a wave of energy/vorticity will quickly pass overhead. In the evening and overnight, heights will start rising as ridging develops over the MS Valley. At the surface, a stationary front will spread from west to east across our area. It's exact location will vary as it meanders north or south as time progresses. There will be more moisture to the south of the front, with PWATs rising to ~1.8, mainly across our GA counties. This value would be well above normal for CHS, per SPC sounding Climatology. The combination of lift from the front, mid-level wave, and moisture, will generate showers/thunderstorms. Both the deterministic models and CAMs seems to indicate an MCS developing well upstream and then moving from west to east across our area during the afternoon. High temperatures should be in the lower to middle 90s away from the coast. But how much instability this generates is somewhat uncertain. Many of the models point towards modest instability, with the highest values along the Altamaha River and just to our south. Shear values tend to be higher, with 0-6 km values generally above 40 kt. So some stronger to marginally severe thunderstorms are possible with this MCS, with the main threat being damaging winds and maybe large hail, especially across our GA counties. Likewise, SPC has our area highlighted for a Marginal Risk of severe thunderstorms. These storms will quickly shift offshore by the evening, with the overnight being dry. Low temperatures will be mild, generally in the mid to upper 60s inland and the lower 70s at/near the beaches.

Monday and Tuesday: Mid-level ridging over the MS Valley Monday morning will gradually increase and shift eastward, becoming located along the spine of the Appalachian by late Tuesday. At the surface, a stationary front spread from west to east across our area Monday morning will gradually lift north, becoming located north of our area by Tuesday. This may usher more deep moisture into our area, with PWATs peaking ~1.8", which is well above normal. High temperatures will be well above normal, in the mid to upper 90s, except cooler at the beaches due to an afternoon sea breeze. The combination of lift and instability will generate isolated to scattered afternoon convection on Monday, and isolated convection on Tuesday. Strong to marginally severe storms are possible both days with the main concern being damaging winds. The convection will dissipate Monday evening, with Monday night being dry. Low temperatures will remain mild Monday night, generally in the upper 60s to lower 70s.

LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/
Wednesday: A strong mid-level trough will pass over our region, with a surface cold front following it. Shear and instability could generate strong to severe thunderstorms. High temperatures should be above normal.

Thursday through Saturday: High pressure will prevail, leading to drier conditions. Below normal high temperatures on Friday will be sandwiched between near to slightly below normal high temperatures Thursday and Saturday.

AVIATION /00Z SUNDAY THROUGH THURSDAY/
17.00Z: VFR conditions expected to prevail throughout the TAF period. Winds taper off tonight while remaining largely out of the west, with dry conditions expected. Chances for convection return during the afternoon hours, especially for areas along and south of the Savannah River Valley, so have included a PROB30 group for some showers for KSAV, while keeping KJZI and KCHS dry.

Extended Aviation Outlook: Brief flight restrictions are possible each afternoon/evening through Tuesday, followed by a more substantial risk for flight restrictions associated with a cold front Wednesday/Wednesday night. VFR returns on Thursday.

MARINE
Through tonight: A surface ridge will remain well southeast of the waters, producing southwest winds of 10-15 knots. Some gusts to near 20 knots through this afternoon, especially closer to the coast. No significant precipitation is expected, with the consensus of models keeping the marine waters dry through the period. Seas generally 2 to 4 feet.

Extended Marine: A stationary front will persist across the region through Tuesday. During this time frame, expect a more typical summertime wind scenario. Each day, winds will back and increase with the formation of the afternoon sea breeze. The strongest winds will be along the land/sea interface and across the Charleston Harbor. Each night, winds will veer. Though, local jetting could form, especially late. No Small Craft Advisories are expected through Tuesday. Wednesday into Wednesday night, a stronger cold front will move through, followed by High pressure for the end of the week. This will generate an enhanced surface pressure gradient, leading to stronger winds. Though, it's borderline whether we'll need Small Craft Advisories.

CLIMATE
NOTE: Both CHS and CXM are on target to either tie or break record High Minimum temperatures for today 5/17. The record for CHS is 74, and so far, CHS has only fallen to 74, which would tie the previous record. The record for CXM is 75, and so far, CXM has only fallen to around 77, which would break the record.
These records will hold of temperatures don't fall below 74 for CHS and 75 for CXM through midnight. Record High Temperatures:

May 17: KCHS: 96/1963 KCXM: 94/1899 KSAV: 97/1899

May 18: KSAV: 97/1899

May 19: KSAV: 97/1996

May 20: KSAV: 96/2006

Record High Minimum Temperatures:

May 17: KCHS: 74/1995 KCXM: 75/1998 KSAV: 74/1995

May 18: KCHS: 75/1995 KCXM: 77/1991 KSAV: 74/1899

May 19: KSAV: 74/1930

May 20: KCHS: 72/2022 KCXM: 76/2022 KSAV: 73/1896

May 21: KCHS: 74/2022 KSAV: 74/2017

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