Marine Weather and Tide Forecast for Summerville, SC

KEY MESSAGES
- 1) Areas of fog expected across portions of southeast Georgia and the South Carolina Lowcountry and adjacent waters tonight into Wednesday morning.

- 2) Unseasonably warm temperatures are expected through early next week with increasing rain chances this weekend.

DISCUSSION
KEY MESSAGE 1: Areas of fog expected across portions of southeast Georgia and the South Carolina Lowcountry and adjacent waters tonight into Wednesday morning.

Many locations across the region have begun to report visibilities <1 mile and webcam observations confirm this. Given the 00Z HRRR probabilities of vsbys <0.5 mi are around 60-70% across the region conditions are expected to worsen across the region into the morning hours. Therefore, a Dense Fog Advisory has been issued for the entire forecast area through 9 AM.
Additionally, sea fog can be seen on GOES nighttime fog satellite imagery offshore of southeastern GA and in the offshore waters of southern SC. This sea fog will likely impact the coastal zones into the morning hours. The fog will likely stick around through at least mid morning before mixing out.

KEY MESSAGE 2: Unseasonably warm temperatures are expected through early next week with increasing rain chances this weekend.

An upper level ridge over the Florida Peninsula will shift east over the Bermuda High, establishing deep-layered high pressure over the Western Atlantic through the weekend. Despite increasing moisture, persistent subsidence associated with this pattern will suppress widespread convection and support a pronounced warming trend.

Slight chance POPs are currently forecast for the far inland counties both Friday and Saturday where subsidence is weakest.
However, as the ridge begins to flatten Sunday and early next week, rain chances will gradually increase, particularly during the afternoon and evening hours. Additionally, a series of weak shortwaves passing to the northwest could provide additional forcing for showers and thunderstorms as deep moisture remains in place.

Afternoon highs will climb into the upper 70s and lower 80s inland each day. Across southeast Georgia, especially near the Altamaha River, temperatures could reach the mid to upper 80s Friday into early next week. Beach communities will remain cooler due to the influence of the cooler shelf waters. Overnight lows will also trend warmer, rising into the upper 50s and lower 60s. These above-normal temperatures are expected to persist through early next week, although no record highs or ties are forecast at this time.

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/
LIFR conditions will start the 12Z TAF period at KCHS/KJZI/KSAV as dense fog impacts all of the terminals. Fog will linger until mid morning, when cigs will lift to MVFR and then eventually VFR by 17Z. VFR will prevail through the afternoon hours. Fog/low stratus could again impact the terminals tonight into Thursday morning bringing additional vsby and cig restrictions.

Extended Aviation Outlook: Restrictive ceilings are possible overnight into the early morning hours each night through the weekend due to low stratus/fog.

MARINE
Satellite imagery shows a large area of dense fog and low stratus across both the nearshore and outer GA waters. A Dense Fog Advisory remains in effect for these waters through noon today. Observations also show that sea fog is present in the southern SC nearshore waters and a Marine Dense Fog Advisory has been issued for those waters through 12 PM. Sea fog is expected to develop again this afternoon and additional Dense Fog Advisories will likely be required.

High pressure will prevail in the western Atlantic through the weekend. Northeast winds will gradually veer out of the southeast by Thursday night and prevail through the weekend. Both winds and seas are expected to stay below Small Craft Advisory levels.

Sea fog will continue be a recurring concern this week as warm, moist air moves over the cooler shelf waters. Periods of fog may redevelop frequently and could persist through the weekend. The fog could become dense at times, reducing visibility for mariners.
Additional Marine Dense Fog Advisories could be needed in the coming days. Winds are then forecast to shift out of the south/southwest by early next week, which could prolong the sea fog threat into that period.

CHS WATCHES/WARNINGS/ADVISORIES
GA...Dense Fog Advisory until 9 AM EST this morning for GAZ087-088- 099>101-114>119-137>141.
SC...Dense Fog Advisory until 9 AM EST this morning for SCZ040- 042>045-047>052.
MARINE...Dense Fog Advisory until noon EST today for AMZ352-354-374.