textproduct: Charleston

WHAT HAS CHANGED

All sections updated.

KEY MESSAGES

- 1) A weak cold front will push through the region this morning, ushering in dry conditions with temperatures at or above normal through the weekend.

- 2) Minor coastal flooding is possible along portions of the South Carolina coast with each evening high tide through Tuesday.

DISCUSSION

KEY MESSAGE 1: A weak cold front will push through the region this morning, ushering in dry conditions with temperatures at or above normal through the weekend.

Using satellite imagery and current observations, a surface cold front can be analyzed across the SC upstate as of 2 AM. As the morning progresses this front will saunter towards the local area, pushing through by 9 AM. Ahead of the approaching front winds have gone light to calm across SE SC, which combined with clear skies and a moist airmass has lead to some ground fog developing. Any fog that develops will quickly dissipate as the front approaches just before sunrise. Behind the front winds will shift to the NW and increase slightly, with gusts 10 to 15 mph forecast into the afternoon with an occasional gust to 20 mph not out of the question. Additionally, the front will usher in a drier airmass. Relative Humidity values this afternoon are expected to drop to 25-30% west of I-95 and 30-35% east of I-95. No fire weather products are expected to be issued today, even though RH values reach critical levels in some spots, the wind gusts are not a concern. High temperatures today will be warmer than the last couple of days, despite cold FROPA, with highs reaching into the low to mid 80s.

Friday, high temperatures should be a touch cooler than the previous day, with afternoon RH values bottoming out in the mid 20s far inland. Though, winds in these locations will be light, generally sustained at 5 mph or less, so there won't be any fire weather concerns.

Mid-level heights will gradually rise over the weekend and the first part of next week as ridging builds over the East Coast. This will cause high temperatures to be a few degrees above normal. Surface High pressure will shift offshore late Friday, then remain in the western Atlantic through early next week. Flow around the High will cause moisture to gradually increase each day. But we're not expecting any convection to initiate along the sea breeze until possibly the middle of next week.

KEY MESSAGE 2: Minor coastal flooding is possible along portions of the South Carolina coast with each evening high tide through Tuesday.

Astronomical tides will be rising due to the upcoming New Moon (on Saturday). In fact, the Charleston astronomical tide alone is expected to peak just above 6.7 ft MLLW with the Saturday and Sunday evening high tides. Therefore, even small positive anomalies could lead to minor coastal flooding for Charleston and Coastal Colleton Counties both of those evenings. This will all be highly dependent on the wind direction the next few days. Overall, each high tide through at least Tuesday will need to be monitored for potential flooding.

AVIATION /06Z THURSDAY THROUGH MONDAY/

Some ground fog has developed across SE SC, with vsbys dropping at times at KJZI. The 06Z TAFs include mention of MIFG at KCHS/KJZI with a TEMPO at KJZI for the lower vsbys. A cold front will push through the region shortly after 12Z this morning, with any fog dissipating just prior to its arrival. Prevailing VFR through the remainder of the 06 TAF period at KCHS/KJZI/KSAV.

Extended Aviation Outlook: VFR.

MARINE

Today and Tonight: A dry cold front is timed to push across the nearshore waters this morning. High pressure will then build into the region, with no advisory level concerns through tonight.

Extended Marine: High pressure will move over the waters on Friday, then shift offshore Friday night. The High will remain over the western Atlantic through the first part of next week. Expect tranquil marine conditions during this entire time period.

Rip Currents: Friday: The swell and period will remain similar, but tidal ranges will increase ahead of the New Moon (on Saturday). Both internal calculations and RCMOS have a Low Risk along our SC beaches and a Moderate Risk along our GA beaches during the daylight hours. Therefore, we maintained the Moderate Risk for our GA beaches, and the Low Risk for our SC beaches.

CHS WATCHES/WARNINGS/ADVISORIES

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