Area Forecast Discussion
Issued by NWS Charleston, SC

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910 FXUS62 KCHS 242348 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 748 PM EDT Fri May 24 2024 .SYNOPSIS... A series of weak disturbances will move through the area through Saturday. Hot conditions expected for Sunday and Memorial Day. A cold front could bring impacts to the region Monday night into Tuesday. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
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Quick early evening update to update the PoPs to match current radar trends. Otherwise, forecast is on track. Convection continues to develop along an east-west oriented boundary developing along a PWat and MLCAPE axis. The steering flow is toward the east, and now that the sea breeze has made some headway inland (roughly near or inland from US-17, there will be a further increase in both the coverage and the strength of t-storms. An MCV will continue to approach from the west-northwest, which will further aid in the forcing for ascent. Convection fades during the mid and late evening with the loss of heating and the passage of the MCV. However, within the west-northwest flow aloft some of the guidance has been implying that at least isolated to scattered activity will persist through the overnight. This seems plausible since there will be lingering outflow boundaries, sufficient moisture, and modest CAPE. This activity though does not look to be severe. There is an outside chance of some stratus and/or fog late at night due to the wet grounds. But this is dependent upon how much clearing takes place. Since most guidance does not have any reductions in visibilities, we do not have any mention in the forecast. The hourly temperatures have been altered to show an atypical curve to account for convection early on. But actually lows will be down only into the upper 60s and lower 70s due to similar dew points.
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&& .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... Saturday: The broad mid-level trough will ripple over the Atlantic during the morning, with heights beginning to rise during the afternoon. Short term guidance indicates that a small disturbance could track SE across the region Saturday afternoon. Surface conditions should feature high temperatures in the low 90s with dewpoints in the low 70s. Model guidance indicates that a field of CAPE of 1500-2000 J/kg with shallow CIN should develop by the heat of the afternoon. Isolated to scattered thunderstorms should develop across the forecast area, especially along a sea breeze. Once again, some areas could see pockets of heavy rainfall given weak shear and PW values in excess of 1.6 inches. Sunday: GFS indicates that a broad H5 ridge will build across the region. Conditions should become hot and humid during the afternoon. High temperatures are expected to range in the mid 90s with dewpoints in the low 70s along the coast. Heat index values may exceed 100 degrees across the coastal counties, especially across SE GA. Given poor mid-level lapse rates, convection will be limited to a SCHC. Memorial Day: The mid-level ridge axis is expected to shift east, but is expected to remain near the region. A cold front is expected to sweep across the Southern Appalachians Monday afternoon. Winds will remain from the southwest through the day. Temperatures should warm similar to values reached on Sunday, generally in the low to mid 90s. A few pockets across the coastal counties may see heat index values rise to around 100 degrees. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... Monday night: During the evening, short term guidance indicates that an MCS may develop over the Midlands of SC ahead of the front. This system may track towards the coast with the cold front Monday night. Given a wide field of instability and weak shear, it is possible that these storms could arrive with damaging wind gusts. This activity may remain into Tuesday morning. Wednesday through Friday: Conditions for the rest of the week should remain dry. High temperatures are forecast to range in the upper 80s each day. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... Showers and thunderstorms will impact the terminals late this afternoon and early evening, and produce flight restrictions. This is mainly between 20Z and 01Z. Convection diminishes thereafter, although some additional convection might advance back into the region late overnight. However, confidence is too low to add any mention to the current terminal forecast. Also, there might be a low end risk for stratus and/or fog closer to daybreak Saturday, dependent on how much clearing can occur. Extended Aviation Outlook: Brief flight restrictions are possible due to showers/thunderstorms each afternoon/evening. && .MARINE...
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This evening and tonight: All terminals are now clear of thunderstorm, however VCSH remains as showers persist this evening. Overall, no flight restrictions included in the 00Z TAFs. Some lighter showers could impact KCHS/KJZI within the 00-02 Z time frame, otherwise the remainder of the 00Z TAF period should be rain free. Saturday through Wednesday: The forecast area will remain between high pressure across the western Atlantic and Gulf of Mexico and a series of low pressure tracking over the Mid West. This pattern should result in a sea breeze to develop each afternoon. A cold front should sweep across the coastal waters Monday night into Tuesday. Wind and sea conditions should remain below Small Craft Advisory conditions.
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&& .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE...