Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
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198 FXUS62 KCHS 220535 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 135 AM EDT Sun Sep 22 2024 .SYNOPSIS... High pressure will linger across the region through early next week. A weak cold front may approach from the west around the middle of next week. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... Tonight: Dry conditions will prevail with sfc high pressure settled across the local area and mid-lvl ridging extending from the west aloft. The setup will favor another night of solid radiational cooling conditions with light/calm winds in place under clear skies aloft. In general, lows should range in the mid 60s inland to low 70s near the beaches where a weak onshore wind prevails. Slightly cooler conditions are possible in the Francis Marion Forest across northern Berkeley and Charleston Counties, where lows could dip into the low 60s. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/... Sunday: The center of a 590 DM ridge will remain centered over TX as a closed low pivots off the coast of New England. Short term guidance indicates that weak mid-level vort max is timed to track across the forecast area during the afternoon. Temperatures under the mid-level ridge will steadily warm through the mid-afternoon, expected to peak in the low 90s for most location. HREF indicates that sea breeze will develop during the mid to late afternoon, surging inland. The hot temperatures over dewpoints around 70 should result in CAPE values between 500-1000 J/kg along and ahead of the sea breeze. CAMs indicate that isolated showers may develop near the sea breeze, primarily over the SC Lowcountry. Monday and Tuesday The axis of a H5 ridge will ripple across the forecast area. GFS forecast soundings indicate that a strong inversion is expected to remain centered around H55, likely keeping conditions capped. The forecast will feature dry and hot weather for Monday and Tuesday. High temperatures are forecast to range from the upper 80s to low 90s. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... Wednesday: The forecast area will remain under the influence of the H5 ridge centered over the western Atlantic. At the sfc, high pressure centered over the Mid-Atlantic States is expected to ridge south across the region. It is possible that a sea breeze could trigger isolated showers during the afternoon. However, the degree of instability remain too uncertain to added PoPs to the forecast. High temperatures should remain in the upper 80s to around 90. Thursday through Saturday: The details of the forecast will largely depend on the intensity, placement, and timing of a potential tropical system sourced from the Gulf of Mexico. See latest NHC Tropical Weather Outlook for latest information. Based on the collaborated low position, the system is expected to remain to the west. The forecast will indicate generally scattered showers at this time. Given the thick cloud cover and anticipated rainfall, high temperatures are forecast to range between 80-85 degrees. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... VFR conditions are expected at CHS/JZI/SAV terminals through 06Z Monday. Extended Aviation Outlook: There are no concerns. && .MARINE... Tonight: A fairly weak pressure gradient will prevail across local waters between high pressure inland and a trough well offshore. In general, east winds between 5-10 kt will back to the northeast approaching daybreak. Seas will range between 2-3 ft across nearshore waters and 3-4 ft across offshore Georgia waters. Sunday through Wednesday: The marine zones will remain under high pressure through the period. Winds should generally remain from the southeast between 5 to 10 kts with seas of 2 to 4 ft. && .TIDES/COASTAL FLOODING... Positive tidal anomalies and high astronomical tides from the recent full moon will lead to elevated tides through early next week. Although the astronomical high tides are lowering, coastal flooding is expected with each daytime high tide cycle along the Charleston and Colleton County coasts. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...DPB SHORT TERM... LONG TERM... AVIATION...DPB MARINE...DPB