Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
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557 FXUS62 KCHS 101717 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 117 PM EDT Fri May 10 2024 .SYNOPSIS... A cold front will push offshore today. High pressure will prevail for the weekend into early next week. A storm system could affect the area by the middle of next week. && .NEAR TERM /THROUGH TONIGHT/... Early this afternoon: Radar imagery shows that the large area of stratiform rainfall from the morning has dissipated and shifted offshore. We are convection-free right now, and should stay that way for the next few hours. Satellite imagery shows that a considerable cirrus shield covers the area and this combined with the stabilizing effect of the morning rainfall will make it difficult for there to be much recovery. Surface analysis shows the cold front is still positioned upstream across the Midlands and is progged to push to the southeast this afternoon and into the evening. Along the front, isolated to scattered convection is expected to develop and could impact portions of the area late this afternoon and into the evening. While we should have sufficient instability develop to support convection, the potential for severe weather is certainly low. The greatest risk for thunderstorms, and a strong to marginally severe storm, is the Charleston Tri-County region and Colleton County. This area lines up very well with the updated Day 1 Severe Weather Outlook from SPC, and is highlighted in the Hazardous Weather Outlook. Temperatures have been held down and slow to rise thanks to the morning rainfall, but we should still have time to warm into the low 80s. The cold front is timed to push off the coast by midnight. In the wake of the front, winds should shift from the north with steady CAA. Given ongoing CAA through daybreak Saturday, low temperatures are forecast to generally range from the mid 50s inland to around 60 along the coast. && .SHORT TERM /SATURDAY THROUGH MONDAY/... Saturday and Sunday: Broad troughing will prevail aloft through the weekend, with high pressure building in at the surface. With high pressure dominating at the surface, the weekend will feature a rather benign weather pattern. Temperatures on Saturday will actually be much cooler than the previous week, owing to FROPA on Friday night. Highs on Saturday are forecast to peak in the mid to upper 70s. Sunday will be slightly warmer, with highs in the low 80s. Sunshine will be plentiful, accompanied by a rain-free forecast. Monday: The upper level pattern shifts a tad on Monday, with models indicating a few shortwave troughs could ripple across the forecast area. This could provide enough forcing for isolated to scattered showers and thunderstorms. Temperatures are forecast to reach into the upper 70s to low 80s. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... Beginning Monday night the forecast turns more active as a warm front approaches the forecast area from the south. Aloft, a mid-level trough is forecast to swing through the southeastern states through Thursday. MOisture is expected to build into the region after the warm front lifts northward, with PWATs approaching 2". Several rounds of showers and thunderstorms are expected as the region remains well within the warm sector with plentiful moisture, aided from the approaching mid-level trough. Temperatures are expected to gradually warm through the period, with upper 70s to low 80s on Tuesday warming to the mid to upper 80s by Thursday. && .AVIATION /17Z FRIDAY THROUGH TUESDAY/... VFR conditions should prevail at KCHS, KJZI, and KSAV through 18z Saturday. The main forecast challenge will be the potential for isolated to scattered showers and thunderstorms late this afternoon and early this evening, primarily near KCHS and KJZI. We have added in a few hours of VCSH as the confidence of direct impacts at KCHS and KJZI remains low. A thunderstorm will be possible too, but chances aren`t high enough to include a mention of TSRA. Whatever activity does develop will shift offshore in the evening and the rest of the period will be dry. Skies will clear out overnight as well. Winds will turn northwesterly and then northerly overnight. Extended Aviation Outlook: VFR conditions will prevail through the weekend. Showers and thunderstorms could bring flight restrictions to the terminals Monday afternoon into the middle of next week. && .MARINE... Winds should remain from west-southwest between 15-20 kts. Wave heights are forecast to range between 3-4 ft. This evening, a cold front will approach from the northwest, timed to reach the coast around midnight. The front should rapidly sweep across the marine zones, turning winds from the north. Speeds will favor values between 15 to 20 kts, gusts could reach 25 kts at times. Seas will change very little overnight, remaining between 2-4 ft. Saturday through Wednesday: Generally tranquil marine conditions are forecast through the weekend as high pressure extends over the local forecast area. Winds will generally be around 10 knots, with seas averaging 1 to 2 feet. Monday night S to SE winds will surge slightly as a warm front lifts northward through the region, generally around 15 knots with some gusts around 20 knots. Seas will also increase, averaging 3 to 4 feet. These conditions will persist into the middle of the week. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...BSH/NED SHORT TERM...CPM LONG TERM...CPM AVIATION...BSH/CPM MARINE...CPM/NED