Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
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918 FXUS62 KCHS 280134 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 934 PM EDT Mon May 27 2024 .SYNOPSIS... A cold front will move into the region tonight, then stall nearby through the middle of the week. High pressure will return for the second half of this week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Late this evening: Well, not only did the severe threat not materialize but there was hardly even a shower that passed through the forecast area this evening. A an area of light stratiform rain is passing through coastal southeast Georgia right now, but that is it. Surrounding radars show some upstream convection across west-central Georgia, but that is still several hours away from even being remotely close to the forecast area. Also, this upstream convection is displaying the same southward trend that we saw this afternoon and early in the evening. Other than a few showers that could scrape southeast Georgia and the adjacent coastal waters, the rest of the overnight is expected to be dry. Lows are forecast to dip into the low 70s for most areas. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday: The mid-levels will consist of a longwave trough over the eastern half of the U.S. At the surface, a cold front will be located along our coast early in the morning. It`s forecasted to transition into a stationary front shortly thereafter and meander along our coast through the early evening. By late evening, it`ll transition back into a cold front and move further offshore, and away from our area. Broad High pressure will be centered over the Northern Plains overnight, with its periphery building into our region. The highest moisture values will remain just offshore, on the other side of the front. With less moisture in place, there won`t be much instability in place across our area, despite temperatures peaking in the lower 90s away from the beaches. The synoptic models and long-range CAMs hint at maybe an isolated shower or thunderstorm, mainly near are coastal SC counties in the afternoon. Further south, more dry air and capping should limit any convection from developing. Anything that does manage to develop over our SC counties should be weak, dissipating by sunset. The evening and overnight will be dry everywhere. Lows will range from the lower 60s far inland to around 70 degrees at the beaches. Wednesday and Thursday: The mid-levels will consist of a longwave trough over the eastern half of the U.S. Wednesday. The trough will become more amplified along the East Coast Wednesday night into Thursday, in response to ridging approaching from the west. At the surface, broad High pressure centered over the Northern MS Valley Wednesday morning will shift to the Great Lakes region by late Thursday. The periphery of this High will reach all the way into the Southeast U.S. both days, bringing dry conditions. Afternoon dew points may fall into the 50s away from the beaches, which will make it feel very comfortable. Temperatures on Wednesday should peak around 90 degrees, and the lower to mid 80s on Thursday. No convection is expected either day, but fair weather cumulus is expected both afternoons. Lows Wednesday night will range from the lower 60s far inland to around 70 degrees at the beaches. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A trough over the East Coast Thursday night will shift offshore by later Friday, followed by a ridge building on Saturday, and possibly prevailing into Monday. High pressure will be the dominant surface feature during the long term. POPs will be around 20% each afternoon with temperatures a few degrees below normal. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... Confidence continues to increase that convection will remain well to the west and south of KSAV, so there is no longer much concern for the late evening and early morning hours. Otherwise, the rest of the TAF period looks quiet. There could be an isolated thunderstorm near KCHS and KJZI Tuesday afternoon, but chances are too low to include at this point. Extended Aviation Outlook: VFR. && .MARINE... Sea breeze influences will help in the enhancement of winds into this evening, with S and SW winds as high as 15 or 20 kt and gusty. There will be a few gusts near 25 kt at times in Charleston Harbor and near the coast of Charleston County. But not enough to warrant a Small Craft Advisories. Winds will veer more SW or WSW at less than 15 through the night, altered temporarily by convection that moves through during the mid or late evening into the early post-midnight hours as an upstream cold front draws closer. Seas will average 2 to 3 feet. Extended Marine: Rather tranquil conditions are expected. A cold front will be located along our coast early Tuesday morning, moving further offshore, and away from our area Tuesday night. High pressure will then gradually move towards our area midweek and prevail through the weekend. Even the sea/land breezes don`t appear to be too strong during this time period. Wind speeds should average 15 kts or less. Seas will be 4 ft or less. && .CLIMATE... Record High Minimum Temperatures: May 27: KCHS: 76/1991 KCXM: 79/2019 KSAV: 77/1878 && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...BSH SHORT TERM... LONG TERM... AVIATION...BSH MARINE...