FXUS62 KCHS 242334 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 734 PM EDT Wed Apr 24 2024 .SYNOPSIS... A weak trough will drop into the region tonight into Thursday. High pressure builds back into the region late week through the early part of next week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Early this evening: Visible satellite imagery really tells the story with a band of mostly mid-level clouds that stretches from eastern North Carolina all the way back across central Georgia, Alabama, and Mississippi. This band of clouds provides a nice visual of where the upstream front is situated and radar imagery shows coincident and mostly isolated shower activity as well. This front will steadily drop southward through the overnight period and by sunrise is expected to be generally still east to west, likely south of Charleston but still running through the Savannah area. The main forecast challenge for the evening and the first part of the overnight will be whether or not some isolated shower activity can develop and impact portions of the forecast area. Hi-res model solutions have consistently said yes and are generally capturing the ongoing radar coverage pretty well. However, even if a few locations get a quick shower, any rainfall amounts will be very light. Model soundings show a shallow moist layer around 6-8 kft, with notable dry air above and below. Within the ongoing clouds and isolated showers, precipitable water values are only running at about 1 inch. We have maintained a narrow band of 20 percent rain chances, primarily for interior southeast Georgia across to the Charleston Tri-County region. Any shower activity should dissipate or shift offshore in the early morning hours. Lows will continue the warming trend tonight with temperatures only expected to dip into the upper 50s in most areas away from the immediate coast. Can't rule out a few mid 50s far inland. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... A weak front/trough will push offshore as a wedge of high pressure builds south Thursday. Aloft, a large omega block will begin to set up with amplifying troughs over the Western Atlantic and Western U.S. A ridge axis over the Central U.S will gradually shift toward the Eastern Seaboard, and settle in place through at least the first half of the weekend. Overall, quiet weather is expected with little to no forcing; however models generate a few light showers at times with onshore flow. Slight chance PoPs are in place for Friday afternoon across inland southeast Georgia where there has been some persistence, but otherwise the chance for measurable rainfall was low enough to preclude mention in the forecast. High temperatures remain within a few degrees of normal, generally in the upper 70s to lower 80s each day. Lows both nights range from the mid/upper 50s inland to the mid 60s along the immediate coast. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... The pattern remains largely unchanged through the early week with the omega block and deep high pressure in place. This favors increasing temperatures and virtually zero rain chances. The upper ridge axis will finally begin to shift offshore Tuesday as a weakening trough and accompanying weak cold front moves into the eastern U.S. It should be another dry day across much of the area, however a few showers could impact inland areas during the latter half of the day. Temperatures will start the period in the upper 70s/low 80s and will rise to the upper 80s/near 90F by the middle of the next week. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... VFR conditions will prevail at KCHS, KJZI, and KSAV through 00z Friday. A band of mostly mid-level clouds ahead of a southward moving front will move across the terminals later this evening through the early morning hours. Ceilings in the 6-8 kft range are expected. Also, we could still see an isolated rain shower near KCHS and KJZI so we have maintained the VCSH mention. No impacts are expected. Extended Aviation Outlook: Prevailing VFR. && .MARINE... Southwest winds will diminish to near 10 kt overnight as a surface trough slips south into the local marine areas. A few showers could impact mainly the South Santee-Edisto Beach nearshore leg and Charleston Harbor during the overnight hours, although the overall precip potential is very low. Seas will average 2-3 ft in the nearshore waters out to 20 NM and the 3-4 ft over the Georgia offshore leg out 20-60 NM. Thursday through Monday: Winds will shift ENE Thursday and then persist through late week as high pressure builds from the north. Brief surge will bring winds to the 15-20 kt range Friday afternoon/evening. Seas in turn will build to 2-4 ft across the nearshore waters out to 20 nm and 5-6 feet across the outer Georgia waters. A Small Craft Advisory could be needed for that particular marine zone for a brief period overnight Friday. Winds veer more southerly early next week with no additional marine concerns. && .EQUIPMENT... The KCLX radar is undergoing electrical maintenance and is tentatively scheduled to return to service April 26th. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...BSH SHORT TERM...BRM LONG TERM...BRM AVIATION...BSH/BRM MARINE...Adam/BRM