Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
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483 FXUS62 KCHS 011728 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 128 PM EDT Sat Jun 1 2024 .SYNOPSIS... High pressure will extend across the area through early next week. A cold front could approach late next week. && .NEAR TERM /THROUGH TONIGHT/... Early afternoon update: Just minor tweaks made to the forecast based on temperature and cloud trends. Morning composite analysis reveals a sharp short-wave ridge axis extending from off the Florida Atlantic coast up through the Carolinas. Short-wave trough axis and corridor of precip is close behind stretching along the central and lower Mississippi River Valley into the Gulf along with a couple of noted vorticity centers; one moving into western KY/TN and a second moving along the Gulf Coast where there is some beefier convection ongoing. Surface high pressure and attending dry air (PWAT value of 0.44" on the CHS 12Z sounding) covers the mid Atlantic and southeast region although the eastern edge of the axis of higher dewpoint air is edging across Georgia. Short-wave ridge axis and attending surface high pressure center will be slipping off the Atlantic coast today while axis of higher PWAT/dewpoint air begins to fold into the region. Upstream precip is still looking to decay rather quickly however, as it runs into the drier air across our region. That said, we will see higher cloud cover gradually spread eastward into the region, and probably some diurnal Cu development...most likely across Georgia. Only minor changes were made to the going forecast, maintaining dry weather and gradually increasing cloud cover. Highs will top out in the lower to middle 80s...coolest along the coast in the easterly onshore flow. Tonight: The aforementioned shortwave will continue to push in from the west should be aligned right on top of the area by early Sunday morning. This will bring a steady rise in precipitable water values, especially in southeast Georgia where values should be around 1.5" by sunrise Sunday. Some high-res model solutions suggest that isolated convection could develop within the arriving higher precipitable water air, but we have opted not to include any mention of anything at this time. However, it isn`t out of the question for there to be an isolated shower or thunderstorm across the west late in the overnight, and rain chances could eventually need to be included in the forecast. Overnight lows will not be as cool as the last few nights, with lows in the low 60s inland and upper 60s to low 70s along the coast. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... Weak upper ridging will prevail Sunday through Tuesday though a few weak shortwaves could ripple through the area. At the surface, Atlantic high pressure will persist, maintaining southerly flow and decent low-level moisture advection. We should see isolated to scattered diurnal convection during the period, primarily driven by a progressive sea breeze. The greatest coverage should be farther inland. Warm advection will result in steadily warming temperatures each day, with highs touching the lower 90s away from the coast by Tuesday. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... A zonal flow mid week will transition to a broad upper trough late week with a possible cold front dropping into the area Thursday or Friday. If this occurs, this would likely be the best chance for greater convective coverage as well as storm intensity. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... VFR conditions will prevail at KCHS, KJZI, and KSAV through 18z Sunday. Extended Aviation Outlook: VFR conditions will prevail through early to mid week. && .MARINE... Today and tonight: Easterly flow this morning will become southeasterly later on in the day and persist through the overnight. Wind speeds should mostly fall into the 10-15 knot range, with some gusts up to around 20 knots mainly along the land/sea interface this afternoon and early this evening. Seas should average 2-3 feet through the period, but could be up to 4 feet at times in the outer Georgia waters. A typical summertime pattern will prevail Sunday through Thursday as Atlantic high pressure remains in place. A decent sea breeze should develop each afternoon along the coast. Winds should remain below 15 kt and seas no higher than 4 ft. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...Adam/BSH SHORT TERM...JRL LONG TERM...JRL AVIATION...Adam/JRL MARINE...BSH/JRL