Area Forecast Discussion
Issued by NWS Wilmington, NC
Issued by NWS Wilmington, NC
042 FXUS62 KILM 171043 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 643 AM EDT Thu Jul 17 2025 .SYNOPSIS... Bermuda High Pressure will remain off the coast through this weekend. Temperatures will increase with a dangerous combination of heat and humidity developing Friday through the weekend. Widely scattered thunderstorms are possible through Sunday with more widespread coverage by early next week as a front drops south into the Carolinas. && .NEAR TERM /THROUGH TONIGHT/... High pressure aloft over the western Atlantic will gradually drift westward toward the southeastern US coast today and attempt to limit widespread convection. Low level moisture advection out of the south will maintain isolated to widely scattered showers this afternoon, but these will be focused along an early afternoon sea breeze and afternoon Piedmont trough. Disruption of the pressure gradient will occur today as a cold front approaches the Mid-Atlantic states. Southerly winds turn toward the SW late in the day, establishing the Piedmont trough as the primary convective generation mechanism. This slight veering of the wind will also set the stage for warmer temperatures this weekend. && .SHORT TERM /FRIDAY THROUGH SUNDAY/... Increasing chance for dangerous heat Fri through the weekend. Mid to upper ridge will be sprawled across the Southeast Fri through Sat. Should see heights as high as 596 dam on Fri with decent westerly flow above the sfc producing dangerous heat. Models continue to show shortwave riding over the ridge into Fri night over the NC/VA border area which could generate a bit more convection to the north, but for our area, expect increased subsidence and dry air aloft keeping limited convection across the local forecast area. The ridge gets suppressed a bit to the south and west on Sat and Sun which could lead to a bit of shortwave energy to reach closer to the area. The SW to W flow should steer any storms or debris clouds toward the coast and should keep sea breeze pinned closer to the coast. Overall, expect very hot and humid weather with better chc of convection Sat and Sun, especially over northern tier of local area and to the north. Highs will be in the mid 90s and will combine with high humidity to produce heat indices likely reaching Heat Advisory thresholds with Heat Warning possible in places Fri through Sun. && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... Mid to upper trough should push frontal boundary south into the Carolinas Sun night into Mon with possibly a low developing along the boundary Mon into Tues. Looks like best chc of pcp will be Mon as that frontal boundary drops south. By Tues the best convection will shift southward over SC with high pressure pushing in from the north. The mid to upper ridge starts building up the Mississippi Valley Tues and builds eastward into the Carolinas through midweek. This should lead to decreasing chc of convection and warming again. Overall, temps will be modified by clouds and pcp on Mon and closer to normal on Tues, but should increase again through midweek as ridge builds back in. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... Land breeze showers along the coast will diminish over the next couple of hours. A brief MVFR restriction is possible if these showers approach a coastal terminal, but their isolated nature should limit meaningful disruptions. Removed the PROB30 for inland areas this afternoon as HREF guidance continues to be dry and keeps most of the Piedmont trough activity west of I-95. S winds turn SW during the afternoon with afternoon gusts up to 20 knots, especially near the coast. MVFR possible for coastal terminals after sunset. Predominately VFR overnight with elevated winds. Some stratus is possible, but tough to provide confident details at this time. Extended Outlook... Isolated showers and thunderstorms may bring brief MVFR ceiling and visibility impacts Friday through Sunday, mainly the afternoon and early evening hours. Coverage may increase Monday as a frontal boundary approaches from the north. && .MARINE... Through tonight...Southerly flow today will veer during the afternoon as a cold front pushes through the Mid-Atlantic states. Some enhancement is expected near the sea breeze with winds up to around 15 knots. Waves around 3-4 feet, primarily wind-driven by diurnal circulations, with periods around 6 to 7 seconds. Showers and storms will continue to be isolated overnight. Friday through Monday... Bermuda high and front pushing down into NC from the Mid Atlantic will produce a SW to W flow across the waters Fri into the weekend. As this boundary drops south and the high weakens, winds will diminish closer to 10 kts or less through the weekend into early next week. Winds should back each aftn in sea breeze and spike up with seas generally 3 to 4 ft dropping to 2 to 3 ft over the weekend as winds drop. A longer period, around 8 second, swell will mix in. && .ILM WATCHES/WARNINGS/ADVISORIES... NC...Beach Hazards Statement through this evening for NCZ106-108. SC...Beach Hazards Statement through this evening for SCZ056. MARINE...None. && $$ SYNOPSIS...ILM NEAR TERM...21 SHORT TERM...RGZ LONG TERM...RGZ AVIATION...21 MARINE...RGZ/21