


Area Forecast Discussion
Issued by NWS Wilmington, NC
Issued by NWS Wilmington, NC
768 FXUS62 KILM 170013 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 813 PM EDT Wed Jul 16 2025 .SYNOPSIS... Bermuda High Pressure will remain off the coast through this weekend but continuing to ridge back across the area. Temperatures will increase Thu thru Sat as high pressure strengthens aloft and a dangerous combination of heat and humidity develops. Widely scattered thunderstorms are possible Thu thru Sun across the area with more widespread coverage by early next week as a front drops southward to the area. && .UPDATE... Took POPs out of the forecast for the remainder of the evening hrs and thru the overnight hrs. Only exception may be a few nocturnal showers/tstorm skirting the Cape Fear area, although am inclined not to include given low level flow more southwesterly as opposed to due south the past several days. Min temps mid to upper 70s except around 80 at the coast given SSTs in the 80s. Hires models keep low stratus and fog development at bay and thus will continue with the mostly clear fcst thru the night with mainly dissipating convective debris mid and upper level clouds overhead. && .NEAR TERM /THROUGH THURSDAY/... Two small but important changes will take place in the weather pattern over the next 24 hours. The first will be 500 mb high pressure centered just south of Bermuda starting to move westward toward Florida. Our 500 mb heights will rise by ~20 meters by tomorrow afternoon with mid level warming and drying anticipated. This should act to reduce (but not eliminate) airmass convection that we`ve seen dot the area the last couple of days. I`ll still hang onto a slight chance of showers and t-storms along and inland from the seabreeze with PoPs 20 percent or less. The other item of note is an area of surface low pressure moving from the Great Lakes tonight northeastward along the US/Canadian border on Thursday. The pressure falls associated with this feature will extend as far south as the Mid Atlantic states and will help to veer our surface wind from south to southwest. This should hold the seabreeze boundary closer to the coast Thursday and delay the arrival of cooler marine air into cities like Conway, Wilmington, and Burgaw. The overall warmer airmass, fewer diurnal storms, and an inhibited seabreeze should allow temperatures to rise into the 93-95 range inland with heat indices approaching 105. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... A westward expansion of the mid-upper ridge axis is anticipated during this period, which will subsequently bring more dry air and subsidence into play going into the weekend, along with higher max temps and less cloud cover. Thus, Heat Advisories will likely be needed for Friday and Saturday as max temps reach into the mid-upper 90s amidst dew points in the low-mid 70s away from the coast. Dry air and subsidence beneath the ridge axis will contribute to more isolated to widely scattered shower and thunderstorm coverage, resulting in mainly low-chance PoPs across the area. Lows in the mid- upper 70s will continue. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... Mid-level troughing well north of the forecast area is expected to nudge heights down later in the weekend as the ridge axis is pushed further westward. Early next week, guidance shows this troughing digging into the western Atlantic, setting up a northwest flow regime over the Carolinas. Although some dry air and subsidence will linger, moisture supplied by daily upstream convection will help to reduce the amount of dry air and keep multi-layered clouds frequently in the sky. In addition, depending on how far south the western Atlantic troughing reaches, and where the ridge axis parks itself to the west, shortwave energy riding down the east side of the ridge may yield one or more convective complexes originating from the higher terrain reaching the forecast area. Near the surface, high pressure is expected to shift over the Gulf, causing winds to be more southwesterly to westerly. Thus, the sea breeze should also become more active and stay nearer to the coast early next week, leading to higher PoPs across the area after this weekend. Temperatures will initially be abnormally hot for this time of year before settling back towards normal, with highs in the mid-upper 90s on Sunday, nudging into the mid-90s on Monday, then low 90s or upper 80s on Tuesday and Wednesday. Lows in the mid-upper 70s are still expected as dew points remain in the mid-upper 70s. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... VFR to dominate overnight as S-SW winds stay active thru the night. GFSLamp guidance keeps the majority of the low stratus at bay and keeps any ground fog development isolated at best. Convection waning pretty quickly as the days insolation ceases. Will deal with convective debris mid and upper level clouds this evening scouring out to mainly thin/opaque cirrus overnight. Upper ridging extending from the Bermuda high well offshore from the SE States Coast, will attempt to keep a lid on any thunderstorm development during daylight Thu. But given the huge amounts of instability/CAPE numbers progged, included VCTS for the MYR and CRE coastal terminals and a POP30 for FLO and LBT terminals where periodic MVFR remains possible. Low level winds become more southwesterly and should keep the majority of the nocturnal Atlantic showers and tstorms just off the coast, possibly skirting the Cape Fear area, not enough to include an ILM terminal inclusion. Looking at SSW 5 to 10 thru the night, SW around 10 kt daylight Thu morning, SW 10 to 15 kt inland terminals Thu afternoon/evening, except S 10-15 kt g20 kt for the coastal terminals. 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 Thursday...Bermuda High Pressure offshore will maintain a southerly wind across the Carolinas tonight, veering more southwesterly on Thursday as pressures fall across the Mid Atlantic states. There will likely be fewer showers developing across the ocean tonight versus the last two nights as the atmosphere aloft becomes warmer and drier. Wind speeds should average 10-15 knots outside of local seabreeze enhancement which could approach 20 knots Thursday afternoon in the Myrtle Beach vicinity and north of Cape Fear. Dominant waves should be 6 seconds period from the south with sea heights averaging 3 to 4 feet. Thursday night through Monday... Bermuda high pressure will maintain steady southwesterly flow over the waters through the weekend with daily enhancements due to the sea breeze, although gusts should stay just shy of SCA criteria. After the weekend, Bermuda high pressure splits with one smaller high centering over the Gulf and another displaced into the central Atlantic. The result should be weaker winds that generally favor westerly, but see a southerly turn during the day due to the sea breeze. Waves will stem from a combination of southerly wind waves around 2-3 ft at 5 sec and southeasterly swell around 1-2 ft with a period around 8 sec. && .ILM WATCHES/WARNINGS/ADVISORIES... NC...None. SC...None. MARINE...None. && $$ SYNOPSIS...ILM UPDATE...DCH NEAR TERM...TRA SHORT TERM...ABW LONG TERM...ABW AVIATION...DCH MARINE...TRA/ABW