FXUS62 KILM 200146 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 946 PM EDT Mon Aug 19 2024 .SYNOPSIS... A cold front will slowly move offshore through tonight, bringing isolated to scattered showers and storms. Behind the front, slightly cooler and drier conditions will return for midweek as high pressure builds in from the north. A surface trough offshore should bring cloudiness and some showers to mainly coastal areas, especially starting later in the week. && .UPDATE... Other than a few tweaks to the forecast for latest conditions, little change was med to going forecast for the night. Coastal Flood Advisory for SC was dropped early as water levels remained below thresholds. && .NEAR TERM /THROUGH TUESDAY/... The main surge of the cooler fall preview air mass will move across the area tonight. The visible satellite imagery is similar to this time yesterday so that alone would be concerning. However the deeper cold air aloft appears to skirt by to the north. The forecast does show some convection in a few hours hopefully not as widespread as last night. Lows tonight should wind up in the upper 60s and middle 80s for highs Tuesday. Finally probably more noteworthy of anything else is the Coastal Flood Warning for Wilmington as tide levels are expected to approach seven feet. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... A compact mid-upper low will stall over New England during this period while broad mid-level troughing sits over the eastern US. A surface cold front should be stalling well-offshore at the start of the period with plenty of dry air and subsidence in the mid-levels. Thus, if there happens to be any leftover shower activity near coast due to the sea breeze, these should collapse during the evening with the loss of solar insolation. Otherwise, surface high pressure initially in the Upper Midwest is forecast to shift to near or over Ohio by Wednesday night, keeping a north to northeasterly flow in place behind the front. This will bring much more comfortable weather into the region with below-normal highs in the mid-80s on Wednesday bookended by morning and nighttime lows in the middle 60s. Some cooler spots should be able to dip into the low 60s while the immediate coast stays in the upper 60s. Dew points generally in the low- mid 60s may dip into the upper 50s during the afternoon on Wednesday. && .LONG TERM /THURSDAY THROUGH MONDAY/... Although the closed low over New England shifts away during the latter half of the work week, a mid-level trough pattern should hold over the eastern US with surface high pressure staying in place to our north. While this should maintain pleasantly dry weather across most of the region through the weekend, the aforementioned cold front which moved offshore early in the week will present a forecasting challenge as it drifts back towards the coast late in the week. The high pressure system to its north should prevent it from making much progress northwestward, but coastal areas may end up seeing unsettled weather over the weekend and into early next week as cloudiness and scattered showers and isolated storms emanate from the ocean and dissipate as they move inland. As a result, chance PoPs are maintained across mainly the coastal counties through the period. With persistent northeasterly flow, dew points should stay mainly in the 60s through the period, offering an extended break from the oppressive humidity more typical of summer and serving as a reminder that Autumn is not too far away. High temperatures in the low-mid 80s are expected with morning lows generally in the mid-upper 60s. Some normally colder spots may dip into the low 60s, particularly if clear skies and calm winds occur. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... Mostly VFR conditions expected but it isn't impossible that isolated to scattered convection could affect northern terminals this evening. This could lead to brief periods of MVFR visibilities and ceilings. Since confidence in SHRA/TSRA affecting individual terminals is low, went with VCTS to address. Extended Outlook...Predominantly VFR Tuesday through Friday as high pressure builds from the north, although there is a low risk for restrictions from low clouds/showers, mainly later in the week near the coast. && .MARINE... Through Tuesday... Southwest winds of 10-15 knots will be in place through the evening hours before the primary surge of cooler air moves across. This will lead to a northerly shift with directions settling from the northeast. Speeds will tick down just a bit with the fresh flow. Significant seas will be 3-4 feet overnight with 2-4 feet more representative for Tuesday. Tuesday night through Saturday... High pressure will hold its position to our north through the period with northeasterly flow dominating. As a stalled front draws nearer to the coast, the pressure gradient tightens and brings stronger winds of 15-20 kts from late Wednesday night through Friday before relaxing by Saturday. Waves initially around 2-3 ft over Tuesday night and Wednesday will increase and become dominated by easterly wind waves over Wednesday night into Thursday. Seas rise to 3-5 ft by late Thursday afternoon and may scrape 6 ft in the outer waters on Friday before subsiding through Saturday. Wave period increases over Thursday night as the long fetch of enhanced ENE flow brings easterly swells into the mix. && .ILM WATCHES/WARNINGS/ADVISORIES... NC...Coastal Flood Warning until 1 AM EDT Tuesday for NCZ107-109. SC...None. MARINE...None. && $$ SYNOPSIS...ILM UPDATE...31 NEAR TERM...SHK SHORT TERM...ABW LONG TERM...ABW AVIATION...31 MARINE...SHK/ABW