FXUS62 KILM 190029 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 829 PM EDT Thu Jul 18 2024 .SYNOPSIS... Showers and thunderstorms will move in ahead of a cold front tonight. The front will linger near or north of the area through the weekend. Rain chances will remain elevated through Monday with temperatures running near to slightly below normal. Unsettled weather may continue into early next week. && .UPDATE... Forecast is largely on track at this point. The cold front is just north of the local forecast area, with a broken line of showers and storms ahead of it. Outflow from the storms is outrunning the front more and more, as expected. Storms should be reaching coastal areas north of Cape Fear within the next couple of hours, with the Grand Strand coast lagging about an hour or so. Some of these storms could become strong at times, with 40-45 mph wind gusts and small hail. High rainfall rates may lead to ponding or nuisance flooding, particularly if the stratiform shield behind the main line slows over a particular area. Elsewhere, updated 00Z TAF discussion found below. && .NEAR TERM /THROUGH FRIDAY/... Thus far have seen minimal development of convection across the local area, but this should change later this evening as weak front and the remains of the Piedmont trough move in from the northwest. Scattered convection developing along the front across the central Carolinas will move southeast, accelerating ahead of the boundary and reaching the forecast area by early evening. Some isolated storms will bubble up along any surface boundaries (ie seabreeze and Piedmont trough) the next few hours, but more widespread and stronger storms will be the ones moving in from the northwest. Any well developed storms will have the potential to produce significant rainfall, with a deep warm cloud layer and precipitable water values around 2.25" in the afternoon and evening. Storm motion of 15-20kt will limit flooding potential, but localized flooding, mainly in typical prone areas, will be possible given the high rainfall rates. Cannot rule out a couple severe storms, but most of the convection will remain sub-severe. Front sags into the area overnight, reinforcing the already moist airmass. Despite the front in the area, boundary winds will be strong enough to keep stave off significant fog development. Lingering debris cloud, low level winds and moisture will continue the stretch of overnight lows above climo. Most of the environmental conditions Fri will be similar to today. High pwats, deep warm cloud layer, and CAPE 2k-3k J/kg. However, there will be a few significant differences. The weakening front will be stalled in or near the area and storm motion will drop closer to 10kt. The presence of the boundary within a very moist/unstable environment should lead to higher coverage of convection and an earlier start to the storms. Increased cloud cover will lead to cooler temperatures. Cooler temperatures coupled with weaker winds and lower shear will curtail any severe weather threat, but the high efficiency of the storms coupled with their slow movement will increase the potential for flooding. && .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/... By the start of the period, a stationary front should be stalled near the coast. A shortwave looks to pass to our NW late Fri into early Sat, with localized low pressure forming along the boundary at the surface. Shower/storm coverage will be enhanced overnight with higher coverage shifting towards the coast during the day Saturday. PWATs will be near 2-2.5" with soundings showing the warm cloud layer 10000-13000 ft. Localized flooding could be possible due to how moist the environment will be. && .LONG TERM /SUNDAY THROUGH THURSDAY/... Unsettled weather holds through the long term period. Ridging will build overhead with vorticity skirting around the CWA, the pattern of showers/storms looking more diurnal in nature with lower POPs overnight increasing in the afternoon/evening near the Piedmont and at the coast. Temps will be fairly steady day to day and near normal. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... Mostly VFR to open the 00Z TAF period, with exceptions. A line of showers and storms ahead of a cold front is moving through the area, affecting KFLO and KLBT to open the period. This line should make it to KILM by 02-03Z, while KCRE/KMYR may linger an hour or so behind. MVFR to IFR restrictions expected within TSRA. MVFR and even IFR ceilings may linger in the wake of the storms overnight, especially inland. Fog will be less of a concern given the strength of boundary layer winds, although brief MVFR visibility cannot be ruled out. Front will be in the area Friday, which should lead to increased coverage of showers and thunderstorms as well as an earlier start time. It could very well be that storms develop before 18Z, but holding off on that idea for now. PROB30 groups represent TSRA timing after 18Z Friday. Extended Outlook...Potential for afternoon and evening MVFR/IFR from showers and thunderstorms each day. && .MARINE... Through Friday... Southwest flow will continue through Fri but speeds will begin decreasing as the gradient relaxes a bit. The combination of cooler temperatures inland and the approach of the weakening surface boundary will drop winds from 15-20 kt this afternoon to 10-15 kt tonight and Fri. While some gusts in excess of 25 kt will remain possible through the evening hours, have no plans for any headlines. Seas will trend down, dropping from 4-5 ft today to 3-4 ft tonight and 2-3 ft Fri. The southerly wind wave will remain dominant, although it will start to weaken Fri. A southeast swell will also be present. Friday Night through Tuesday... South to southwest flow will remain dominant with speeds 10-15 kts remaining sub-SCA thresholds. Seas will be 2-3 ft with an increase to 3-4 ft late Saturday through the end of the period as the 8-10 seconds SE swell increases. && .ILM WATCHES/WARNINGS/ADVISORIES... NC...None. SC...None. MARINE...None. && $$ SYNOPSIS...ILM UPDATE...IGB NEAR TERM...III SHORT TERM...LEW LONG TERM...LEW AVIATION...IGB MARINE...III/LEW