FXUS62 KILM 190215 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 1015 PM EDT Wed Sep 18 2024 .SYNOPSIS... A cold frontal passage and the passage of an upper level trof will result in a chance for showers and isolated thunderstorm thru Thu. Slightly cooler and drier weather will accompany persistent north-northeasterly winds Fri thru the weekend as high pressure builds in from the north. && .UPDATE... Coastal flooding has come to an end along the immediate coast and advisories for all area beaches have expired. There have been some slight changes to PoP as showers continue to persist across portions of southeastern NC and west of the I-95 corridor. Previous update remains valid in regards to the ongoing synoptic setup. Previous update... A sfc cold front dropping southward and a closed low opening up into a trof that will slide to the coast by daybreak Thu. Both will maintain the chance for showers and isolated storms across the FA overnight, with the main thunder threat likely over the waters overnight. Kept fog patchy given various cloud decks across the FA. This may also require a degree or 2 upwards adjustment for tonights lows. && .NEAR TERM /THROUGH THURSDAY/... Upper level reflection of former PTC8 now more open and less impressive. No surprise then that convection has been hard-pressed to produce lightning. Guidance is in good agreement in keeping this so as well as confining coverage to western half of the CWA. Expect a diurnally-driven downward trend in coverage overnight, perhaps to zero for a time. Patchy fog is possible overnight especially in areas that see rain. Slightly better coverage of storms tomorrow but very poor lapse rates will keep lightning to a minimum and rainfall amounts light while we see temperatures similar to those of this afternoon. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... Best rain chances will be near the coast at the start of the period as low pressure departs to our northeast. High pressure will build in from the west where the forecast now remains mostly dry. Some isolated showers and storms could form along the sea breeze Friday afternoon but they should remain shallow and chances of rainfall accumulation >0.05" will be low. Highs in the low to mid 80s with lows in the low to mid 60s. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... Guidance now keeps the offshore low far to our northeast, which diminishes chances of enhanced forcing clipping our area. The period is now looking mostly dry with some temperature complications due to ridging high pressure. Depending on how quickly the high pressure moves in, temperatures could drop into the 70s by Sunday staying seasonable into early next week. The coolest day is looking to be Monday currently. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... Recent thunderstorm coverage has weakened to mainly shower activity while moving across Northeast SC into Southeast NC this evening. May either include a prevailing p6sm -shra or indicate a tempo group to cover this overall dissipating pcpn. Otherwise looking at a mid and high level cloud decks overnight. If a high deck prevails toward daybreak, may see MVFR/IFR fog and/or low stratus especially in the 08 to 12z time frame. CFP to occur during Thu morning with calm winds becoming N-NE around 5 kt, sfc pg rather relaxed in the wake of the FROPA. May observe several VFR cloud decks at different levels once morning stratus and fog dissipates and the cold front sinks further southward. Will maintain the prob30 convective group especially at the coastal terminals during Thu aftn. Extended Outlook...Morning MVFR/IFR possible Friday morning otherwise VFR should dominate the extended. && .MARINE... Through Thursday...Light SW to at times variable winds early in the period with wave energy that continues to abate. A weak boundary turns flow to the north on Thursday as mainly swell waves of 9 seconds remain in the 2-3 ft range. Thursday Night through Monday...N to NE flow will remain dominant through the period due to departing low pressure. Wind speeds will be generally around or above 10 kts with strongest wind speeds (15- 20 kts) expected Sunday into Monday due to ridging high pressure from the north. Waveheights generally 2-4 ft with building 5 footers towards the end of the period due to increasing N-NE swells. && .TIDES/COASTAL FLOODING... High astronomical tides during this full moon cycle will lead to bouts of minor coastal flooding during both the daytime and night time high tide cycles into and likely thru the upcoming weekend. This includes the immediate coasts of both Northeast SC and Southeast NC Coasts. The lower Cape Fear River will also experience minor coastal flooding during each successive high tide cycle into and possibly thru the upcoming weekend. Both high astronomical tides and the runoff from the heavy rains early in the week working its way downstream. && .ILM WATCHES/WARNINGS/ADVISORIES... NC...Coastal Flood Advisory until 2 AM EDT Thursday for NCZ107. SC...None. MARINE...None. && $$ SYNOPSIS...ILM UPDATE...DCH/21 NEAR TERM...MBB SHORT TERM...LEW LONG TERM...LEW AVIATION...DCH MARINE...MBB/LEW TIDES/COASTAL FLOODING...ILM