Area Forecast Discussion
Issued by NWS Wilmington, NC

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489 FXUS62 KILM 170630 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 111 AM EST Sun Nov 17 2019 .SYNOPSIS... Periods of rain, very strong wind, and unseasonably cool temperatures will prevail through the remainder of the weekend, as powerful low pressure deepens off the Carolina coast. The storm will move away from the area late Sunday, with rain and wind trending down. High pressure will follow early next week, with drier and warmer weather into mid week. A cold front is expected to move through the area late next week. && .UPDATE... WINDS: Almost all synoptic/mesoscale models show the strongest 975 mb winds (45-50 kt) affecting the coast between now and 06z. The Frying Pan Shoals buoy has gusted to 58 kt/67 mph within the past hour. Gusts on the beaches have reached 59 mph at Wrightsville Beach, and 45 mph on Topsail Island. Weatherflow station peak gusts include 51 mph at Federal Point, NC; 49 mph at Oak Island, NC; and 48 mph at Lake Arrowhead near Myrtle Beach, SC. At the Wilmington airport gusts have reached 47 mph, with 46 mph at North Myrtle Beach. The Wind Advisory was earlier expanded one tier of zones westward, and continues into Sunday. TEMPS: Temps may rise a bit along the NC coast overnight, with steady to slowly falling temps anticipated across most of northeastern South Carolina. Forecast lows are raised to around 40 on the I-95 corridor, mid 40s SC beaches, and upper 40s NC beaches. Used a raw model-based curve (non-diurnal) to calculate hourly temps through Sunday morning. POPS/WX: Used 18z NAM and 22z HRRR to nudge PoPs/Wx grids overnight. Inland rain should largely dry up around midnight, but waves of rain and some evening elevated convection will continue overnight nearer to the coast. Overall reduced QPF forecasts, especially inland. COASTAL FLOODING: Expanded the coastal flood advisory to cover the Brunswick County coast. Despite offshore winds, the offshore storm has pushed water levels high enough along the entire Carolina coastline to produce flooding during Sunday morning`s high tide. This is one to watch: the latest ETSURGE guidance has Wrightsville Beach getting within about 3 inches of moderate (warning-level) coastal flooding Sunday. && .NEAR TERM /THROUGH SUNDAY/... High Surf Advisory for Pender, New Hanover beaches ongoing through much of Sunday, as 8-13 foot breakers crash onshore. This threat will escalate with Sunday morning`s high tide, as coastal flooding and high water run-up reach peak, increasing the danger for beachgoers, especially anyone entering the surf, or venturing too close to the surf`s edge without a flotation device. Strong winds caught in the pressure grip of the potent coastal low will peak this evening, holding strong overnight, with more notable abating of wind Sunday afternoon. As a result the `Wind Advisory` for the NC coast will remain intact, with N gusts as high as 45-50 mph from Surf City to Wrightsville Beach to Carolina Beach to Fort Fisher to Bald Head Island, to eastern Brunswick county coast tonight and early Sunday. Weakened trees or large branches from Hurricane Dorian`s impacts could topple as winds peak late today, overnight, and early Sunday morning. Approximate center-line of QPf ensembles, pointing to an additional 1.5-2 inches along the NC coast, 3/4-1.25 inches along the NE SC coastal zones, and 1/3-1 inch for most of inland SE NC and NE SC. Areas west of I-95 may only see additional amounts around 1/4 inch. Do not anticipate big flooding problems, but isolated training of rain, or brief high rain-rates, could cause localized flooding, and dangerous water ponding on highways. Wind, clouds, rain, and a singular air mass, will keep temperatures at and by the coast, nearly flat-lined, whereas diurnal temperature ranges well inland will show greater spreads between max-T/min-T. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... A mid level trough will move across the area through the day Monday and guidance, although seemingly going back and forth is once again developing some light showers across the area. Have added little activity (pop) with this development and to align with adjacent offices as well. Highs Monday will be in the middle to upper 50s and lows Tuesday morning with some clearing will be a couple of degrees either side of 40. && .LONG TERM /TUESDAY THROUGH SATURDAY/... The extended period remains relatively unchanged with the mid level trough moving across early in the week transitioning to a somewhat progressive mid level ridge. A broad split flow wants to develop late although there are timing differences with the guidance. A cold front, mainly associated with the northern branch moves across very late in the period. Not necessarily a significant system but low pops are warranted. No significant changes to the temperature forecast which offers little deviation from climatology until late when warmer readings develop. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... Predominantly MVFR thru 13z inland and 19z coastal terminals. There will be bouts of IFR due to ceilings along the coastal terminals thru 14Z. VSBY at p6sm inland terminals even with occasional -ra thru daybreak. At the coastal terminals also p6sm -ra with occasional 5sm in R thru 15Z. Fog or mist for the most part not a player in reducing VSBY. The main problem for pilots will be the gusty northerly winds thru midday today. Inland terminals will see g20-30 kt thru midday and the coastal terminals g25-40 kt also thru midday. As the intensifying pulls away, the sfc pg will slowly relax and the Tafs reflect this diminishing trend. With the ILM terminal at the closest proximity to the deepening sfc low, have continued the low level wind shear at 2k ft at 50-55 kt speeds thru 13Z. Extended Outlook...Mainly VFR thru Thu. Except for possible MVFR ceilings Sunday night into Monday affecting the coastal terminals. And possible MVFR all terminals Thursday morning due to fog. && .MARINE... Dangerous marine conditions, venturing out and especially offshore is highly discouraged. Storm Force winds will rip across the NC waters and buoy 41013 has already reported gusts to 51 knots, or about 59 mph. Gale force winds will rake the SC waters, with a few storm force gusts possible beyond 15 nm tonight and early Sunday. Noticeable lessening of winds will be seen by Sunday afternoon, but still dangerous as large seas propagate through the waters. Seas made up of NE waves 9-14 every 10-12 seconds, with lashing N chop in the mix on top of these large waves. If all this were not convincing enough to stay in port, isolated TSTMs are possible offshore, mainly beyond 10 NM through this evening. No real significant systems to drive winds and seas too high for basically the short and long term period. More variability in the winds, which is typical if anything. A decent northwest flow of 10-15 knots will be in place initially associated with the waning impacts from this weekend`s coastal storm. Weak high pressure will dominate the mid week period with a weak boundary moving across later Tuesday to kick up the winds briefly. A decent and prolonged (at least for the winter season) return flow develops late and increases gradually in magnitude. Could see some 15-20 knot speeds here. Significant seas basically follow the winds with 2-4 feet with maybe an increase late with the better fetch. && .TIDES/COASTAL FLOODING... Dangerous beach conditions through Sunday morning. Tidal flooding will combine with large storm-waves, to bring significant coastal flooding and sea-water run-up at areas beaches. The offshore wind at Brunswick county will help stem the reach and advance of water there, and to a lesser extent at east facing beaches. Erosion will occur Sunday morning, as water levels approach the more rare `moderate` flooding threshold, possibly breaching low dune spots, with exception of Brunswick county. Right now, predicted water levels to make the upper reaches of `minor` category, but this could change to moderate with any increases in predicted levels. The lower Cape Fear river also to experience significant water rises Sunday morning, especially with all the rain run-off, and river levels also approach moderate stages, resulting in much more extensive impacts to residents affected by high water levels on the lower Cape Fear river, and adjacent roadways. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...Wind Advisory until noon EST Sunday for SCZ054. Coastal Flood Advisory until 2 PM EST Sunday for SCZ054-056. NC...Wind Advisory until noon EST Sunday for NCZ105>110. High Surf Advisory until 6 PM EST Sunday for NCZ106-108. Coastal Flood Advisory until 2 PM EST Sunday for NCZ106-108- 110. Coastal Flood Advisory from 10 AM to 2 PM EST Sunday for NCZ107. MARINE...Gale Warning until noon EST Sunday for AMZ254-256. Storm Warning until 6 AM EST Sunday for AMZ250-252. && $$ SYNOPSIS...SHK UPDATE...TRA NEAR TERM...MJC SHORT TERM...SHK LONG TERM...SHK AVIATION...DCH MARINE...MJC/SHK TIDES/COASTAL FLOODING...TRA/MJC is the U.S. government's official web portal to all federal, state and local government web resources and services.