Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 211103 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 603 AM EST Fri Feb 21 2020 .SYNOPSIS... Low pressure offshore from the Carolina coasts this morning will further intensify as it accelerates away from the mainland this afternoon through Sat. Any ongoing light snow early this morning will quickly end by mid-morning. Cold and dry Canadian high pressure will build in and dominate this weekend. A warm front will lift across the area early Mon bringing milder temperatures thru Tue. A cold front will push across the region late Tue with cold and dry high pressure following for the mid- week period. && .NEAR TERM /THROUGH SATURDAY/... This update will remove Marlboro and Dillon Counties from the Winter Wx Adv with the remaining NC Counties untouched. Will issue a SPS for all locations not in the Winter WX Adv for ice covered roadways, walkways and etc. Temps are right at 32 degrees and may drop 1 or 2 more degrees by sunrise. Decent CAA this morning will slow the diurnal rise of temperatures back above freezing, with guidance suggesting by the mid daytime morning hrs. The back edge of the pcpn shield extends from Elizabethtown, Bladen County, to Myrtle Beach. The back edge will slide off the Carolina Coasts altogether by or just after daybreak. A couple of tenths of an inch of additional snowfall remains possible for Pender and northern New Hanover Counties. Elsewhere, a trace to no additional snow accumulation. Black Ice will be hit hard within the various statements that WFO ILM issues this morning. The intensifying Gale(Storm?) Low with Storm Gusts, up to 50+ kts just offshore from the NC Coastline, will continue to accelerate ENE, away from the U.S. mainland today. The tightened sfc pg combined with CAA surge will keep winds brisk across the FA today with wind chill readings in the upper teens well inland this morning, and the low to mid 20s closer to the coast. The positive tilted mid-level trof pushes off the Southeast Coast by sunset. This will allow the 1035+ mb sfc high to migrate east to the Carolinas late tonight with it`s center becoming sprawled across the Eastern Carolinas by Sat night. Max temps today will run in the upper 30s across locations that received measurable snowfall and elsewhere in the lower 40s. For tonights lows, will highlight the low to mid 20s and that includes an active N to NE wind to prevent temps from bottoming out altogether with progged dewpoints in the teens. Sat max temps will see a 10+ degree change to the milder side with 50 to 55 degree readings. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... The short term period will see very quiet conditions after a long period of unsettled weather. The mid level pattern will continue to relax as arctic high pressure moves overhead then makes the transition offshore. Temperatures will not necessarily be a prelude to spring as lows Sunday morning will be at or below freezing once again only recovering to the middle to upper 50s Sunday afternoon. A return flow setting up keeps lows Monday morning somewhat above freezing. && .LONG TERM /MONDAY THROUGH THURSDAY/... An active southern stream will bring pops back in the picture rather quickly later Monday as low pressure ejecting across the southwest moves into the midwest. We have likely to even categorical pops in place but I have a feeling this system may weaken in time like most following this pattern this season. Beyond this even more uncertainty as a digging trough to the west seems to keep the baroclinic zone parked over the coast with a period or two of unsettled conditions. Global guidance is in agreement on moving this system out near weeks end with another round of possibly freezing temperatures. && .AVIATION /11Z FRIDAY THROUGH TUESDAY/... Flurries coming to an end across the area as dry air surges southward. Northerly winds will increase in intensity this afternoon as the BL develops and a few gusts to 20-25 knots. Skies will clear quickly this morning with some areas in SC already seeing the mid- level deck scour out. VFR this afternoon as winds decrease overnight as high pressure moves overhead. Extended Outlook...VFR will persist through the weekend as cold, dry Canadian high pressure prevails. Flight restrictions will likely return on Monday. && .MARINE... Today thru Sat: N to NNE Winds across the area waters remain solidly in Gales with sustained 30-35 kt and frequent gusts at 40 to 45 kt. Gale Warning remains active across all waters. Latest winds and seas are close to their peaks with this deepening low. With Storm Force gusts, 50+ kt, having been recorded offshore at the Onslow Bay Outer Buoy 41064. Across the ILM Coastal Waters, plenty of gusts in the 40 to 45 kt range with 41037, just offshore from Wrightsville Beach having recorded a 47 kt gust, just shy of Storm conditions. MOS Guidance from both the NAM and GFS for our local buoys indicate winds to peak thru daybreak followed by a slow diminishing trend, below Gale force late in the day. The tightened sfc pg and the cold surge will continue combine to keep winds at SCA thresholds well into tonight. The high`s center will approach the Eastern Carolinas during Sat and as a result, the sfc pg will relax and the CAA will have become neutral. Winds will further lower to 10-15 kt. Significant seas will peak thru midday, with up to 12 to 14 ft just offshore and beyond the ILM coastal waters from Onslow Bay south across the outer Frying Pan Shoals. The northerly component in the wind field has limited the fetch for which waves to build upon, but given the high Gale and low Storm Force wind gusts, seas have become quite monumental with periods at just 8 seconds. That is major league wind chop!!! Seas will initially drop once wind speeds lower today but then will follow a slow subsiding trend with back waves or swell from the departing low affecting the waters Sat. Sat Night thru Tue: ALight wind fields will be in place for the first day or so of the short and long term marine periods. A northerly component will remain for a day or so before the transition to a return flow develops late Sunday and becomes more pronounced Monday. Winds will peak at 15-20 knots late Monday into Tuesday from the southwest ahead of the next system. This boundary never moves across according to the latest projections but the southwest flow does lose some zest. Finally a system late in the work week will turn the winds offshore and seemingly with some authority. Significant seas will be modest early on with a range of 2-3 feet ramping up with the winds into possibly small craft criteria Tuesday and again late in the period with the offshore flow. && .TIDES/COASTAL FLOODING... Have placed the NC beaches in a Coastal Flood Advisory that runs thru 8 am this morning. The latest Johnny Mercer Pier tide forecast has levels reaching just shy of 6.5 ft MLLW at the 549 am high tide this morning. This level breaches the 6.0 ft MLLW threshold for minor coastal flooding to occur. The SC beaches will remain just below minor coastal flood thresholds via latest Springmaid Pier tidal data. The Lower Cape Fear River from Wilmington south has also been included in a Coastal Flood Adv for river levels to reach 5.9 ft MLLW. This forecast level is above the Minor coastal Flood threshold of 5.5 ft MLLW. High tide will occur around 8am at the river gage near downtown Wilmington. Minor flooding will occur up to 3 hrs centered at the time of high tide. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...Winter Weather Advisory until 10 AM EST this morning for NCZ087-096-099-105>107-109. Coastal Flood Advisory until 8 AM EST this morning for NCZ106- 108-110. Coastal Flood Advisory until 10 AM EST this morning for NCZ107. MARINE...Gale Warning until 6 PM EST this evening for AMZ250-252-254- 256. && $$ SYNOPSIS...DCH NEAR TERM...DCH SHORT TERM...SHK LONG TERM...SHK AVIATION...21 MARINE...DCH/SHK TIDES/COASTAL FLOODING...ILM is the U.S. government's official web portal to all federal, state and local government web resources and services.