Area Forecast Discussion
Issued by NWS Wilmington, NC

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS62 KILM 251729 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 129 PM EDT Mon Sep 25 2017 .SYNOPSIS... Hurricane Maria is expected to remain offshore and move slowly north, with its center passing about 250 miles east of Cape Fear Tuesday night. Dangerous beach and marine conditions will prevail much of the week. A cold front should reach the area late Friday, bringing cooler and drier air into next weekend. && .NEAR TERM /THROUGH TONIGHT/... As of 1030 AM Monday...A persistent area of low clouds along with a smattering of coverage from high level moisture is holding down temperature trends across the eastern two thirds of the area this morning. I have adjusted the current grids and high temperature forecast down accordingly. No other changes. Previous discussion follows: Ridging aloft over the Mid-Atlantic and 5h low/trough over the eastern Gulf Coast will gradually weaken today as Hurricane Maria moves slowly northward. Maria will pass well east of the area later today and tonight. The pinched gradient between the surface high nosing down the coast and Maria is likely to create breezy conditions this afternoon and evening, especially along the NC coast. Although there will much deeper moisture compared to the last few days, precip chances are not any higher. Maria will be spreading moisture below 500mb over the region but the subsidence on the periphery of the storm will keep the atmosphere capped. Despite precipitable water values approaching 1.9 inches it appears measurable precip will be hard to come by. Scaled back pop a bit for today, taking out any mention of showers into the evening. Did hold onto slight chance pop for the NC coastal counties overnight as Maria moves ever so closer. Do not have a lot of confidence in this but there will be an abundance of low level moisture and a bit of convergence right along the coast. High temperatures will trend a little cooler today compared to Sun with low to mid 80s expected. Lows will likely trend slightly warmer due to increased boundary layer winds and moisture/cloud cover, ranging from mid 60s to around 70. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... As of 327 AM Monday...This period will witness a slow migration north of Maria, forecast to be a Category 1 as it passes 250 NM east of Cape Fear late Tuesday night. Primary hazards are powerful surf and large breaking waves due to the speed of the long-period sets. As a result the `high surf advisory` will likely remain posted at least through Tuesday, laced with lethal rip currents and clipping, swift beach run-up. A few outer bands may be flung ashore Tuesday but no severe threats anticipated, in fact moisture remains shallow to the extent only showers are advertised. Peak low-level winds appear timed for Tuesday and any landward moving rain bands could throw a 30-35 mph gust at the coast, favored mainly from Cape Fear northward where greater easterly longitude in intrinsic there. Maximum temperatures both Tue/Wed mid 80s. Winds and a few clouds may hold minT values up at around 70s both Wed/Thu morning. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 3 PM Sunday...Maria, forecast to be well to the east- northeast of the area at the onset of the period, will continue moving north and east away from the area. A cold front will drop into the area Thursday night and move out to sea Friday, ushering in cooler and drier air for the weekend. Outside of a small chance of showers Wednesday, mainly over northeast sections of the forecast area, the extended range looks mainly dry. High temperatures in the mid 80s to around 90 Wednesday and Thursday will cool to the mid 70s by Sunday. Min temperatures in the upper 60s to lower 70s will cool to the upper 50s to lower 60s by Saturday night. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... As of 1800Z...MVFR conditions reside at the coastal terminals while inland sites are mostly VFR. This will continue to be the pattern through the period as the broad circulation around Maria will advect deeper moisture in along the coast. Guidance has the coastal sites going down into IFR tonight and I followed this with several hours starting at 03 UTC. Ceilings gradually lift Tuesday with MVFR developing once again along the coast. Extended Outlook...Conditions will improve from mid week on as Marie moves further away. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 1030 AM Monday...No changes to the coastal waters forecast with the mid morning update. Rugged seas and strong winds will continue for the next couple of days. Previous discussion follows: Although Hurricane Maria remains well to the southeast, the gradient between the storm and high pressure to the north will maintain northeast winds today, becoming north winds overnight. Speeds will stay in the 20 to 25 kt range through the period and gusts will have the potential to exceed 30 kt. Seas, mostly made up of swell from Maria, will range from 5 ft near shore to as high as 11 ft across outer edges of the NC waters. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... As of 327 AM Monday...Sea heights will peak Tuesday as Maria moves slowly north about 250 miles offshore of Cape Fear, with 7-14 foot high waves on tap, highest offshore, and lowest inshore along SC where sea bottom friction will consume a chunk of the swell energy. Inlet turbulence may be expected during outgoing tides much of this week. Large breaking waves will pose a threat near sand bars, and the surfzone will extend much farther than usual due to the large and long period waves. Winds will peak Tuesday N 20-30 KT, and well offshore a few gusts to 35 KT will probably occur, although confidence is not high for full Gale conditions to be expected at this time. At a minimum, SCA cond are expected through this entire period. LONG TERM /WEDNESDAY THROUGH FRIDAY/... As of 3 PM Sunday...Northwest winds of 15 to 25 KT Wednesday morning will diminish to 10 to 15 KT by Thursday morning. A shift to the north then northeast will occur Friday and Friday night. Seas of 4 to 7 FT south and 7 to 9 FT north will subside through the period, falling to 3 to 4 FT by Friday. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...High Rip Current Risk through Tuesday evening for SCZ054-056. High Surf Advisory until 9 PM EDT Tuesday for SCZ054-056. NC...High Rip Current Risk through Tuesday evening for NCZ106-108- 110. High Surf Advisory until 9 PM EDT Tuesday for NCZ106-108-110. Coastal Flood Advisory until 3 PM EDT this afternoon for NCZ107. MARINE...Small Craft Advisory until 6 PM EDT Wednesday for AMZ250-252- 254-256. && $$ SYNOPSIS... NEAR TERM...III/SHK SHORT TERM...MJC LONG TERM...DCH AVIATION...SHK is the U.S. government's official web portal to all federal, state and local government web resources and services.