Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 240423 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 1223 AM EDT WED AUG 24 2016 .SYNOPSIS... High pressure will extend along the East Coast through Thursday, maintaining comfortable conditions. An upper ridge will expand overhead late in the week and into the weekend, bringing a return to seasonable heat and humidity. Isolated showers and thunderstorms may return this weekend. && .NEAR TERM /THROUGH TODAY/...
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As of 1230 AM Wednesday...Midnight temperatures near the coast were running well above prior forecast curves. This appears to be due to easterly winds which haven`t yet died down. Air temps are still in the 80s on the east and southeast-facing beaches, and if winds don`t die down and/or back to the northeast soon there`s not much to change this. Farther inland temperatures are much closer to prior forecasts. Changes with this update include increasing sky cover for the next couple of hours as a region of scattered to occasionally broken mid-level clouds (thin moisture trapped beneath the strong subsidence inversion aloft) traverses the area from north to south, and increasing forecast wind speeds and temperatures along the coast. Wilmington`s string of consecutive 70+ days is still going, and the updated forecast low of 69 assumes we have at least a few good hours of radiational cooling with light winds before sunrise. We`ll see... Discussion from 1000 PM follows... Some patchy mid and and high clouds were still moving across the forecast area late this eve, but the trend has been for fewer clouds with time. A comfortable night by late Aug standards is expected, as measured by temperature and humidity. Ridging at the surface and aloft will be the name of the game through the period. Low-level northeast flow will continue overnight with light winds. Lows will be in the mid and upper 60s with lower 70s at the beaches.
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&& .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... As of 300 PM Tuesday...Surface and mid level ridging will remain in control of the region through the period. Elongated surface high pressure extending from the Mid-Atlantic coast to off the New England coast will slowly shift east through the period, maintaining low level northeast flow through Thu night. Meanwhile ridging aloft will move from the Gulf Coast Wed AM to over the Carolinas later Thu, strengthening a little as it moves north. Increasing subsidence under the ridging aloft will limit deep moisture and likely suppress any convection. Mixing is likely to keep low level moisture limited during the day, especially on Wed, despite low level onshore flow. Temperatures will be near climo through the period. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... As of 300 PM Tuesday...A broad ridge at the surface and aloft will dominate the pattern through the long term, although there is a bit of uncertainty at the end of the period which will depend upon the state of any tropical development and movement. At this point ensembles do not show any tropical systems influencing our area, so we are looking at fairly benign weather through the period. Subsidence under the upper ridge in combination with moisture-starved upper levels will keep a lid on convection, although the odd diurnally driven shower or thunderstorm cannot be ruled out. Expect mostly sunny to partly cloudy skies with afternoon cu developing each day, with skies clearing at night. A blend of guidance keeps temperatures a notch above seasonal levels through the period. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... As of 00Z...High pressure will contine over the TAF site through 00 UTC on Wednesday. VFR is expected with light and variable winds overnight. After the morning inversion erodes the winds will return from the northeast wind around 6 to 8 knots before slowly turning to the east at 8 to 10 knots after 18-19 UTC. Models moisture indicates scattered clouds will form between 4000 and 5000 feet by midday into the afternoon. Extended Outlook...VFR. && .MARINE...
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NEAR TERM /THROUGH TONIGHT/... As of 1230 AM Thursday...Fairly strong east-northeast winds are blowing across the coastal waters in the gradient between high pressure to our north and lower pressure over the northern Bahamas and Florida. Latest wind gusts include 21 knots at Wrightsville Beach and the Frying Pan Shoals buoy, 24 mph at Kure Beach and at the Southport River Pilots Office, and 22 mph at Topsail Beach. These wind speeds are anywhere from 4 to 8 knots stronger than previously forecast, and this update increases our forecast winds to sustained 15-20 knots for the next several hours, diminishing to 10-15 kt toward sunrise. In addition to this shift in the forecast, sea heights are running 1-1.5 feet higher than predicted with the nearshore Wrightsville Beach buoy reported 4 feet only 5 miles from shore. Conditions appear to be as bad as they`ll get currently, and wind speeds and wave heights should both be diminishing by sunrise. We`ll watch this trend closely because any worsening conditions could require an exercise caution headline in the forecast. Discussion from 1000 PM follows... Surface high pressure to the north will maintain northeast winds of 10 to 15 kt across the waters. Seas will continue in the 3 to 4 ft range with wave periods of 4 to 5 seconds. Wave periods will begin to lengthen in the coming days as swell begins to reach the area from distant tropical systems. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... As of 300 PM Tuesday...Northeast flow continues through the period as the surface high to the north becomes elongated as it retreats northeast. Gradient will remain unchanged with speeds on the higher end of the 10 to 15 kt range. Seas will generally be 2 to 3 ft with isolated 4 ft near 20 nm possible. LONG TERM/FRIDAY THROUGH SUNDAY/... As of 300 PM Tuesday...A broad and weak high pressure system extending across the waters will keep winds NE to E at around 10 kt or so through much of the period, with seas of right around 3 ft. However, seas on Sunday may build to 4 or 5 ft as long-period swell from distant tropical systems impinge upon the local waters.
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&& .CLIMATE... As of 700 PM Tuesday...Wilmington has broken its record for the most consecutive days with low temperatures of 70 degrees or warmer. We are not expected to drop below 70 before this climatological day has ended. However, the record string will end overnight as the low temp at the Wilmington International Airport is expected to drop to 67 degrees near daybreak. Wilmington`s temperature records began in 1874. Wilmington`s Consecutive Days with Low Temperatures 70+ degrees #1 58 days 6/27/2016 to 8/23/2016 #2 56 days 6/29/2012 to 8/23/2012 #3 52 days 6/22/1941 to 8/12/1941 #4 48 days 7/ 6/1986 to 8/22/1986 #5 46 days 6/28/1991 to 8/12/1991 In Florence, SC the record for consecutive 70+ degree low temperatures has also been broken. Florence temperature records began in 1948. Florence`s Consecutive Days with Low Temperatures 70+ degrees #1 62 days 6/22/2016 to 8/22/2016 #2 60 days 6/26/2005 to 8/24/2005 #3 55 days 7/ 6/1975 to 8/29/1975 #4 46 days 7/10/2010 to 8/24/2010 #5 45 days 6/11/2015 to 7/25/2015 #5 45 days 6/28/1991 to 8/11/1991 && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...REK NEAR TERM...TRA/RJD SHORT TERM...III LONG TERM...REK AVIATION...DRH is the U.S. government's official web portal to all federal, state and local government web resources and services.