Area Forecast Discussion
Issued by NWS Wilmington, NC

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694 FXUS62 KILM 231450 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 1050 AM EDT TUE AUG 23 2016 .SYNOPSIS... High pressure will extend along the East Coast through Thursday, maintaining comfortable conditions. Upper ridge will expand overhead late week and into the weekend bringing a return to seasonable heat and humidity. Isolated showers and thunderstorms may return this weekend. && .NEAR TERM /THROUGH TONIGHT/...
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As of 1030 AM Tuesday...Quiet day on tap with surface high centered north of the area and 5h ridge centered to the south. The combination of moist low level northeast flow around the surface high and strong capping around 7k ft may lead to a little more cloud cover than would be expected, especially along the NC/SC coast. Any diurnal cumulus that do develop will remain flat, tops below 10k ft, with no chance of producing any rainfall. Clouds quickly dissipate with loss of heating this evening. Only minimal changes needed for morning update. Previous discussion from 0630 follows: This morning`s landbreeze front has pushed up to 10 miles off the coast. A few showers have even developed off the Horry County SC coast. Radar cross-sections reveal the reflectivity abruptly ends at 9000-10000 feet AGL, just above where the strong subsidence inversion begins. Look for these showers to fall apart later this morning as the landbreeze falls apart. 500 mb high pressure centered over Florida will retrograde slowly westward today. Massive subsidence in the vicinity of this ridge continues to cover the Carolinas. In fact the scattered clouds we have around the area this morning are mainly due to a thin layer of moisture trapped beneath the subsidence inversion around 7000 feet AGL. Surface high pressure centered over the Mid- Atlantic states is feeding a stream of fairly cool, dry air southward from Southeastern Canada. This airmass has obviously modified a great deal from its passage across the warm western Atlantic waters, but compared to the rest of the summer it`s a refreshing change. Today`s highs should run a degree or two cooler than yesterday, 87- 91, mainly due to the airmass cooling in the continued NE flow. However 850 mb temps of +14C to +15C are only about 1.5 degrees C below normal. The surface high should edge off the Mid-Atlantic coast tonight with NE winds continuing. Lows should range from 65- 70, warmest at the beaches.
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&& .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... As of 300 AM Tuesday...The 500 mb ridge over the Gulf Coast on Wednesday will move into western NC by late Thursday. Massive subsidence aloft will continue to completely cap the airmass to deep convection. At the surface, high pressure off the Mid-Atlantic coast will move farther out to sea while extending a ridge axis southwestward back into the Carolinas. This should maintain a northeasterly low-level flow with little temperature change expected from today. && .LONG TERM /FRIDAY THROUGH MONDAY/... As of 300 AM Tuesday...Broad high pressure centered off the New England coast will remain the dominant feature into next week as it ridges weakly down into the Carolinas. While this occurs, expanding mid-level ridge will amplify and encompass much of the Southeast, leading to a return to above seasonable warmth and humidity while keeping POP very low. 850mb temps climb back towards 20C, which when combined with ample sunshine and easterly flow will bring a return to heat index values a few degrees either side of 100 for the extended. While this heat and humidity would support aftn convection, significant subsidence beneath the ridge will suppress all but the strongest updrafts, which by themselves will be difficult to achieve due to weak lapse rates thanks to the warm mid- level temps. Still, deep E/NE flow this wknd will bring PWATs back to normal values for late August so will continue with very SCHC POP for the latter half of the extended. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... As of 12Z...High confidence for VFR through the valid TAF period as high pressure continues to settle into the region. Passing mid to high clouds this morning, few in nature, will give way to nearly clear skies later this morning, and persist through the remainder of the valid TAF period. Light northeasterly winds this morning will become east-northeasterly this afternoon, increasing to 5 to 10 kts before becoming light and variable again tonight. Extended Outlook...VFR. && .MARINE...
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NEAR TERM /THROUGH TONIGHT/... As of 1030 AM Tuesday...Surface high centered north of the area will maintain northeast to east flow over the waters today and tonight. A slow but steady increase in the gradient is expected today and tonight in response to the tropical wave southeast of the Bahamas moving ever closer. Solid 15 kt winds expected this afternoon and overnight with seas running 3 ft. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... As of 300 AM Tuesday...High pressure will move farther east off the Mid- Atlantic coast through the period but will extend a ridge axis southwestward across the Delmarva and into western North Carolina. This should maintain a northeasterly wind across the area with speeds 10-15 kt. Seas of 3-4 feet will subside Thursday night as wind speeds diminish. LONG TERM/FRIDAY THROUGH SATURDAY/... As of 300 AM Tuesday...Broad high pressure will move offshore New England but maintain a ridge axis down the coast into the upcoming weekend. This will persist E/NE winds at 5-10 kts both Friday and Saturday, with subtle shifts to SE at times. Seas will feature a low amplitude E wind wave, but will be dominated by an amplifying SE 9 sec swell, creating wave heights of 2-3 ft, with some 4 fters developing late in the period.
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&& .CLIMATE... As of 300 AM Tuesday...Wilmington has broken its record for the most consecutive days with low temperatures of 70 degrees or warmer. It remains to be seen if we make it down below 70 before sunrise, potentially tacking on one more day to this record-breaking string. Wilmington`s temperature records began in 1874. Wilmington`s Consecutive Days with Low Temperatures 70+ degrees #1 57 days 6/27/2016 to 8/22/2016 #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...JDW NEAR TERM...III SHORT TERM...TRA LONG TERM...JDW AVIATION...SGL is the U.S. government's official web portal to all federal, state and local government web resources and services.