Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 230645 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 216 AM EDT Fri Jun 23 2017 .SYNOPSIS...
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Bermuda High pressure will build westward over the Eastern Carolinas through today. The remnants of Cindy moving up from the Gulf coast will get absorbed into a cold front marching east reaching the Carolinas tonight into Saturday with an increasing chance of showers and thunderstorms heading into and through the weekend. This cold front will reach the coast by Sunday but will not get pushed completely out of the area until a second front sweeps through by Tuesday. Dry High pressure will build in through the middle of next week.
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&& .NEAR TERM /THROUGH FRIDAY/... As of 730 PM Thursday...Only subtle changes to the forecast this evening with some very near term tweaks to cloud cover and temperature trends. Most guidance has showers ending almost completely over the next few hours and even though we aren`t carrying much I resisted removing pops completely as any outflow or residual boundary could trigger some activity. No other changes. Previous discussion follows: Plenty of tropically-sourced moisture in the column now with soundings showing P/W values in the 2 inch range. This will change in the early morning hours of Friday as dryer air at the mid-levels moves in. High-res guidance handling present convection well with a focus along the coast and secondary activity well inland. Have relied on this guidance for the very near term, with pops dropping to slight chance overnight and only isolated convection for Friday. Temperatures will remain very seasonally-correct and do expect warmer readings on Friday as we will see more breaks on the cloud cover. We will be seeing the beginnings of a pattern shift during the Near Term, with the Bermuda ridge pushing east as the upper H/5 ridge breaks down as a broad upper trough descends upon eastern CONUS. && .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/... As of 3 PM Thursday...The upper ridging extending across the Southeast States, including the ILM CWA, will peak Fri evening. This will help keep the remnants of Cindy west and north of the FA Friday night with models taking it off the DELMARVA Coast during Saturday morning. The flow aloft will suppress the upper ridging during Saturday with models indicating the upper longwave trof expanding southward as a result of weak mid-level s/w trofs/vorts rotating thru it. The wavelength of this upper trof is quite extensive, affecting a good chunk of U.S. real estate by and during this upcoming weekend. At the sfc, the remnants of Cindy will hook up with a cold front Fri night. The cold front is progged to be oriented NE to SW across the western Carolinas early Saturday and will slowly sink toward the southeast Saturday and likely across portions of the FA Sat night. Any leftover diurnally induced convection Fri evening should become pop-less Fri night into early Sat. Convection will fire up by mid to late Sat morning inland and extend to and off the Carolina coasts during Sat and Sat night. Will have forcing from the front, pinned sea breeze, differential heating and very weak but effective perturbations in the mid-level flow. Pops will be ramped up to Good Chance just shy of likely, for Sat aftn and night. The sfc pg will remain tightened thruout this period except come Sat night when the cold front itself will be nearly overhead. As for winds, expecting SSW-SW 10 to 15 mph, except up to 20 mph at the coast, winds will become SW-WSW 10-20 mph during Sat then finally decrease Sat night as the sfc pg relaxes. && .LONG TERM /SUNDAY THROUGH THURSDAY/... As of 3 PM Thursday...Cold front will be stalled along the coast Sunday and Monday before being pushed offshore and out of the area during Tuesday. The stalled boundary combined with deep SW flow aloft and residual moisture from the departing remnants of TS Cindy will create a good chance for showers and thunderstorms the first half of the extended. The GFS has been consistent with widespread activity Sunday and Monday, and now the latest ECM/CMC have trended in that direction as well. PWATs climb towards 2.25 inches Sunday before slowly falling Monday, so the highest POP will be Sunday, but an unsettled period is expected until a secondary front beneath an anomalously deep trough clears everything out on Tuesday. This secondary front will usher in much cooler air for the remainder of the period. 850mb temps crash towards +10C, near the bottom 10th percentile for late June, and highs will likely remain at least 5 degrees below climo Tue/Wed with dewpoints potentially falling into the 50s! This will feel quite refreshing, especially after the high humidity of Sunday. By Thursday the surface high shifts offshore and height rises begin again, so temps and humidity will increase, but remain below seasonable norms into late week. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/...
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As of 06Z...Moisture streaming north mainly in the way of mid to high clouds with bkn ceilings between 15k and 25k but expect some bkn to ovc stratus developing mainly inland between 800 ft and 1500 ft, lifting shortly after daybreak. Therefore LBT and FLO should have IFR ceilings this morning. Expect mostly VFR along the coast through the period, but added some SCT lower ceilings and some SHRA/TSRA possible mainly just inland from coastal terminals this afternoon with possible deck of strato cu mixing in with some AC/CI. Included VCSH to acct for that. Southwest winds around 5 to 7 kts should keep fog out of the forecast although guidance shows it possible in FLO and LBT right around daybreak. Extended Outlook...MVFR ceilings/vsbys Saturday as tropical moisture associated with Cindy remnants traverse the region. More MVFR/IFR conditions possible in SHRA/TSRA with cold front late Saturday through Sunday possibly again on Monday
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&& .MARINE... NEAR TERM /THROUGH FRIDAY/... As of 730 PM Thursday...No changes to the coastal waters forecast with the evening update. Previous discussion follows: Persistent S to SWly winds will persist over the waters around the back-side of the Bermuda High through the Near Term. Main change will be a gradual tightening of the gradient with winds increasing from present 5 to 10 kt range to 10 to 15 kts tonight and 15 to 20 kts by Friday afternoon. Seas will likewise increase, from around 2 ft this afternoon to 2 to 3 ft tonight and up to 4 ft on friday. Winds and seas will be higher in the vicinity of thunderstorms this afternoon. SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/... As of 3 PM Thursday...SCA conditions Fri night thru Saturday. Dropping back to SCEC conditions during Sat night. Bermuda high pressure centered off the Southeast U.S. Coast will lose a portion of its grip across the local waters this period. This in response to a sfc cold front dropping southeast and becoming oriented NE-SW just inland from the Atl waters by late Sat night. At the start of this period, a well tightened sfc pg will exist across the local waters, which will continue thru Fri night and daytime Sat. During Sat night, models finally and slowly relax the pg across the area waters. Wind directions will basically run from the SSW-SW Fri night and SW-WSW Sat into Sat night. Significant seas will be elevated thruout this period, peaking Fri night thru early Sat evening. Locally produced wind driven waves at 3 to 5 second periods will dominate this period. The SW-WSW winds will result in a limited fetch for the seas to develop off of. Scattered to widespread convection Sat afternoon and night will pose the usual hazards to mariners. LONG TERM /SUNDAY THROUGH TUESDAY/... As of 3 PM Thursday...Cold front will stall along the coast and waver in the vicinity Sunday and Monday before a secondary front pushes everything out the sea and clears the waters on Tuesday. Winds will fluctuate between S and W Sunday/Monday, but the weak gradient immediately near the front will keep winds at 10 kts or less regardless of direction. As the second front kicks everything off to the east on Tuesday, winds will northerly, with speeds around 10 kts. A 2 ft/8sec SE swell will exist in the spectrum each day, and thanks to light winds Sun/Mon will likely be the predominant wave group despite a present S/SW wind-wave. Seas will be 3-4 ft very early Sunday before falling to 2-3 ft most of Sun/Mon, and then fall further to 1-2 ft Tuesday as the winds turn offshore. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...Small Craft Advisory from midnight Friday night to 6 AM EDT Sunday for AMZ250-252-254-256. && $$ SYNOPSIS...REK NEAR TERM...REK/SHK SHORT TERM...DCH LONG TERM...JDW AVIATION...SHK is the U.S. government's official web portal to all federal, state and local government web resources and services.