Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 121012 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 612 AM EDT Thu Oct 12 2017 .SYNOPSIS... Unseasonably warm and humid weather will continue through the weekend. A weak cold front will reach the Carolinas late today, with relatively drier and slightly cooler weather heading into the weekend, but continuing unseasonably warm. Fall-like weather should arrive next week as a stronger cold front moves through. && .NEAR TERM /THROUGH TONIGHT/... As of 3 AM Thursday...Mid-level ridge shifting southwest of the area will contribute to west-northwest flow aloft. The combination of northwest flow aloft and weak mid-level subsidence will lead to a decrease in precipitable water with values ranging from 1.60 to 1.80 inches this afternoon. Well below the 2.20-2.40 inches experienced earlier this week. Despite the reduction in moisture aloft the Bermuda High continues to push low level moisture into the region. This will keep the lower level warm and humid and high temperatures will once again run in the mid 80s. The low level moisture will also continue to support diurnally driven showers and thunderstorms, with some help from interaction with cold front moving into the area from the northwest. Forcing associated with the slow moving front is weak however, both the front and the sea breeze will work to enhance diurnally driven convection. The freezing level remains over 16k ft and warm cloud layers will once again be on the order of 13k-14k ft. As such very heavy rain will be possible as storms the do develop will be very efficient at producing rainfall. Low topped showers may continue overnight, especially in the vicinity of the slow moving front. Slightly cooler and drier air will try to work its way into the area as the front moves east, but is likely to have limited success. Temperatures overnight will continue to run well above climo, ranging from upper 60s to lower 70s. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 3 AM Thursday...Moist layer will be much shallower in the wake of a weak cold frontal passage, with the front moving east of the forecast area and offshore by daybreak on Friday. Moisture will be mainly confined below 850mb as advected in off the ocean in a NEly low-level flow. P/W values will be down around 1.50 to 1.75 inches rather than the 2.00 inches plus that we have been experiencing recently. Best chances for precip early in the period on Friday, with chance pops throughout, dropping to slight chance Friday night with silent pops beyond that. This is a cold front in name only, with little in the way of thermal support. Temperatures will remain well above normal, with highs in the lower 80s both days and lows in the mid to upper 60s. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 230 PM Wednesday...Temperatures will be well above normal through the weekend into early next week with H5 ridge across the Southeast United States. The ridge is shown to break down early next week which could open the door to a cold frontal passage and a much cooler airmass for Tuesday and Wednesday. However, the H5 pattern becomes less amplified by early next week creating some doubt that the front will move through late Mon/Tue as currently advertised by the GFS. A slower progression of the front would carry rainfall chances into Tuesday as well. Followed a blend of MEX/ECE max and min temperatures Sat-Monday but leaned toward the warmer MEX temps Tue-Wed time frame. && .AVIATION /12Z THURSDAY THROUGH MONDAY/...
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As of 12Z...For the very near term, through the early morning hours based on IR satellite data, good confidence that the coastal sites will start out VFR, with MVFR cigs for our inland sites. After this, we have a lower confidence forecast through the TAF valid period regarding both timing and magnitude of vsby and cig flight restrictions. Ample tropically-sourced moisture will lead to the potential for MVFR/IFR cig and vsby conditions, especially this evening and overnight, with a multi-layered deck present in some form throughout the period. Best chance for convection will be this afternoon and evening. Extended Outlook...MVFR/IFR conditions are possible during the mornings Friday and Saturday from ceilings and/or reduced vsby from fog. Scattered showers are expected each day which could produce brief MVFR/IFR conditions.
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&& .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 3 AM Thursday...Bermuda High will maintain southerly flow into the evening before weak cold front moves across the waters from the northwest. Prior to the slow moving front`s passage, southerly flow will run 5 to 10 kt. Gradient tightens a little overnight as high pressure starts to build down the coast, resulting in a slight bump in north to northeast winds. Speeds will be on the low end of the 10 to 15 kt range as the period ends. Seas 2 to 3 ft for much of the period will build to a solid 3 ft, mainly across NC waters, following the development of northeast surge overnight. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 3 AM Thursday...Winds will have turned NE at 10 to 15 kts in the wake of a weak cold front that will have just moved just east of the waters Friday morning. Winds will slacken to around 10 kts Friday night, gradually veering to the E by Saturday night while staying light. Seas will range right around 3 ft through the period. LONG TERM /SUNDAY THROUGH MONDAY/... As of 230 PM Wednesday...Weak high pressure will prevail at the onset of the long term period. The high will shift offshore allowing winds to veer to a southerly direction during Sunday. A cold front is expected to approach the waters during Monday but the GFS may be too fast translating into a longer period of southerly winds. Seas are expected to average 3 ft or less through the period && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...99 NEAR TERM...III SHORT TERM...REK/RGZ LONG TERM...SRP AVIATION...REK MARINE...REK/III/SRP is the U.S. government's official web portal to all federal, state and local government web resources and services.