Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 232340 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 640 PM EST Fri Feb 23 2018 .SYNOPSIS... High pressure off the coast will bring unseasonable warmth through the weekend. A cold front is expected on Monday tempering the warmth some. Seasonable temperatures are expected Tuesday and Wednesday before another warmup Thursday. A stronger cold front will arrive Friday. && .NEAR TERM /THROUGH SATURDAY/... As of 300 PM Friday...As of 330 PM Friday...A maritime surge of cooler air has tripped off sea fog along the Pender and New Hanover coast, and shows no signs of easing up quickly. As a result have extended a `Dense Fog Advisory` for these areas, and a Marine DFA is posted north of Cape Fear. Radiational fog is expected across the remainder of the forecast area overnight into early Saturday, similar to the previous days. Very low-end shower chances off the water tonight, and again inland with heating Saturday afternoon, but moisture terribly lacking above 6000 feet will result mostly in moderate diurnal cumulus, and near record warmth. Record maximum temperatures for tomorrow include, ILM 81 in 1982, CRE 78 in 1996, and FLO 82 in 1962. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... As of 3 PM Friday...Surface and mid-level ridge will continue to sink south and east in the face of approaching 5h trough Sat night. Region remains under the influence of ridging Sat night and Sun with temperatures well above climo. Increasing low level jet Sat night helps keep boundary layer well mixed. Mixing coupled with low level moisture and cloud cover will keep lows in low to mid 60s. Strong warm advection continues on Sun but weakening subsidence and increasing cloud cover may work to limit temps a bit. Despite some limiting factors highs will still end up more than 20 degrees above climo for most areas with low to mid 80s likely. GFS is faster than the ECMWF to bring in showers and the front, something which seems less likely to happen given the presence of such strong ridging, even if it is weakening and retreating. Plan to favor the drier solution offered by the ECMWF and only carry chance pop Sun with an increase to high chance or likely Sun night. As mentioned, best pop chances will be Sun night as the cold front moves into the area. Influence of ridging aloft will be weakening and forecast soundings suggest precipitable water may exceed 1.6 inches late Sun into Sun night. Although the flow aloft is divergent there is an overall lack of shortwave activity and it may end up low level convergence is the main driver of activity Sun night. This is not to say there won`t be some shortwave/PVA enhancement overnight, but the waves that are present are on the weak side. Result will be decent coverage of showers but total rainfall will be limited. Most areas are likely to end up with a quarter inch or less while a few spots may approach half an inch. Temperatures will continue above climo despite the location of the front. Cold advection is well displaced from the boundary and the front will be losing its push as it moves into the area. && .LONG TERM /MONDAY THROUGH FRIDAY/... As of 300 PM Friday...A slow moving cold front is forecast to come through on Monday. The surface boundary will be accompanied by a dry WNW mid level flow. Normally this is not conducive for significant rainfall and Monday appears to be no different. Tuesday will be the one day that high pressure wedges in from the north behind the front. By Wednesday the high moves offshore and return flow gets underway. Models are not in agreement regarding the pace at which this leads to cloudiness and rain chance. Will show a gradual trend through Wednesday into Wednesday night as usually with moisture advection slower solutions tend to be better ones. A more substantial cold front arrives late Thursday or Friday. Guidance varies considerably with the pattern aloft casting uncertainty regarding rain prospects with this stronger boundary. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
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As of 00Z...Moderate confidence in IFR overnight as fog and stratus likely redevelop as it has the past few nights. Large Bermuda ridge remains in place across the Atlantic with a weakening front lifting north into VA. This leaves the terminals in a warm and moist advection regime on return flow, nearly identical to the past few nights. High res guidance and soundings suggest fog and stratus again affecting all terminals, and although nocturnal PBL winds are slightly stronger than last night, moisture content is a bit higher as well. Have used a combination of persistence and the HRRR to try to time IFR development, and expect all terminals will drop to IFR, with LIFR/VLIFR possible, especially at FLO/LBT. Confidence is not high enough attm to indicate any landing mins being exceeded, but that is possible, and will need to be addressed with the next TAF issuance. Fog and stratus will erode slowly after daybreak, with IFR lifting to MVFR, and eventually VFR by late morning. Once again, sea fog and stratus may slow improvement at the coastal terminals, especially the Myrtles on Saturday where SREF probs suggest a better chance for sea fog, but this is typically a very near term and low confidence forecast parameter until it develops. Winds will slowly veer from the south tonight, to S/SW on Saturday, with speeds climbing to 10 kts or more during Saturday aftn. Extended Outlook...Approaching cold front will bring increasing chances for showers and MVFR Sunday and Monday. VFR Tuesday. Showers possible Wednesday.
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&& .MARINE... NEAR TERM /THROUGH SATURDAY/... As of 300 PM Friday...As of 330 PM Friday...Marine `Dense Fog Advisory` remains posted for the 0-20 NM waters north of CApe Fear for sharply restricted visibilities. Aside from the hazard of reduced vision in sea fog, wind and waves will be welcoming. SE waves 3 feet every 9 seconds will be co-joined with a light chop. Seas possibly up to 4 ft outer waters, but this wave energy is not steep. No TSTMS this period, but isolated showers and bouts of sea fog should be expected tonight and Saturday. SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... As of 3 PM Friday...High pressure will remain off the coast through the period. Southwest flow will gradually increase Sat night and Sun with speeds peaking in the 15 to 20 kt range Sun afternoon. Gradient will start to weaken later Sun or Sun night as slow moving cold front reaches the area. Flow remains out of the southwest but speeds will drop to 10 to 15 kt. Seas will run 3 to 4 ft through the period. LONG TERM /MONDAY THROUGH WEDNESDAY/... As of 300 PM Friday...Frontal passage on Monday will lead to a shift from W to NW winds. This front will be weak and so not expecting any surge of high pressure, cold air, or gusty winds. High pressure behind the front does not drive very far south as it progresses off the coast to our north heading into Tuesday. This turns winds to NE and then E with no significant change in wind speeds. The onshore flow direction however will allow for slightly larger seas. No headlines are planned at this time. Wind and waves may build at the end of the period or just beyond with the approach of the next front, which will be much stronger. && .ILM WATCHES/WARNINGS/ADVISORIES...
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SC...None. NC...Dense Fog Advisory until 7 PM EST this evening for NCZ106-108. MARINE...Dense Fog Advisory until 7 PM EST this evening for AMZ250.
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&& $$ SYNOPSIS... NEAR TERM...JDW/MJC SHORT TERM...III LONG TERM...MBB AVIATION...JDW MARINE... is the U.S. government's official web portal to all federal, state and local government web resources and services.