Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 180513 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 1213 AM EST Thu Jan 18 2018 .SYNOPSIS... A cold front will bring a mix of rain and snow, and will clear the coast late tonight. Cold and dry Arctic air, will spread into the region through Thursday. Temperatures will warm into the weekend as high pressure moves offshore. Another cold front will bring rain chances by Monday evening, but little cooling, and temperatures are expected to remain above normal into next week. && .NEAR TERM /THROUGH TODAY/... As of 900 PM Wednesday...Much of the moisture has scoured out across the ILM CWA, well ahead of the upper closed low. This potent closed low will move across the FA late this evening and overnight with continued limited moisture across the FA. Some Atlantic moisture will be drawn in, however areas north of the ILM CWA, from Cape Lookout northward, will be the beneficiaries. Basically, will have to rely on the dynamics of the upper closed low and it`s accompanying moisture, which is not much. Due to the moisture dilemma, we have downgraded the Winter Storm Warning to a Winter Weather Advisory for those 2 counties. Have continued the Winter Wx Adv for the 4 inland counties. Due to the limited moisture, have lowered the total snow accumulations to 1 to 2 inches across the northern periphery and that`s being very generous, elsewhere, looking at 1 inch or less for the those 4 counties within the initial Winter WX Adv. Wind chills by morning will be in the upper single digits well inland. Any further decrease in temps and/or higher wind gusts would produce wind chill advisory numbers which is 5 degrees or less. Previous................................................. As of 300 PM Wednesday...A Winter Storm Warning continues for Marlboro and Robeson counties, and a Winter Weather Advisory remains in effect for Darlington, Marlboro, Bladen, and Pender counties. GOES-East water vapor is showing the mid-level trough moving into the western Carolina`s. At the surface the cold frontal boundary is entering into the western portions of the forecast area. The 2 pm observations is showing rain over most of the forecast area. The latest HRRR is showing the best chances of snow in the western half of the area after 3 PM and will slowly make it to the coast. Timing for the coast appears to be after 8 PM. With the dry air it appears after the initial shot of precipiation that we will see light snow or flurries well after midnight. Also, with delay in the system making eastward have extended the warnings and advisories to 1 AM. Also, for areas south of the warning and advisory area will have to watch for black ice as any liquid precipiation that does fall will likely freeze. As the storm pushes off the coast, winds will increase and combined with the low temperatures will see wind chills in the the 8 to 13 degree range around sunrise Thursday. This is just above the Wind Chill Advisory criteria. On Thursday skies will clear but temperatures will struggle to get to 40 degrees with brisk winds. && .SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/... As of 300 PM Wednesday...The mid level pattern will have evolved into a split flow regime initially and translate into a southwest flow ahead of a mid level low by Saturday morning. Although seemingly busy at the mid levels, surface high pressure will be the dominant feature. This high will move across the Gulf of Mexico then out into the Atlantic by the end of the period. Once again a temperature forecast throughout and expect lows Friday in the lower to middle 20s. Highs Friday will rebound into the 50s. && .LONG TERM /SATURDAY THROUGH THURSDAY/... As of 300 PM Tuesday...The chief caption this period "Warming Trend". Even in wake of a cold front early next week, minimal cold air advection is seen, as the upper pattern sees a SE ATLC upper ridge gradually expand NW into the area. A weak cold pool aloft meanders eastward along the Gulf Coast this weekend and offshore by Monday, will little sensible weather impacts here. As a result, much of next week may feature sunshine and 60s in the afternoons, likely feeling like an early spring compared to the recent weather pattern. Aside from late Monday and early Tuesday, this entire period will maintain a dry column and low PWAT values. The coldest period, will be Saturday morning, near freezing, the mildest, perhaps just ahead of the cold front Monday into the upper 60s by afternoon. Tuesday looks to be the breeziest day in wake of the cold front, with W-NW breezes. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... As of 06Z...Patches of very light snow should move out of the Myrtle Beach and Wilmington area by 08Z. Low clouds still blanket the area currently, but I expect SKC to develop inland (LBT and FLO) around 08Z, spreading down to the coast (ILM, CRE, MYR) around 10Z. Breezy northwest winds could gust to 20 knots at times early this morning. SKC will continue tonight with wind speeds diminishing. Extended Outlook...VFR. && .MARINE... NEAR TERM /THROUGH THURSDAY/... As of 930 PM Wednesday...Continued the SCA timeline for all waters. The NW offshore winds have begun increasing across the local waters and should breach SCA thresholds after midnight. The CFP followed by a tightening sfc pg combined with Arctic Air Advection, will result in NW winds 20-25 kt with gusts up to 30 kt possible overnight through midday Thu. At the moment, significant seas are responding and have increased 1 to 2 ft during the past hour. The dominant 3 foot ESE ground swell at 10-12 second periods for the past few days will give way to building wind driven waves that will overtake the dominance held by the ground swell. Previous....................................................... As of 300 PM Wednesday...Currently winds are from the east with seas running 3 to 4 feet. This will change quickly as the front and a developing low shifts to the northeast off the coast. Winds are expected to reach 20 to 25 knots late this evening and seas will increase to 5 to 7 feet. The winds will weaken and with an offshore flow the seas should settle back out to 3 to 5 feet by Thursday afternoon. SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... As of 300 PM Wednesday...Surface high pressure will move from the northern Gulf of Mexico to well offshore during the period. Between this feature and the general cyclonic flow to the north a west to southwestern flow will prevail across the waters. Wind speeds will be fairly uniform in a 10-15 knot range leaning moreso toward the higher end early then the lower end late. Significant seas will generally fall into a 2-3 foot range. LONG TERM /SATURDAY THROUGH MONDAY/... As of 300 PM Wednesday...Welcoming and friendly marine conditions this period, particularly in wake of recent weather. As high pressure slips offshore by the weekend, a milder return SW flow will prevail, with seas 3 feet or less, and even 1-2 feet at times, with winds less than 15 kt. Seas will begin to build Monday as sustained SE fetch offshore, starts pushing wave energy toward our coast. By Monday night seas of 4-5 ft in 7 second intervals, may be rolling in. No TSTMS this period, but a few rain showers can be expected Monday night, as a cold front crosses the coast. Inshore water temperatures were in the upper 40s to lower 50s. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...Winter Weather Advisory until 1 AM EST early this morning for SCZ017-023-024. NC...Winter Weather Advisory until 1 AM EST early this morning for NCZ087-096-105. MARINE...Small Craft Advisory until 7 AM EST this morning for AMZ254- 256. Small Craft Advisory until 1 PM EST this afternoon for AMZ250- 252. && $$ SYNOPSIS...MJC NEAR TERM...DCH/DRH SHORT TERM...SHK LONG TERM...MJC AVIATION...TRA MARINE... is the U.S. government's official web portal to all federal, state and local government web resources and services.