Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 211147 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 747 AM EDT Fri Oct 21 2016 .SYNOPSIS... Mild weather will prevail through today before chillier air behind a cold front comes crashing into the eastern Carolinas Friday night. The weekend will be characterized by seasonably cool temperatures with lows in the 40s and highs remaining below 70 degrees Saturday and Sunday. A brief warm-up Monday will be followed by a reinforcing shot of dry and cool air Monday night. This will set the stage for dry and fair conditions in the upcoming week with temperatures near normal for the season. && .NEAR TERM /THROUGH TONIGHT/... As of 600 AM Friday...Areas of dense fog covers the majority of the ILM CWA with a dense fog advisory now in effect for those locations. The exception is for the 3 ILM NC Coastal counties where onshore movement of low cloud deck, that once produced showers prior to reaching the coast, will prevent fog in general from developing. Otherwise, major changes on the way for the ILM CWA. Morning will start out like previous mornings...mild with 60s for temps. Additional clouds may be seen across the western portions of the ILM CWA due to the approaching eastward moving cold front. The main dynamics associated with the mid-level s/w trof approaching remain north of the ILM CWA as well as it`s associated sfc low. The further south from the sfc low one goes, the moisture availability lowers. However, the FA is in the Right Rear quadrant of the upper jet this afternoon and combined with strong frontal dynamics, that should produce 15 to 34 percent chance for showers with isolated thunderstorm possible mainly across the ILM NC CWA. For the most part, HRRR and RAP models remain on the lower side of pcpn chances whereas the Hireswrf is much wetter. Will stay closer with the drier bias. The strong cold front will reach the western portions of the ILM late this morning and by late this afternoon or early evening the cold front will have pushed off the mainland. Light sw-w winds ahead of the front will switch and increase dramatically to w to nw at 10 to 20 mph with hier gusts. Winds will become nw thruout tonight at 10 to 20 mph speeds with the hier speeds closer to the coast. The tightened sfc pg and caa will combine to keep winds gusty at times thru the night. The caa can be seen with 850mb temps that drop from roughly 13 to 15 degrees celsius midday today to 4 to 5 degrees celsius by daybreak Sat. This also goes along with the tight packing of various thickness schemes that advect across the ILM CWA, ie. 1000-850mb thickness. Stayed closer to the slightly hier European Mos guidance for todays highs. However, did a blend of the various models for tonights mins. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... As of 330 AM Friday...The new change in the upper longwave pattern affecting the the ILM CWA this period will be upper troffing affecting the Eastern U.S. basically from the Great Lakes eastward. And, upper ridging across the western 2/3rds of the U.S. The mean upper trof axis will lie just off the East Coast of the U.S. No embedded mid-level s/w trofs are expected to affect the ILM CWA this period. With this pattern, pcpn chances will be null and void. For Saturday, at the sfc, the FA will be under continued gusty NW winds that will slowly abate during the aftn and evening. With the center of high pressure progged to drop to the Gulf Coast States for Sunday, winds will not totally drop out but will subside from what transpired during the day on Saturday. Sky conditions thru the period will be clear any cloud that makes it across the Appalachians will scour out quickly under NW downslope trajectory flow. For now will use a blend of the available model data for max/min temps thruout this period. Not entirely bought on any 1 Mos guidance given the change in airmass. && .LONG TERM /MONDAY THROUGH THURSDAY/... As of 300 AM Friday...A rebound in temps into the mid 70s for early in the week in light W-SW flow will be knocked back down once again as a dry cold front drops south through Mon aftn. This boundary is barely evident when looking at pcp water field as the values rise from around a half inch up to .75 inch right along it. Do not expect any pcp with this front. N-NW will follow as High pressure builds in behind it, but ridging in the upper atmosphere and bright October sunshine will offset the cooling to produce temps around 70 most places. High pressure will shift off the east coast on Thurs with a W-SW return flow allowing temps to warm once again. Overall dry weather with plenty of sunshine through the week. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/...
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As of 12Z...With the exception of VFR at KILM, MVFR/IFR/LIFR prevails across the this morning as areas of dense fog continue. Expect conditions to improve within the next few hours as westerly winds increase to around 5 kts. Through the rest of today, a strong cold front will propagate west to east across the area, bringing VCSH and westerly winds around 10 to 12 kts with gusts near 20 kts, becoming northerly behind the front. Overnight, light northwesterly winds and nearly clear skies are expected. Extended Outlook...Expect VFR.
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&& .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 600 AM Friday...SCA has been raised for the SC waters starting by the mid afternoon and for the NC waters by early evening. The story for mariners will be initially the easterly swell affecting the local waters from the low now roughly located about 420 miles southeast of Cape Fear. Weak showers rotating around this low could reach the local waters from the east this morning before drying up. This low is progged to turn NE, hooking up or in this case getting absorbed with the strong cold front, well northeast of the local waters, in association with the progressive mid-level s/w trof. The main story for mariners will be the passage of the strong cold front late this afternoon or early evening followed by the tightened sfc pg which will last across the local waters thru tonight. With excellent CAA after the cfp, this will combine with the tightened sfc pg to produce strong SCA conditions with possible Gale force wind gusts especially off Cape Fear or Cape Romain. Significant seas will build late this afternoon and tonight due to building wind driven waves. The easterly swell from the exiting low will continue to affect the local waters tonight which may boost seas a little higher than what guidance is dictating. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... As of 330 AM Friday...Winds are expected to remain active thruout this fcst period. The highest NW winds are slated early Saturday due to the tightened sfc pg and continued or reinforcing CAA across the local waters. The center of the sfc hi drops to the Gulf Coast States Saturday night and remains in this position into Monday. The sfc pg does slightly relax in addition to neutral advection. Thus winds will peak Sat and lower to below SCA thresholds by sunset Saturday for all waters. Winds will slightly lower further on Sunday thru Sunday night backing to a more westerly direction around 15 kt. Significant seas will peak early Saturday then slowly drop off as the easterly swell from the exiting low decays. Wind driven waves will become the main and dominant producer of sig. seas thruout this fcst period. Should see a nice range of seas Saturday thru Saturday evening then become more uniform during Sunday into Sunday night. LONG TERM /MONDAY THROUGH TUESDAY/... As of 300 AM Friday...Light W-SW winds early Monday will veer to the NW as a dry cold front moves across the waters Mon aftn. Another surge of cool air as high pressure builds down from the north behind front. Expect winds to kick up out of the N-NW from 15 to at least 20 KT Monday night shifting to the N-NE by Tues as high pressure migrates east as it extends down from Canada. WNA showing seas remaining below SCA thresholds running 2 to 3 ft ahead of front early Mon and then jacked back up to 4 to 5 ft Mon night into Tues in gusty northerly winds. && .TIDES/COASTAL FLOODING... As of 615 AM Friday...Looks like between the hours of noon and 5 pm for the next chance for the Lower Cape Fear River to spill out of it`s banks. At this point, it could breach the Moderate flooding thresholds of 6.7 ft MLLW as forecast and observed at the downtown Wilmington gage. Expect the next advisory or warning to be issued within the next 3 to 4 hours. the following are high tides for the gage on the Lower Cape Fear River of downtown Wilmington thru Sunday... High tide 2:57 PM on Fri. High tide 3:23 AM on Sat. High tide 3:56 PM on Sat. High tide 4:22 AM on Sun. High tide 4:53 PM on Sun. && .EQUIPMENT... As of 300 AM Friday...The ASOS at the Lumberton, NC airport (KLBT) has no power and the emergency generator which had maintained power since Hurricane Matthew has run out of fuel. LBT is awaiting a fresh supply of fuel so the equipment can be up and running again. Observations and climate data from Lumberton will remain missing until further notice. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...Dense Fog Advisory until 9 AM EDT this morning for SCZ017-023- 024-032-033-039-053>056. NC...Dense Fog Advisory until 9 AM EDT this morning for NCZ087-096- 099. MARINE...Small Craft Advisory from 5 PM this afternoon to 5 PM EDT Saturday for AMZ254-256. Small Craft Advisory from 5 PM this afternoon to 9 PM EDT Saturday for AMZ250-252. && $$ SYNOPSIS...RGZ NEAR TERM...DCH SHORT TERM...DCH LONG TERM...RGZ AVIATION...SGL TIDES/COASTAL FLOODING...DCH EQUIPMENT...RGZ is the U.S. government's official web portal to all federal, state and local government web resources and services.