Area Forecast Discussion
Issued by NWS Wilmington, NC

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
570 FXUS62 KILM 211110 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 715 AM EDT Sat Oct 21 2017 .SYNOPSIS... Warm and dry weather is expected through the weekend, as high pressure moves off to the northeast. A coastal front will bring showers and a few thunderstorms late Monday and Tuesday. Cooler temperatures will overspread the region through mid-week, as a cold front sweeps off the coast. && .NEAR TERM /THROUGH TONIGHT/... As of 333 AM Saturday...Some patchy fog will be possible in the few hours before sunrise, given calm winds, clear skies, and dewpoint depressions near or at zero. Any fog that does develop will quickly burn off after sunrise. Otherwise, high pressure surface-aloft will transition west to east across the area today. The result will be plenty of insolation and high temperatures around 80 degrees, which is about 5-6 degrees above climatology. Time-height cross sections show some cirrus thickening tonight, along with some return-flow moisture below 850 mb as winds veer around towards the southeast. This will keep Saturday night min temps 4-5 degrees higher than those we experience in the early morning hours today. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... As of 333 AM Saturday...The weekend will close out with plenty sunshine, and above normal temperatures. Moisture advection will increase Monday bringing clouds, and rain chances late Monday as a semi-tropical coastal warm front lifts north. This will allow for another warm day Monday in this late october, even with increasing clouds. Rain chances will peak Monday night into early Tuesday as moisture and over-running aloft increase ahead of an approaching system. The moisture sources include SFC-700 mb Atlantic and H7-H4 Gulf taps. This is shown well in model animations of PWAT, depicting an elevated swath of precipitable water surging through 00z-12z Tuesday. No cool air, as the WAA pattern prevails this period, but a chance of rainfall, with current QPF over a half inland along i-95 and quarter inch near the coast Monday night. && .LONG TERM /TUESDAY THROUGH FRIDAY/... As of 3 PM Friday...Week begins with highly amplified pattern over the eastern CONUS. Deep 5h trough, which may or may not become briefly cutoff, will be over the Mississippi Valley Mon morning and steadily moving east, pushing a cold front with it. Mid-level ridging along the Southeast will also shift east, but the rate at which these features move ultimately determines when showers and thunderstorms ahead of and along the front reach the area. Strong warm advection ahead of the front will push temps close to 10 degrees above normal Mon while ensuring abundant moisture. Still to early to say if strong or severe storms are a threat but low level jet Mon night and Tue will be 40-50 kt so at least some potential exists. Front crosses the area during Tue but cold advection will be delayed and temps will be near to slightly above climo. A shortwave dropping southeast across the western Great Lakes and into the OH/KY Valleys Tue night drives a cold surge into the southeast Wed. Cold advection will drop 850 temps from low teens late Tue to near zero Wed night, ushering in a 36 to 48 hour period of temperatures 5 to 10 degrees below climo. Mid-level trough axis shifts off the coast Thu morning and lifts northeast during the day. Warm advection will already be under way at this point but cold air will linger at the surface through Thu. Thu night or Fri will see temperatures return to levels typical of late October in the southeast. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... As of 12Z...Any fog leftover this morning will quickly dissipate by 13Z. High pressure will remain in control through Sunday. Very little in the way of a pressure gradient with a strong radiational inversion set up. Look for light winds most of the morning with an east southeast sea breeze at the coast by noon. Light winds tonight with patchy fog possible after 06Z. Extended Outlook...Showers and thunderstorms may result in flight restrictions Mon-Tue. && .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 333 AM Saturday...Surface high pressure centered north of the waters over the Mid-Atlantic will shift east and off the DelMarVa today. This will allow winds to veer towards the east- northeast today, and the weak gradient should keep speeds around 10 knots. A weak trough in the pressure field may develop tonight, but would only serve to keep a bit more of a northeast component in the wind direction. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... As of 333 AM Saturday...A welcoming marine environment greets mariners Sunday, but conditions deteriorate Monday as a coastal front ahead of an approach storm system moves north across the 0-20 NM waters. This will bring limited visibility in rain and isolated TSTMS Monday night and early Tuesday. A small craft advisory will likely be needed from Monday afternoon through Tuesday, as SE-S winds gusts between 20-25 kt, and seas offshore build to 7-8 ft overnight into Tuesday. Sunday`s sea spectrum includes 1 ft E waves every 4-5 seconds and ESE waves 2 ft every 9 seconds. SE wave energy will begin to increase wave amplitude Monday, primarily in 6-7 second intervals. LONG TERM /TUESDAY THROUGH WEDNESDAY/... As of 3 PM Friday...Cold front approaching from the west will lead to increasing southerly flow on Mon. Winds start out east- southeast 10 to 15 kt but turn more southerly during the day, increasing to a solid 15 kt later in the day. Winds peak at 20 to 25 kt late Mon night and continue in the 20 to 25 kt range into Tue evening before dropping under 20 kt Tue evening/night and shifting to offshore as the front passes. Seas ahead of the front will build to 5 to 7 ft Mon night and exceed 8 ft in places on Tue. Headlines will likely be raised early Mon night and continue through Tue and into the first part of Tue night. Combination of offshore flow and decreased speeds late Tue night and Wed should allow conditions to drop below headline thresholds. Cold advection following the front is delayed so offshore flow will not be strong right behind the front. However cold air is expected to arrive near the end of the period and offshore winds approach 20 kt Wed night. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...MJC NEAR TERM...CRM SHORT TERM...MJC LONG TERM...III AVIATION...43

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.