Area NWS Forecast Discussion
893 FXUS62 KILM 190447 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 1247 AM EDT Mon Aug 19 2019 .SYNOPSIS... A front will meander across the Carolinas through Monday before slowly weakening into a surface trough. A cold front will move in from the northwest on Friday and will stall along the coast. Showers and thunderstorms will be more scattered in nature for the next few days. && .UPDATE... No changes are planned at this time. && .NEAR TERM /THROUGH TUESDAY/... Latest model upper level analysis and water vapor imagery show westerly winds with clearing skies moving into the region from the west. Within the last 24 hours, many locations received between 2 and 4+ inches. Latest radar observations show the line of showers and thunderstorms that was positioned over the Cape Fear region the past two days has now moved offshore. Visible satellite imagery has a cumulus field east of I-95, with thick broken clouds for Wilmington and surrounding communities that has been slow to break this afternoon. Temperatures across the region this afternoon were in the mid to upper 80s, which is between 5 and 10 degrees above this time yesterday afternoon. Weak tropical wave moving up the coast will continue to collect and take moisture away from the region today, with mostly cloudy skies near the coast and mostly clear skies inland. A break from rainfall is expected through tonight. A weak cold front will move through the coastal Carolinas Monday and bring a return of some chances for showers and thunderstorms Monday into Monday night. Afternoon temperatures will be near to slightly above normal with a return of southerly windfall and breaking cloud cover. Patchy fog is possible each night with relative humidities approaching 100%. Precipitation Monday will be much lighter than the rainfall the past few days. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... Weak 5h cutoff develops in the break in mid-level ridge over the Southeast early Tue. This feature is slow to move northeast, with deep southerly flow helping to spread moisture over the eastern Carolinas. As the low drifts east-northeast, it will send an occasional shortwave across the area. The enhancement of upward motion ahead of each wave coupled with diurnal instability and deep moisture will produce a convectively active period. The sea breeze and lingering convective boundaries will also act as potential triggers for daily convection. Presence of forcing outside of diurnal heating does suggest activity may continue into the overnight periods, however this will depend on timing. Passage of any shortwave will be followed by a period of decreased or even no activity before the post wave subsidence moves off and the environment becomes more favorable. Highs will be near to slightly above climo each afternoon with lows running above climo. && .LONG TERM /THURSDAY THROUGH SUNDAY/... Unsettled conditions will continue through the start of next week with weak mid-level troughing and deep moisture lingering over the Southeast. Piedmont trough and sea breeze will act as triggers while weakly divergent flow aloft aids upward motion. -Scattered showers and thunderstorms each afternoon and evening. At this point severe weather does not appear to be a concern. -High temperatures near climo with low temperatures above climo. && .AVIATION /04Z MONDAY THROUGH FRIDAY/... Mainly VFR this morning with possible sct/bkn MVFR low stratus, ie. bkn015, mainly along the coast. Inland terminals could drop to MVFR from fog and if winds decouple, IFR from fog may occur. Diurnal heating will fuel the increasing instability and the convergent sfc boundaries, sea breeze and inland troffiness, will aid with UVVS. At this time have indicated vicinity TSRA during the afternoon coastal terminals and from mid-afternoon thru mid-evening for the inland terminals. Later fcsts should be able to identify any tempo TSRA groups. Flow overnight will range from 220-250 at 5 kt or less, and this will continue thru late morning. Coastal terminals will see the sea breeze develop by midday, ie, 170-200 at 10-15 kt, and will progress inland with impeding flow aloft not very strong. Extended...Mainly VFR each day. Exceptions...Brief MVFR/IFR from tstorms each aftn thru early evening...and MVFR from early morning fog and/or low stratus each day mainly for the inland terminals. && .MARINE... Significant wave heights between 3 and 5 feet this afternoon will decrease between 2 and 4 feet by this evening from the S/SW at 7 seconds for the next 36 hours. Light SE swell at 10 seconds. Southwest flow will continue through Fri with Bermuda High sitting offshore. Changes to the gradient, as the Piedmont trough strengthens and then weakens, will lead to southwest flow around 10 kt each morning increasing to a solid 15 kt each afternoon and evening before dropping closer to 10 kt overnight. Seas follow a similar to trend to winds Tue and Wed, building to around 3 ft in the afternoon before dropping closer to 2 ft overnight. Southerly wind wave at 4 to 5 seconds will be dominant early in the period, but a secondary south to southeast swell around 9 seconds will help increase seas Thu and Fri to 3 to 4 ft. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...MBB UPDATE...MBB NEAR TERM...MCK SHORT TERM...III LONG TERM...III AVIATION...DCH MARINE...III/MCK