Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 291137 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 737 AM EDT MON AUG 29 2016 .SYNOPSIS... A warm and humid tropical airmass will remain in place through much of the week across the Carolinas. A tropical depression over the Atlantic will approach the Outer Banks through Tuesday. Another tropical depression in the Gulf of Mexico should move up through the coastal waters off the southeast coast on Friday while a cold front drops down from the northwest. Cooler and drier high pressure will build in behind the front over the weekend. && .NEAR TERM /THROUGH TONIGHT/... As of 600 AM Monday...Several small and light showers dotted the landscape this morning with heavier convection offshore. Low stratus was plentiful. Tropical Depression Eight was dealing with considerable shear this morning and will continue to battle some drier air and this will at least slow any significant development. It is still possible the cyclone reaches tropical storm status later today or tonight. For this reason, Tropical Storm Watches have been posted for portions of the Outer Banks. Further south, across southeast North Carolina and northeast South Carolina, the environment will be tropical in nature today. An upper low was located off the Georgia and southern South Carolina which will help draw moisture north and west. The column will exhibit precipitable water values around 2 inches. We expect offshore showers and some thunderstorms to continue to roll inland and these showers will make good inland progress as much deeper moisture has replaced the drier air experienced inland on Sun. For this reason, we have increased POPs, mainly 40 to 50 percent for the eastern third of the Forecast Area and 30 to 40 elsewhere, slightly lower west of Interstate 95. Considerable cloud cover should keep highs in the mid and upper 80s. Lows will be in the lower 70s. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... As of 300 AM Monday...A tropical cyclone will be on a NW course as it nears the Outer Banks of North Carolina Tue. As the cyclone nears the immediate coast, it should begin to get picked up by the developing east coast trough and get steered north. A tropical environment will remain across southeast North Carolina and northeast South Carolina Tue with some drier and more subsident air perhaps working into the area on Wed on the backside of the departing tropical cyclone which will be accelerating away from the Outer Banks Wed and Wed night. We expect showers and some thunderstorms will continue to roll ashore, making good inland progress. Will carry highest POPs along the coast Tue, up to 50 percent for the Cape Fear area. POPs will trend lower as you move westward, with a slight chance west of Interstate 95. Then by Wed, will carry mainly chance at the coast with the bulk of the remainder of the area in the slight chance category. The rip current risk is expected to remain elevated through the period. Temperatures will be within a few degrees of seasonal norms through the period. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 300 AM Monday...NHC keeping TD #9 on a track from Gulf waters south of the panhandle of Florida on Thurs moving NE reaching off the coast of GA/SC through Friday. This system will be lifted north as a mid to upper trough digs down from the Great Lakes and picks it up. Although there are model differences in terms of intensity and exact track, they seem in agreement that it will be lifted north tracking to the E-NE off the southeast coast following around the periphery of Atlantic ridge. At the same time this trough will push a cold front south into and through the forecast area. This should make for a unsettled day on Thurs into early Fri with plenty of clouds and increased chc of shwrs/tstms. The greatest QPF should remain over the waters associated with TD #9.The GFS shows greatest plume of tropical moisture with pcp water values above 2 inches running up through the off shore coastal waters about 250 miles southeast of the Cape Fear coast Thurs night. At the same time another enhanced area of moisture and lift will be aligned with along and ahead of cold front with values up close to 2 inches of pcp water. Plenty of drier and cooler air will make its way in behind the cold front as Tropical system, now known as TD #9, makes its way off to the NE. With this current forecast pcp water values drop close to an inch by Sat morning as high pressure builds down from the north. The mid to upper trough should clear the coast by late Saturday with deeper drier and cooler air moving in northerly flow on back end. Temps up closer to the mid to upper 80s through Fri will only reach the lower to mid 80s through the weekend. The big change will in low temps as dewpoint temps up into the 70s will drop down below 65 in most places with overnight lows a good 5 to 10 degrees cooler. If the models stay of track with this forecast, it could make for a beautiful Labor Day weekend. && .AVIATION /12Z MONDAY THROUGH FRIDAY/...
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As of 12Z...A similar pattern this TAF valid period as the previous with showers/isolated thunderstorms moving on shore through this morning, and other showers/isolated thunderstorms developing and moving across inland areas through the day. LIFR/IFR this morning will lift to MVFR/VFR 12-14Z. Some MVFR possible through mid- morning, but predominate VFR expected the remainder of the day. The chance of sub-VFR with any shower activity will be difficult to time due to the scattered nature of the activity thus confidence is low. But if sub-VFR does occur, it should be brief. Winds will be NE around 10 kts, favoring a more E direction mid- morning to mid-evening coastal terminals. Winds decrease this evening and back to the NE. LIFR/IFR again likely around midnight northern terminals and after midnight southern terminals. Isolated to scattered showers mainly coastal terminals overnight. EXTENDED OUTLOOK...Chance of IFR/LIFR cigs morning hours, with TEMPO sub VFR associated with tropical convection through Tuesday. Generally VFR Wed/Thu. Shower potential increases again beginning Friday.
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&& .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 600 AM Monday...Tropical Depression Eight was dealing with considerable shear this morning and was still battling some drier air which was keeping the system weak and disorganized. It is still possible the cyclone reaches tropical storm status later today or tonight. For this reason, Tropical Storm Watches have been posted for portions of the Outer Banks. We have issued a Small Craft Should Exercise Caution headline this afternoon and tonight from Cape Fear to Surf City for 4 to 5 ft seas. Otherwise seas will be mainly 3 to 4 ft. These higher seas are due to increasing swell energy moving across our waters from distant hurricane Gaston. The easterly swell will have periods of near 15 seconds. NE winds will range from 10 to 15 kt, but up to 15 to 20 kt for the northernmost waters very late tonight. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... As of 300 AM Monday...The tropical cyclone is expected to be on a NW course Tue as it approaches the Outer Banks of NC. A developing trough across the east coast is expected to turn the cyclone to the N and then NE. Even if the depression becomes a storm it should remain rather weak and far enough removed such that its influences will be modest at best. Distant Hurricane Gaston will still be producing an easterly swell with periods of 12 to 14 seconds Tue through Wed night. NE winds Tue morning will be up to 15 to 20 kt far northern waters, otherwise up to 10 to 15 kt during the forecast period throughout. The wind direction will be more easterly on Wed, but should back to the N on the back side of the departing tropical cyclone. Seas will be up to 4 to 5 ft, subsiding to 3 to 4 ft Wed night. LONG TERM /THURSDAY THROUGH FRIDAY/... As of 300 AM Monday...If TD #9 remains on its current forecast, the tropical low should make its way up through the off shore coastal waters off the southeast coast Thurs into Fri. At the same time a cold front will drop down from the N-NW. This should maintain a lighter more northerly flow on the back end of system but winds should come around to the south ahead of cold front Thurs aftn or become variable depending on the track and intensity of this system. Once the low tracks off to the E-NE on Friday and cold front drops south, a deep N-NW flow should pick up to 15 kts or so. Seas 2 to 4 feet through early Fri will rise up possibly above 6 ft over outer waters in northerly surge. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...High Rip Current Risk through this evening for SCZ054-056. NC...High Rip Current Risk through this evening for NCZ106-108-110. MARINE...None. && $$ NEAR TERM...RJD SHORT TERM...RJD LONG TERM...RGZ AVIATION...MRR is the U.S. government's official web portal to all federal, state and local government web resources and services.