Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 200005 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 805 PM EDT Mon Jun 19 2017 .SYNOPSIS... Bermuda high pressure will remain offshore this week, while a tropical disturbance moves into the Gulf of Mexico, possibly becoming a Tropical Storm by Tuesday. Moisture from the Gulf will bring periods of wet weather to the Carolinas this week. Rain may be heavy at times since the moisture is tropical in nature. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 245 PM Monday...Sea breeze and Bermuda High convergence is shifting the storm focus farther inland this afternoon. GOES-16 low- level water vapor shows the mid-level cap well inland is beginning to erode from WSW to ENE this afternoon and may allow for storms to become more numerous along the I-95 corridor into mid/late afternoon. Untapped air and larger downdraft CAPES in this area could lead to stronger storms in the hours ahead. Active period through Tuesday, as an upper trough trough slowly translates east toward the area coupled with a feed of tropical moisture. PW values will climb a bit more and exceed 2 inches. Low-levels winds not very strong Tuesday so the primary threat looks to be localized flooding, as storms drop tropical moisture while exhibiting sluggish storm motion. As buoyancy increases tonight over the waters, scattered deep convection should develop late tonight into very early Tuesday, and a portion of this may get directed onshore into the coast. Meanwhile, upper support will increase well inland as the trough aloft nears, so most places will have a shot at rain overnight. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... As of 3 PM Monday...Front stalled west of the area at the start of the period will gradually dissipate Tue night and Wed. Although the surface boundary will be ill defined there will be an abundance of deep moisture moving into the area as the 5h trough taps into moisture plume associated with the Gulf of Mexico system. Currently it appears that the system will not have a direct impact on the region during the period. However, there is some uncertainty with respect to how much moisture spreads over the Southeast and how long the moisture lingers. The GFS has a huge plume of moisture spreading over the area Tue night and lingering through the end of the period. The Canadian and ECMWF has a toned down version of the tropical plume and have the moisture shifting east during Wed with decreasing precip chances late Wed and Wed night. Precipitable water values climb above 2 inches Tue night as the plume arrives but forcing may be limited, outside of already ongoing diurnal convection from Tue afternoon and evening. The odd shortwave rotating around the base of the 5h trough could help light off convection but the best shot may be with diurnal heating Wed, provided the tropical moisture hangs around into peak heating. Low temperatures will run well above climo while highs on Wed will be held below climo by cloud cover and rainfall. && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 300 PM Monday...Unsettled weather with a chance for showers and thunderstorms is expected through the extended period though chances for showers and thunderstorms will diminish a little Friday and Saturday as upper ridge builds west into the area. Upper troughing will return for Sunday and Monday resulting in increasing chances for showers and thunderstorms again. High temperatures will increase from the mid to upper 80s thursday to the upper 80s to lower 90s for the weekend before moderating slightly to the mid to upper 80s for Monday. Lows should be in the low to mid 70s through the period. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/...
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As of 00Z...Brief reprieve in the pcpn action along the immediate coast this evening into the pre-dawn Tue hrs. For the inland terminals, convection will occur just beyond 25 nm from the inland terminals. May indicate VCTS for those inland terminals to account for the relatively closeness of the thunder. The near term models, HRRR, RAPS and HIRESW do not agree with one another with respect to the placement and movement of the current convection as well as down the line. Tstrm parameters, specifically instability, remains avbl all night long and into daytime Tue. Mid-level vorts, somewhat sheared, are progged to move across the Eastern Carolinas mainly during the daylight hours of Tue. As a result, will ramp up the convection for all locations and have it become the prevailing condition across all terminals by late Tue morning or early Tue aftn. Winds will slightly back from 180 degrees to around 230 degrees by daybreak Tue...followed by a slow veering trend back to 180-200 degrees during Tue aftn. With PWs over 2 inches, heavy rain will dominate the convection, enough to briefly lower vsby to 2sm or less at times. Extended Outlook...The risk for flight restrictions due to thunderstorms will continue through the period. The probability for reduced ceilings and visibility in thunderstorms with heavy rain should be highest Tue night through Wed and possibly again on Fri.
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&& .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 245 PM Monday...An `Exercise Caution` headline was needed to account for seas up to 5 feet offshore and widespread 20 KT SW winds remainder of this afternoon and overnight. TSTMS will also increase overnight, leading to localized strong winds in and near convection. Spectral data indicates see energy is dominated by SSW waves in 5-6 second wave periods, with fading long period east swell. Mariners are encouraged to obtain a radar update before heading out this evening and overnight as a few robust storms are expected to move onshore late tonight. Seas 3-4 feet near shore will remain bumpy through tonight as winds remain elevated. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... As of 3 PM Monday...Bermuda High will maintain southwest flow through the period with speeds peaking on the high end of the 10 to 15 kt range late Wed afternoon and evening. Seas will run around 3 ft through the period with an occasional 4 ft creeping in late in the period. LONG TERM /THURSDAY THROUGH SATURDAY/... As of 300 PM Monday...South to southwest winds of 10 to 15 kt are expected through the period with seas of 2 to 4 ft. Winds and seas may run higher in scattered thunderstorms. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...Beach Hazards Statement until 9 PM EDT this evening for SCZ054- 056. NC...Beach Hazards Statement until 9 PM EDT this evening for NCZ106- 108. MARINE...None. && $$ SYNOPSIS...DCH NEAR TERM...MJC SHORT TERM...III LONG TERM...RAN AVIATION...DCH is the U.S. government's official web portal to all federal, state and local government web resources and services.