Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 301804 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 204 PM EDT MON MAY 30 2016 .SYNOPSIS... Moisture associated with the remnants of Bonnie will be very slow to leave the area even as the actual system does by Wednesday. The weather may then turn even more unsettled by Friday and into the weekend as a cold front drops into the area and stalls. && .NEAR TERM /THROUGH TONIGHT/... As of 1230 PM Monday...Bonnie is now a remnant low spinning along the Santee River west of Georgetown. Uncapped CAPE of 1000-2000 j/kg continues to create a pinwheel of showers north of the low across most of the area more than 20 miles inland. The coast has remained relatively dry so far although showers are observed on radar approaching Cape Fear from the south. PoPs have been increased to 90-100 percent along the I-95 corridor where the latest HRRR focuses its best convective threat through the afternoon. PoPs and QPF have been lowered in the Myrtle Beach/Whiteville/Elizabethtown corridor where it appears a dry slot of sorts is rotating up the east side of the low. Discussion from 930 AM follows... Tropical depression Bonnie`s circulation is wandering between Charleston and Kingstree this morning. Surface obs...satellite...and radar imagery suggest a center over Williamsburg County. Widespread showers extend well north of the center across Bennettsville...Lumberton and Fayetteville. Models are in unanimous agreement that destabilization from daytime heating will create even more coverage of showers over the next several hours. Forecast soundings suggest developing CAPE of 1000 j/kg inland and 2000+ j/kg across SE North Carolina where temperatures should reach 81-82 this afternoon. This opens the possibility for thunderstorms with heavy rain potential. Precipitable water is around 1.7 inches which is at the 80th percentile for this time of the year. Our forecast is for a widespread 1 inch of rain today inland from the coast...but training cells could produce localized areas of 2-3 inches. If antecedent rainfall totals were higher over the past few days we might consider a flood watch...but soils can probably take a couple inches without significant problems. WPC has our area outlooked in a `slight risk` for excessive rainfall today. Convection should weaken (but not dissipate entirely) tonight with the loss of heating. Bonnie`s decaying swirl may begin to pick up some motion toward the northeast overnight. The best chance of showers tonight will develop offshore and across coastal north carolina where cell motion will tend to advect maritime convection inland. Remaining humid with lows upper 60s to around 70. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... As of 300 AM Monday...The remnants of Bonnie will be drifting northward and should be creeping along the Cape Fear coast Tue and Tue night and then up across the Outer Banks Wed and Wed Night. This does eventually allow for some weak subsidence and drier air aloft. However...more in the way of heating will stimulate the atmosphere and moisture combined with instability will allow for the development of showers and a few thunderstorms. There may be slightly less coverage of convection Wed and Wed night as compared to Tue and Tue night, but even that may be optimistic given increasing low-level convergence along a developing seabreeze. Highs both days will be in the 80s...warmest Wed. Lows will be in the upper 60s to near 70. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 300 AM Monday...It looks like the long term may be summed up as a period that goes from being somewhat unsettled to one that ends up even more active. Early on we will be in a pattern of very light flow through much of the column, not unlike during the heart of summer. A weak mid level ridge will try to build over the area while the surface pressure pattern remains quite poorly defined. There will also be quite a bit of low level moisture remaining following our brush with Bonnie. Saturday is when the aforementioned transition to even more unsettled weather is expected. A cold front will drop into the area and stall. This will argue for increased rain chances while more prevalent cloud cover tempers afternoon highs. This boundary may be weakening over the area on Monday but another one may be already poised to move into its place as Great Lakes troughiness deepens. && .AVIATION /18Z MONDAY THROUGH SATURDAY/...
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As of 18Z...Areas to widespread convection will occasionally affect all terminals thru sunset. The inland terminals from diurnally driven convection within this juicy tropical airmass, and the coastal terminals from the onshore movement of strings of showers which will further develop into thunderstorms after moving inland and aided by the increased instability. the majority of the convection will dissipate around sunset due to the loss of the days heating. The exception will be continued convection in the vicinity of the remnant Bonnie low which will be snaking across Northeast SC thru early tue and then snailing into Southeast NC during the day on Tue. May or may not include the threat for overnight convection for CRE and MYR. Otherwise, tonight will feature the thinning out of the debris convective clouds overhead. One or 2 of the models analyzed wants to paint a low stratus deck during the pre-dawn Tue hours. Not on entirely on the bandwagon with this attm but will mention mvfr fog. In addition, the bulk of the onshore movement of strings/bands of pcpn and the direct line of flow from the tropics will get shunted ne-e of the FA by Tue. The circulation associated with the remnant Bonnie low could locally produce and draw in the showers from off the adjacent Atlantic waters overnight into daytime Tue morning. Will only need several hrs of the days heating Tue morning to produce favoring instability for convection to once again develop over land, resulting with MVFR conditions. Extended Outlook...tropical airmass and daytime heating will result in areas to widespread convection thru thursday, with resulting mvfr/ifr conditions.
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&& .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 1230 PM Monday...Seas have fallen by about half a foot over the past three hours at the buoys near cape fear. We`ll continue to watch this trend and may end up dropping the marine headlines early if it continues. Otherwise we`re still watching scattered showers affecting mainly the Brunswick county beaches with another cluster approaching Topsail Island. Discussion from 930 am follows... Small craft advisory conditions remain possible across our north carolina coastal waters mainly due to seas. Wave heights at the Frying Pan Shoals buoy are 6 feet with 4-5 foot waves currently reported closer to shore. Conditions are only slightly better along the upper South Carolina coastline where 3-5 foot seas should continue into this evening. Little change in wave heights is expected through tonight as the weak center of tropical depression Bonnie drifts along the South Carolina coastline. While the bulk of the shower and t-storm activity will remain inland...scattered activity will push northward across the waters today...perhaps becoming a little more concentrated across the cape fear area tonight. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... As of 300 AM Monday...The remnants of Bonnie will be lifting slowly N across the North Carolina waters Tue and Tue night and then further NE and away from the area Wed and Wed night. As the weak circulation lifts N, winds will veer. SW or WSW winds will dominate Tue with WNW to NW winds Tue night. A weak gradient should allow the seabreeze circulation to dictate the wind direction Wed, with winds returning to SW or S. The strongest winds will be Tue, up to 15 to 20 kt. The highest seas will be Tue, up to 3 to 4 ft with some 5 ft seas lingering across the northern waters. Winds and seas will thereafter steadily lower. LONG TERM /THURSDAY THROUGH FRIDAY/... As of 300 AM Monday...A light southwesterly flow becomes established on Thursday. Any remnants of Bonnie will be off to our northeast and a weak surface troughiness may be left behind down the coast. Otherwise there shouldn`t be much to give shape to the surface pressure gradient making for some light and somewhat variable winds. The approach from the northwest of a cold front Friday should make local winds more decidedly southwesterly but an increase in wind/gradient/seas is not anticipated. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...High Rip Current Risk until 8 PM EDT this evening for NCZ106- 108. MARINE...Small Craft Advisory until 5 AM EDT Tuesday for AMZ250-252. && $$ SYNOPSIS...TRA NEAR TERM...TRA SHORT TERM...TRA LONG TERM...RGZ AVIATION...DCH is the U.S. government's official web portal to all federal, state and local government web resources and services.