Area Forecast Discussion
Issued by NWS Wilmington, NC

Current Version | Previous Version | Text Only | 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
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
646 FXUS62 KILM 301947 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 347 PM EDT SAT JUL 30 2016 .SYNOPSIS...
-- Changed Discussion --
High pressure will continue to bring oppressive heat and humidity to the region through today. The high will break down late this weekend into early next week, allowing a cool front to drop slowly across the area by Wednesday. This will bring a high chance for thunderstorm activity during the mid-week period of next week. In addition, daily temperatures will drop back to near normal for the middle and end of next week.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
As of 300 PM Saturday...The heat advisory has been expanded to include all of the forecast area until 8pm this evening. Dry air has mixed down and dewpoint temps have lowered over much of the area down closer to lower 70s. Although dewpoints have dropped, temps have soared well into the 90s and the combination has produced widespread heat indices above 105. Moisture is abundant today with pcp water values up above 2 inches. Although we are slowly losing our cap on convection as Atlantic ridge slips away over the weekend, still holding on to the east and southeast and expect convection to basically remain less widespread today. Soundings showed sfc based CAPE values up close to 4k J/kg around noon but then decreasing as drier air mixed down. Expect any stronger storms to produce gusty winds on top of already gusty S-SW winds through this afternoon. Current temps behind sea breeze have dropped down several degrees while dewpoint temps crept up a bit. Better coverage and stronger convection will remain north aligned closer to lingering front draped down into Hatteras. Radar showed first storms popping along sea breeze as winds backed toward the south along the coast converging with more southwesterly winds inland. This boundary should remain closer to the coast with the stronger SW component to the flow...especially along SC coast, and storms will be steered off to the NE running mainly parallel to the coast. Other storms were developing along trough inland and will reach into portions of forecast area from the W-SW this afternoon through this evening, dissipating by late evening after loss of heating. Both the NAM and Canadian models show some potential for convection closer to the coast overnight and will include some iso pops there. Temps will remain above 80 through much of the evening and overnight along the coast, but will drop into the mid 70s well inland by daybreak.
-- End Changed Discussion --
&& .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
-- Changed Discussion --
As of 300 PM Saturday...Similar pattern through Sunday with Atlantic ridge in place to the southeast and Piedmont trough to the west. A deep SW flow of moist air will continue to feed into the Carolinas. Looks like convection will once again be focused along sea breeze in the afternoon and along trough inland on Sunday with mainly scattered coverage. On Monday, The mid to upper trough to the northwest will push a cold front/trough south and east into the Carolinas. Local area will lose cap as ridge slips farther east and minor shortwaves ride across the base of the mid to upper trough. The increased instability along with upper level support will produce more widespread convection Mon aftn. The strong westerly push will steer the storms into the area but also expect a little more organized convection for Monday. The H5 heights and 850 temps look like they will decrease slightly Sun and Mon and the development of clouds and convection should all combine to limit temps increasing greater than 95 on Sunday and much past 90 most places on Monday. Therefore do not expect heat advisory thresholds to be met.
-- End Changed Discussion --
&& .LONG TERM /TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
As of 200 PM Saturday...Pattern changes occur Tuesday as a trough digs along the east coast driving a cold front into the Carolinas. This front will be accompanied by good chances for showers and tstms Tue/Wed as it crawls southward before dissipating on Thursday. This dissipating is cause by the parent trough pushing off to the east, allowing for mid-level ridge to re-blossom into the Mid-Atlantic. The ECM/CMC stall this front longer with better convective chances as the trough is slower to eject to the east, but the GFS has ensemble support and its solution is more represented by WPC and the inherited grids, so will continue to hedge towards a warmer/drier solution late in the week and into the weekend. Convective chances will drop back to seasonable or slightly below, with temps right around climo Fri/Sat, after a period of around or slightly below normal temps with higher POP the first half of the extended.
-- End Changed Discussion --
&& .AVIATION /18Z SATURDAY THROUGH THURSDAY/... As of 18Z...All the near term guidance, RAP, WRF and HRRR indicate scattered convection to occur along the sea breeze. Elsewhere, tstorm coverage will be isolated. As a result, have included tempo groupings for tstorms along the coastal terminals thru early this evening. Inland terminals will remain VCTS unless coverage increases. The sea breeze will be slow to progress inland as evidenced at MYR and CRE with latest winds still w to nw and temps in the upper 90s. In the wake of the sea breeze, the coastal terminals will see winds back to ssw at 10 to 15 kt whereas elsewhere, winds will run wsw to sw at 10 to 15 with g20 kt. Convection will taper by mid-evening across all sites. A low level jet will likely keep winds active all night at the sfc, ie. sw at 5 to 10 kt, in turn keeping fog development at bay. For Sunday, convection will likely begin to re-fire by late morning. EXTENDED OUTLOOK...Isolated to scattered afternoon and evening convection each day may result in localized MVFR/IFR conditions. Each morning may also observe brief MVFR/IFR from fog and/or low ceilings. Otherwise, expect VFR. && .MARINE...
-- Changed Discussion --
NEAR TERM /THROUGH TONIGHT/... As of 300 PM Saturday...Much of the same with the Bermuda High and Piedmont trough over central NC dominating the weather. This will keep SW winds winds over the waters of 10 to 15 knots, with a spike late aftn into early evening due to influence of sea breeze and inland trough. Seas will basically remain in the 2 to 3 ft range with some 4 fters through tonight with a low-level jet keeping winds up to 15 knots. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... As of 300 PM Saturday...Similar pattern will continue with Bermuda High and Piedmont trough dominating the weather and maintaining a SW flow over the waters. By Monday a cold front will drop into the Carolinas but will make slow progress toward the local waters but should see a veering of wind, becoming more westerly by Monday night into early Tues. A tightened gradient Mon night will produce an increase in SW winds up to 15 to 20 kts and push seas up to 4 to 5 ft in outer waters. Otherwise seas will remain in the 2 to 4 ft range through the period. You can also expect a better chc of thunderstorms over the waters, especially Mon. LONG TERM /TUESDAY THROUGH WEDNESDAY/... As of 200 PM Saturday...A cold front will cross the waters during Tuesday turning winds slowly from SW at 10-15 kts, to NW at 5-10 kts Tuesday night. This front will dissipate on Wednesday leaving a diffuse pressure gradient as high pressure re-expands slowly from the Atlantic. This will bring mostly East to SE winds Wed/Thu, at speeds around 10 kts. Seas will be highest on Tuesday, 3-4 ft, as the SW winds and residual SE swell drive an amplified spectrum. Behind the cold front, as the winds ease and become variable, the wind wave will shift to the E/NE on top of the residual SE swell, but seas fall to around 2 ft the latter half of the period.
-- End Changed Discussion --
&& .ILM WATCHES/WARNINGS/ADVISORIES... SC...Heat Advisory until 8 PM EDT this evening for SCZ017-023-024- 032-033-039-053>056. NC...Heat Advisory until 8 PM EDT this evening for NCZ087-096-099- 105>110. MARINE...None. && $$ NEAR TERM...RGZ SHORT TERM...RGZ LONG TERM...JDW AVIATION...DCH

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