Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 242215 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 618 PM EDT SUN JUL 24 2016 .SYNOPSIS... A ridge of high pressure will expand across the Carolinas bringing uncomfortable levels of heat and humidity this week. Isolated to scattered showers and thunderstorms are possible each afternoon and evening. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... As of 320 PM Sunday...Another day, another widespread set of 90+ temperatures as this hot July continues. Massive ridge continues to evolve and expand across the southern tier, and heights/mid-level temps have warmed today. The combination of these temps plus dewpoints in the low to mid 70s has pushed heat index values to around 105 degrees, and while many places are falling just short will leave the HT.Y unchanged for now as slightly higher dewpoints during recovery may push HI`s to 105 for a bit this evening. This airmass is also very unstable, as evidenced by recent mesoanalysis showing 1500-2000 J/kg MLCAPE. This is truly the only forcing to drive convection today however, as the aforementioned mid- level warming and drying is keeping mid-level lapse rates very weak, and thus only the sea breeze boundary is strong enough to push updrafts up into showers/tstms today. A few storms have fired along this boundary, and the current POP grids reflect slow westward advancement of SCHC. This activity will wane quickly after dark though since no other forcing exists to tap elevated residual instability. Mins tonight will remain quite warm as return flow persists, dropping only into the mid 70s. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... As of 320 PM Sunday...A subtle cooldown Monday will be followed by even hotter temperatures beginning Tuesday as the expansive upper ridge dominates the southern tier of the CONUS. Weak height falls occur Monday, likely in response to a mid-level impulse moving across Florida. While the mid-level flow becomes more SE than E, this remains a drying direction, and PWATS are forecast to drop to around 1.25 inches. 850mb temps still up around 18C will support slightly above climo temps, around 90 at the coast and low to mid 90s well inland, but with slightly lower dewpoints as well, heat index values will likely remain just below advisory criteria on Monday. While it is rare to have a day in July around here without at least a few diurnal tstms, the soundings suggest no activity on Monday, and will keep POP silent. Return flow around Bermuda high will only allow temps to fall Monday night into the mid 70s. A hotter day forecast on Tuesday, and heat index values are again expected to necessitate a heat advisory. The mid-level ridge builds overhead once again and 850mb temps climb towards 20C. Persistent moist return flow will allow dewpoint recovery even during the aftn, so highs in the mid 90s combined with dewpoints in the low to mid 70s will cause heat index values to rise above 105 degrees. This slightly more moist column will allow for at least a SCHC of tstms along the piedmont trough and sea breeze boundary, before convection wanes nocturnally and temps fall back in the mid and upper 70s by Wed morning. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 320 PM Sunday...Little change required in the extended period as the mid level pattern will feature slowly falling heights across the east with a corresponding ridge out west. The relevant surface features for the eastern Carolinas are the Piedmont trough and Bermuda high pressure. The front associated with the trough remains well to the north. The highest pops reside over the weekend based on increasing PWs and the subtle trough. There is at least a slight chance all days however and basically all periods. No significant changes to the temperature forecast with basically above normal readings across the board. && .AVIATION /00Z MONDAY THROUGH FRIDAY/...
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As of 00Z...High confidence in predominately VFR through the valid TAF period. Some patchy ground fog is possible overnight, but not likely. Little to no convection is expected tomorrow due to an increasing subsidence inversion. South southwest flow is forecast, mainly below 10 kts. EXTENDED OUTLOOK...Isolated to scattered afternoon convection Tuesday through Friday may create periods of MVFR/IFR. Otherwise expect VFR.
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&& .MARINE... NEAR TERM /THROUGH TONIGHT/... As of 320 PM Sunday...Other than the near shore southerly sea breeze, which will weaken this evening, winds will be consistently SW at 10-15 kts across the waters through tonight. This will allow the sea state to remain unchanged from this aftn, and 2-3 ft seas are forecast to persist thanks to an 8 sec SE wave and 4 sec SW wave. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... As of 320 PM Sunday...Bermuda high remains into mid-week, driving consistent SW winds across the waters. As temperatures warm however and the ridging strengthens, wind speeds will increase from 10-15 kts Monday, up to 15-20 kts late Tuesday. The near shore waters will be influenced by a strong sea breeze each aftn as well, producing a slight backing in wind direction to the south along with a subtle increase in speed. Wave heights will remain consistently around 2-3 ft, with an 8 sec SE swell and a 4-5 sec SW wind wave comprising the spectrum. LONG TERM /WEDNESDAY THROUGH FRIDAY/... As of 320 PM Sunday...Bermuda high pressure and the piedmont trough inland will maintain the south to southwest flow through the period. Speeds will be of the standard summertime variety with 10-15 knots. Not a real clear signal of much enhancement via nocturnal low level jetting at least to this point. Significant seas remain typical of the season and modest wind fields with 1-3 feet. && .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. && $$ SYNOPSIS...SHK NEAR TERM...JDW SHORT TERM...JDW LONG TERM...SHK AVIATION...43 is the U.S. government's official web portal to all federal, state and local government web resources and services.