Area Forecast Discussion
Issued by NWS Wilmington, NC
Issued by NWS Wilmington, NC
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745 FXUS62 KILM 161410 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 1010 AM EDT Tue Jul 16 2024 .SYNOPSIS... Hot and humid conditions will continue for most of the upcoming week. Shower and thunderstorm coverage will increase each day as a cold front approaches and stalls to our northwest. && .UPDATE... Not much to change this morning. Based on current observed dewpoints suspect this afternoon`s heat index may fall short of Excessive Heat Warning criteria. However, values should still be on the high end of advisory criteria so will not cancel the warning as to not muddle the message. Still expect afternoon convection will develop and spread across parts of the area, but hard to pinpoint where it will start. Also have less confidence in coverage. Limited mid-level support and only weak forcing along the sea breeze and Piedmont trough may end up limiting coverage to the chance realm. && .NEAR TERM /THROUGH TONIGHT/... Heat Advisory has been upgraded to an Excessive Heat Warning (EHW) for the entire ILM CWA. Heat indices will be borderline EHW but given the NWS Heat Risk Map illustrating a good portion of the ILM CWA within the "EXTREME" (the highest of 5 categories) category, opted for the more serious EHW. Atlantic sfc high pressure ridging from Bermuda to Florida combined with a sfc trof across the west/central NC and SC area, spells hot and humid conditions under an active SW wind that also will remain active at night. This the result of a tightened sfc pg that will persist across the FA between the 2 wx aforementioned wx features. Like Mon, tstorms will again have an opportunity to occur from mid-afternoon the mid-evening before decaying altogether by midnight. Looking at pops of 20-40 percent with coverage ranging from isolated to scattered. The sea breeze and initiation along the inland Carolinas sfc trof will spark interacting outflows to keep convection going into the evening. Unlike previous nights, toward daybreak Wed, an upper level impulse will approach from the south accompanied by shower and thunderstorm activity. This may reach the Georgetown/Williamsburg area at the end of the tonight period. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... The transition to a more active pattern will be well underway Wednesday although arguably...depending on how things play out today the past few days have seen quite a bit of convection. Global guidance and to an extent high resolution shows after convection moves offshore Wednesday morning the inland areas and eventually the coast lights up with deep convection. It appears the enhancement of the inland trough is in part responsible for the coverage Wednesday while Thursday more subtle height falls are added to the mix. Overall good coverage expected both afternoon and evening periods. With no changes in the air mass heat related headlines are once again possible both days. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... No changes really necessary to the extended forecast as it continues to look rather unsettled. I do like the fact guidance has trended a bit higher with max temperatures as although unsettled conditions will be in place the numbers seemed a little cool with mid 80s or so. There is a subtle drying trend Sunday into Monday as the Bermuda Ridge seems to build back to the west. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... VFR to dominate this period. Boundary layer SW winds stay active enough to keep fog at bay early this morning and again late tonight. The potential for flight restrictions this period will come after 18Z, like previous days. Will include VCTS for the aftn/evening across all terminals but provide a prob30 tsra group for the inland terminals given what occurred Mon. After sunset, will deal with decaying tstorms with dissipating convective debris mid and upper level clouds. SW winds will dominate and remain active thru the period. The coastal terminals will again observe an active sea breeze with occasionally gusts to 20+ kt this aftn/evening. Extended Outlook...Periodic chance for flight restrictions from showers/storms Wed. Periodic prevailing flight restrictions possible Thu through Sat as a cold front stalls in the vicinity combined with weak impulses aloft passing across the region. && .MARINE... Through Tonight...Bermuda high pressure ridging to Florida and the sfc trof across the western Carolinas will combine to yield a semi-tightened sfc pg across the waters thru tonight. This will alone produce SW winds 10-15 kt. Add an active sea breeze followed with nocturnal surging, ie. the presence of an active low level jet. The 2 features will being SW winds up to 15 to 20 kt with some infrequent g25 kt. Seas generally start off 2 to 4 ft and build to 3 to 5 ft on the cusp of possibly reaching 6 ft across the outer waters late tonight. The SE swell at 9 second periods has decayed-some but will remain present and accounted for thru this period. Short period, 5 seconds or less, wind waves will become the primary wave in the seas power spectrum. Thunderstorm activity rather null and void early on, looks to increase mainly late tonight as an upper impulse approaches from the south. Wednesday through Saturday Night...Stronger inland trough combined with Bermuda High pressure will keep a decent southwest flow of 15-20 knots over the area Wednesday and Thursday. Its possible the flow will be somewhat distorted at times due to convection. Wind speeds decrease somewhat Friday through the weekend as the aforementioned features weaken. Significant seas will be 3-5 feet early on with the higher winds with but settle down in time to 2-4 feet. && .TIDES/COASTAL FLOODING... Other - Rip Currents - Strong Longshore Currents: With an increasing gradient between the inland trough and Bermuda High Pressure...a strong south to north longshore current is expected today across the east facing beaches. A moderate risk for rip currents is expected as well for all areas. && .ILM WATCHES/WARNINGS/ADVISORIES... NC...Excessive Heat Warning until 7 PM EDT this evening for NCZ087- 096-099-105>110. Beach Hazards Statement until 8 PM EDT this evening for NCZ106- 108. SC...Excessive Heat Warning until 7 PM EDT this evening for SCZ017- 023-024-032-033-039-054>056-058-059. Beach Hazards Statement until 8 PM EDT this evening for SCZ056. MARINE...None. && $$ SYNOPSIS...ILM UPDATE...III NEAR TERM...DCH SHORT TERM...SHK LONG TERM...SHK AVIATION...DCH MARINE...DCH/SHK TIDES/COASTAL FLOODING...