Key MESSAGE 1, Heat and humidity will continue to build into ENC from the north and west. The heat peaks today, as low level thicknesses soar to around 1440M, indicative of high temps around 100 for interior areas of ENC, threatening some record highs (see Climate section below), as evident with inland obs currently showing 99deg. These temps combined with Tds in the low 70s have pushed heat indices into the 105-110 degree range, and heat advisory remains in effect for inland ENC and the NOBX. Beach locales will escape the high heat with afternoon seabreeze cooling them below HeatAdvy criteria, though heat indices expected to remain in the 100-105 range here.
Have continued to blend NBM with ECS/MAV/MET guide which is closer to reality as NBM continues several degrees too high with MaxTs. Tds also running a bit high with NBM, and today's obs support this decision from yesterday.
Tomorrow's forecast calls for lower Ts resulting in slightly lower AppTs. Though only certain areas barely reach Heat Advisory criteria, the compounding nature of the multiple days of heat and little relief with Ts remaining in the 80s until after midnight, and only "cooling" down to the mid to upper 70s in the early morning, have gone ahead and issued a Heat Advisory for SUN for all mainland zones away from the immediate coast (Crystal Coast will be cooled enough by seabreeze again).
However, as we move into early next week, we will lose the extremely hot temps as boundary layer moistens and Tds creep higher. Despite the lowered temps (MaxTs only in the low/mid 90s), the higher Tds well into the 70s to approaching 80 on the coast by Monday will act to produce oppressively warm overnight lows, and may need to extend heat advisories through the overnight periods as little relief will be seen at night. Afternoon heat indices will cont AoA 100 due to the higher Tds even though MaxTs will be lower.
KEY MESSAGE 2, Return to a pattern of increased shower and tstorms chances early next week (Mon and Tue). A series of shortwaves, inland troughing, and a very slow moving backdoor front will converge to produce higher than climo coverage of showers and storms each afternoon to early evening, and have increased pops a bit into the 50-70% range, with much needed rain across a good portion of ENC expected.
Beyond Tue, pops return back to climo (20-40%) as more typical seabreeze showers/storms return. Hts/thicknesses slowly build in the process as ridging begins to build once again, with heat indices 100-105 in the forecast.
KEY MESSAGE 3, Aforementioned ridging builds further towards the end of next week and especially next weekend, as ensemble mean heights rise back to above normal, and forecast temps reach the mid to possibly upper 90s, pushing heat indices to potentially AoA 105deg again.
00z Sunday through Thursday No significant changes to the aviation forecast on this update as there have been no significant optimistic or pessimistic shifts in guidance for tonight's and tomorrows forecast. Vfr flight cats expected through the first half of tonight with SKC with only some patchy cirrus expected. As we get further into tonight, high pressure offshore sinks a little further S, opening low level moisture transport off the water. Select HiRes guidance shows IFR or lower stratus developing offshore with moisture trapped underneath the nocturnal inversion and pushing ashore with the light onshore flow after midnight tonight, though there is little consensus on how far it will push inland. Have shown this stratus potential with FEW and/or SCT stratus prevailing groups and included TEMPO groups for the terminals with the best chance (still not high enough confidence to include in prevailing group) of seeing subMVFR flight cats. In addition to this, there is potential for patchy fog to develop over OAJ where winds will be lighter. Have included the fog potential in OAJ's tempo group. Should stratus develop, it will scour out quickly Sun morning leading to a VFR day with some patchy diurnal cu and light winds become more SEerly behind a slightly stronger seabreeze than today.
Outlook (Sun night through Thurs): Upper ridge breaks down Monday with shortwave energy bringing good chances for showers and thunderstorms and sub-VFR conditions Mon into Tue. By Wed, more typical iso to sct showers and storms are expected with this continuing into Thurs.
Light winds generally 5-15 kt will cont, with the lightest winds in the morning, inc in the afternoon to evening as thermal gradient tightens, but gusts generally remain at or below 20 kt. Seas cont around 2-3 ft with up to 4 ft possible across the outer zones.
Outlook (Sun through Wed): The Bermuda high remains dominant through the weekend with light winds 5-15 kt and seas around 2-3 ft. Bermuda high pulls offshore late Sunday into Monday with a front slowly dropping south across the Mid- Atlantic serving to tighten gradients a bit and expect winds to increase to around 10-20 kt and seas building to 3-5 ft, but at this time no SCA conditions are expected through at least mid week.
Nc, heat advisory until 8 pm EDT this evening for ncz029-044>047- 079>081-090>092-094-193-194-198-203. Heat advisory from noon to 8 pm EDT Sunday for ncz029-044>047- 079>081-090>092-094-193-194-198. Marine, none.
