Key MESSAGE 1, Anomalously warm low-level thicknesses and dewpoints beneath strong ridging aloft will continue to keep temperatures well above normal with potential record breaking heat continuing through Saturday, with heat index values peaking at 105-110 deg today for most of the area, and possibly again for srn zones on Saturday.
Today continues to have the strongest signal for the peak of this week's heat wave, with highs ranging 95-100 for the interior coastal plain, with low 90s coast. Thermal gradient should be strong enough to allow for fast seabreeze progression and thus preclude heat indices reaching 105 for portions of the immediate coast. The combo of hot temps well above 90 inland coupled with TD's well into the 70s bring heat indices 105+ once again inland. Some locales may once again flirt with vals above 110 again, but not long enough or widespread for issuance of heat warnings. Href probs remain below 20%.
Saturday a cold front will begin sinking southward through the area, but at the same time TD vals inc with moisture gradient tightening ahead of it, and with temps fcst to reach into the mid to possibly upper 90s in swrn zones, another day of heat indices 105-110 degrees is possible before expected numerous showers and storms ends the heat later in the day. Best chances to reach criteria are generally along and s of Hwy 70.
KEY MESSAGE 2, A strong upper level trough will develop off the U.S. East Coast over the weekend, and this will help drive a strong cold front south through the Carolinas on Saturday and Saturday night. Strong heating of a moist boundary layer ahead of the front should allow strong instability to develop from the Mid-Atlantic south into North Carolina today. While some residual subsidence/capping may be present beneath the ridge, especially across NC, guidance show a decent signal for convection developing upstream of ENC, and making a run towards the nrn zones late this afternoon and evening. If convection can arrive early enough, severe potential is there, esp north of Hwy 70 and best chances north of Hwy 264. Cams have generally inc in covg here. Instability is above the climo max for the first week of September, and deep layer shear above 25 kt. Main threat will be potential for damaging wind gusts.
On Saturday, the ridge will continue to get suppressed further south and west with less influence across the Carolinas. This plus increased forcing along the cold front should support an improved risk of deep convection, and less limiting factors, compared to Friday. Pw's/td's inc further and with lowering hts aloft, instability will be very strong. In fact, vals will be well above the avg max for first week of September according to the KMHX sounding climatology, with ML CAPE vals advertised by the 03/12Z RRFS/ECM/NAM3k reaching or exceeding 4,000 J/KG! If convective timing aligns with fropa/shortwave passage in the afternoon, a significant severe weather signal may be met as this aligns with deep layer shear of 35-45kt. Machine learning severe probs for damaging wind have increased for parts of ENC. In addition to the severe threat, will have to watch for potential flash flood threat, as PW's surge to 2.25" or higher, and with the expected numerous convection, very heavy rain rates are possible with deeper convection and lend to instances of flash flooding.
KEY MESSAGE 3, Behind the front, temperatures and humidity will finally get knocked down closer to normal for early September, with more comfortable conditions lasting into early next week. Still some residual moisture lingering on Sunday and may see some sct showers, but overall trend is for drier esp as we begin the work week with pops less than 20% lasting through mid week. Highs in the mid 80s with lows in the 60s is fcst and is where our temps should be for the first half of September.
09z Friday through Tuesday Mix of VFR and LIFR across the terminals early this morning, with mix of patchy fog and low stratus. Still looks like best chances at OAJ/EWN and ISO, where a few hours of IFR are possible. Any patchy fog/low stratus quickly dissipates by about 13Z with VFR conditions then returning to all of ENC through this evening. Afterwards potential for showers/tstms bringing sub VFR conditions begin to increase across the far northern zones, especially after 21-00Z. Greatest risk would be to PGV/ISO terminals.
NOTE: AMD NOT SKED has been appended to the EWN TAFs as the site is not transmitting through normal channels. The site is still reporting via telephone so it will be monitored, but not as frequently as when it is completely operational. The next closest ASOS is at Cherry Point (KNKT).
Outlook (Sat through Tue): Better chances for widespread showers and storms on Sat as cold front drops through the area. Sub-VFR conditions will be possible with any TSRA during this time. Behind the front, a northeasterly wind shift will occur, with northeasterly flow continuing into early next week and pred VFR returning.
Latest obs show SW winds 5-15 kt with seas 2-3 ft. Stronger thermal gradient develops this afternoon and evening, with winds increasing to 10-20 kt with potential for a few hours of 25 kt gusts for the eastern sounds/Alligator river and nearshore ctrl waters. Issued SCA for the Pamlico Sound and central waters. Strong to severe thunderstorms could affect nrn sounds and waters late this afternoon and esp evening as storms move south from VA. Strong wind gusts and freq lightning are the main threat with these storms.
Outlook (Sat through Tue): More widespread storms could affect the remainder of the ENC waters Saturday as a cold front moves through. Winds will shift becoming NE behind the front Sat and Sat night. Moderate to gusty NE winds will develop Sunday and continue into Monday, with seas building to 4-7 ft, highest across the outer waters. Winds and seas will begin to ease Tuesday as high pressure builds in.
Nc, heat advisory from 11 am this morning to 8 pm EDT this evening for ncz029-044>047-079>081-090>092-094-193>195-198-199- 203. Marine, small craft advisory from 5 pm this afternoon to 11 pm EDT this evening for amz135-152-154.
