Key MESSAGE 1, Today's fcst calls for lower Max temps by several degrees compared to yesterday's records, and thus apparent t's will drop a few degrees as TD's remain the same. This will bring marginal heat adv criteria with vals around 105 for inland areas of ENC. No changes to current heat headlines.
Have continued to blend NBM with ECS/MAV/MET guide which is closer to reality as NBM continues several degrees too high with MaxTs.
For tonight, increasing moisture with rising TD's will make for a very oppressive overnight with min T's around the 80th% per latest EFI. Lows range from the mid/upr 70s interior to low 80s coast.
Monday, temps cont to drop a few degrees again, with highs mainly in the low 90s inland to upper 80s coast. However, with the aforementioned higher TD's in place, heat indices may actually be a few degrees higher than Sunday's readings. Contemplated extending the heat advisory through the Sunday night into the Monday afternoon period, though held off as convective initiation may occur by as early as noon Monday.
KEY MESSAGE 2, Return to a pattern of increased shower and tstorms chances Mon into Tue, possibly into Wed as well. 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 pops cont in the 50-70% range, with much needed rain across a good portion of ENC expected. No severe expected, as wind shear will be very low. With any summer storm, cannot rule out some wet microbursts as PW's will be quite high, in the 2.25" range. Another round of decent covg of afternoon showers/storms possible Wed as the aforementioned boundaries may still be in place.
Beyond mid week, 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 mid to late week into the weekend, as ensemble mean heights rise back to above normal, and forecast temps reach well into the 90s, pushing heat indices to potentially AoA 105 deg again as a very humid atmosphere will be in place as well. Efi for both min and max t's are pushing into the 80th percentile esp late in the week.
KEY MESSAGE 4, With the aforementioned high heat and humidity expected, a very unstable atmosphere develops per med range guidance hinting at ML CAPES aoa 3.5k J/KG, and SFC based instability between 4-5k J/KG. As is typical this time of year, deep layer shear will not be too strong, but any storms that can develop with some upper level support could produce strong downdraft/microburst winds and very heavy rain characterized by PW's exceeding 2".
09z Sunday through Thursday Patchy fog will linger up to 12Z at OAJ where winds will be lighter, and thus far have seen vsbys bounce between 1/2sm and 3sm. Have maintained the fog potential in OAJ's tempo group. Some low level stratus will develop in respoonse to a steadily moistening atmosphere, but will scour out quickly this morning leading to a VFR day with just some patchy diurnal cu. Have added a tempo group for several hours as the afternoon through early evening sea breeze pushes through, with gusts approaching 20 just behind the sea breeze passage.
Outlook (Mon through Thurs): Upper ridge breaks down Monday with shortwave energy bringing good chances for showers and thunderstorms and sub-VFR conditions Mon into Tue, possibly into Wed as well. Beyond mid week, more typical iso to widely sct activity expected as ridging rebuilds into ENC.
Light winds generally 5-15 kt will cont today, 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 (Mon through Wed): Bermuda high pulls offshore into Monday with a front slowly dropping south across the Mid- Atlantic serving to tighten gradient a bit and expect winds to increase to around 15-20 kt and seas building to 3-5 ft. Guidance forecasting gusts around 25 kt for Mon night esp Pamlico sounds and adjacent nearshore waters, so will have to watch for potential future SCA issuance for a time. The gradient relaxes Tue morning with winds returning to 5-15 kt. Weakening front moves into the waters on Wed, though as is typical in July, the front appears to wash out, with any nern flow behind it short lived with return flow developing as early as Wed evening.
Nc, heat advisory from noon today to 8 pm EDT this evening for ncz029-044>047-079>081-090>092-094-193-194-198. Marine, none.
