Key MESSAGE 1, Temperatures peak today and Friday as flow turns more southwesterly and low-level thicknesses peak, with highs in the low to mid 90s. Dew points also peak on Friday, resulting in maximum heat index values returning to around 100F. At this time the odds of issuing a Heat Advisory continue to be less than 10%, but trends will continue to be monitored.
KEY MESSAGE 2, Mid- level subsidence continues aloft, keeping low end shower chances (15%) confined to areas where sea/sound/river breezes converge today. Brought down PotThunder to keep thunder mentions out of the forecast today, as a notable dry layer above 700mb will make it difficult for updrafts to grow tall enough for lightning.
Friday the high continues to shift offshore and a front sweeps south through the Mid-Atlantic region. Ahead of this front, continuous warm, moist advection in southerly flow will help build PWATs to near 2". This will bring scattered sea breeze showers/tstorms back into the forecast. Coverage may be limited as models are suggesting mid level subsidence and a dry layer lingering into Friday. Guidance continues to lock in on a solution where the front largely bisecting eastern NC by Friday, although a small minority still shows it stalling farther north along the VA border. Wherever the boundary ends up setting up will be the focus for the highest risk of training showers and thunderstorms contributing to a localized flash flooding threat. Forecast 0-6km shear looks to be around 15-25 knots along the front, giving the northern tier of counties (hwy 264 and areas north, the best chance of organized convection and higher rainfall totals.
The front lifts back north Saturday into Sunday as a shortwave moves through NC. This shortwave will bring slightly better chances for showers and thunderstorms this weekend. Like Friday, flooding concerns remain the primary risk with PWATs still around 2" but effective shear slightly higher at 15-20 kt. Available instability remains a question mark for that day given potential convective evolution on Friday and the risk for lingering convective debris overnight and/or low stratus that may develop on the cooler side of the frontal boundary. The NBM probabilistic envelope has shifted slightly cooler for Saturday but still remains high compared to both deterministic and MOS guidance, suggesting a cooler and therefore lower instability solution will prevail. If more instability can develop, the modest uptick in shear may provide a slightly more favorable environment for an isolated stronger storm or two. One deviation from previous model run iterations of note is the potential for the shortwave to move through to our west. This would decrease overall forcing in eastern NC and confine storms to areas generally west of hwy 17. This trend has been reflected in slightly lower PoPs for Saturday afternoon/evening (down from 80% to 70% inland), and a PoP free forecast for much of the coastline.
There is higher confidence on a low- CAPE outcome Sunday (less than 2000 J/kg). While heavy showers and some thunderstorms are possible with the shortwave, the severe threat appears to be more muted.
KEY MESSAGE 3, A more typical summertime pattern will settle in again early next week as a large high sits over the southeast. Based on current model outputs, we have enough moisture and instability present for some afternoon/evening sea breeze convection early next week, but there are no larger scale synoptic features of note that would promote any additional forcing.
06z Thursday through Monday VFR conditions will prevail at the terminals through the TAF period. There is a low chance (10-20%) for shallow fog development late tonight near Onslow and Duplin counties, roughly 8-11z, where decoupling occurs. Have a TEMPO
Breezier day tomorrow as front approaches the north, and a few gusts to 15-20 kt are likely both inland and across OBX terminals especially after 18z. Could see an isolated thunderstorm tomorrow, mainly along the sea breeze, although the risk of a strong storm is minimal.
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 (Friday through Monday): A front is expected to approach the region and stall Friday and Saturday bringing a chance of showers and thunderstorms with periods of sub-VFR conditions possible. Shower and isolated thunderstorm threat extends into Sunday before more typical summertime weather returns Monday.
Benign marine conditions ongoing with winds generally out of the south to southwest at 5-15 kt and seas around 2-3 feet. Conditions deteriorate slightly later today as southwest winds increase ahead of an approaching front. Sw winds will peak around 15-20 kt late Thurs into Friday morning, and a few gusts to 25 kt are possible across the Albemarle Sound and northern waters. Probabilities of 25+ kt are still around 20% and elected not to issue a SCA. If conditions look to be exceeding the forecast later today, a MWS or last minute SCA is not out of the question.
Outlook (Fri through Mon): A coastal trough may also set up Thursday night into Friday, bringing increased tstorm chances along the Gulf Stream. Front bisects area waters on Friday then lifts northward on Saturday. Sub-sca conditions expected but shower and thunderstorm risk will continue at least into Sunday. High pressure builds in early next week with benign boating conditions returning.
Nc, none. Marine, none.
