Key MESSAGE 1, Latest surface analysis shows high pressure now sitting off the coast of the mid-Atlantic while broad ridging continues to expand over much of the CONUS' southern tier. Winds across the area are now out of the south to southeast and temperatures have climbed a few degrees from yesterday into the mid to upper 80s. Dews have also jumped as well, into the low to mid 60s.
Temperatures peak tomorrow 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 between 100-105. At this time the odds of issuing a Heat Advisory look to be less than 10%, but trends will continue to be monitored.
KEY MESSAGE 2, Mid- level subsidence aloft will keep precipitation chances very subdued this afternoon despite the uptick in instability, although cannot completely rule out an isolated shower or two along typical sound and sea breeze convergence zones. Shortwave approaches from the central plains tomorrow, weakening the ridge and aiding in a slightly more favorable environment for isolated to widely scattered showers and thunderstorms.
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 to numerous sea breeze showers/tstorms back in the forecast. After some waffling the past few runs, guidance has come into far better agreement showing 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 effective shear has trended down on Friday to generally less than 15 kt, so the risk of any stronger storms is less than 5%.
The front lifts back north Saturday into Sunday as a shortwave moves through the region. 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.
There is higher confidence on a low- CAPE outcome Sunday. 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.
18z Wednesday through Monday VFR conditions in place across eastern NC as high pressure shifts offshore and a more typical warm season pattern takes hold under light south to southeasterly winds. Winds will gradually veer southwesterly overnight as high moves even farther offshore. Where winds decouple there will once again be a risk of fog or low stratus, but at all terminals the risk of this is 10-20% and opted to keep out of TAFs this cycle.
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. Expecting iso to widely scattered showers and storms tomorrow, 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 this afternoon with winds generally out of the south to southeast at 5-10 kt and seas around 2-3 feet. Quiet conditions expected through tonight, but conditions deteriorate slightly tomorrow 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 around 20% and a potential advisory was deferred for the midnight shift's consideration.
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.
Nc, none. Marine, none.
