Key MESSAGE 1, Tonight still looks like the best candidate so far for fairly widespread frost, especially west of NC 17 as skies remain clear and winds inland will likely be calm with high pressure building overhead tonight. As is typical in these environments, deterministic guidance for lows is not aggressive enough, so blended in NBM 10th percentile and the previous forecast to keep forecast lows into the mid to upper 30s. Could see a few well sheltered areas make a run towards the low 30s but this should be rather isolated. Frost Advisory continues for areas along and west of Hwy 17 overnight. Tuesday night is forecast to remain slightly warmer as high cirrus is forecast to stream into ENC from the west preventing good radiational cooling Tue night limiting frost potential. So while it is unlikely tomorrow night it's not completely out of the question for inland sheltered spots.
KEY MESSAGE 2, Not much has changed with this weekends system as there remains good agreement amongst guidance for increasingly unsettled weather across the eastern CONUS. A complex mid-level low will deepen over the region and steer multiple shortwaves over the Mid-Atlantic. While there are still some differences in exact details that will need to be hashed out in the coming days it remains likely that a complex low will sweep across the Ohio River Valley and Mid-Atlantic Wed into Thursday with a coastal low developing off the Mid-Atlantic coast Thurs into Friday with this coastal low then deepening offshore as it meanders around the the Northeast this weekend though its intensity and track remain uncertain. Probabilistic guidance favors a northern track for these areas of low pressure, which would keep heavier precipitation away from our area though isolated to widely scattered showers wouldn't be out of the question. Either way not expecting much QPF from any shower that impacts the area Thurs into Fri before we dry out.
The biggest threat with this aforementioned low will be the associated gusty winds. In general, probabilities for a period of 20-30 mph W-NW winds and gusts potentially in excess of 35-45 mph Fri into Sat remain high. If this is realized, at least some coastal flooding concerns could arise soundside along the Outer Banks. Given spread of guidance, it is too early to state the potential magnitude of impacts. Stay tuned for future updates.
Behind the system, unseasonably cool air will flood into the area knocking highs down into the 50s for the weekend and offer the first real opportunity for a freeze Sat night and Sun night.
06z Tuesday through Saturday As of 0030EST, High pressure will gradually build overhead tonight bringing mainly VFR conditions to all terminals. Strong radiational cooling expected overnight with clear skies and light to calm winds opening the door for a ground fog and frost threat if there's enough moisture left in the lower levels. Brief patchy fog will be possible at all terminals early Tue morning. Have continued 00Z TAF's tempo mention of MVFR VIS due to fog with the 3sm mention for PGV. Greenville briefly fogged up to IFR last night/yesterday morning so the 3sm shows that possibility of lower VIS here, but not enough confidence to include IFR explicitly in TAFs. Mrh obs currently shows that this site has decoupled. Fog will also be possible here, but MRH has the best chance of getting some mixing overnight being along the coast. Increasing high clouds expected Tue afternoon. Patchy fog will again be possible Tue night/Wed morning.
Outlook: Mainly VFR conditions are forecast through Wed as high pressure and a much drier airmass remain in place. Approaching storm system at the end of the week brings an increase in shower chances, some gusty winds, and sub-VFR conditions.
High pressure has begun to build in from the west behind a departing surface trough giving way to light winds and subsiding seas overnight and early Tue. Latest obs show variable winds 5-10 kt with seas mainly 2-4 ft, 3-5 ft further offshore. Light winds becoming SW 5-15 kt this afternoon with seas 2-4 ft.
Outlook: Decent boating conditions expected through Wednesday. Attention then turns to a coastal low likely to develop off the Mid-Atlantic coast Thursday. Although magnitude of impacts remains uncertain, trend has been for stronger winds and the probability for strong SCA and Gales remains elevated, especially for the waters from Raleigh Bay north. Timing and intensity remains a point of uncertainty, so mariners are encouraged to continue monitoring future forecasts.
Nc, frost advisory until 7 am EST this morning for ncz029-044-079- 080-090>092-193-198. Marine, none.
