Key MESSAGE 1, Overall the synoptic environment has not changed much as we still expect a strong shortwave to push through the region on Monday. This system is forecast to have fairly strong dynamics with sharp-ish troughing aloft pivoting over ECONUS to become more negatively tilted as it approaches. At the surface a cold front will push through the region with moisture pooling out ahead of the front as PWATs surge to about 1.25 to 1.75 inches across ENC by Mon morning. Latest guidance suggest front will push through our northern zones around sunrise and pushing S toward the Crystal Coast in the afternoon.
Biggest change over the last 24 hours is that the severe threat has shifted south, confined to areas south of Hwy 70 and along the Crystal Coast/offshore waters. This jives with the latest Hi-Res guidance, which show scattered to widespread shower and thunderstorm activity near the Crystal Coast by Monday afternoon with a few isolated strong to severe thunderstorms while further to the north more isolated showers and a lower tstm threat resides. Main threat within the strongest storms would be damaging wind gusts, heavy downpours, and hail. Instability will be maximized in the convergence zone between the seabreeze and the cold front and this looks to occur closer to the coast, generally E of HWY17 and S of HWY70. Long skinny CAPE profiles generally show instability values between 0.5-1.5kJ/KG. Event total QPF has decreased for far inland and Nern zones that are away from the greatest instability and convergence, light showers with little vertical development early, a tenth to a quarter of an inch. The area mentioned above could see in excess of an inch of precip under stronger cells. Spc has shrunk the marginal threat (level 1/5) to just the immediate Crystal Coast and points south this afternoon, so as mentioned above the threat for severe weather is diminishing but not zero just yet. Stout CAA out of the N behind the front (strongest winds over coast, 20-25kt gusts) will bring in cool air and keep skies mostly clear into WED. Maybe upper 40s, but most likely low 50 Mins and low 70s TUE.
KEY MESSAGE 2, A stacked low cutting across the Sern extent of the Great Lakes and high pressure migrating offshore brings warm and moist air across the Carolinas mid week ahead of the next front set to cross the area Wednesday night into Thursday time frame. Will need to watch this system for severe potential as well.
00z Monday through Friday Winds will go light to calm tonight, which will create an opportunity for shallow radiational fog to develop. Models have backed off a bit on fog probs with the 18Z guidance, but ingredients are all still there so still kept them in the TAFs. I did go up from 2SM (IFR) to 3SM (MVFR) for OAJ and EWN with this update given the trend. This is a low confidence forecast however, and IFR/LIFR fog is within the suite of possible outcomes. Cold front passage in the early morning hours paired with low Tds this afternoon decrease fog probs for inland sites (PGV, ISO), with higher Tds and later frontal passage keeping probs elevated for OAJ and EWN.
Low stratus may be possible during this time as well, but cloud cover is still expected to be FEW to SCT.
A cold front will cross the area tomorrow, bringing lowering CIGs and chances for showers and thunderstorms as well as a wind shift to the northeast. Best chances for showers and thunderstorms are along the Crystal Coast, this prompted a VCTS add for EWN and OAJ. Thunderstorms will be capable of strong wind gusts 40-60 mph and small hail.
Outlook: Another round of sub-VFR conditions may be possible Monday night/early Tuesday but confidence is higher mid-week when the next system will move through the area with additional showers and thunderstorms.
Great boating weather today with 5-10 kt W'rly winds and 3-4 ft seas noted across the region. Further out to sea from about 20-60NM expecting 3-4ft seas at about 7-8sec out of the SE. Winds become SW-W at 10-15 kts tonight. Waters inside of ~40nm expected to remain shower and tstorm free. Swerly winds strengthen some Monday morning ahead of next fropa with SCA conditions becoming more likely with post frontal northerly flow of 25+ kt Mon evening and into Tuesday. Scas remain in place for all coastal waters and Pamlico Sound this forecast cycle with the northern sounds and Alligator RIver also recently added as well as funneling N winds should produce frequent 25+ kt gusts across these areas as well.
Outlook (Sunday night through Thursday): Gale potential continues to decrease for the offshore waters overnight Monday into early Tuesday morning, but the threat for brief periods of gale force gusts does remain over offshore waters S of Cape Hatteras. Winds diminish later Tuesday into Wednesday as high pressure briefly reestablishes itself. Mondays front lifts back N through the region mid-week ahead of the next front to cross late Wednesday into Thursday bringing yet another potential round of SCA conditions to our waters.
Nc, none. Marine, small craft advisory from 11 am to 8 pm EDT Monday for amz131- 230-231. Small craft advisory from 2 pm Monday to 8 am EDT Tuesday for amz135. Small craft advisory from 11 am Monday to 8 am EDT Tuesday for amz150. Small craft advisory from 2 pm Monday to 8 pm EDT Tuesday for amz152-154. Small craft advisory from 4 pm Monday to 8 pm EDT Tuesday for amz156-158.
