Key MESSAGE 1, Strong but slow-moving cold front is expected to approach the Carolinas late Friday into Saturday as disorganized shortwave energy over the Northern Plains phases over the Great Lakes and digs across the mid-Atlantic. Mid-level heights will remain well above average for late March (up to 1-2 sigma), and temperatures will consequently rebound through the rest of the week, hitting upper 70s to around 80 today and upper 80s inland on Friday. Temps on Friday will threaten multiple records - see the CLIMATE section for details.
KEY MESSAGE 2, Increased moisture advection along the southward- advancing frontal zone looks to support the next appreciable chance of showers and a few thunderstorms, focused mainly Friday night into Saturday with the best chances north of US Highway 70. Instability continues to look meager with less than 500 J/kg MLCAPE, and the severe thunderstorm risk appears to be very low (less than 2%). Overall moisture does not look to be deep enough to support heavy rainfall, with average amounts a tenth of an inch or less save higher amounts in thunderstorms.
KEY MESSAGE 3, Behind this front, another surge of northerly winds is expected Friday night and Saturday, along with cooler, below normal temperatures returning over the weekend. There is a potential for frost Saturday night with NBM probs currently around 50 percent across inland counties up to 70% across western Martin Co.
06z Thursday through Monday VFR conditions are present across the airspace early this morning with high pressure offshore and light southerly flow across ENC. There remains a possibility for patchy fog formation later this morning, but recent trends in both guidance and observations, cast some doubt on this development. Elevated winds and periods of mid/high cloudiness have kept temps mild so far tonight, with decreasing chances we meet the necessary crossover temps for radiational fog. Nevertheless, some isolated areas of patchy MVFR fog are possible, with best chances along the US 17 corridor where higher moisture was present yesterday. Soon after sunrise any fog that's formed will quickly burn off, and VFR conditions will continue through the day and into tonight with only some scattered clouds in the 4000-5000 ft range. Winds will continue to increase with gusts to 15-25 mph possible this afternoon and evening.
Outlook: The next cold front is forecast to reach ENC late Friday, pushing offshore by Saturday morning. Similar to this recent front, there will be a risk of SCT SHRA, isolated TSRA, and a notable northerly wind shift. Once again it looks like there will be a risk of 20-35kt wind gusts behind the front. Sub VFR conditions may develop as well, especially where SHRA develop.
High pressure is now well offshore this morning with south to southwesterly winds on its western periphery 5-10 kt, but closer to 15 kt over the warmer Gulf Stream waters. Seas are sitting at around 3-4 feet with periods of 10-11 seconds. S to SW winds will gradually increase this afternoon as gradients tighten in advance of the frontal system. There remains a weak signal for some sea fog tomorrow morning with increasing moisture advection over relatively cool near-shore waters where H20 temps remain in the 40s and 50s, but probability is too low to mention in the forecast.
The next round of impactful winds and seas is expected to develop late tonight into Friday and persist through Saturday as the next cold front moves through. Once again, a period of northerly post-frontal gales will be possible Friday night into Saturday morning. Sca headlines were issued for all offshore waters this morning, and further headlines will likely be needed for soundside waters in following shifts. Confidence is lower in start times for Onslow Bay and the far northern waters where cooler water temps may temper more robust mixing, but probabilistic guidance was elevated enough (50-60% chance) to justify issuing advisories.
Outlook: Seas will likely remain elevated into at least Sunday. Mostly benign conditions expected for much of next week as stagnant pattern takes hold.
Nc, none. Marine, small craft advisory from 5 am Friday to 8 am EDT Sunday for amz150. Small craft advisory from 11 pm this evening to 8 pm EDT Sunday for amz152-154. Small craft advisory from 2 am Friday to 8 pm EDT Sunday for amz156. Small craft advisory from 8 am Friday to 8 pm EDT Sunday for amz158.
