Key MESSAGE 1, Strong but slow-moving cold front will approach the Carolinas today 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), with low level thicknesses supporting highs in the mid to upper 80s inland. This will threaten a few record highs - 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 an isolated thunderstorm or two, 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 rather stubborn convective inhibition, and the severe thunderstorm risk appears to be very low (less than 2%). Further inhibiting thunderstorm chances is the anafrontal nature of this boundary, with the bulk of precipitation expected to fall on the cooler, more stable side of the front. The HRRR does suggest a risk of a few thunderstorms developing just ahead of the front, but this is juxtaposed with a narrow corridor of uninhibited CAPE mainly west of our area. This will likely fall apart by the time it reaches ENC.
Overall moisture does not look to be deep enough to support significant rainfall, although several 12z models are showing higher QPF amounts to around a quarter inch with some HiRes models showing up to a half inch. Highest amount still appear to be across the northern tier.
KEY MESSAGE 3, Behind this front, another surge of northerly winds is expected tonight and Saturday, along with cooler, below normal temperatures returning over the weekend. There is a potential for frost Saturday night with latest NBM probs showing greater than 70 percent across inland counties, and north of 80 percent along and north of Highway 64.
06z Friday through Tuesday VFR conditions are expected this morning and into the afternoon with fair weather ahead of a cold front. The front will move through the forecast area from north to south late this afternoon through the evening hours leading to the development of MVFR conditions and even brief periods of IFR conditions late tonight.
In the near term, skies will remain mostly clear with breezy SW winds. Llws concerns will continue through around or shortly after sunrise. Rain showers and lower level ceilings will move into northern NC late this afternoon, likely reaching KPGV and KISO early this evening, and a couple hours later reaching KEWN and KOAJ. Ceilings will drop to 1500-2500 ft early tonight, and will continue to lower overnight as rain showers continue. Cloud heights will dip to 1000-1500 ft after midnight, with further reductions in ceiling height (and IFR conditions) possible by early tomorrow morning before drier air quickly moves into behind the front.
Outlook: Behind the cold front Saturday morning, skies will quickly clear with VFR conditions returning. Winds will be strong out of the NE at 15-20 kts with gusts to 30 kts possible Saturday afternoon. Winds subside by Sunday with mostly VFR conditions continuing.
Sw winds slowly increasing this morning around 15-20 kt and seas around 3-5 ft. Winds and seas will continue to build this morning into the afternoon with strengthening SW flow ahead of an approaching cold front. That boundary will push south across the waters late this afternoon and evening with a strong northerly surge developing behind the front. The strongest CAA will occur after midnight through much of Saturday when Gale Force conditions are possible with highest chances across the coastal waters and Pamlico Sound. Seas will build to 6-10+ ft peaking during the day Saturday.
Marine headlines were not changed from the previous forecast apart from minor timing adjustments over the Pamlico Sound. Upgrades to Gale Warnings may be needed this afternoon.
Outlook: Seas will likely remain elevated into at least Sunday. Mostly benign conditions expected for much of next week with high pressure centered off the coast.
Nc, none. Marine, small craft advisory from 4 pm this afternoon to 8 pm EDT Saturday for amz131-230-231. Small craft advisory until 8 am EDT Saturday for amz135-150. Gale watch from Saturday morning through Saturday afternoon for amz135-150. Small craft advisory from 8 pm this evening to 8 pm EDT Saturday for amz136-137. Small craft advisory until 3 am EDT Saturday for amz152-154- 156-158. Gale watch from late tonight through Saturday evening for amz152-154-156. Gale watch from late tonight through Saturday afternoon for amz158.
