Key MESSAGE 1, Latest analysis this morning depicts a stalled frontal boundary stalled just off the coast of the Carolinas, extending over portions of the Deep South and settling along the northern Gulf coast. Large-scale cyclonic flow aloft continues to swirl over the Great Lakes and southeastern Canada, but some weaker vort maxes migrating along the frontal boundary are providing enough lift to promote a broad area of rain and embedded showers across the southeastern CONUS and into the Carolinas. Some light rain is spreading south of US 70 this hour and will likely be present for this morning's commute especially in the vicinity of the Crystal Coast.
Pool of low-level moisture trapped under the frontal inversion will keep cloudy and occasionally drizzly conditions in place for most of ENC today, which will also keep temps from climbing much beyond the low to to mid 70s. Later this afternoon, dry air advecting in with a reinforcing boundary and building high pressure will begin a clearing trend from NW to SE with TDs diving well into the 50s and even upper 40s inland by this time Tues AM.
High pres builds further tomorrow into Wed, resulting in very pleasant mild and dry days with highs near climo in the 75-80 range (low 70s OBX), but cooler than normal lows well down into the 50s for the mainland, and perhaps a few 40s for the normally cooler sheltered locales. The strongest signal for this is on Wednesday when the high crests overhead and environment is most favored for radiational cooling.
KEY MESSAGE 2, Mid-level zonal flow returns Thu into the weekend, and this will bring a modest warming trend back to ENC. Sw flow returns by Friday as a broad but weak mid-level low develops and meanders over the southern plains, bringing a return of Gulf moisture by the end of the week. There are still plenty of details to sort out and some timing differences, but general ensemble consensus is that frontal boundary still stalled to our south will be pulled northward as one or potentially multiple lows develop along it and lift northward. This will bring a return for rain chances, and with the moisture having Gulf origins some heavier rainfall is not implausible.
10z Monday through Friday All terminals remain socked in under IFR or LIFR conditions this morning as low-level moisture remains pooled under a strong frontal inversion with spotty fog closer to I-95. Current conditions will change little through this morning, but by this afternoon dry air will advect in from the NW as high pressure builds into the area. Guidance has trended a bit faster on the onset of VFR conditions compared to 06z, especially for terminals closer to the coast. After 20-21z, VFR expected to be prevailing for the remainder of the period for all terminals.
Outlook (Tues through Fri): Mainly VFR conditions expected from Tuesday onward, both day and night with lowered dewpoints. Overall fog chances appear low each night at around 10% or less. In the wake of the boundary Tuesday, NE winds may gust up to 20 kt at times especially for near-shore terminals.
Sca headlines remain unchanged from this afternoon as reinforcing boundary migrates across area waters tonight with high pressure building in its wake. 00z suite has continued to trend downward just slightly, but at least some period of SCA conditions remain likely from Oregon Inlet southward but more likely beyond 5-10 nm offshore.
Seas of 2 to 4 ft continue through today, then build to around 6 feet south of Oregon Inlet overnight. Seas eventually subside back below 6 ft by late tomorrow afternoon.
Outlook (Tues through Friday): Northeasterly flow of 10-15 kt expected mid week as high pres will be anchored to the north, and winds/seas remain below SCA thresholds. Deteriorating conditions likely on Friday and extending into the weekend as frontal boundary begins to lift back northward from the Gulf coast with increasing NE winds particularly over Onslow Bay.
Nc, none. Marine, small craft advisory from 10 pm this evening to 2 pm EDT Tuesday for amz152-154-156. Small craft advisory from 10 pm this evening to 5 pm EDT Tuesday for amz158.
