Key MESSAGE 1, Temperatures peak today across ENC with near record to potentially record high temperatures. Low level E to NE'rly flow from Sat becomes SW'rly today allowing for warm air advection to begin in earnest. This will also allow for above normal low level thicknesses across the region for the time of year and therefore very warm temperatures on Sunday. Dry conditions expected with temps reaching well into the 80s across our interior zones and 70s along the coast. Once again, did manually bring up temps for NOBX Sunday with SW flow bringing a warmer continental airmass over the NOBX area so relied more on MOS guidance as compared to the NBM as the NBM typically under does these regimes. This results in mid-upper 70s across the NOBX. Some inland locales could exceed their record temps for the day so a CLIMATE section has been kept in place for Sunday.
KEY MESSAGE 2, An upper level trough dives south from the central Canadian Provinces and into the Ohio River Valley and Northeast, extending as far south as the Mid-Atlantic on Mon and into Tue. Its associated mid level shortwave rounds the base of this trough at the same time. At the surface this brings a backdoor cold front quickly through the area on Mon. Moisture has trended up ahead of this front, especially along the Crystal Coast extending inland towards New Bern and Jacksonville. Current model PWATs Monday afternoon are in the 1.5-1.75" range. Afternoon timing of cold front will allow us to warm up and increase instability ahead of the front, with 500-1000J/kg of MLCAPEs forecast. Ahead of this front, 0-6km bulk shear is forecast to be 30-40kt, sufficient for structured tstorm development. As the front collides with the afternoon sea breeze, numerous showers and some tstorms are likely to form at the intersection point. Steep low level lapse rates can help bring some stronger winds down to the surface in the strongest of storms.
A low confidence aspect of this event is the chance for brief, weak tornadoes or waterspouts. Current model hodographs aren't too supportive of anything spinning up, but as the front interacts with the sea breeze, it is possible for the front to slow down a tad at the surface due to the collision, but still progressing SE'ward above the sea breeze. This would cause some more curvature to the hodograph than models indicate, as SW winds at the surface are superimposed by N winds aloft. Localized enhancements of low level SRH could occur, should this setup happen. Again, this is a low confidence outcome, but was worth a mention as a "worst case" scenario.
Progressive nature of front should prevent showers/storms from lingering too long, preventing any hydro concerns. Behind the front, we will see a rapid increase of northerly winds with temps dropping through the afternoon and into evening. If this front were to blow through in the morning, we would have had some fire weather concerns with stronger winds and drier air moving in, but an afternoon progression prevents any fire issues outside of the wind switch.
KEY MESSAGE 3: A positively tilted upper trough moves through the eastern seaboard late week as a shortwave/low crosses the Great Lakes, rounding the base of a more potent low over Hudson Bay. A weak cold front trails from this weaker of the two lows, progged to move through the Carolinas late week. We have a chance of rain in the forecast for this frontal system, but as of right now no major concerns are expected.
06z Sunday through Thursday A small cluster of SHRA over SE NC should continue to weaken as it moves southeast towards the coast. It may glance KOAJ with SHRA and a brief period of VFR CIGs (5-6k ft). In the wake of this activity, we'll be monitoring the area for the potential of BR/MIFG development. Runways in the Outer Banks are already seeing some reduced VIS, and this area may expand some overnight. Daytime heating and mixing should lead to a quick reduction to any areas of sub-VFR VIS Sunday morning. Strengthening southwest flow develops quickly on Sunday well in advance of a cold front that will be approaching the region from the NW. Gusty winds up to 20-25kt are expected at times Sunday. This then transitions to an increased risk of LLWS impacts Sunday evening as the front draws closer, and as a southwest low-level jet develops ahead of it.
Of note, afternoon cumulus are expected along the seabreeze today, and a seabreeze SHRA or TSRA cannot be ruled out, but for now the probability of TSRA this afternoon is <10%.
Outlook: A cold front will move south through the area on Monday, bringing an increased risk of SHRA and TSRA, a SW to N wind shift, sub-VFR conditions, and gusty winds (20-25kt).
Winds light and variable tonight before become S/SW'rly across all waters, gradually increasing in magnitude through the day today. As we get into tonight the pressure gradient will tighten with the approach of a cold front increasing SW'rly winds to 15-20 kts with gusts up to 25-30kts along the Gulf Stream, and 4-7 ft seas. This will bring a return of the small craft advisories to our coastal waters south of Oregon Inlet where the warmer Gulf Stream Waters are. Cold front moves through Monday, with a quick switch to strong northerly winds (20-30 kt gusting to 25-40kt) behind it. Gale Watches are now in effect for coastal waters south of Oregon Inlet to Surf City with this update, starting Monday afternoon and ending Tuesday morning. North of Oregon Inlet, a brief period of marginal gale force gusts are possible right behind the front, but confidence and duration were too low to add these waters to the Gale Watch, instead electing to go for a Small Craft Advisory. Seas build to 6-10 ft behind the front, highest over the Gulf Stream. Additional Small Craft Advisories issued this morning include all inland sounds and Alligator River for the northerly flow behind the front.
Outlook: By Tuesday evening conditions ease and more benign boating conditions are forecast by midweek as high pressure ridging builds in from the north and west. Late week frontal system may bring another round of elevated wind gusts and seas.
Nc, none. Marine, small craft advisory from 2 pm Monday to 8 am EDT Tuesday for amz131-230-231. Small craft advisory from 2 pm Monday to 2 pm EDT Tuesday for amz135. Small craft advisory from 2 pm Monday to 8 pm EDT Tuesday for amz150. Small craft advisory from 8 pm this evening to 2 pm EDT Monday for amz152-154-156-158. Gale watch from Monday afternoon through Tuesday morning for amz152-154-156-158.
