textproduct: Newport/Morehead City

WHAT HAS CHANGED

Stratiform rain chances continue to increase Saturday. Chances for low pressure forming offshore increasing, strength of low still uncertain.

KEY MESSAGES

1) Dry with record heat possible through Friday.

2) Cold front moves through early Saturday, forming a low pressure system offshore.

3) Drastically cooler behind the front and low for Sunday, along with continued breezy northeasterly winds.

Marine: Prolonged large seas this weekend into next week as offshore front stalls with long period fetch of northeasterly swell and increasing chances of low pressure development off the southeast coast.

DISCUSSION

KEY MESSAGE 1...High pressure builds in from the west through most of this week with sunny skies. Building hts as upper ridge strengthens sends temps soaring through the 80s and nearing 90 for some interior locales (record high climate section below). A dry back door front moves into nrn parts of ENC later today with some increasing cloud cover and slightly cooler temps behind it, but quickly retreats north by early Friday with another surge of swrly flow ahead of much stronger front.

KEY MESSAGE 2...Trend of a delayed frontal progression continues, with majority of guidance suggesting a low pressure forms offshore as the front encounters the higher baroclinicity of the Gulf Stream. A trend towards a slower frontal arrival and progression, with low pres development along the frontal zone on Saturday. In addition, stratiform rain chances continue increasing behind the front Saturday. There seem to be three camps of model guidance, ALL of which result in hazardous marine conditions and some level of coastal concerns as high building in pinches the pressure gradient over ENC.

1. The first and most likely outcome (would currently give this a 60% chance of occurring) is a low pressure system forms pretty soon after the cold front reaches the Gulf Stream, as early as 00Z Sunday. The is supported by the 00Z Thursday runs of Euro (deterministic and ensemble), Euro AI, RRFS, and NAM. There is still a wide range of outcomes for strength, but weak steering flow should allow the low pressure system to meander offshore, tapping into the warm gulf stream waters and deepening. Eventual track and strength are still very uncertain. While unlikely, an eventual westward track back towards ENC is not out of the question.

2. The second outcome (would currently give this a 30% chance of occuring) is the front stalls along the Gulf Stream, forming a low hundreds of miles offshore a later on (around Mon-Tue). This outcome is supported by the deterministic GFS, some GEFS members and CMC. this outcome would still bring strong NE winds, but shorter in duration and less wave energy reaching coastal areas.

3. The third and least likely outcome (would currently give this a 10% chance of occurring) is the front stalls offshore and never generates a low pressure system. Strong NE winds would still occur as the high builds in, but like scenario 2, winds would be shorter duration and wave energy would be on the lower end.

Regardless of which scenario plays out, there is HIGH confidence of marine impacts, and potential for waves 7+ ft reaching portions of the OBX. Winds advisory potential exists for the OBX zones, as well as perhaps portions of the adjacent coastal mainland. Will have to watch for minor coastal flood concerns for srn portions of Pamlico Sound and the coastal areas of the OBX with the sustained NE flow.

KEY MESSAGE 3...Coolest and driest airmass for the fall season thus far builds in behind the front Sat night and beyond with temps taking a nosedive with highs in the 60s and lows in the 40s (inland) and 50s (beaches). However, depending how offshore the front makes it, could keep things a bit milder than fcst if some clouds advect in from offshore keeping the nighttime mins a bit warmer than advertised.

AVIATION /06Z THURSDAY THROUGH MONDAY/

VFR SKC continues with light swrly breezes. No guidance shows ANY fog development with all model suites showing winds remaining AoA 2-3kt through the overnight. Kept tempo MVFR for OAJ, which seems to be verifying well early this morning. There was a fire NW of the terminal in Duplin county as well as one NE of the terminal. Smoke plume was never dense enough to show on radar, and visible satellite showed the plume was thinning just before sunset. Did not include FU in the TAFs because of this, but lingering smoke could aid fog development/further dampen VIS should winds decouple. A dry backdoor front sags into the FA later today from N to S before briefly stalling somewhere between the Pamlico and Neuse Rivers overnight. No precip is expected, mostly just a wind shift and maybe some increased cloud coverage along and near the front. Chances for lowered CIG and VIS (with IFR/LIFR potential) increasing Thursday night, especially along and behind the stalled front.

Outlook (Fri through Mon): Sub-VFR chances along and behind the meandering back door cold front early Friday. Pred VFR conditions return in the daytime Friday with swrly breezes inc ahead of cold front. Strong and slow moving cold front brings widespread light rain on Sat, with sub VFR likely behind the front later Sat with frontal inversion developing, along with gusty north winds through the day Sat. Clearing skies Sat night with winds tapering off as high pres attempts to build in for the latter half of the weekend into next week.

MARINE

Latest obs show continuing SW winds 5-10 knots most locales with seas mainly 1-3 ft. High pressure will continue to the north allowing for predom swrly flow but no higher than 5-15 kt tonight with some gusts nearing 15 kt. Backdoor front oozes through the nrn waters and sound later today, though does not make it past Pamlico sound. To the north of the bndry, nerly breezes expected though remaining light, and to the south, generally swrly to srly continued light flow.

Outlook (Fri through Mon): A strong cold front has trended slower, now not expected to clear the waters until Sat, at which point it is likely to form a low pressure system offshore. Strong nrly winds develop in it's wake on Sat, peaking later afternoon through Sat evening with gales appearing likely for all coastal waters and most of the sounds including Alligator river. There is potential for winds, gusts, and seas to be higher than forecast if a deepening low pressure system outcome occurs. Seas build quickly as well, with seas of 6-10+ ft appearing more likely through the weekend. Duration of gale force gusts is uncertain at this point, and there is potential for 6+ seas to linger well into next week.

CLIMATE

Record High temps for 10/15 (Thursday)

LOCATION TEMP/YEAR New Bern 88/1935 (KEWN ASOS) Cape Hatteras 84/1919 (KHSE ASOS) Greenville 89/1985 (COOP - Not KPGV AWOS) Morehead City 86/1990 (COOP - Not KMRH ASOS) Kinston 89/1985 (COOP - Not KISO AWOS) Jacksonville 90/1975 (NCA ASOS)

Record High temps for 10/16 (Friday)

LOCATION TEMP/YEAR New Bern 86/1975 (KEWN ASOS) Cape Hatteras 83/1919 (KHSE ASOS) Greenville 90/1968 (COOP - Not KPGV AWOS) Morehead City 84/1917 (COOP - Not KMRH ASOS) Kinston 86/2008 (COOP - Not KISO AWOS) Jacksonville 88/1975 (NCA ASOS)

MHX WATCHES/WARNINGS/ADVISORIES

NC...None. MARINE...None.