textproduct: Newport/Morehead City

WHAT HAS CHANGED

Winds have slightly decreased Monday into Tuesday.

Updated Aviation Discussion.

KEY MESSAGES

1) Periods of moderate to heavy rain to continue through Sunday along with a risk of flooding

2) Cool high pressure leads to more fall-like temps next week, but a prolonged period of moderate onshore winds poses localized coastal flooding concerns for areas along the OBX with compromised dune structures.

DISCUSSION

KEY MESSAGE 1...An area of enhanced low-mid level convergence along a frontal zone will interact with moderate instability and a plume of rich, deep, anomalous moisture, supporting scattered to numerous showers and thunderstorms with rainfall rates of 1-3"/hr. Convection is not expected to be all that deep, and may not contain much lightning, but PWATs above the 90th percentile for early October and slow storm motions will pose a risk of some hydro concerns, including at least a modest risk of a few instances of flash flooding. The highest rainfall rates, and greatest risk of hydro impacts, looks to be focused along and southwest of a Greenville to Morehead City line. It's this area where the highest instability will overlap with the greatest forcing and lift. Ensemble guidance continue to suggest 1-3" of rain, on average, in this area. Where convection is the most persistent/trains, the potential exists for amounts as high as 3-6". Across the northeastern counties of ENC, and the OBX, weaker instability should limit rainfall rates and amounts, with a much lower flooding risk.

Convection may wane some tonight, although there should still be sufficient lift and elevated instability to keep a risk of showers and thunderstorms going through the night. On Sunday, a weak area of low pressure will ride along the stalled frontal zone and will continue to support periods of moderate to heavy rain and a few thunderstorms. Instability should take a step down tomorrow, and rainfall rates may not get quite as high. However, given the anomalous moisture present, there may continue to be some hydro impacts, especially for areas that see repeated rounds of heavier rain on top of what falls today. The heaviest rain is expected to end from north to south late Sunday into Monday morning.

KEY MESSAGE 2...In the wake of the weekend front, a stiff NEerly breeze will develop and peak MON night into TUE. This will lead to building seas and elevated water levels. Astronomical tide levels will luckily be on the way down, but seas building to 7ft, though relatively choppy periodicity of 7 sec, may be enough to lead to further beach and dune erosion concerns across the areas with severely diminished dune structures. However, this risk appears to be decreasing some due to the strongest winds and highest seas shifting south of Hatteras Island. Strongest winds of 20-25 kt with higher gusts expected MON night into TUE morning. Winds remain out of the N-NE into late- week, but speeds diminish to 10-15kt late TUE and beyond.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

Sub-VFR conditions will prevail through the TAF period. A cold front is currently situated from roughly DPL to MRH with heavier showers and potentially an isolated thunderstorm with widespread light to moderate showers across most rtes early this evening. Currently seeing IFR conditions north of the front and MVFR to the south. The front will continue to slowly push swd this evening with IFR to LIFR conditions developing across all rtes overnight. Low pressure develops along the front and lifts NE on Sunday which will allow the front to push back toward the coast. Some uncertainty with just how far inland the front pushes but cigs will likely lift to MVFR and potentially VFR to the south and east of the boundary. MRH has the highest probs of seeing improving cigs during the day Sunday, OAJ and EWN has the most uncertainty whether any improvement will occur, while PGV and ISO has the highest probabilities to remain IFR throughout the day.

Outlook: RA and a few TSRA will gradually end from north to south late Sunday night into Monday morning as a cold front moves through. Behind the front, the winds will become northeasterly. CIGs should improve by Sunday evening, with VFR conditions then prevailing into the middle of next week.

MARINE

A modest northerly wind of 10-15kt is ongoing across much of the central and northern waters in the wake of a slowing cold front. South of that front, light southwest winds of 5-10kt are ongoing across the southern waters. The front is slowing down and may not get through the southern waters through tonight. The front then lifts back north on Sunday as a weak area of low pressure moves along it. As the low moves offshore, it will drag the cold front back south through all waters Sunday night into Monday. The northerly surge behind that front will be stronger than today's surge, with marine headlines likely needed for some waters. Guidance has trended down some with the winds during this time, but still appear supportive of a period of 20-30kt winds. A few gusts to gale- force will be possible south of Cape Lookout. Seas of 2-3ft this weekend should eventually build to 4-7ft by Monday and Tuesday as the above-mentioned northerly surge moves through.

Outlook: Northeasterly flow of 10-15kt continues into the middle of next week, but should be lighter than Monday/Tuesday.

MHX WATCHES/WARNINGS/ADVISORIES

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