textproduct: Newport/Morehead City

WHAT HAS CHANGED

Frost advisory continues for tonight across the Coastal Plain.

Updated Aviation Discussion

KEY MESSAGES

1) Cool and dry conditions linger for the next couple of days with frost concerns tonight.

2) Approaching storm system near the end of the week will bring well below normal temperatures, breezy conditions, and a chance of rain.

DISCUSSION

KEY MESSAGE 1... A warm and pleasant fall afternoon on tap for ENC today as temps have warmed into the upper 60s to low 70s under clear skies and steady W to NW winds behind a departing surface trough.

As we've been mentioning for the past couple of days, tonight looks like the best candidate so far for fairly widespread frost, especially west of NC 17 as skies remain clear and winds inland will likely be calm with high pressure building overhead tonight. As is typical in these environments, deterministic guidance for lows is not aggressive enough, so blended in NBM 10th percentile and the previous forecast to keep forecast lows into the mid to upper 30s. Could see a few well sheltered areas make a run towards the low 30s but this should be rather isolated. As a result a frost advisory has been issued for much of the Coastal Plain west of Hwy 17 tonight between midnight and 7AM Tue. Tuesday night is forecast to remain slightly warmer as high cirrus is forecast to stream into ENC from the west preventing good radiational cooling Tue night limiting frost potential. So while it is unlikely tomorrow night it wont be impossible.

KEY MESSAGE 2...Not much has changed with this weekends system as there remains good agreement amongst guidance for increasingly unsettled weather across the eastern CONUS. A complex mid-level low will deepen over the region and steer multiple shortwaves over the Mid-Atlantic. While there are still some differences in exact details that will need to be hashed out in the coming days it remains likely that a complex low will sweep across the Ohio River Valley and Mid-Atlantic Wed into Thursday with a coastal low developing off the Mid-Atlantic coast Thurs into Friday with this coastal low then deepening offshore as it meanders around the the Northeast this weekend though its intensity and track remain uncertain. Probabilistic guidance favors a northern track for these areas of low pressure, which would keep heavier precipitation away from our area though isolated to widely scattered showers wouldn't be out of the question. Either way not expecting much QPF from any shower that impacts the area Thurs into Fri before we dry out.

The biggest threat with this aforementioned low will be the associated gusty winds. In general, probabilities for a period of 20-30 mph W-NW winds and gusts potentially in excess of 35-45 mph Fri into Sat remain high. If this is realized, at least some coastal flooding concerns could arise soundside along the Outer Banks. Given spread of guidance, it is too early to state the potential magnitude of impacts. Stay tuned for future updates.

Behind the system, unseasonably cool air will flood into the area knocking highs down into the 50s for the weekend and offer the first real opportunity for a freeze Sat night and Sun night.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

High pressure will gradually build overhead tonight bringing mainly VFR conditions to all terminals. Strong radiational cooling expected overnight with clear skies and light to calm winds opening the door for a ground fog and frost threat if there's enough moisture left in the lower levels. Brief patchy fog will be possible at all terminals early Tue morning. Increasing high clouds expected Tue afternoon. Patchy fog will again be possible Tue night/Wed morning.

Outlook: Mainly VFR conditions are forecast through Wed as high pressure and a much drier airmass remain in place. Approaching storm system at the end of the week brings an increase in shower chances, some gusty winds, and sub-VFR conditions.

MARINE

High pressure has begun to build in from the west behind a departing surface trough allowing for winds and seas to quickly decrease across our waters today. Latest obs show widespread 5-15 kt W-NW winds with gusts up towards 20 kts and 2-4 ft seas. As high pressure builds overhead expect these benign boating conditions to continue with winds becoming light at 5 kts or less tonight and shifting to a S-SW'rly direction. As high pressure pushes offshore on Tue winds remain SW'rly but increase slightly to 5-15 kts. With the lighter winds seas will lower to 2-4 ft tonight and remain at these heights into Tue evening.

Outlook: Decent boating conditions expected through Wednesday. Attention then turns to a coastal low likely to develop off the Mid-Atlantic coast Thursday. Although magnitude of impacts remains uncertain, trend has been for stronger winds and the probability for Gales remains elevated, especially for the waters from Raleigh Bay north. Timing and low intensity remains a point of uncertainty, so mariners are encouraged to continue monitoring future forecasts.

MHX WATCHES/WARNINGS/ADVISORIES

NC...Frost Advisory from 1 AM to 7 AM EST Tuesday for NCZ029-044- 079-080-090>092-193-198. MARINE...None.