textproduct: Newport/Morehead City

WHAT HAS CHANGED

Increasing confidence for significant winter storm to impact portions of eastern NC this weekend. Though still quite a bit of uncertainty in the specifics, snow probabilities continue to decrease slightly (highest probs north of Hwy 264), while the probability for ice has increased (highest probs west of Hwy 17).

KEY MESSAGES

1) Gradual warming trend the next few days. Coastal trough developing tonight may bring isolated showers.

2) An Arctic front will push through the area late Friday with a low pressure system passing along the coast over the weekend, bringing a threat threat for winter weather impacts to ENC. Confidence is increasing that winter weather will occur over the area and may bring impactful snow and ice accumulations. Gale force winds possible across the coastal waters this weekend. Stronger north winds may lead to minor coastal impacts.

3) Very cold airmass will settle into the area late weekend into early next week, with record cold and an extended period of sub-freezing temperatures possible.

DISCUSSION

KEY MESSAGE 1... High pressure will gradually slide offshore, with southerly flow developing this afternoon and tonight. Weak coastal trough will develop, which could lead to iso coastal showers overnight. After a cold start, highs will climb into the 50s for most of the area this afternoon and mid 50s to low 60s Thu.

KEY MESSAGE 2... A series of northern stream shortwaves will reinforce deep troughing over the Eastern US late this week through early next week. A strong cold front will push through the area late Friday with Arctic high pressure building into the area from the north setting the stage for maintaining cold temperatures across the region. Low pressure will then develop along the stalled front offshore before pushing farther out to sea Sunday, with precip overspreading the area interacting with the arctic airmass. There continues to be quite a bit of uncertainty with precipitation types as the depth of a warm layer aloft (that would allow for a melting layer around 850 mb) and the cold layer below remain uncertain. It still remains too early to try to pinpoint amounts or where specific precip types will set up as the depth of these layers and the subsequent precipitation types/amounts will be influenced by the magnitude of the cold air working its way in from the north as well as the proximity of the final low track to the coastline. 00z guidance continues the trend of favoring a mix of snow, sleet and freezing rain inland and mostly rain for much of the immediate coast. At this time higher snow accum probs for areas north of Hwy 264, and higher ice accum probs along and west of Hwy 17. Despite the uncertainties, significant impacts from snow, sleet, and freezing rain are possible over the weekend. Impacts could begin as early as Sat morning, with the main window likely late Sat and Sun, as stronger warm nose develops. Continue to stay tuned to the forecast over the next several days with the increasing threat for wintry weather.

Prolonged period of stronger north winds may lead to minor coastal impacts this weekend.

KEY MESSAGE 3... Arctic high pressure will build in early next week behind the departing low with record cold possible. Lows in the 20s return Friday through Sunday nights, with daytime highs only expected to push to near 30 inland (near 40 Outer Banks). Could then see overnight lows and wind chills fall into the single digits Sunday night into Monday night, with highs continuing to struggle to reach freezing in some areas. Thus, it is possible for at least portions of ENC to see record cold and an extended period of sub-freezing temperatures this weekend into next week.

AVIATION /08Z WEDNESDAY THROUGH SUNDAY/

VFR conditions expected through the period. High pressure shifts offshore today, but with the atmosphere so dry, mostly clear skies will persist through the day. Increasing moisture tonight may lead to some coastal low/mid cloudiness, but cloud heights should be at or above 5000 ft.

Outlook: Mostly VFR conditions will continue through Friday despite a few weak disturbances moving through the region. An extended period of sub-VFR conditions is likely this weekend as a significant winter storm impacts the area. All winter precip types are possible across local terminals.

MARINE

Latest obs show NW-NE winds 5-15 kt and seas 2-4 ft. Weak coastal trough will develop offshore late today and tonight. Winds will grad veer becoming southerly this afternoon and tonight. SW winds will increase to 10-20 kt tonight, with potential for periods of light rain.

Thursday through Sunday: Light to moderate winds expected through Friday with seas 2-4 ft. An arctic front and low pressure system will then impact the waters this weekend, which will likely bring strong SCA conditions and a chance for Gale Force winds over portions of the waters. Gale potential looks to be increasing late Fri night and Sat.

MHX WATCHES/WARNINGS/ADVISORIES

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