textproduct: Newport/Morehead City

WHAT HAS CHANGED

We continue to closely watch guidance for a potentially significant winter weather event this weekend. A lot of uncertainty remains with this system, especially in regard to precipitation types across ENC. Over the past 12 hours, the snow probabilities have decreased slightly while the probability for ice has increased slightly.

KEY MESSAGES

1) Below normal temperatures continue through tonight, with low temperatures expected to drop to around 15 to 20 F tomorrow morning for all areas away from the immediate coast.

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.

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... Arctic high pressure currently analyzed over the Tennessee River Valley will continue to build in through today, becoming centered over the Mid-Atlantic region tonight into tomorrow. Highs will struggle to reach the mid-40s today across ENC. Calm winds and clear skies will then support favorable conditions for radiational cooling tonight, with lows expected to drop into the 15-20 F range for all areas away from the immediate coast tomorrow morning. Probabilities continue to look low (<20%) for reaching Cold Weather Advisory criteria (apparent Temp <15 degrees). Thus, will continue to hold off on any product issuance at this time.

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 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. Despite these uncertainties, potential continues to increase for significant impacts, with snow, sleet, and freezing rain all possible over the weekend. Continue to stay tuned to the forecast over the next several days with the increasing threat for wintry weather.

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 /18Z TUESDAY THROUGH SUNDAY/

VFR conditions will persist through the TAF period. High pressure continues to build east over Eastern NC this afternoon and will push off the Mid-Atlantic coast tonight, allowing winds to shift southerly on Wednesday. Mostly sunny/clear skies will continue through the TAF period. No restrictions to aviation expected through Wednesday due to strong, dry high pressure over the region.

Outlook: Predominant VFR conditions expected across Eastern NC through Thursday with high pressure offshore. Sub-VFR conditions are likely starting Saturday and continuing into Sunday due to a complex winter weather system that will impact the region with potential for a mix of wintry weather precipitation types.

MARINE

Latest obs show northwesterly winds 10-20 kts with gusts 15-20 kts. A few occasional gusts to 25 kts are still lingering across the central coastal waters, but gusts will continue to abate over the next couple of hours as high pressure works its way into the region.

Wednesday through Saturday: 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.

MHX WATCHES/WARNINGS/ADVISORIES

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