textproduct: Newport/Morehead City

WHAT HAS CHANGED

Winter Storm Watch upgraded to Winter Weather Advisory. Expanded Winter Weather Advisory for most of ENC except Eastern Carteret and Hatteras and Ocracoke Islands for light mixed precipitation later Saturday.

Cold Weather Advisory issued for some inland zones with a Wind Advisory for Hatteras and Ocracoke Islands.

Gale Warning expanded to remaining sounds and Alligator River.

KEY MESSAGES

1) An Arctic front will push through the area tonight with a low pressure system passing through ENC this weekend, bringing a wintry mix of some snow, but mostly sleet and freezing rain to ENC, highest impacts far inland ENC. Winter Storm Watch upgraded to Winter Weather Advisories.

2) Cold airmass builds in through much of next week with below normal temperatures with highs in the 30-40 degree range and lows into the teens and 20s. Winds chill may fall below 15 degrees a few mornings, including Saturday morning and Tuesday morning. Possibly even colder temperatures Thursday and Friday with wind chills approaching 0.

DISCUSSION

KEY MESSAGE 1... An arctic cold front will push through the area late tonight, with scattered areas of light sprinkles or showers out ahead of it through this evening. Temps will be safely above freezing and therefore all liquid. Arctic high pressure builds into the area from the north on Saturday with very cold and dry airmass, while at the same time mid and upper level fgen inc ahead of next system to the west. With isentropic ascent increasing through the afternoon, light mixed precip may break out in the afternoon for all of ENC and have expanded the advisory for remaining zones except E Carteret and Hatteras and Ocracoke Islands. While not guaranteed to precipitate and only 30 pops in fcst, anything that falls will be freezing drizzle, light sleet, or snow and impacts may occur esp on bridges and overpasses with temps at or below freezing all day with the widespread cloud cover. Cold apparent temperatures will be in place through Sat morning for nrn zones and have issued a cold wx advisory for apparent T's of less than 15 degrees through noon.

By Saturday night into Sunday, low pressure will develop along stalled front, coastal trough offshore and begin to more northeastward and penetrate into Eastern NC through the overnight.Substantial warming aloft begins in earnest Sat night, with 850mb temps fcst to reach between 5-10C by daybreak Sunday, while stubborn CAD remains at the sfc west of Hwy 17. Little change in 00z model guidance, which brings sfc warming above freezing from E to W across ENC through the overnight, limiting duration of icing for areas along and east of Hwy 17 and thus winter weather advisory ending during the evening to early morning hours. West of Hwy 17, the CAD holds strong through Sunday morning, leading to more prolonged QPF at below freezing temps. At this time fzra amounts have trended downwards as QPF forecast has decreased, and icing totals are in the .10-.20" range, which is just shy of warning criteria, though does not diminish the fact that travel impacts will be high in these zones. CAD still expected to erode further inland along with dry slot moving into ENC and ending the advisory early afternoon on track.

Sunday night all of ENC in warm sector with temps on the coast cont to rise through the 50s to low 60s, and inland areas remaining cool but above freezing in the upper 30s to near 40. Out ahead of sfc front, rain shower chances inc again with some instability on the coast, and QPF/pops raised as a result. Rain quickly ends by around sunrise Mon with CAA ensuing and temps falling through the afternoon to below freezing again by Mon evening.

Regarding winds with arctic front tonight and Sat morning, sustained winds of 35 mph on the OBX have prompted wind advisory to be issued along with gales for coastal waters and all sounds including Alligator River. Water level rises may rise a bit above normal for southern areas of Pamlico Sound, but brief surge and below normal water levels due to drought conditions should limit any impacts.

KEY MESSAGE 2...

Arctic high pressure will build in behind the departing system through much of next week. Temperatures will be quite a bit below normal, with highs in the 30-45 degree range, and lows in the 15-25 degree range. Wind chill values will be at or below 15 degrees for Monday night and Tuesday morning. A reinforcing cold front will move through mid week, with this air mass appearing even colder, with wind chills approaching 0 for Friday and Saturday mornings.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

BKN to OVC low and mid level clouds will persist through the night with light variable winds becoming northerly and increasing to 10-15 kt with gusts to 20 kt. There may be some additional scattered light showers (all liquid) through the overnight hours, but hi-res guidance keeps the bulk of this activity closer to the coast and offshore.

Temperatures will plummet through the night as a strong Arctic front crosses the area, dropping temps to sub-freezing by early tomorrow morning. Winds will veer to the NE with gusts to 15-20 kt continuing through the day. Sleet, snow, and freezing rain are possible at all terminals through tomorrow with chances increasing into the afternoon and evening. Precip will be scattered in nature, but even a small amount could become hazardous and create a glaze, especially on elevated surfaces. ISO and PGV are of greatest concern as the western edge of the CWA is where confidence is greatest in impactful ice accretion. However, all terminals have the potential to be impacted.

For now, all terminals have been kept at VFR through the period, but this is subject to change if/when scattered precipitation impacts a terminal. BKN to OVC CIGs will be flirting with MVFR levels through the period, especially towards the end of the TAF period when PoPs increase across the CWA.

Outlook: The bulk of the freezing rain is forecast to occur overnight Saturday into Sunday. ISO and PGV have a 60-70% chance of at least 0.1" of ice accretion while OAJ and EWN have less than a 10% chance. Temperatures will warm to above freezing by Sunday afternoon, changing any remaining precip back to rain. Arctic high pressure will then build in through much of next week with pred VFR conditions expected.

MARINE

Latest obs show N winds in the 5-15 kt range with seas 2-4 ft. Light to moderate N-NE winds will continue through this evening. An arctic front will push through tonight with strong northerly winds developing and seas quickly building to 6-9 ft. Gale Warnings for all zones except Pamlico and Neuse river which are in SCA, with winds slowly diminishing from north to south through the day Sat.

Saturday night through Tuesday: Winds become E-SE Sat night then swrly on Sunday as low pressure tracks just inland from the coast. Strong SCA to low end gales redevelop with swrly strong gradient in WAA flow on the Gulf waters later Sunday, with SCA or lower winds on remaining waters. Next cold front moves through Sunday night into Monday morning with strong nwrly CAA winds redeveloping later Monday into Monday night. Winds and seas more benign into mid week.

MHX WATCHES/WARNINGS/ADVISORIES

NC...Cold Weather Advisory from 5 AM to 1 PM EST Saturday for NCZ029-044>046-079>081-091. Winter Weather Advisory from 1 PM Saturday to 1 PM EST Sunday for NCZ029-044-079-090-091. Winter Weather Advisory from 1 PM Saturday to 4 AM EST Sunday for NCZ045-080-092-193-198. Winter Weather Advisory from 1 PM Saturday to midnight EST Saturday night for NCZ046-047-081-094-194-195-199-203. Wind Advisory from 1 AM to noon EST Saturday for NCZ204-205. MARINE...Gale Warning from 1 AM to 8 AM EST Saturday for AMZ131-150-230- 231. Gale Warning from 1 AM to noon EST Saturday for AMZ135-152-154. Small Craft Advisory from 1 AM to 10 PM EST Saturday for AMZ136-137. Gale Warning from 1 AM to 3 PM EST Saturday for AMZ156-158.