textproduct: Newport/Morehead City

WHAT HAS CHANGED

Gales have dropped for all waters this evening, but ramp up with srly to swrly flow over the warmer Gulf waters between Oregon Inlet and Cape Lookout on Sunday into Sunday evneing.

KEY MESSAGES

1) A complex low pressure system will pass through ENC tonight and on Sunday, bringing a wintry mix of some snow, but mostly sleet and freezing rain to ENC through Sunday afternoon with rain forecast Sunday night for ENC, highest impacts far inland ENC.

2) Cold airmass builds in through much of next week with below normal temperatures forecast with highs in the 30-40 degree range and lows into the teens and 20s. Winds chill forecast to between 5-15 degrees Tuesday morning. Possibly even colder temperatures Thursday and Friday with wind chills approaching 0.

DISCUSSION

KEY MESSAGE 1...

Arctic front is now well offshore as strong 1040mb Arctic high pressure system centered over the Northeast continues to wedge itself southwards into the Carolinas today. This has brought a cold and dry airmass over ENC this afternoon. Temps are struggling to get out of the 30s and should change little into this evening. At the same time, mid and upper level fgen begin to gradually increase out ahead of a deepening low to the south and west. Isentropic ascent increases through the afternoon, though latest trends suggest any substantial lift doesn't get to ENC until this evening or tonight which will delay the onset of widespread precipitation. As a result latest forecast shows SChc PoP's entering into the northern zones and OBX closer to 4-6PM this evening and then spreading everywhere else later tonight. Temps should be cold enough at the surface and aloft this afternoon to have precip start out as some light snow/sleet, though minimal accumulation is forecast if any at all occurs this afternoon/evening. While precip isn't expected until later this evening did keep the winter weather advisory start time at 1PM in case some isolated precip occurs earlier than expected. Continued to keep E Carteret County, and Hatteras/Ocracoke Islands without any winter headlines as little to no mixed precip is expected across these zones.

By tonight into Sunday morning, low pressure will develop along a stalled front to our south and begin to move northeastward and penetrate into Eastern NC by early Sunday morning. As precip continues to expand and we get later into this evening, atm profiles (especially east of Hwy 17) are forecast to steadily warm aloft as a combination of latent heat release from ongoing precip and mid level WAA from the approaching low overspread ENC. Soundings suggest much if not all of the area seeing temps at the mid levels (700-850mb) around 5-10C by Sun morning. With strong CAD keeping cold air at the surface away from the immediate coast and OBX, this is forecast to result in a transition to a wintry mix of sleet/freezing rain and eventually plain freezing rain across our inland zones with coastal areas and the OBX quickly becoming plain rain tonight. Will note models do tend to handle strong shallow cold air poorly so could see a low end threat for some freezing rain/sleet to stick around slightly longer than currently forecast, especially across the inner banks, but this remains less likely. West of Hwy 17, the CAD holds strong through Sunday morning, leading to more prolonged QPF at below freezing temps. Icing totals remain 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.

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

Winds remain rather gusty primarily across Hatteras and Ocracoke Islands with sustained winds of 30-40 mph noted here so the wind advisory continues at these locations until 4PM Sat. With gales for adjacent waters. 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 robust upper trough and reinforcing cold front will move through mid week. Moisture is somewhat limited but could see snow showers producing minor accumulations. The air mass behind this front appears even colder, with wind chills approaching 0 for Friday and Saturday mornings.

AVIATION /02Z SUNDAY THROUGH THURSDAY/

MVFR conditions will quickly develop across ENC as mixed precipitation from a winter storm moves in this evening and strengthening frontal inversion develops in response to slowly eroding CAD and strong WAA aloft. Cigs will fall further to IFR and then LIFR later tonight through Sun.

Fzra for the interior TAF sites through tonight, and lingering through much of the morning hours for KISO and KPGV while KEWN and KOAJ swicht to rain with the warmer coastal front pushing inland. Some areas of strong southerly LLWS will develop tomorrow ahead of a strong cold front as much of ENC remains under the strong frontal inversion.

Outlook: Widespread IFR or lower CIGs and LLWS concerns continue through Sunday night. After the front passes offshore early Monday morning, VFR conditions returns Arctic high pressure builds in, lasting through much of next week.

MARINE

Another period of Gales expected across the central coastal waters off from Oregon Inlet to C Lookout where the warmer gulf stream resides as south to southwest flow inc Sun into Sun night.

NE winds will be slowly improving through early tonight to 15-25 kts. Then winds will weaken and veer overnight before restrengthening early tomorrow morning to 20-30 kts out of the SE/S. Winds will further increase over the warmer Gulf Stream waters off of Cape Hatteras to 30-35 kts with gusts to 40 kts, while other areas see occasional 35 kt wind gusts ahead of a strong cold front. Winds subside slightly but remain strong tomorrow night at SW 20-30 kts.

Seas will be up and down through tomorrow night but will mostly be within the range of 6-12 ft.

Outlook: Behind a strong cold front Monday morning winds will strengthen to NW 20-30 kts through Tuesday morning. Slightly improving conditions expected Tuesday through Wednesday with winds W/NW at 15-25 kts. Another period of stronger winds with marginal Gale Conditions expected Thursday.

MHX WATCHES/WARNINGS/ADVISORIES

NC...Winter Weather Advisory until 1 PM EST Sunday for NCZ029-044- 079-090-091. Winter Weather Advisory until 7 AM EST Sunday for NCZ045-080- 092-193-198. Winter Weather Advisory until midnight EST tonight for NCZ046- 047-081-094-194-195-199-203. MARINE...Small Craft Advisory until 4 AM EST Sunday for AMZ131-230-231. Small Craft Advisory until 3 PM EST Sunday for AMZ135. Small Craft Advisory until midnight EST tonight for AMZ137. Small Craft Advisory until 1 PM EST Tuesday for AMZ150. Gale Warning from 8 AM Sunday to 5 AM EST Monday for AMZ152- 154-156. Gale Warning until 10 PM EST this evening for AMZ158.