textproduct: Newport/Morehead City

WHAT HAS CHANGED

High likelihood for a winter storm to develop along the Southeast coast this weekend, bringing moderate to major impacts to Eastern North Carolina.

Winter Storm Watches have been issued for all of Eastern North Carolina.

Storm Watches have been issued for all marine zones save for the Pamlico and Pungo Rivers (Gale Watch) starting Saturday evening.

A High Wind Watch has been issued for the Northern Outer Banks and Hatteras and Ocracoke Islands starting Saturday evening.

KEY MESSAGES

1) High likelihood for a strong winter storm to bring significant accumulating snowfall, blowing and drifting snow due to strong winds, and coastal flooding.

2) More extreme cold is expected behind the winter storm, with wind chills likely falling below 0 Sunday and Monday mornings.

3) MARINE...Potential for extremely dangerous marine conditions this weekend as a low pressure system deepens rapidly off the NC coast. Storm conditions are likely with the potential for Hurricane Force wind gusts.

DISCUSSION

KEY MESSAGE 1...All signs continue to point to an impactful winter storm developing near the Carolinas this weekend with increasing confidence of at least several inches of accumulating snow. Additionally, the rapidly deepening low will produce very strong winds across the area (35-50 mph inland and 50-65 mph along the coast), which could lead to power outages, reduced visibilities, and potentially blizzard conditions along the coast.

A deep positively tilted upper level trough will dig across the Plains later this week, becoming neutral to negatively tilted this weekend as it crosses the ECONUS. A southern stream shortwave originating from the Pacific northwest will track south and east across the Gulf states late this week and into this weekend while a northern stream shortwave will simultaneously dive into the SECONUS from the Hudson Bay. These features are forecast to result in surface cyclogenesis off the SE coast this weekend. These shortwaves are expected to phase together, allowing the low to rapidly intensify as it moves northeast near the coast of the Carolinas.

Precipitation may start as early as Friday night with snow across the coastal plain, a rain/snow mix along the coast, and rain along the OBX. All P-types are expected to change over to snow Saturday night and continue into Sunday morning, and this is when the heaviest accumulations will occur. Northwest winds will ramp up Saturday night and peak early Sunday, causing blowing and drifting snow and potentially blizzard conditions along the coast. Wind chills will also be dangerously cold during this time, bottoming out in the sub-zero to single digit range, and low temperatures may flirt with records.

The WPC Winter Storm Severity Index now shows a greater than 95% chance of moderate impacts and a 70-80% chance of major impacts across Eastern North Carolina. For the majority of Eastern North Carolina, there's a 85-95% chance of more than 4", a 60-80% chance of more than 8", and a 35-55% chance of more than 12". Guidance continues to hit northeastern zones (north of HWY 264 and east of HWY 17) as the sweet spot for higher accumulations, showing a 80-90% chance of >4", 40-60% chance of >8", and 50-70% chance of >12".

Historically, this storm's setup is most like the December 24, 1989 and early March 1980 storms. Both of these historic events produced 12+" of snow for Eastern North Carolina with accumulations from the March 1980 storm nearing 24" in some areas. While there's potential for this weekend's snow accumulations to be comparable to these past events, keep in mind that we're still more than 48 hours out from when the heaviest snow is expected to fall, which means there's still room for adjustments (up or down) in the accumulation forecast. However, with the probabilities of higher snow amounts consistently going up, the higher end amounts should not be taken lightly when thinking about storm preparation. No matter how much snow falls, it will not melt quickly due to the extremely cold air that will build in behind this system. Temperatures aren't expected to approach freezing until Monday, but some areas may not get above freezing until Tuesday.

A High Wind Watch has been issued for the Outer Banks from Duck to Ocracoke from Saturday evening through Sunday afternoon and a Wind Advisory will eventually be needed for coastal counties. Gusts will be 50-65 mph along the Outer Banks and 35-50 mph inland.

Due to these powerful winds, moderate to locally significant coastal flooding impacts will be possible, both soundside and oceanside. This could lead to travel impacts for vulnerable portions of NC-12, especially for Hatteras and Ocracoke Islands. This storm will also coincide with a higher tide cycle, which will exacerbate coastal flooding impacts, especially along the Outer Banks. Coastal Flood Watches and High Surf Advisories will be needed for portions of the area in future updates.

Preparations you can take at this time: Have emergency supplies in your home and your car, check your smoke and carbon monoxide detectors, and replenish fuel for your car and heating sources. Make sure you have multiple ways to receive warnings, you're stocked up on food, water, and medications, and make plans to bring your pets inside from the extreme cold.

KEY MESSAGE 2... Extremely cold air will stick around behind the winter storm with the potential to set additional new record low temperatures Monday and Tuesday mornings. Lows will be in the low tens to low 20s Sunday night/Monday morning with dangerously cold wind chills in the sub- zero to single digit range. High temperatures will approach freezing on Monday, but it's possible some inland areas to remain below freezing from tomorrow night until Tuesday.

AVIATION /15Z THURSDAY THROUGH MONDAY/

VFR conditions with mo sunny skies through today. N to NW'rly breezes today with gusts upwards of 10-15 kt at times. NW winds and gusts relax tonight as high pressure builds back in.

Outlook: VFR conditions will likely continue through Friday as cold high pressure remains in place. This weekend, an extended period of poor flying conditions as a coastal low develops and brings significant snow, poor visibilities, and potential blowing and drifting snow due to wind gusts of 35-40 kt to inland East NC.

MARINE

Current SCAs will drop this afternoon as NW winds decrease to 10-15 kt and seas subside to 3-5 ft. Benign marine conditions will then persist until Friday night.

Outlook: A rapidly deepening low pressure system will produce extremely dangerous marine conditions this weekend. Storm force winds are likely with the potential for Hurricane Force wind gusts, especially near the Gulf Stream waters. Seas could reach 12-20 ft. Storm Watches have been issued for all marine zones save for the Pamlico and Pungo Rivers (Gale Watch) starting Saturday evening. Conditions will slowly improve Sunday night with winds forecast to drop below SCA criteria by Monday afternoon. 6+ ft seas may linger well into Tuesday.

MHX WATCHES/WARNINGS/ADVISORIES

NC...Winter Storm Watch from late Friday night through Sunday afternoon for NCZ029-044>047-079>081-090>092-094-193>196- 198-199-203. High Wind Watch from Saturday evening through Sunday afternoon for NCZ203>205. Winter Storm Watch from Saturday evening through Sunday evening for NCZ204-205. MARINE...Storm Watch from Saturday evening through Sunday morning for AMZ131-137. Small Craft Advisory until 1 PM EST this afternoon for AMZ135. Storm Watch from Saturday evening through Sunday afternoon for AMZ135-154-156-230-231. Gale Watch from Saturday afternoon through Sunday afternoon for AMZ136. Small Craft Advisory until 2 PM EST this afternoon for AMZ150- 156-158. Storm Watch from Saturday evening through Sunday afternoon for AMZ150-152. Small Craft Advisory until 3 PM EST this afternoon for AMZ152- 154. Storm Watch from Saturday evening through Sunday morning for AMZ158.