textproduct: Wakefield

WHAT HAS CHANGED

Winter Storm Warnings have been issued for the majority of the region for Saturday afternoon through Sunday night for coastal areas and Monday night for inland areas, excluding far Northeast North Carolina. Winter Storm Advisories have been issued for far Northeastern North Carolina for Saturday afternoon through Sunday afternoon. Confidence is high in a devastating winter storm for a large portion of the area.

KEY MESSAGES

1) A devastating winter storm for a large portion of the area will impact the region Saturday afternoon/evening through Sunday night with snow, sleet, freezing rain, and rain expected.

2) A Cold Weather Advisory remains in effect for the entire forecast area tonight into Saturday morning ahead of the winter storm as wind chills drop to the single digits or low-end negatives behind a strong Arctic front.

3) A prolonged period of very cold temperatures is expected beginning Saturday AM and persisting much of next week with the potential for temperatures to remain below freezing for several days. Impacts from the winter storm are likely to last well into next week due to the very cold temperatures.

DISCUSSION

As of 400 PM EST Friday...

KEY MESSAGE 1...A devastating winter storm for a large portion of the area will impact the region Saturday afternoon/evening through Sunday night with snow, sleet, freezing rain, and rain expected.

Winter Storm Warnings and Advisories have been issued with this forecast cycle.

An inverted trough sets up over the southeast US with CAD developing over the local area as strong high pressure (1045+ mb) builds over the Midwest and moves east Saturday. The cold front that moves through the area will stall over the southeast CONUS and a low pressure will form along it in the Gulf, then move toward the Appalachian mountains. A secondary low will form off the Carolina coast and move to the northeast. There will be ample Pacific and Gulf moisture feeding into the area with P-WATs 200-300% above normal. Forecast storm total QPF has decreased slightly with the latest guidance, but is still between 1.25-2.25", with the lower values in the SE VA/NE NC areas.

12z model package continues with the trends of the winter storm with only minor variations. A very cold airmass filters into the area behind the strong cold front with temperatures during the day only reaching in the 20s. During the day, dewpoints will be in the negatives, but ample moisture will push back into the region late afternoon into evening. The onset of wintry precipitation is expected to be after sunrise on Saturday, starting as snow across the area before transitioning Saturday night into a wintry mix, starting in the southern areas. Sleet will quickly mix in across the southern third of the area, potentially lifting northward to near the I-64 corridor by around midnight. Freezing rain will also mix in across the southern half of the area early Sunday morning. Still some uncertainty regarding the depth of the warm nose aloft with the NAM lifting the warmer air aloft into the area quicker than the GFS/GEFS, which would result in a quicker transition to wintry mix than snow. The differences with respect to the thermal profiles aloft decrease with time into Sunday morning with mixed precip indicated across all of our area before sunrise. The majority of the snow and sleet accumulations will occur overnight with the highest snow/sleet totals still expected across the north and northwest portions of the area. Snow/sleet totals drop off quickly with southeastward extent. The latest thermal profiles show a quick shift to freezing rain across the majority of the area Sunday morning and lasting through as late as early Monday morning. The storm ice totals remain relatively similar to the previous forecast with the highest amounts of up to 0.75" of ice across the south central to Richmond metro areas in addition to 2 to 5 inches of snow/sleet. There has been a slight shift in favoring sleet rather than freezing rain for the far northern counties, but ice totals up to 0.5" of ice is expected, on top of the 4 to 7 inches of snow/sleet. The precip will likely end as another batch of light snow before moving away from the area. These amounts of the combined wintry precip will lead to devastating impacts and widespread power outages and tree damage. Very cold temperatures and windy conditions early next week will lead to long last impacts. In result, all of the VA and MD counties, along with Hertford, Northampton, NC, and Gates counties, have been upgraded to a Winter Storm Warning through Monday night as winds pick up on Monday, continuing the threat of additional tree damage and power outages.

Significant warm air at the surface and aloft will spread inland from the coast on Sunday with roughly the eastern third of the CWA, switching precip to plain rain during the afternoon Sunday. This area includes all of NE NC, Hampton Roads and the VA/MD Eastern Shore. ALthough the change in plain rain, the VA/MD Eastern Shore, Hampton Roads, and NE NC excluding Northampton, Hertford, and Gates counties have been included in the Winter Storm Warning as a mix of snow/sleet and light glazes of ice could still allow for dangerous travel conditions.

KEY MESSAGE 2...A Cold Weather Advisory remains in effect for the entire forecast area tonight into Saturday morning ahead of the winter storm as wind chills drop to the single digits or low- end negatives behind a strong Arctic front.

Ahead of the major winter storm, a strong cold front will move across the region this afternoon into overnight, bringing an Arctic airmass to the area. Behind the front, northerly winds will be breezy overnight and into the early morning at around 10-15 mph with gusts to 25 mph. This combined with temperatures in the teens will allow wind chills to drop to around -3 in the north to near 10F in NE NC. Cold Weather Advisories remain in effect for tonight into Saturday morning.

KEY MESSAGE 3...A prolonged period of very cold temperatures is expected beginning Saturday AM and persisting much of next week with the potential for temperatures to remain below freezing for several days. Impacts from the winter storm are likely to last well into next week due to the very cold temperatures.

Behind the winter storm this weekend, strong high pressure (1030+ mb) from the Canadian plains will shift over the SE CONUS with potent upper level troughing. The combination of these features will keep very cold temperatures over the area through much of next week. This, along with any snowpack, will likely keep high temperatures below freezing for an extended period of time. Low temperatures Tuesday night/Wednesday AM will likely be the coldest we have seen in some time, with readings ranging from around 0 across the NW Piedmont, to single digits for much of the inland forecast area, and teens closer to the coast/SE. These cold temperatures, combined with a W to NW breeze, will result in wind chills ranging from -10 to -5 inland and 0 to 10 across the southeast and along the coast. Extreme Cold headlines will likely be needed for a majority of the area with Cold Weather Advisories elsewhere. Overnight lows in the single digits and teens will be common for the remainder of the week. Long term model guidance is showing the potential for another Arctic blast by midweek, potentially sending our high temperatures back into the 20s by Thursday and overnight lows into the mid to lower single digits.

This prolonged period of very cold temperatures behind the winter storm could be very dangerous for those without power. It is important that all take precautions in event that power is unable to be restored in a timely manner.

AVIATION /06Z SATURDAY THROUGH WEDNESDAY/

As of 1220 AM EST Saturday...

VFR conditions are expected to prevail through this evening with cloud bases gradually lowering throughout the day to 8-12kft AGL by 21z. The well advertised winter storm will begin to impact the terminals after 00z, with snow expected to begin at RIC/SBY/PHF/ORF between 01-04z, with a rain/snow/sleet mix possible at ECG at the onset before precip changes to rain. The snow will increase in intensity by 04-06z (possibly becoming moderate-heavy at times with 1/4-1/2SM VSBY at RIC/SBY). A quick changeover to sleet then plain rain is expected at ORF/PHF between 05-08z Sunday AM (and at SBY later Sunday AM). However, impacts will be significant at RIC with precip changing to sleet (possibly heavy at times) then freezing rain as temps likely don't get above 32F throughout the day. FZRA will continue at RIC through 03-06z Monday before finally diminishing. VSBYs of 1/2-1 1/2SM are likely in snow, with 1-3SM VSBYs in sleet. CIGs will drop to IFR or LIFR late tonight with LIFR/IFR CIGs continuing through Sun and Sun night. N-NE winds of ~15 kt with gusts to 20-30 kt (highest at the coast) will continue through the morning/midday before diminishing slightly during the aftn. However, winds will remain gusty through the rest of the TAF period.

Outlook: VFR/dry conditions return on Monday and continue through the middle of the week. There is a low-end chance of light snow Wed night-Thu AM.

MARINE

As of 355 PM EST Friday...

Key Messages:

- Gale Warnings remain in effect tonight for the Chesapeake Bay and coastal waters south of Cape Charles Light (and have been added for the Currituck sound). A Small Craft Advisory is in effect elsewhere. A Freezing Spray Advisory has been issued for the Chesapeake Bay and Atlantic coastal waters north of the VA/NC border.

- Strong winds continue Sunday (NE to E) as developing coastal low pressure slowly lifts NE offshore, shifting to the NW Monday with high pressure gradually building on from the SW.

- Another period of Gale Warnings are likely to be needed Monday night and early Tuesday. Light winds early this evening out ahead of an approaching arctic high pressure, which is currently just west of the waters as of this writing. That front crosses the waters early this evening, with strong cold air advection to quickly develop in its wake. Winds quickly veer around to the NNW winds, increasing to 25-30 kt w/ gusts to 35 kt over the bay, southern coastal waters, and Currituck sound, with SCA conditions farther NE along the middle and upper Atlantic coast and over the rivers.

Winds decrease below Gale thresholds Saturday morning, but will remain solid SCA, and Gales will likely need to be replaced by SCA for a time over the Gale Warning area. SCA headlines through 4th period/early Sunday morning for the lower James and northern coastal waters (but have the headline ending in the upper rivers Sat aftn given a 6-12 hr lull). Did not extend them, as it appears that another period of Gales appear increasingly likely Monday night, on the back side of the departing low. Waves and seas will build along with the stronger winds early Saturday and likely peak on Sunday in the 3-5 ft and 6-9 ft ranges, respectively. Freezing Spray Advisory has been added over the Bay and coastal waters north of the VA/NC border tonight into Saturday. Additional Advisories are likely to be needed Monday night and Tuesday, as Arctic high pressure quickly builds across the eastern CONUS.

AKQ WATCHES/WARNINGS/ADVISORIES

MD...Cold Weather Advisory until 10 AM EST this morning for MDZ021>025. Winter Storm Warning from 1 PM this afternoon to 7 PM EST Monday for MDZ021. Winter Storm Warning from 1 PM this afternoon to 7 PM EST Sunday for MDZ022>025. NC...Cold Weather Advisory until 10 AM EST this morning for NCZ012>017-030>032-102. Winter Storm Warning from 1 PM this afternoon to 7 PM EST Monday for NCZ012>014. Winter Weather Advisory from 1 PM this afternoon to 1 PM EST Sunday for NCZ015>017-030>032-102. VA...Cold Weather Advisory until 10 AM EST this morning for VAZ048- 060>062-064>069-075>090-092-093-095>100-509>525. Winter Storm Warning from 1 PM this afternoon to 7 PM EST Monday for VAZ048-060>062-064>069-075>090-092-093-096- 509>524. Winter Storm Warning from 1 PM this afternoon to 7 PM EST Sunday for VAZ095-097>100-525. MARINE...Gale Warning until 7 AM EST this morning for ANZ630>634-638- 652-654. Freezing Spray Advisory until 9 AM EST this morning for ANZ630>632-634-650-652-654-656. Small Craft Advisory until 1 PM EST this afternoon for ANZ635>637. Gale Warning until 4 AM EST early this morning for ANZ650. Gale Warning until 10 AM EST this morning for ANZ656-658.