Date: December 14, 2020 at 12:46:20 PM EST
To: 200-block-10th-st-se <200-block-10th-st-se@...>
Subject: High-Impact Winter Storm Midweek For The Mid-Atlantic and Northeast

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Hi Neighbors,

Areas to our west and north will have snow on Wednesday- Thursday. ?For DC, we are on the rain-snow line. Be sure to check forecast updates.?

See details below.

-Maureen (NOAA)

From: National Weather Service Operations Center?
Date: December 14, 2020 at 12:07:16 PM EST
To: _NWSOC Sigevent?
Subject: Significant Event Outlook - High-Impact Winter Storm Midweek For The Mid-Atlantic and Northeast

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High-Impact Winter Storm Midweek For The Mid-Atlantic and Northeast

Key Points

• The forecast ingredients are coming together and confidence is increasing on a high-impact winter storm midweek for the Mid-Atlantic and Northeast.
• This potential Nor'easter would impact the two areas on Wednesday and Thursday with the focus on frozen precipitation and especially heavy snowfall.

• The large scale weather setup:
• A quick-moving storm is moving through the East today with mainly locally heavy rain.
• This system will clear the way for a cold area of high pressure to build into the East and anchor into the Northeast on Tuesday.?
• The large surface ridge will feature polar and arctic air, while wedging down leeside of the Appalachians into the Mid-Atlantic and Southeast.
  
• Meanwhile, a potent disturbance is dropping through the Intermountain West today before ejecting into the Southern U.S. on Tuesday.
• As the system moves through the South and Tennessee Valley on Wednesday, an area of low pressure will begin to form along the North and South Carolina coast.
• This rapidly strengthening low pressure system will ride up and along the Mid-Atlantic coast and off the Northeastern Seaboard, while a wealth of Gulf of Mexico and Atlantic Ocean moisture surges into the cold air mass.
• The result will be a multi-hazard event from a potentially paralyzing snowfall, freezing rain and icing, locally heavy rain, some severe thunderstorms and coastal impacts.

• ?Forecast details as of right now:
  
• A large deal of forecast uncertainty?continues leading up to this event, including the critical surface low track up the coast and the positioning of the rain/snow line.
• Here is the NWS collaborated messaging as of this morning:
• A major winter storm is expected to impact portions of the Mid-Atlantic and Northeast on Wednesday and Thursday.
• Heavy snow is expected from eastern West Virginia into western Maryland, Pennsylvania, northwest New Jersey, eastern New York and southern New England.
• Freezing rain and ice accumulations are expected in northwest North Carolina and across much of southwest and central Virginia.
• Confidence is high that this winter storm will result in significant impacts including travel disruptions and power outages.

Links

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Graphics

Weather Prediction Center - Winter Weather Key Messages (As of 10AM ET).?

Weather Prediction Center - Content Presented at NWSOC Operations Briefing This Morning (Slide #1).

Weather Prediction Center - Content Presented at NWSOC Operations Briefing This Morning (Slide #2).

Ocean Prediction Center - IDSS for USCG??

WFO LWX - Social Media

WFO BOX - Social Media??

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Information in this report was?provided by the ER-ROC, AWC FAA NAMs, NWC, OPC and WPC.

Please note that some of the information contained in this report may be administratively sensitive, please limit forwarding to additional parties.????

NWSOC Mission:?The NWS Operations Center provides timely Impact-Based Decision Support Services to meet the evolving needs of NWS partners and stakeholders and supports agency readiness by proactively collaborating and facilitating the exchange of critical information, setting operational posture, and briefing leadership.

NWSOC Vision:?A Weather-Ready Nation that makes informed and timely decisions based upon the best environmental and situational awareness information achieved through continuous and effective collaboration.