Alert archive / Virginia / Winter Storm Warnings in 2020

Winter Storm Warning 3, NWS Baltimore/Washington

December 15, 202022 counties in Virginia; 8 counties in Maryland; 8 counties in West Virginia

NWS Baltimore/Washington issued this winter storm warning at Dec 15, 2020, 4:09 AM EST for 22 counties in Virginia; 8 counties in Maryland; 8 counties in West Virginia. It took effect at Dec 16, 2020, 7:00 AM EST. It was in force for 19 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Dec 15, 2020, 4:09 AM EST (09:09 UTC)
In effect from: Dec 16, 2020, 7:00 AM EST
Expired: Dec 17, 2020, 1:51 AM EST
In force: 19 hr
Issued by: NWS Baltimore/Washington

All 38 counties

Allegany County, MD, Baltimore County, MD, Carroll County, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Montgomery County, MD, Washington County, MD, Albemarle County, VA, Amherst County, VA, Augusta County, VA, City of Charlottesville, VA, City of Harrisonburg, VA, City of Staunton, VA, City of Waynesboro, VA, City of Winchester, VA, Clarke County, VA, Fauquier County, VA, Frederick County, VA, Greene County, VA, Highland County, VA, Loudoun County, VA, Madison County, VA, Nelson County, VA, Page County, VA, Rappahannock County, VA, Rockbridge County, VA, Rockingham County, VA, Shenandoah County, VA, Warren County, VA, Berkeley County, WV, Grant County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Mineral County, WV, Morgan County, WV, Pendleton County, WV

The radar

The Sterling radar (KLWX), 74 km from the middle of the area, began a volume at 09:08 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 9.2 hours before the alert went out and 80 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1227 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 10 m²/s²
0-3 km storm-relative helicity: 12 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this winter storm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Baltimore/Washington wrote its last area forecast discussion before this winter storm warning went out at Dec 14, 8:59 PM EST, 7 hours 10 minutes earlier.

Area forecast discussion, Dec 14, 8:59 PM EST, 7 hours 10 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Hazardous weather outlook, Dec 14, 7:11 PM EST, 8 hours 58 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

The office that day

Everything else NWS Baltimore/Washington issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 15, 4:23 AM EST	Small Craft Advisory	LWX		6 hr
Dec 15, 8:08 AM EST	Small Craft Advisory	LWX		4 hr
Dec 15, 11:54 AM EST	Flood Watch	LWX	Arlington, Fairfax, City of Alexandria, City of Fairfax, City of Falls Church	34 hr
Dec 15, 1:11 PM EST	Gale Warning	LWX		39 hr
Dec 15, 1:11 PM EST	Small Craft Advisory	LWX		48 hr
Dec 15, 4:00 PM EST	Winter Weather Advisory	LWX	Arlington, Culpeper, Fairfax, Fauquier, Orange, City of Alexandria and 2 more	33 hr

Nearby

Winter Storm Warnings in Virginia, 2020 Winter Storm Warnings in Maryland, 2020 Winter Storm Warnings in West Virginia, 2020 Every winter storm warning in 2020

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.