Alert archive / Virginia / Winter Storm Watches in 2021

Winter Storm Watch 5, NWS Baltimore/Washington

February 10, 202120 counties in Virginia; Saint Mary's County, Maryland; Pendleton County, West Virginia

NWS Baltimore/Washington issued this winter storm watch at Feb 10, 2021, 3:33 AM EST for 20 counties in Virginia; Saint Mary's County, Maryland; Pendleton County, West Virginia. It took effect at Feb 11, 2021, 4:00 PM EST. It was in force for .

The area

The counties it named.

The facts

Issued
Feb 10, 2021, 3:33 AM EST (08:33 UTC)
In effect from
Feb 11, 2021, 4:00 PM EST
Expired
Feb 11, 2021, 3:28 AM EST
In force
Issued by
NWS Baltimore/Washington
All 22 counties

Saint Mary's County, MD, Albemarle County, VA, Amherst County, VA, Augusta County, VA, City of Charlottesville, VA, City of Fredericksburg, VA, City of Harrisonburg, VA, City of Staunton, VA, City of Waynesboro, VA, Greene County, VA, Highland County, VA, King George County, VA, Madison County, VA, Nelson County, VA, Orange County, VA, Page County, VA, Rappahannock County, VA, Rockbridge County, VA, Rockingham County, VA, Spotsylvania County, VA, Warren County, VA, Pendleton County, WV

The radar

The Sterling radar (KLWX), 117 km from the middle of the area, began a volume at 08:36 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

Roanoke, VA (KRNK), launched 00:00Z, 8.6 hours before the alert went out and 148 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-pSkew-T log-p diagram, Roanoke, VA at 00:00Z on 2021-02-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Roanoke, VA at 00:00Z on 2021-02-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 168 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
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
1074 m above ground
0-6 km bulk shear
79 kt
0-1 km storm-relative helicity
168 m²/s²
0-3 km storm-relative helicity
236 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 watch 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 watch went out at Feb 9, 9:36 PM EST, 5 hours 57 minutes earlier.

Area forecast discussion, Feb 9, 9:36 PM EST, 5 hours 57 minutes before
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Hazardous weather outlook, Feb 9, 5:17 PM EST, 10 hours 16 minutes before
Hazardous Weather Outlook
National Weather Service Baltimore MD/Washington DC
517 PM EST Tue Feb 9 2021

ANZ530>543-DCZ001-MDZ008-011-013-014-016>018-504-506-508-
VAZ052>057-102230-
Chesapeake Bay north of Pooles Island MD-
Chesapeake Bay from Pooles Island to Sandy Point MD-
Chesapeake Bay from Sandy Point to North Beach MD-
Chesapeake Bay from North Beach to Drum Point MD-
Chesapeake Bay from Drum Point MD to Smith Point VA-
Tidal Potomac from Key Bridge to Indian Head MD-
Tidal Potomac from Indian Head to Cobb Island MD-
Tidal Potomac from Cobb Island MD to Smith Point VA-
Patapsco River including Baltimore Harbor-
Chester River to Queenstown MD-Eastern Bay-
Choptank River to Cambridge MD and the Little Choptank River-
Patuxent River to Broomes Island MD-
Tangier Sound and the inland waters surrounding Bloodsworth
Island-District of Columbia-Cecil-Southern Baltimore-
Prince Georges-Anne Arundel-Charles-St. Marys-Calvert-
Central and Southeast Montgomery-Central and Southeast Howard-
Southeast Harford-Prince William/Manassas/Manassas Park-Fairfax-
Arlington/Falls Church/Alexandria-Stafford-Spotsylvania-
King George-
517 PM EST Tue Feb 9 2021

This Hazardous Weather Outlook is for the Maryland portion of the
Chesapeake Bay, Tidal Potomac River, and I-95 corridor through
central Maryland, northern Virginia, and District of Columbia.

.DAY ONE...Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

There is a moderate winter storm threat Thursday into Friday
morning. A Winter Storm Watch will likely be required by this
evening. Potential impacts include significant travel delays and
closures. Plan ahead to minimize impact on you and your family.

A slight winter threat exists for Saturday. If the threat
materializes, it may cause travel disruptions.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be necessary through tonight.

MDZ003>006-503-505-507-VAZ025>031-036>040-050-051-501-502-505>508-
WVZ050>053-055-102230-
Washington-Frederick MD-Carroll-Northern Baltimore-
Northwest Montgomery-Northwest Howard-Northwest Harford-Augusta-
Rockingham-Shenandoah-Frederick VA-Page-Warren-Clarke-Nelson-
Albemarle-Greene-Madison-Rappahannock-Orange-Culpeper-
Northern Fauquier-Southern Fauquier-Western Loudoun-
Eastern Loudoun-Northern Virginia Blue Ridge-
Central Virginia Blue Ridge-Hampshire-Morgan-Berkeley-Jefferson-
Hardy-
517 PM EST Tue Feb 9 2021

This Hazardous Weather Outlook is for portions of eastern West
Virginia, northern and central Virginia, and central and western
Maryland.

.DAY ONE...Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

A Winter Storm Watch has been issued for Hardy and Hampshire
counties from 00Z to 15Z on Thursday.

There is a moderate winter storm threat Thursday afternoon into Friday
morning. A Winter Storm Watch will likely be required by this
evening. Potential impacts include significant travel delays and
closures. Plan ahead to minimize impact on you and your family.

A slight winter threat exists for Saturday. If the threat
materializes, it may cause travel disruptions.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be necessary through tonight.

MDZ001-501-502-VAZ503-504-WVZ501>506-102230-
Garrett-Extreme Western Allegany-Central and Eastern Allegany-
Western Highland-Eastern Highland-Western Grant-Eastern Grant-
Western Mineral-Eastern Mineral-Western Pendleton-
Eastern Pendleton-
517 PM EST Tue Feb 9 2021

This Hazardous Weather Outlook is for the Allegheny Front
counties in western Maryland, eastern West Virginia, and Highland
County Virginia.

.DAY ONE...Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

A Winter Storm Watch has been issued Wednesday night into Thursday
morning.

There is a moderate winter storm threat Thursday afternoon into
Friday morning.

A slight winter threat exists for Saturday. If the threat
materializes, it may cause travel disruptions.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be necessary through tonight.

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 10, 3:33 AM ESTWinter Weather AdvisoryLWXAlbemarle, Amherst, Arlington, Augusta, Clarke, Fairfax and 21 more30 hr
Feb 10, 4:15 AM ESTSmall Craft AdvisoryLWX4 days
Feb 10, 6:11 PM ESTSmall Craft AdvisoryLWX39 hr
Feb 10, 12:40 PM ESTWinter Storm WarningLWXAllegany, Baltimore, Carroll, Cecil, Frederick, Harford and 1 more21 hr

Nearby

Winter Storm Watches in Virginia, 2021Winter Storm Watches in Maryland, 2021Winter Storm Watches in West Virginia, 2021Every winter storm watch in 2021

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.