Alert archive / Virginia / Severe Thunderstorm Watches in 2021

Severe Thunderstorm Watch 206

May 26, 20216 states

The Storm Prediction Center issued this severe thunderstorm watch at May 26, 2021, 2:48 PM EDT for 6 states. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
May 26, 2021, 2:48 PM EDT (18:48 UTC)
Expired
May 26, 2021, 10:00 PM EDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 108 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Allegany County, MD, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Carroll County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Frederick County, MD, Garrett County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Saint Mary's County, MD, Somerset County, MD, Talbot County, MD, Washington County, MD, Wicomico County, MD, Worcester County, MD, Atlantic County, NJ, Bergen County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Essex County, NJ, Gloucester County, NJ, Hudson County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Morris County, NJ, Ocean County, NJ, Passaic County, NJ, Salem County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Berks County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA, Accomack County, VA, Albemarle County, VA, Arlington County, VA, Augusta County, VA, Caroline County, VA, City of Alexandria, VA, City of Charlottesville, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Harrisonburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Staunton, VA, City of Waynesboro, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, Greene County, VA, Highland County, VA, King George County, VA, Lancaster County, VA, Loudoun County, VA, Louisa County, VA, Madison County, VA, Nelson County, VA, Northumberland County, VA, Orange County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Richmond County, VA, Rockingham County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Westmoreland 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), 49 km from the middle of the area, began a volume at 18:47 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

40 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 26, 2:48 PM EDTSevere Thunderstorm WarningLWXFrederick, Shenandoah, Warren, City of Winchester42 min
May 26, 2:51 PM EDTSevere Thunderstorm WarningLWXFrederick, Washington39 min
May 26, 3:21 PM EDTSevere Thunderstorm WarningLWXFrederick, Washington39 min
May 26, 3:24 PM EDTSevere Thunderstorm WarningLWXClarke, Frederick, Warren39 min
May 26, 3:31 PM EDTSevere Thunderstorm WarningLWXFrederick, Washington44 min
May 26, 3:39 PM EDTSevere Thunderstorm WarningPHIBerks56 min
May 26, 3:40 PM EDTSevere Thunderstorm WarningLWXMontgomery28 min
May 26, 3:56 PM EDTSevere Thunderstorm WarningLWXCarroll, Frederick49 min
May 26, 3:59 PM EDTSevere Thunderstorm WarningLWXFrederick, Montgomery9 min
May 26, 4:05 PM EDTSevere Thunderstorm WarningLWXFairfax, Fauquier, Loudoun, Prince William, City of Fairfax, City of Manassas and 1 more40 min
May 26, 4:10 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh65 min
May 26, 4:35 PM EDTSevere Thunderstorm WarningLWXArlington, Fairfax, Prince William, City of Alexandria, City of Fairfax, City of Falls Church and 2 more40 min
May 26, 4:46 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Chester, Lehigh, Montgomery, Northampton44 min
May 26, 4:52 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery38 min
May 26, 4:54 PM EDTSevere Thunderstorm WarningLWXCharles, Prince George's66 min
May 26, 5:00 PM EDTSevere Thunderstorm WarningLWXAnne Arundel, Howard, Montgomery, Prince George's45 min
May 26, 5:22 PM EDTSevere Thunderstorm WarningLWXFairfax, Prince William, City of Alexandria24 min
May 26, 5:26 PM EDTSevere Thunderstorm WarningLWXAnne Arundel, Baltimore, Harford, Howard, City of Baltimore49 min
May 26, 5:27 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer48 min
May 26, 5:34 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Warren41 min
May 26, 5:37 PM EDTSevere Thunderstorm WarningPHIChester53 min
May 26, 5:52 PM EDTSevere Thunderstorm WarningLWXAnne Arundel, Calvert, Charles, Prince George's38 min
May 26, 5:53 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Hunterdon, Mercer, Middlesex, Monmouth and 2 more67 min
May 26, 6:08 PM EDTSevere Thunderstorm WarningPHIHunterdon, Middlesex, Morris, Somerset31 min
May 26, 6:12 PM EDTSevere Thunderstorm WarningOKXBergen, Essex, Hudson, Passaic, Union46 min
May 26, 6:15 PM EDTSevere Thunderstorm WarningLWXClarke, Frederick, City of Winchester45 min
May 26, 6:17 PM EDTSevere Thunderstorm WarningLWXCecil, Harford58 min
May 26, 6:51 PM EDTSevere Thunderstorm WarningLWXFrederick, Montgomery, Washington39 min
May 26, 6:52 PM EDTSevere Thunderstorm WarningPHIBerks38 min
May 26, 6:54 PM EDTSevere Thunderstorm WarningOKXBergen, Passaic24 min
May 26, 7:06 PM EDTSevere Thunderstorm WarningLWXGreene, Page, Rockingham, City of Harrisonburg20 min
May 26, 7:21 PM EDTSevere Thunderstorm WarningLWXCarroll, Frederick, Howard, Montgomery39 min
May 26, 7:27 PM EDTSevere Thunderstorm WarningLWXMontgomery48 min
May 26, 7:50 PM EDTSevere Thunderstorm WarningLWXFairfax, Fauquier, Loudoun, Prince William, City of Fairfax, City of Falls Church and 2 more40 min
May 26, 7:53 PM EDTSevere Thunderstorm WarningLWXBaltimore, Carroll, Harford, Howard, City of Baltimore52 min
May 26, 7:59 PM EDTSevere Thunderstorm WarningLWXMontgomery, Prince George's46 min
May 26, 8:21 PM EDTSevere Thunderstorm WarningLWXCharles, Prince George's39 min
May 26, 8:53 PM EDTSevere Thunderstorm WarningLWXCharles, Prince George's52 min
May 26, 9:19 PM EDTSevere Thunderstorm WarningLWXAnne Arundel, Charles, Prince George's41 min
May 26, 9:35 PM EDTSevere Thunderstorm WarningLWXAnne Arundel, Calvert, Charles, Prince George's, Saint Mary's27 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 6.8 hours before the alert went out and 51 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, Washington/Dulle, VA at 12:00Z on 2021-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 478 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, Washington/Dulle, VA at 12:00Z on 2021-05-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 square meters per square second.193958Sfc1 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
478 J/kg
Mixed-layer CIN
-132 J/kg
Mixed-layer LCL
922 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
50 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

076 
WWUS20 KWNS 261844
SEL6  
SPC WW 261844
CTZ000-DCZ000-DEZ000-MDZ000-NJZ000-NYZ000-PAZ000-VAZ000-WVZ000-CWZ00
0-270200-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 206
NWS Storm Prediction Center Norman OK
245 PM EDT Wed May 26 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Western Connecticut
  District Of Columbia
  Delaware
  Maryland
  New Jersey
  Southeast New York
  Eastern Pennsylvania
  Northern Virginia
  Eastern Panhandle of West Virginia
  Coastal Waters

* Effective this Wednesday afternoon and evening from 245 PM
  until 1000 PM EDT.

* Primary threats include...
  Scattered damaging wind gusts to 70 mph possible
  Isolated large hail events to 1 inch in diameter possible

SUMMARY...Thunderstorms are expected to continue to develop over
parts of Pennsylvania and spread eastward across the watch area
through the evening hours.  Damaging winds will be the main threat
with the strongest cells.

The severe thunderstorm watch area is approximately along and 65
statute miles north and south of a line from 45 miles northwest of
Staunton VA to 5 miles south southeast of Lakehurst NJ. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU6).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 205...

AVIATION...A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few
cumulonimbi with maximum tops to 500. Mean storm motion vector
26030.

...Hart

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 26, 1:21 PM EDTMesoscale DiscussionSPCKent, New Castle, Sussex84 min
May 26, 4:41 PM EDTMesoscale DiscussionSPCKent, New Castle64 min
May 26, 6:34 PM EDTMesoscale DiscussionSPCKent, New Castle, Sussex116 min
May 26, 12:16 PM EDTMesoscale DiscussionSPCAllegheny, Armstrong, Beaver, Blair, Bradford, Butler and 39 more119 min
May 26, 12:59 PM EDTSevere Thunderstorm WatchSPCAdams, Allegheny, Armstrong, Beaver, Bedford, Blair and 50 more7 hr

Nearby

Severe Thunderstorm Watches in Virginia, 2021Severe Thunderstorm Watches in Maryland, 2021Severe Thunderstorm Watches in New Jersey, 2021Every severe thunderstorm 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.