Alert archive / Virginia / Severe Thunderstorm Watches in 2001

Severe Thunderstorm Watch 468

June 22, 20014 states

The Storm Prediction Center issued this severe thunderstorm watch at Jun 22, 2001, 7:00 PM EDT for 4 states. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jun 22, 2001, 7:00 PM EDT (23:00 UTC)
Expired
Jun 22, 2001, 11:00 PM EDT
In force
4 hr
Issued by
the Storm Prediction Center
All 58 counties

New Castle County, DE, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Carroll County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Talbot County, MD, Chester County, PA, Delaware County, PA, Lancaster County, PA, Philadelphia County, PA, York County, PA, Amelia County, VA, Appomattox County, VA, Arlington County, VA, Buckingham County, VA, Campbell County, VA, Caroline County, VA, Charlotte County, VA, Chesterfield County, VA, City of Alexandria, VA, City of Danville, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Richmond, VA, Culpeper County, VA, Cumberland County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Fluvanna County, VA, Goochland County, VA, Halifax County, VA, Hanover County, VA, King George County, VA, Louisa County, VA, Lunenburg County, VA, Mecklenburg County, VA, Nottoway County, VA, Orange County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Prince William County, VA, Spotsylvania County, VA, Stafford County, VA, Westmoreland County, VA

The radar

The Sterling radar (KLWX), 116 km from the middle of the area, began a volume at 23:00 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.

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jun 22, 7:07 PM EDTFlash Flood WarningPHICecil113 min
Jun 22, 7:24 PM EDTFlash Flood WarningLWXMontgomery3 hr
Jun 22, 7:28 PM EDTSevere Thunderstorm WarningPHICecil47 min
Jun 22, 7:30 PM EDTFlash Flood WarningCTPYork6 hr
Jun 22, 7:31 PM EDTSevere Thunderstorm WarningLWXPrince William, City of Manassas, City of Manassas Park59 min
Jun 22, 7:31 PM EDTSevere Thunderstorm WarningLWXFauquier59 min
Jun 22, 8:41 PM EDTFlash Flood WarningLWXHoward3 hr
Jun 22, 9:21 PM EDTFlash Flood WarningCTPLancaster4 hr
Jun 22, 9:55 PM EDTFlash Flood WarningLWXCarroll3 hr
Jun 22, 10:22 PM EDTFlash Flood WarningLWXCity of Alexandria3 hr
Jun 22, 10:30 PM EDTFlash Flood WarningLWXMontgomery3 hr
Jun 22, 10:41 PM EDTFlash Flood WarningLWXHoward3 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.0 hours before the alert went out and 116 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 2001-06-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 933 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 2001-06-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 108 square meters per square second.1939Sfc1 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
933 J/kg
Mixed-layer CIN
-78 J/kg
Mixed-layer LCL
704 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
108 m²/s²
0-3 km storm-relative helicity
103 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.3

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 22, 2:00 PM EDTSevere Thunderstorm WatchSPCAnne Arundel, Baltimore, Carroll, Cecil, Charles, Frederick and 6 more5 hr

Nearby

Severe Thunderstorm Watches in Virginia, 2001Severe Thunderstorm Watches in Maryland, 2001Severe Thunderstorm Watches in Pennsylvania, 2001Every severe thunderstorm watch in 2001

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.