Alert archive / Maryland / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 19

February 25, 20114 states

The Storm Prediction Center issued this severe thunderstorm watch at Feb 25, 2011, 12:19 PM EST for 4 states. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Feb 25, 2011, 12:19 PM EST (17:19 UTC)
Expired
Feb 25, 2011, 3:48 PM EST
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt
All 36 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline 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, Saint Mary's County, MD, Talbot County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Ocean County, NJ, Salem County, NJ, Arlington County, VA, City of Alexandria, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Manassas Park, VA, Fairfax County, VA, King George County, VA, Prince William County, VA, Spotsylvania County, VA, Stafford County, VA

The radar

The Dover AFB radar (KDOX), 65 km from the middle of the area, began a volume at 17:21 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
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
5%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
50%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Feb 25, 1:04 PM ESTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester56 min
Feb 25, 1:11 PM ESTSevere Thunderstorm WarningPHINew Castle64 min
Feb 25, 1:16 PM ESTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean59 min
Feb 25, 1:25 PM ESTSevere Thunderstorm WarningLWXAnne Arundel, Baltimore, Howard, Montgomery, Prince George's, City of Baltimore33 min
Feb 25, 1:36 PM ESTSevere Thunderstorm WarningPHIKent54 min
Feb 25, 1:48 PM ESTSevere Thunderstorm WarningPHIAtlantic, Burlington, Camden, Cumberland, Gloucester, Ocean and 1 more57 min
Feb 25, 1:52 PM ESTSevere Thunderstorm WarningLWXAnne Arundel, Calvert, Charles, Prince George's38 min
Feb 25, 1:55 PM ESTSevere Thunderstorm WarningPHIKent, New Castle65 min
Feb 25, 2:09 PM ESTSevere Thunderstorm WarningPHIAtlantic, Cape May, Cumberland51 min
Feb 25, 2:19 PM ESTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's, Talbot56 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, 5.3 hours before the alert went out and 125 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 2011-02-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2011-02-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 557 square meters per square second.1939587897Sfc1 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
482 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
557 m²/s²
0-3 km storm-relative helicity
622 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 25, 11:36 AM ESTMesoscale DiscussionSPCKent, New Castle, Sussex84 min
Feb 25, 2:40 PM ESTMesoscale DiscussionSPCKent, New Castle, Sussex65 min
Feb 24, 11:59 PM ESTSevere Thunderstorm WatchSPCLee5 hr
Feb 25, 1:48 AM ESTMesoscale DiscussionSPCAlleghany, Bland, Buchanan, Carroll, Craig, Dickenson and 16 more27 min

Nearby

Severe Thunderstorm Watches in Maryland, 2011Severe Thunderstorm Watches in Virginia, 2011Severe Thunderstorm Watches in New Jersey, 2011Every severe thunderstorm watch in 2011

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.