Alert archive / Maryland / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 291

May 12, 20025 states

The Storm Prediction Center issued this severe thunderstorm watch at May 12, 2002, 5:15 PM EDT for 5 states. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
May 12, 2002, 5:15 PM EDT (21:15 UTC)
Expired
May 12, 2002, 10:00 PM EDT
In force
5 hr
Issued by
the Storm Prediction Center
All 37 counties

Kent County, DE, New Castle County, DE, Anne Arundel County, MD, Baltimore County, MD, Caroline County, MD, Cecil 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, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Gloucester County, NJ, Mercer County, NJ, Monmouth County, NJ, Ocean County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Manassas, VA, City of Manassas Park, VA, Fairfax County, VA, Fauquier County, VA, Prince William County, VA

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 12, 5:32 PM EDTSevere Thunderstorm WarningPHIKent, Queen Anne's43 min
May 12, 5:40 PM EDTSevere Thunderstorm WarningPHIBerks, Chester35 min
May 12, 5:42 PM EDTSevere Thunderstorm WarningPHIBerks, Chester33 min
May 12, 6:08 PM EDTSevere Thunderstorm WarningPHIKent, New Castle37 min
May 12, 6:19 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Philadelphia26 min
May 12, 6:23 PM EDTSevere Thunderstorm WarningLWXMontgomery52 min
May 12, 6:33 PM EDTSevere Thunderstorm WarningPHICumberland, Salem42 min
May 12, 6:39 PM EDTSevere Thunderstorm WarningLWXBaltimore, Harford51 min
May 12, 6:45 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester45 min
May 12, 7:12 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean33 min
May 12, 7:24 PM EDTSevere Thunderstorm WarningLWXMontgomery21 min
May 12, 7:43 PM EDTSevere Thunderstorm WarningLWXAnne Arundel, Howard, Montgomery, Prince George's47 min
May 12, 7:53 PM EDTSevere Thunderstorm WarningLWXFrederick, Montgomery22 min
May 12, 8:07 PM EDTSevere Thunderstorm WarningPHIKent38 min
May 12, 8:58 PM EDTSevere Thunderstorm WarningLWXMontgomery, Prince George's47 min

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.3 hours before the alert went out and 128 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 2002-05-12Temperature 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 2002-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 150 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1104 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
150 m²/s²
0-3 km storm-relative helicity
143 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
May 12, 3:30 PM EDTSevere Thunderstorm WatchSPCNew Castle6 hr
May 12, 10:45 AM EDTSevere Thunderstorm WatchSPCAllegheny, Armstrong, Beaver, Bedford, Butler, Cambria and 11 more5 hr

Nearby

Severe Thunderstorm Watches in Maryland, 2002Severe Thunderstorm Watches in New Jersey, 2002Severe Thunderstorm Watches in Virginia, 2002Every severe thunderstorm watch in 2002

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.