Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2004
Severe Thunderstorm Warning 197, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 18, 2004, 3:29 AM EDT for Chester County, Pennsylvania; Cecil County, Maryland. It was in force for 31 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Sep 18, 2004, 3:29 AM EDT (07:29 UTC)
- Expired
- Sep 18, 2004, 4:00 AM EDT
- In force
- 31 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Counties, with a storm outline in the text
Counties Cecil County, MD, Chester County, PA
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 00:00Z, 7.5 hours before the alert went out and 150 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.
- Mixed-layer CAPE
- 1144 J/kg
- Mixed-layer CIN
- -3 J/kg
- Mixed-layer LCL
- 556 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 168 m²/s²
- 0-3 km storm-relative helicity
- 235 m²/s²
- Significant tornado parameter
- 0.8
- Supercell composite
- 4.2
The text
As transmitted, in the capitals the NWS used until 2016.
000 WUUS51 KPHI 180729 SVRPHI MDC015-PAC029-180800- /X.NEW.KPHI.SV.W.0001.040918T0729Z-040918T0800Z/ BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 329 AM EDT SAT SEP 18 2004 THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... NORTHERN CECIL COUNTY IN NORTHEAST MARYLAND SOUTHERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA * UNTIL 400 AM EDT * AT 328 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM. THIS STORM WAS LOCATED 9 MILES SOUTH OF OXFORD...OR ABOUT 10 MILES WEST OF NEWARK...AND MOVING NORTH AT 30 MPH. * THE SEVERE THUNDERSTORM WILL BE NEAR... OXFORD BY 340 AM EDT WEST GROVE BY 345 AM EDT DOPPLER RADAR HAS INDICATED SOME WEAK ROTATION WITHIN THIS STORM. WHILE NOT IMMEDIATELY LIKELY...A TORNADO MAY STILL DEVELOP. IF A TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM. LAT...LON 3961 7607 3961 7583 3982 7579 3982 7600 $$ JRP/MPD
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 18, 6:09 AM EDT | Flash Flood Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 4 hr |
| Sep 18, 7:07 AM EDT | Flash Flood Warning | PHI | Bucks, Montgomery | 4 hr |
| Sep 18, 9:48 AM EDT | Flash Flood Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 4 hr |
| Sep 18, 10:31 AM EDT | Flash Flood Warning | PHI | Chester, Delaware | 3 hr |
| Sep 18, 10:57 AM EDT | Flash Flood Warning | PHI | Bucks, Montgomery | 3 hr |
| Sep 18, 1:45 PM EDT | Flash Flood Warning | PHI | Bucks, Chester, Delaware, Montgomery | 2 hr |
| Sep 18, 2:00 PM EDT | Flash Flood Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 3 hr |
| Sep 18, 3:11 PM EDT | Flash Flood Warning | PHI | Cecil | 3 hr |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2004Severe Thunderstorm Warnings in Maryland, 2004Every severe thunderstorm warning in 2004
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.