Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2004
Severe Thunderstorm Warning 152, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 4, 2004, 7:49 PM EDT for Delaware County, Montgomery County, Philadelphia County, Pennsylvania; Cecil County, Maryland; New Castle County, Delaware. It was in force for 56 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
- Aug 4, 2004, 7:49 PM EDT (23:49 UTC)
- Expired
- Aug 4, 2004, 8:45 PM EDT
- In force
- 56 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Counties, with a storm outline in the text
Counties New Castle County, DE, Cecil County, MD, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 105 km from the middle of the area, began a volume at 23:51 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.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Aug 4, 7:10 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 11.8 hours before the alert went out and 187 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
- 24 J/kg
- Mixed-layer CIN
- -92 J/kg
- Mixed-layer LCL
- 1125 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- -2 m²/s²
- 0-3 km storm-relative helicity
- -4 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
WUUS51 KPHI 042349
SVRPHI
DEC003-MDC015-PAC045-091-101-050045-
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
748 PM EDT WED AUG 4 2004
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA.
PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA.
DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA.
CECIL COUNTY IN NORTHEAST MARYLAND.
NEW CASTLE COUNTY IN NORTHERN DELAWARE.
* UNTIL 845 PM EDT
* AT 742 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
FROM COLLEGEVILLE TO RISING SUN...OR ALONG A LINE EXTENDING FROM 23
MILES NORTHWEST OF PHILADELPHIA TO 13 MILES WEST OF NEWARK...AND
MOVING EAST AT 45 MPH.
* SEVERE THUNDERSTORMS WILL BE NEAR...
NORRISTOWN AND KING OF PRUSSIA BY 755 PM EDT...
RADNOR TOWNSHIP...PLYMOUTH MEETING...AMBLER AND NEWARK BY 800 PM
EDT...
LIMA...BRYN MAWR...BROOMALL AND TALLEYVILLE BY 805 PM EDT...
THIS STORM HAS A HISTORY OF PRODUCING WIDESPREAD WIND DAMAGE ACROSS
SOUTHEAST PENNSYLVANIA. THIS IS AN EXTREMELY DANGEROUS SITUATION.
SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM
WINDOWS
LAT...LON 3972 7611 3972 7579 3982 7569 3984 7561
3987 7561 3999 7544 4007 7537 4013 7551
4015 7550 4015 7553 4021 7559 4027 7553
4010 7499 3961 7572 3965 7617
$$
SZATKOWSKIThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 4, 7:02 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester | 73 min |
| Aug 4, 7:54 PM EDT | Severe Thunderstorm Warning | PHI | Kent | 51 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2004Severe Thunderstorm Warnings in Maryland, 2004Severe Thunderstorm Warnings in Delaware, 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; radar from the NEXRAD Level II archive.