Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2004
Severe Thunderstorm Warning 170, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 11, 2004, 5:28 PM EDT for Philadelphia County, Pennsylvania. It was in force for 32 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 11, 2004, 5:28 PM EDT (21:28 UTC)
- Expired
- Aug 11, 2004, 6:00 PM EDT
- In force
- 32 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Counties, with a storm outline in the text
County Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 60 km from the middle of the area, began a volume at 21:29 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 11, 12:55 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Brookhaven, NY (KOKX), launched 12:00Z, 9.5 hours before the alert went out and 210 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
- 1077 J/kg
- Mixed-layer CIN
- -31 J/kg
- Mixed-layer LCL
- 599 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 72 m²/s²
- 0-3 km storm-relative helicity
- 130 m²/s²
- Significant tornado parameter
- 0.3
- Supercell composite
- 1.2
The text
As transmitted, in the capitals the NWS used until 2016.
000
WUUS51 KPHI 112128
SVRPHI
PAC101-112200-
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
527 PM EDT WED AUG 11 2004
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA.
* UNTIL 600 PM EDT
* AT 525 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
AN EXPLOSIVELY DEVELOPING SEVERE THUNDERSTORM OVER PHILADELPHIA
CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DESTRUCTIVE WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED NEAR
PHILADELPHIA...OR ABOUT OVER PHILADELPHIA...AND MOVING NORTHEAST AT
20 MPH.
THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.
LAT...LON 4012 7499 4011 7497 4004 7499 3997 7510
3991 7514 4000 7524 4002 7522 4004 7524
4007 7519 4005 7512 4013 7502
$$
TFGThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 11, 2:21 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 54 min |
| Aug 11, 2:40 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 95 min |
| Aug 11, 3:12 PM EDT | Tornado Warning | PHI | Chester | 78 min |
| Aug 11, 4:04 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 41 min |
| Aug 11, 5:09 PM EDT | Special Marine Warning | PHI | 81 min | |
| Aug 11, 5:25 PM EDT | Severe Thunderstorm Warning | PHI | Berks | 65 min |
| Aug 11, 5:37 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 53 min |
| Aug 11, 5:56 PM EDT | Severe Thunderstorm Warning | PHI | Montgomery | 34 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 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.