Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2009
Severe Thunderstorm Warning 52, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 9, 2009, 7:20 AM EDT for 4 counties in Pennsylvania. It was in force for 55 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
- Jun 9, 2009, 7:20 AM EDT (11:20 UTC)
- Expired
- Jun 9, 2009, 8:15 AM EDT
- In force
- 55 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 82 km from the middle of the area, began a volume at 11:21 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.
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 00:00Z, 11.3 hours before the alert went out and 214 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
- 245 J/kg
- Mixed-layer CIN
- -32 J/kg
- Mixed-layer LCL
- 1873 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- -5 m²/s²
- 0-3 km storm-relative helicity
- -6 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 091120 SVRPHI PAC029-045-091-101-091215- /O.NEW.KPHI.SV.W.0052.090609T1120Z-090609T1215Z/ BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 720 AM EDT TUE JUN 9 2009 THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... EAST CENTRAL CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA... THIS INCLUDES THE CITY OF WEST CHESTER... NORTHERN DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA... SOUTHERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA... WESTERN PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA... * UNTIL 815 AM EDT * AT 717 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED NEAR PAOLI...OR 7 MILES NORTHEAST OF WEST CHESTER...AND MOVING EAST AT 25 TO 30 MPH. * THE SEVERE THUNDERSTORM WILL BE NEAR... PAOLI AROUND 725 AM EDT... VALLEY FORGE AROUND 730 AM EDT... NEWTOWN SQUARE AROUND 740 AM EDT... RADNOR TOWNSHIP...KING OF PRUSSIA AND BROOMALL AROUND 745 AM EDT... BRYN MAWR AND TROUT LAKE AROUND 750 AM EDT... MORRIS PARK AND PLYMOUTH MEETING AROUND 800 AM EDT... LAT...LON 4019 7513 3989 7517 3988 7567 4012 7569 TIME...MOT...LOC 1119Z 270DEG 19KT 4004 7555 $$ JRP
1 follow-up statement
000 WWUS51 KPHI 091144 SVSPHI SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 744 AM EDT TUE JUN 9 2009 PAC029-045-091-101-091215- /O.CON.KPHI.SV.W.0052.000000T0000Z-090609T1215Z/ DELAWARE PA-PHILADELPHIA PA-CHESTER PA-MONTGOMERY PA- 744 AM EDT TUE JUN 9 2009 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 AM EDT FOR SOUTH CENTRAL MONTGOMERY...EAST CENTRAL CHESTER...WESTERN PHILADELPHIA AND NORTHERN DELAWARE COUNTIES... AT 744 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED NEAR RADNOR TOWNSHIP...OR 13 MILES WEST OF PHILADELPHIA... MOVING EAST AT 25 MPH. THE SEVERE THUNDERSTORM WILL BE NEAR... BROOMALL BY 750 AM EDT... BRYN MAWR...WEST CONSHOHOCKEN...ARDMORE AND CONSHOHOCKEN BY 755 AM EDT... NARBERTH AND PENN WYNNE BY 800 AM EDT... LAT...LON 3990 7558 4011 7552 4019 7513 3989 7517 TIME...MOT...LOC 1144Z 270DEG 19KT 4004 7538 $$ JRP
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 9, 4:17 AM EDT | Dense Fog Advisory | PHI | 5 hr | |
| Jun 9, 5:38 AM EDT | Severe Thunderstorm Warning | PHI | Berks | 67 min |
| Jun 9, 8:00 AM EDT | Severe Thunderstorm Warning | PHI | Delaware, Philadelphia | 60 min |
| Jun 9, 8:06 AM EDT | Severe Thunderstorm Warning | PHI | Philadelphia | 54 min |
| Jun 9, 8:20 AM EDT | Areal Flood Advisory | PHI | Delaware, Montgomery, Philadelphia | 3 hr |
| Jun 9, 8:42 AM EDT | Areal Flood Advisory | PHI | Bucks | 3 hr |
| Jun 9, 9:56 AM EDT | Flash Flood Warning | PHI | Chester | 105 min |
| Jun 9, 1:49 PM EDT | Flash Flood Watch | PHI | Delaware, Philadelphia | 5 hr |
| Jun 9, 2:20 PM EDT | Flash Flood Warning | PHI | Berks, Chester | 3 hr |
| Jun 9, 2:24 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester, Montgomery | 66 min |
| Jun 9, 2:59 PM EDT | Tornado Warning | PHI | Chester | 32 min |
| Jun 9, 3:08 PM EDT | Tornado Warning | PHI | Chester | 28 min |
| Jun 9, 3:14 PM EDT | Tornado Warning | PHI | Chester | 46 min |
| Jun 9, 3:29 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 61 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2009Every severe thunderstorm warning in 2009
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.