Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2009
Severe Thunderstorm Warning 38, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 29, 2009, 5:10 PM EDT for Delaware County, Philadelphia County, Pennsylvania; Gloucester County, New Jersey. It was in force for 42 min. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- May 29, 2009, 5:10 PM EDT (21:10 UTC)
- Expired
- May 29, 2009, 5:52 PM EDT
- In force
- 42 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties Gloucester County, NJ, Delaware County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 71 km from the middle of the area, began a volume at 21:13 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| May 29, 5:13 PM EDT | TSTM WND DMG | 1 N Chester, PA | COUPLE OF TREES DOWN. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| May 29, 1:26 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
The nearest sounding before it
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 9.2 hours before the alert went out and 90 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
- 4 J/kg
- Mixed-layer CIN
- -283 J/kg
- Mixed-layer LCL
- 620 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 58 m²/s²
- 0-3 km storm-relative helicity
- 139 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 292110
SVRPHI
NJC015-PAC045-101-292215-
/O.NEW.KPHI.SV.W.0038.090529T2110Z-090529T2215Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
510 PM EDT FRI MAY 29 2009
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
SOUTHERN PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
THIS INCLUDES THE CITY OF PHILADELPHIA...
NORTHWESTERN GLOUCESTER COUNTY IN SOUTHERN NEW JERSEY...
* UNTIL 615 PM EDT
* AT 508 PM 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
CHELSEA...OR 11 MILES SOUTHEAST OF WEST CHESTER...AND MOVING EAST
AT 30 MPH.
* THE SEVERE THUNDERSTORM WILL BE NEAR...
NETHER PROVIDENCE TOWNSHIP AND SWARTHMORE AROUND 515 PM EDT...
GIBBSTOWN AND DREXEL HILL AROUND 520 PM EDT...
FOLCROFT...PHILADELPHIA INTERNATIONAL AIRPORT...YEADON AND EAST
LANSDOWNE AROUND 525 PM EDT...
SOUTH PHILADELPHIA AROUND 530 PM EDT...
WOODBURY AROUND 535 PM EDT...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM EDT FRIDAY
EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN NEW
JERSEY AND SOUTHEAST PENNSYLVANIA.
&&
LAT...LON 3997 7509 3998 7511 3995 7514 3988 7514
3984 7510 3982 7511 3978 7542 3980 7542
3983 7548 3994 7550 4004 7538 4004 7535
3998 7528 4001 7522 4003 7524 4003 7503
TIME...MOT...LOC 2110Z 265DEG 27KT 3988 7540
$$
JJM1 follow-up statement
000
WWUS51 KPHI 292152
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
552 PM EDT FRI MAY 29 2009
NJC015-PAC045-101-292202-
/O.CAN.KPHI.SV.W.0038.000000T0000Z-090529T2215Z/
GLOUCESTER NJ-DELAWARE PA-PHILADELPHIA PA-
552 PM EDT FRI MAY 29 2009
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN PHILADELPHIA...
DELAWARE AND NORTHWESTERN GLOUCESTER COUNTIES IS CANCELLED...
STORMS HAVE MOVED TO THE EAST. A SEVERE THUNDERSTORM WATCH REMAINS
IN EFFECT UNTIL 800 PM EDT FRIDAY EVENING FOR DELAWARE AND
NORTHEASTERN MARYLAND AND SOUTHERN NEW JERSEY AND SOUTHEAST
PENNSYLVANIA.
LAT...LON 3997 7509 3998 7511 3995 7514 3988 7514
3984 7510 3982 7511 3978 7542 3980 7542
3983 7548 3994 7550 4004 7538 4004 7535
3998 7528 4001 7522 4003 7524 4003 7503
TIME...MOT...LOC 2152Z 265DEG 27KT 3991 7500
$$
JJMThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 29, 3:28 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester | 62 min |
| May 29, 3:38 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 67 min |
| May 29, 5:03 PM EDT | Special Marine Warning | PHI | 87 min | |
| May 29, 6:16 PM EDT | Special Marine Warning | PHI | 119 min | |
| May 29, 7:47 PM EDT | Special Marine Warning | PHI | 88 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2009Severe Thunderstorm Warnings in New Jersey, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.