Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2011
Severe Thunderstorm Warning 252, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 18, 2011, 7:59 PM EDT for 4 counties in Pennsylvania; Burlington County, Camden County, New Jersey. It was in force for 61 min. 4 reports 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
- Aug 18, 2011, 7:59 PM EDT (23:59 UTC)
- Expired
- Aug 18, 2011, 9:00 PM EDT
- In force
- 61 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties Burlington County, NJ, Camden County, NJ, Bucks County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 69 km from the middle of the area, began a volume at 00:01 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 |
|---|---|---|---|
| Aug 18, 8:05 PM EDT | TSTM WND DMG | Lower Merion Twp, PA | TREES DOWN. |
| Aug 18, 8:20 PM EDT | TSTM WND DMG | Maple Shade Twp, NJ | TREES AND WIRES DOWN. |
| Aug 18, 8:25 PM EDT | TSTM WND DMG | Abington, PA | TREES DOWN. |
| Aug 18, 8:25 PM EDT | TSTM WND DMG | Moorestown, NJ | TREES AND WIRES DOWN. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 12.0 hours before the alert went out and 98 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
- 780 J/kg
- Mixed-layer CIN
- -64 J/kg
- Mixed-layer LCL
- 1022 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 83 m²/s²
- 0-3 km storm-relative helicity
- 143 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
123
WUUS51 KPHI 182359
SVRPHI
NJC005-007-PAC017-045-091-101-190100-
/O.NEW.KPHI.SV.W.0252.110818T2359Z-110819T0100Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
759 PM EDT THU AUG 18 2011
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
SOUTHEASTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
NORTHEASTERN DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
SOUTHEASTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
THIS INCLUDES THE CITY OF PHILADELPHIA...
NORTHWESTERN BURLINGTON COUNTY IN SOUTHERN NEW JERSEY...
NORTHWESTERN CAMDEN COUNTY IN SOUTHERN NEW JERSEY...
THIS INCLUDES THE CITY OF CAMDEN...
* UNTIL 900 PM EDT
* AT 757 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED NEAR
NARBERTH...OR 8 MILES WEST OF PHILADELPHIA...AND MOVING EAST AT 15
MPH.
* THE SEVERE THUNDERSTORM WILL BE NEAR...
NARBERTH AND MORRIS PARK AROUND 805 PM EDT...
ROXBOROUGH AROUND 810 PM EDT...
CHESTNUT HILL AROUND 815 PM EDT...
GERMANTOWN AROUND 820 PM EDT...
PHILADELPHIA...KENSINGTON AND CENTER CITY AROUND 825 PM EDT...
JENKINTOWN AROUND 835 PM EDT...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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.
PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.
&&
LAT...LON 3989 7531 4006 7538 4007 7537 4008 7538
4021 7493 3995 7479
TIME...MOT...LOC 2359Z 256DEG 15KT 3999 7528
$$
HEAVENER2 follow-up statements
343 WWUS51 KPHI 190036 SVSPHI SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 836 PM EDT THU AUG 18 2011 PAC045-190047- /O.CAN.KPHI.SV.W.0252.000000T0000Z-110819T0100Z/ DELAWARE PA- 836 PM EDT THU AUG 18 2011 ...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN DELAWARE COUNTY IS CANCELLED... PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY. LAT...LON 3991 7513 4011 7527 4021 7493 3995 7479 TIME...MOT...LOC 0037Z 256DEG 15KT 4003 7508 $$ NJC005-007-PAC017-091-101-190100- /O.CON.KPHI.SV.W.0252.000000T0000Z-110819T0100Z/ CAMDEN NJ-PHILADELPHIA PA-MONTGOMERY PA-BUCKS PA-BURLINGTON NJ- 836 PM EDT THU AUG 18 2011 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 900 PM EDT FOR NORTHWESTERN BURLINGTON...SOUTHEASTERN BUCKS...SOUTHEASTERN MONTGOMERY...NORTHEASTERN PHILADELPHIA AND NORTHWESTERN CAMDEN COUNTIES... AT 835 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED NEAR WISSINOMING...OR NEAR PHILADELPHIA...MOVING EAST AT 15 MPH. THE SEVERE THUNDERSTORM WILL BE NEAR... TACONY...HOLMESBURG...RIVERTON AND PALMYRA BY 845 PM EDT... CINNAMINSON AND NORTHEAST PHILADELPHIA BY 850 PM EDT... RIVERSIDE...ANDALUSIA AND MOORESTOWN-LENOLA BY 855 PM EDT... DELANCO BY 900 PM EDT... PRECAUTIONARY/PREPAREDNESS ACTIONS... PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY. && LAT...LON 3991 7513 4011 7527 4021 7493 3995 7479 TIME...MOT...LOC 0037Z 256DEG 15KT 4003 7508 $$ HEAVENER
640 WWUS51 KPHI 190056 SVSPHI SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 856 PM EDT THU AUG 18 2011 NJC005-007-PAC017-091-101-190106- /O.EXP.KPHI.SV.W.0252.000000T0000Z-110819T0100Z/ CAMDEN NJ-PHILADELPHIA PA-MONTGOMERY PA-BUCKS PA-BURLINGTON NJ- 856 PM EDT THU AUG 18 2011 ...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN BURLINGTON... SOUTHEASTERN BUCKS...SOUTHEASTERN MONTGOMERY...NORTHEASTERN PHILADELPHIA AND NORTHWESTERN CAMDEN COUNTIES WILL EXPIRE AT 900 PM EDT... PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY. LAT...LON 3991 7513 4011 7527 4021 7493 3995 7479 TIME...MOT...LOC 0056Z 256DEG 15KT 4005 7498 $$ HEAVENER
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 18, 2:57 AM EDT | Special Weather Statement | PHI | Berks | 63 min |
| Aug 18, 3:53 AM EDT | Special Weather Statement | PHI | Berks | 52 min |
| Aug 18, 4:48 AM EDT | Special Weather Statement | PHI | Chester, Montgomery | 57 min |
| Aug 18, 5:45 AM EDT | Special Weather Statement | PHI | Delaware, Montgomery, Philadelphia | 60 min |
| Aug 18, 6:04 AM EDT | Special Weather Statement | PHI | Berks, Chester | 41 min |
| Aug 18, 6:35 AM EDT | Areal Flood Advisory | PHI | Berks, Bucks, Chester, Delaware, Lehigh, Montgomery and 2 more | 3 hr |
| Aug 18, 7:29 AM EDT | Special Weather Statement | PHI | Bucks, Delaware, Montgomery, Philadelphia | 61 min |
| Aug 18, 8:16 AM EDT | Special Weather Statement | PHI | Philadelphia | 59 min |
| Aug 18, 9:29 AM EDT | Areal Flood Advisory | PHI | Delaware | 2 hr |
| Aug 18, 3:12 PM EDT | Flash Flood Watch | PHI | Berks, Carbon, Delaware, Lehigh, Monroe, Northampton and 1 more | 29 hr |
| Aug 18, 5:30 PM EDT | Special Weather Statement | PHI | Monroe | 60 min |
| Aug 18, 5:48 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 57 min |
| Aug 18, 6:18 PM EDT | Special Weather Statement | PHI | Chester | 57 min |
| Aug 18, 6:39 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 66 min |
| Aug 18, 6:59 PM EDT | Flash Flood Warning | PHI | Chester | 2 hr |
| Aug 18, 7:14 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware | 50 min |
| Aug 18, 7:28 PM EDT | Special Weather Statement | PHI | Chester | 62 min |
| Aug 18, 7:31 PM EDT | Special Weather Statement | PHI | Monroe | 59 min |
| Aug 18, 7:37 PM EDT | Severe Thunderstorm Warning | PHI | Delaware, Philadelphia | 53 min |
| Aug 18, 7:47 PM EDT | Areal Flood Advisory | PHI | Carbon, Monroe, Northampton | 3 hr |
| Aug 18, 7:58 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Montgomery | 31 min |
| Aug 18, 4:53 AM EDT | Special Weather Statement | PHI | Morris, Somerset, Sussex | 52 min |
| Aug 18, 8:57 AM EDT | Areal Flood Advisory | PHI | Atlantic, Burlington, Camden, Cumberland, Gloucester, Monmouth and 1 more | 3 hr |
| Aug 18, 3:32 PM EDT | Special Weather Statement | PHI | Burlington | 58 min |
| Aug 18, 3:50 PM EDT | Areal Flood Advisory | PHI | Burlington, Camden | 51 min |
| Aug 18, 4:17 PM EDT | Special Weather Statement | PHI | Monmouth | 58 min |
| Aug 18, 4:55 PM EDT | Special Weather Statement | PHI | Burlington | 65 min |
| Aug 18, 5:20 PM EDT | Severe Thunderstorm Warning | PHI | Burlington, Monmouth, Ocean | 33 min |
| Aug 18, 6:12 PM EDT | Special Weather Statement | PHI | Middlesex | 63 min |
| Aug 18, 6:33 PM EDT | Special Weather Statement | PHI | Mercer | 57 min |
| Aug 18, 7:34 PM EDT | Special Weather Statement | PHI | Monmouth | 56 min |
| Aug 18, 7:43 PM EDT | Severe Thunderstorm Warning | PHI | Morris, Sussex, Warren | 62 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2011Severe Thunderstorm Warnings in New Jersey, 2011Every severe thunderstorm warning in 2011
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.