Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2011
Severe Thunderstorm Warning 96, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 9, 2011, 7:27 PM EDT for 4 counties in Pennsylvania; New Castle County, Delaware. It was in force for 48 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
- Jun 9, 2011, 7:27 PM EDT (23:27 UTC)
- Expired
- Jun 9, 2011, 8:15 PM EDT
- In force
- 48 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties New Castle County, DE, Berks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 100 km from the middle of the area, began a volume at 23:27 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 |
|---|---|---|---|
| Jun 9, 7:50 PM EDT | TSTM WND DMG | Westtown Twp, PA | WIND DAMAGE TO A GROVE OF TREES... 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 |
|---|---|---|---|
| Jun 9, 2:34 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 11.5 hours before the alert went out and 81 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
- 734 J/kg
- Mixed-layer CIN
- -235 J/kg
- Mixed-layer LCL
- 1935 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- -20 m²/s²
- 0-3 km storm-relative helicity
- 28 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
724
WUUS51 KPHI 092327
SVRPHI
DEC003-PAC011-029-045-091-100015-
/O.NEW.KPHI.SV.W.0096.110609T2327Z-110610T0015Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
727 PM EDT THU JUN 9 2011
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
SOUTHEASTERN BERKS COUNTY IN EASTERN PENNSYLVANIA...
NORTHERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...
CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
THIS INCLUDES THE CITY OF WEST CHESTER...
WESTERN DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
WESTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
* UNTIL 815 PM EDT
* AT 723 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
PUGHTOWN...OR 14 MILES NORTH OF WEST CHESTER...AND MOVING EAST
AT 30 TO 35 MPH.
* THE SEVERE THUNDERSTORM WILL BE NEAR...
PHOENIXVILLE AND ROYERSFORD AROUND 735 PM EDT...
VALLEY FORGE AND PAOLI AROUND 740 PM EDT...
9 MILES NORTH OF NEWTOWN SQUARE AROUND 745 PM EDT...
CONSHOHOCKEN...RADNOR TOWNSHIP...BRYN MAWR AND 7 MILES NORTH OF
TROUT LAKE AROUND 750 PM EDT...
PLYMOUTH MEETING AROUND 755 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.
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
THURSDAY EVENING FOR NORTHERN DELAWARE AND NORTHEAST MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA.
&&
LAT...LON 4036 7554 4006 7543 4014 7528 4004 7528
3972 7563 3973 7605 4020 7582
TIME...MOT...LOC 2326Z 278DEG 38KT 4014 7565
$$1 follow-up statement
544
WWUS51 KPHI 092352
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
752 PM EDT THU JUN 9 2011
PAC011-100002-
/O.CAN.KPHI.SV.W.0096.000000T0000Z-110610T0015Z/
BERKS PA-
752 PM EDT THU JUN 9 2011
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN BERKS COUNTY IS
CANCELLED...
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
THURSDAY EVENING FOR NORTHERN DELAWARE AND NORTHEAST MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA.
LAT...LON 3974 7594 3983 7577 4001 7559 4019 7548
4006 7543 4014 7528 4004 7528 3972 7563
TIME...MOT...LOC 2352Z 278DEG 38KT 4010 7529
$$
DEC003-PAC029-045-091-100015-
/O.CON.KPHI.SV.W.0096.000000T0000Z-110610T0015Z/
DELAWARE PA-CHESTER PA-MONTGOMERY PA-NEW CASTLE DE-
752 PM EDT THU JUN 9 2011
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM EDT
FOR NORTHWESTERN NEW CASTLE...SOUTH CENTRAL MONTGOMERY...SOUTHEASTERN
CHESTER AND WESTERN DELAWARE COUNTIES...
AT 749 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 BRIDGEPORT...OR 13 MILES NORTHWEST OF PHILADELPHIA...
MOVING EAST AT 35 MPH.
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.
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
THURSDAY EVENING FOR NORTHERN DELAWARE AND NORTHEAST MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA.
&&
LAT...LON 3974 7594 3983 7577 4001 7559 4019 7548
4006 7543 4014 7528 4004 7528 3972 7563
TIME...MOT...LOC 2352Z 278DEG 38KT 4010 7529
$$The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 9, 4:41 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Monroe | 64 min |
| Jun 9, 5:43 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Carbon, Lehigh, Monroe, Northampton | 62 min |
| Jun 9, 6:24 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester, Montgomery | 66 min |
| Jun 9, 6:44 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Bucks, Carbon, Chester, Lehigh, Monroe and 2 more | 61 min |
| Jun 9, 7:42 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Chester, Montgomery, Philadelphia | 33 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2011Severe Thunderstorm Warnings in Delaware, 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.