Alert archive / Pennsylvania / Tornado Warnings in 2011
Tornado Warning 25, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this tornado warning at Aug 27, 2011, 10:23 PM EDT for 4 counties in Pennsylvania. It was in force for 37 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 27, 2011, 10:23 PM EDT (02:23 UTC)
- Expired
- Aug 27, 2011, 11:00 PM EDT
- In force
- 37 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), 64 km from the middle of the area, began a volume at 02:09 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 27, 7:56 PM EDT | Tornado Watch | SPC | 9 hr |
The nearest sounding before it
Brookhaven, NY (KOKX), launched 00:00Z, 2.4 hours before the alert went out and 216 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
- 957 J/kg
- Mixed-layer CIN
- -1 J/kg
- Mixed-layer LCL
- 466 m above ground
- 0-6 km bulk shear
- 14 kt
- 0-1 km storm-relative helicity
- 110 m²/s²
- 0-3 km storm-relative helicity
- 269 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
786
WFUS51 KPHI 280223
TORPHI
PAC029-045-091-101-280300-
/O.NEW.KPHI.TO.W.0025.110828T0223Z-110828T0300Z/
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1023 PM EDT SAT AUG 27 2011
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* TORNADO WARNING FOR...
EAST CENTRAL CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
NORTHEASTERN DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
SOUTHEASTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
CENTRAL PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
THIS INCLUDES THE CITY OF PHILADELPHIA...
* UNTIL 1100 PM EDT
* AT 1022 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR
PHILADELPHIA...MOVING NORTHWEST AT 45 MPH.
* THE TORNADO WILL BE NEAR...
CHESTNUT HILL...NARBERTH AND BRYN MAWR BY 1030 PM EDT...
CONSHOHOCKEN...NORRISTOWN...PLYMOUTH MEETING AND RADNOR TOWNSHIP BY
1035 PM EDT...
KING OF PRUSSIA BY 1040 PM EDT...
6 MILES NORTHEAST OF PAOLI BY 1045 PM EDT...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
WHEN A TORNADO WARNING IS ISSUED BASED ON DOPPLER RADAR...IT MEANS
THAT STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY
ALREADY BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY. IF YOU
ARE IN THE PATH OF THIS DANGEROUS STORM...MOVE INDOORS AND TO THE
LOWEST LEVEL OF THE BUILDING. STAY AWAY FROM WINDOWS. IF DRIVING...DO
NOT SEEK SHELTER UNDER A HIGHWAY OVERPASS.
THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.
IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.
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.
A TORNADO WATCH REMAINS IN EFFECT UNTIL 500 AM EDT SUNDAY MORNING FOR
SOUTHERN DELAWARE AND NEW JERSEY.
&&
LAT...LON 4001 7504 3999 7507 3997 7509 3998 7511
3995 7514 3990 7514 4003 7550 4020 7540
4005 7502
TIME...MOT...LOC 0223Z 116DEG 40KT 4002 7517
$$
HAYES/GAINES2 follow-up statements
937
WWUS51 KPHI 280247
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1047 PM EDT SAT AUG 27 2011
PAC029-045-091-101-280300-
/O.CON.KPHI.TO.W.0025.000000T0000Z-110828T0300Z/
DELAWARE PA-PHILADELPHIA PA-CHESTER PA-MONTGOMERY PA-
1047 PM EDT SAT AUG 27 2011
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1100 PM EDT FOR
SOUTHEASTERN MONTGOMERY...EAST CENTRAL CHESTER...CENTRAL PHILADELPHIA
AND NORTHEASTERN DELAWARE COUNTIES...
AT 1047 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO. THIS TORNADO WAS LOCATED NEAR KING OF PRUSSIA...
OR 14 MILES NORTHWEST OF PHILADELPHIA...MOVING WEST AT 30 MPH.
THE TORNADO WILL BE NEAR...
AUDUBON...CHESTERBROOK...TROOPER AND EAGLEVILLE BY 1055 PM EDT...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
WHEN A TORNADO WARNING IS ISSUED BASED ON DOPPLER RADAR...IT MEANS
THAT STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY
ALREADY BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY. IF YOU
ARE IN THE PATH OF THIS DANGEROUS STORM...MOVE INDOORS AND TO THE
LOWEST LEVEL OF THE BUILDING. STAY AWAY FROM WINDOWS. IF DRIVING...DO
NOT SEEK SHELTER UNDER A HIGHWAY OVERPASS.
THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.
IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.
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.
A TORNADO WATCH REMAINS IN EFFECT UNTIL 500 AM EDT SUNDAY MORNING FOR
DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND SOUTHEAST
PENNSYLVANIA.
&&
LAT...LON 4001 7504 3999 7507 3997 7509 3998 7511
3995 7514 3990 7514 4003 7550 4020 7540
4005 7502
TIME...MOT...LOC 0248Z 111DEG 24KT 4009 7538
$$
HAYES/GAINES015
WWUS51 KPHI 280258
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1058 PM EDT SAT AUG 27 2011
PAC029-045-091-101-280309-
/O.EXP.KPHI.TO.W.0025.000000T0000Z-110828T0300Z/
DELAWARE PA-PHILADELPHIA PA-CHESTER PA-MONTGOMERY PA-
1058 PM EDT SAT AUG 27 2011
...THE TORNADO WARNING FOR SOUTHEASTERN MONTGOMERY...EAST CENTRAL
CHESTER...CENTRAL PHILADELPHIA AND NORTHEASTERN DELAWARE COUNTIES
WILL EXPIRE AT 1100 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.
A TORNADO WATCH REMAINS IN EFFECT UNTIL 500 AM EDT SUNDAY MORNING FOR
DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND SOUTHEAST
PENNSYLVANIA.
LAT...LON 4001 7504 3999 7507 3997 7509 3998 7511
3995 7514 3990 7514 4003 7550 4020 7540
4005 7502
TIME...MOT...LOC 0259Z 111DEG 24KT 4012 7547
$$
HAYES/GAINESThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 27, 8:28 PM EDT | Flash Flood Warning | PHI | Chester | 12 hr |
| Aug 27, 9:29 PM EDT | Tornado Warning | PHI | Delaware | 31 min |
| Aug 27, 9:43 PM EDT | Areal Flood Warning | PHI | Berks, Bucks, Chester, Lehigh, Montgomery, Northampton | 6 hr |
| Aug 27, 9:58 PM EDT | River Flood Warning | PHI | Monroe, Northampton | 48 hr |
| Aug 27, 9:58 PM EDT | River Flood Warning | PHI | Monroe, Northampton | 17 hr |
| Aug 27, 10:14 PM EDT | Tornado Warning | PHI | Chester, Delaware | 31 min |
| Aug 27, 10:36 PM EDT | Tornado Warning | PHI | Bucks, Montgomery, Philadelphia | 24 min |
| Aug 27, 11:21 PM EDT | Areal Flood Warning | PHI | Carbon, Monroe | 6 hr |
| Aug 27, 11:22 PM EDT | Tornado Warning | PHI | Bucks, Montgomery | 23 min |
| Aug 27, 11:37 PM EDT | Flash Flood Warning | PHI | Bucks, Chester, Delaware, Montgomery, Philadelphia | 12 hr |
| Aug 28, 3:50 AM EDT | Flash Flood Warning | PHI | Berks, Bucks, Chester, Lehigh, Montgomery, Northampton | 10 hr |
| Aug 28, 5:17 AM EDT | Flash Flood Warning | PHI | Carbon, Monroe | 10 hr |
| Aug 28, 11:07 AM EDT | Areal Flood Warning | PHI | Bucks, Chester, Delaware, Montgomery, Philadelphia | 18 hr |
| Aug 28, 1:27 PM EDT | Areal Flood Warning | PHI | Berks, Bucks, Lehigh, Montgomery, Northampton | 8 hr |
| Aug 28, 3:23 PM EDT | Areal Flood Warning | PHI | Carbon, Monroe | 8 hr |
| Aug 28, 6:47 PM EDT | River Flood Warning | PHI | Lehigh | 2 hr |
Nearby
Tornado Warnings in Pennsylvania, 2011Every tornado warning in 2011Tornadoes 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.