Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2011
Severe Thunderstorm Warning 10, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 5, 2011, 5:23 AM EDT for 7 counties in Pennsylvania. It was in force for 67 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
- Apr 5, 2011, 5:23 AM EDT (09:23 UTC)
- Expired
- Apr 5, 2011, 6:30 AM EDT
- In force
- 67 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties Berks County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA
The radar
The Philadelphia radar (KDIX), 109 km from the middle of the area, began a volume at 09:26 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 |
|---|---|---|---|
| Apr 5, 5:07 AM EDT | Severe Thunderstorm Watch | SPC | 2 hr |
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 00:00Z, 9.4 hours before the alert went out and 224 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 4112 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km storm-relative helicity
- 284 m²/s²
- 0-3 km storm-relative helicity
- 328 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
735
WUUS51 KPHI 050923
SVRPHI
PAC011-017-029-045-077-091-095-051030-
/O.NEW.KPHI.SV.W.0010.110405T0923Z-110405T1030Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
523 AM EDT TUE APR 5 2011
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
BERKS COUNTY IN EASTERN PENNSYLVANIA...
THIS INCLUDES THE CITY OF READING...
LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
THIS INCLUDES THE CITY OF ALLENTOWN...
SOUTH CENTRAL NORTHAMPTON COUNTY IN EASTERN PENNSYLVANIA...
BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
NORTHERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
EXTREME NORTH CENTRAL DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
* UNTIL 630 AM EDT
* AT 521 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
FROM TOPTON TO LAURELDALE TO NEW MORGAN TO 7 MILES SOUTHWEST OF NEW
MORGAN...OR ALONG A LINE EXTENDING FROM 13 MILES WEST OF ALLENTOWN
TO 6 MILES NORTHEAST OF READING TO 9 MILES SOUTH OF READING TO 14
MILES SOUTH OF READING...AND MOVING EAST AT 35 MPH.
* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
LYONS...CLAUSSVILLE...BIRDSBORO...SCHNECKSVILLE...ELVERSON...
NEFFS...COFFEETOWN...GLENMOORE...ANCIENT OAKS...NORTHAMPTON...
BECHTELSVILLE...PUGHTOWN...BALLY...CHESTER SPRINGS...EMMAUS...
CEDARVILLE...GILBERTSVILLE...POTTSTOWN...ZIONSVILLE...BETHLEHEM...
EAST GREENVILLE...PHOENIXVILLE...ROYERSFORD...GERYVILLE...VALLEY
FORGE...TRAPPE...HELLERTOWN...COLLEGEVILLE...GREEN LANE...KING OF
PRUSSIA...SCHWENKSVILLE...SPRING MOUNT...NORRISTOWN...SPRINGTOWN...
CONSHOHOCKEN...PLEASANT VALLEY...QUAKERTOWN...PLYMOUTH MEETING...
SOUDERTON...LANSDALE...HATFIELD...AMBLER...PERKASIE...FRICKS...
REVERE...CHALFONT...PIPERSVILLE...OTTSVILLE...GARDENVILLE...
BEDMINSTER...TINICUM TOWNSHIP...ROBESONIA...DUBLIN AND DOYLESTOWN
PRECAUTIONARY/PREPAREDNESS ACTIONS...
THIS SEVERE THUNDERSTORM MAY CONTAIN LITTLE OR NO LIGHTNING. DO NOT
WAIT FOR THUNDER BEFORE TAKING COVER. SEEK SHELTER IMMEDIATELY INSIDE
A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS.
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 AM EDT
TUESDAY MORNING FOR NORTHEAST MARYLAND AND NEW JERSEY AND EASTERN
PENNSYLVANIA.
&&
LAT...LON 4068 7589 4071 7532 4054 7521 4051 7513
4038 7503 4031 7493 4003 7535 4011 7594
4014 7590 4026 7607 4029 7610
TIME...MOT...LOC 0922Z 248DEG 33KT 4056 7571 4039 7583
4020 7594 4013 7598
$$
HAYES3 follow-up statements
488
WWUS51 KPHI 050943
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
543 AM EDT TUE APR 5 2011
PAC011-017-029-045-077-091-095-051030-
/O.CON.KPHI.SV.W.0010.000000T0000Z-110405T1030Z/
DELAWARE PA-CHESTER PA-MONTGOMERY PA-BERKS PA-LEHIGH PA-
NORTHAMPTON PA-BUCKS PA-
543 AM EDT TUE APR 5 2011
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 AM EDT
FOR BUCKS...SOUTH CENTRAL NORTHAMPTON...LEHIGH...BERKS...
MONTGOMERY...NORTHERN CHESTER AND EXTREME NORTH CENTRAL DELAWARE
COUNTIES...
AT 538 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE
EXTENDING FROM CLAUSSVILLE TO 13 MILES SOUTHEAST OF READING...MOVING
EAST AT 40 MPH.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 AM EDT
TUESDAY MORNING FOR NORTHEAST MARYLAND AND NEW JERSEY AND EASTERN
PENNSYLVANIA.
&&
LAT...LON 4068 7589 4071 7532 4054 7521 4051 7513
4038 7503 4031 7493 4003 7535 4011 7594
4014 7590 4026 7607 4029 7610
TIME...MOT...LOC 0943Z 248DEG 33KT 4060 7563 4045 7559
4026 7570 4019 7574
$$
HAYES887
WWUS51 KPHI 051003
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
603 AM EDT TUE APR 5 2011
PAC011-017-029-045-077-091-095-051030-
/O.CON.KPHI.SV.W.0010.000000T0000Z-110405T1030Z/
DELAWARE PA-CHESTER PA-MONTGOMERY PA-BERKS PA-LEHIGH PA-
NORTHAMPTON PA-BUCKS PA-
603 AM EDT TUE APR 5 2011
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 AM EDT
FOR BUCKS...SOUTH CENTRAL NORTHAMPTON...EASTERN LEHIGH...EAST CENTRAL
BERKS...MONTGOMERY...NORTHEASTERN CHESTER AND EXTREME NORTH CENTRAL
DELAWARE COUNTIES...
AT 600 AM EDT...A LINE OF SEVERE THUNDERSTORMS WAS REPORTED CAPABLE
OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM CATASAUQUA TO COOPERSBURG TO
GREEN LANE TO SANATOGA...OR ALONG A LINE EXTENDING FROM ALLENTOWN TO
8 MILES SOUTHEAST OF ALLENTOWN TO 19 MILES SOUTH OF ALLENTOWN TO 20
MILES NORTH OF WEST CHESTER...MOVING EAST AT 40 MPH.
OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
COLLEGEVILLE...AUDUBON...HELLERTOWN...SPRING MOUNT...EVANSBURG...
TRUMBAUERSVILLE...FREEMANSBURG...KING OF PRUSSIA...SCHWENKSVILLE...
EAGLEVILLE...TROOPER...WEST NORRITON...PLEASANT VALLEY...
RICHLANDTOWN...QUAKERTOWN...SPRINGTOWN...BRIDGEPORT...SKIPPACK...WEST
CONSHOHOCKEN...NORRISTOWN...CONSHOHOCKEN...EAST NORRITON...
HARLEYSVILLE...PLYMOUTH MEETING...KULPSVILLE...BLUE BELL...
SELLERSVILLE...TELFORD...PERKASIE...NORTH WALES...SOUDERTON...
LANSDALE...HATFIELD...AMBLER...SPRING HOUSE...SILVERDALE...FORT
WASHINGTON...REVERE...MONTGOMERYVILLE...MAPLE GLEN...FRICKS...
OTTSVILLE...BRITTANY FARMS-HIGHLANDS...BEDMINSTER...CHALFONT...
DUBLIN...HORSHAM...PIPERSVILLE...GARDENVILLE...TINICUM TOWNSHIP...
ROBESONIA...NEW BRITAIN AND DOYLESTOWN
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 1000 AM EDT
TUESDAY MORNING FOR NORTHEAST MARYLAND AND NEW JERSEY AND EASTERN
PENNSYLVANIA.
&&
LAT...LON 4008 7573 4015 7565 4020 7568 4028 7568
4070 7554 4071 7532 4054 7521 4051 7513
4038 7503 4031 7493 4003 7535
TIME...MOT...LOC 1003Z 248DEG 33KT 4066 7540 4051 7536
4032 7547 4025 7551
$$
HAYES277
WWUS51 KPHI 051025
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
625 AM EDT TUE APR 5 2011
PAC011-017-029-045-077-091-095-051035-
/O.EXP.KPHI.SV.W.0010.000000T0000Z-110405T1030Z/
DELAWARE PA-CHESTER PA-MONTGOMERY PA-BERKS PA-LEHIGH PA-
NORTHAMPTON PA-BUCKS PA-
625 AM EDT TUE APR 5 2011
...THE SEVERE THUNDERSTORM WARNING FOR BUCKS...SOUTH CENTRAL
NORTHAMPTON...EASTERN LEHIGH...EAST CENTRAL BERKS...MONTGOMERY...
NORTHEASTERN CHESTER AND EXTREME NORTH CENTRAL DELAWARE COUNTIES WILL
EXPIRE AT 630 AM EDT...
THE LINE OF STORMS THAT PROMPTED THE WARNING ARE WEAKENING AND
MOVING OUT OF THE AREA.
A SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 1000 AM EDT
TUESDAY MORNING FOR NORTHEAST MARYLAND AND NEW JERSEY AND EASTERN
PENNSYLVANIA.
LAT...LON 4008 7573 4015 7565 4020 7568 4028 7568
4070 7554 4071 7532 4054 7521 4051 7513
4038 7503 4031 7493 4003 7535
TIME...MOT...LOC 1025Z 248DEG 33KT 4073 7515 4058 7511
4039 7522 4032 7526
$$
HAYESThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 5, 4:03 AM EDT | Special Weather Statement | PHI | Berks | 57 min |
| Apr 5, 5:01 AM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware | 74 min |
| Apr 5, 5:58 AM EDT | Special Weather Statement | PHI | Monroe, Northampton | 62 min |
| Apr 5, 6:05 AM EDT | Special Weather Statement | PHI | Philadelphia | 55 min |
| Apr 5, 6:30 AM EDT | Special Weather Statement | PHI | Philadelphia | 60 min |
| Apr 5, 8:55 AM EDT | Special Weather Statement | PHI | Bucks, Chester, Delaware, Lehigh, Montgomery, Northampton | 65 min |
| Apr 5, 9:37 AM EDT | Special Weather Statement | PHI | Bucks, Chester, Delaware, Montgomery, Philadelphia | 53 min |
| Apr 5, 10:16 AM EDT | Severe Thunderstorm Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 44 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.