Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2012
Severe Thunderstorm Warning 219, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 18, 2012, 2:23 PM EDT for Chester County, Montgomery County, Pennsylvania. It was in force for 30 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
- Sep 18, 2012, 2:23 PM EDT (18:23 UTC)
- Expired
- Sep 18, 2012, 2:53 PM EDT
- In force
- 30 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties Chester County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 103 km from the middle of the area, began a volume at 18:24 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 |
|---|---|---|---|
| Sep 18, 12:10 PM EDT | Tornado Watch | SPC | 9 hr |
The nearest sounding before it
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 6.4 hours before the alert went out and 95 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
- 330 J/kg
- Mixed-layer CIN
- -6 J/kg
- Mixed-layer LCL
- 519 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 265 m²/s²
- 0-3 km storm-relative helicity
- 275 m²/s²
- Significant tornado parameter
- 0.4
- Supercell composite
- 2.3
The text
As transmitted, in the capitals the NWS used until 2016.
672
WUUS51 KPHI 181823
SVRPHI
PAC029-091-181915-
/O.NEW.KPHI.SV.W.0219.120918T1823Z-120918T1915Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
223 PM EDT TUE SEP 18 2012
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
NORTHEASTERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
WESTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
* UNTIL 315 PM EDT
* AT 220 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
OF 60 MPH. THIS STORM WAS LOCATED NEAR CHESTER SPRINGS...OR 8
MILES NORTH OF WEST CHESTER...AND MOVING NORTHEAST AT 50 MPH.
* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
PUGHTOWN...PHOENIXVILLE...CEDARVILLE...ROYERSFORD...POTTSTOWN...
COLLEGEVILLE...TRAPPE...GILBERTSVILLE...SCHWENKSVILLE...SPRING
MOUNT...LANSDALE...GREEN LANE...HATFIELD...SOUDERTON AND EAST
GREENVILLE
PRECAUTIONARY/PREPAREDNESS ACTIONS...
DOPPLER RADAR HAS INDICATED SOME ROTATION WITHIN THIS STORM. WHILE
NOT IMMEDIATELY LIKELY...A TORNADO MAY STILL DEVELOP. IF A TORNADO IS
SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A STURDY
STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.
THIS STORM MAY CONTAIN LITTLE OR NO LIGHTNING. DO NOT WAIT TO
HEAR THUNDER BEFORE TAKING COVER. SEEK SHELTER IMMEDIATELY INSIDE A
STURDY STRUCTURE AND STAY 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.
A TORNADO WATCH REMAINS IN EFFECT UNTIL 700 PM EDT TUESDAY EVENING
FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND EASTERN
PENNSYLVANIA.
&&
LAT...LON 4023 7569 4044 7553 4027 7523 4005 7560
4010 7570
TIME...MOT...LOC 1823Z 212DEG 45KT 4011 7560
$$
GORSE2 follow-up statements
606
WWUS51 KPHI 181836
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
236 PM EDT TUE SEP 18 2012
PAC029-181845-
/O.CAN.KPHI.SV.W.0219.000000T0000Z-120918T1915Z/
CHESTER PA-
236 PM EDT TUE SEP 18 2012
...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CHESTER COUNTY IS
CANCELLED...
THE STORM HAS EXITED THE AREA, THEREFORE THE WARNING HAS BEEN
CANCELLED.
PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.
A TORNADO WATCH REMAINS IN EFFECT UNTIL 700 PM EDT TUESDAY EVENING
FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND EASTERN
PENNSYLVANIA.
LAT...LON 4044 7553 4027 7524 4016 7548 4020 7556
4021 7556 4020 7557 4021 7559
TIME...MOT...LOC 1835Z 212DEG 45KT 4023 7550
$$
PAC091-181915-
/O.CON.KPHI.SV.W.0219.000000T0000Z-120918T1915Z/
MONTGOMERY PA-
236 PM EDT TUE SEP 18 2012
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 315 PM EDT
FOR CENTRAL MONTGOMERY COUNTY...
AT 233 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH. THIS STORM WAS LOCATED NEAR TRAPPE...OR 18 MILES
NORTH OF WEST CHESTER...MOVING NORTHEAST AT 50 MPH.
OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
SKIPPACK...SCHWENKSVILLE...SPRING MOUNT...KULPSVILLE...
HARLEYSVILLE...GREEN LANE...HATFIELD...RED HILL...SOUDERTON...
PENNSBURG AND EAST GREENVILLE
PRECAUTIONARY/PREPAREDNESS ACTIONS...
DOPPLER RADAR HAS INDICATED SOME WEAK ROTATION WITHIN THIS STORM.
WHILE NOT IMMEDIATELY LIKELY...A TORNADO MAY STILL DEVELOP. IF A
TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A
STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.
THIS STORM 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.
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 700 PM EDT TUESDAY EVENING
FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND EASTERN
PENNSYLVANIA.
&&
LAT...LON 4044 7553 4027 7524 4016 7548 4020 7556
4021 7556 4020 7557 4021 7559
TIME...MOT...LOC 1835Z 212DEG 45KT 4023 7550
$$
GORSE259
WWUS51 KPHI 181853
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
253 PM EDT TUE SEP 18 2012
PAC091-181903-
/O.CAN.KPHI.SV.W.0219.000000T0000Z-120918T1915Z/
MONTGOMERY PA-
253 PM EDT TUE SEP 18 2012
...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL MONTGOMERY COUNTY IS
CANCELLED...
THE CELL THAT PROMPTED THE WARNING HAS MOVED OUT OF THE AREA,
THEREFORE THE WARNING HAS BEEN CANCELLED.
PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.
A TORNADO WATCH REMAINS IN EFFECT UNTIL 700 PM EDT TUESDAY EVENING
FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND EASTERN
PENNSYLVANIA.
LAT...LON 4044 7553 4027 7524 4016 7548 4020 7556
4021 7556 4020 7557 4021 7559
TIME...MOT...LOC 1853Z 212DEG 45KT 4042 7534
$$
GORSEThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 18, 4:13 AM EDT | Coastal Flood Advisory | PHI | Delaware, Philadelphia | 21 hr |
| Sep 18, 12:58 PM EDT | Areal Flood Advisory | PHI | Carbon, Monroe | 93 min |
| Sep 18, 12:59 PM EDT | Special Weather Statement | PHI | Berks, Lehigh | 46 min |
| Sep 18, 1:05 PM EDT | Areal Flood Advisory | PHI | Berks, Lehigh | 115 min |
| Sep 18, 1:32 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Lehigh | 43 min |
| Sep 18, 2:00 PM EDT | Special Weather Statement | PHI | Chester, Montgomery | 60 min |
| Sep 18, 2:18 PM EDT | Special Weather Statement | PHI | Carbon, Monroe | 57 min |
| Sep 18, 2:25 PM EDT | Flash Flood Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 4 hr |
| Sep 18, 2:52 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Lehigh, Northampton | 17 min |
| Sep 18, 3:07 PM EDT | Areal Flood Warning | PHI | Berks, Lehigh | 8 hr |
| Sep 18, 3:16 PM EDT | Special Weather Statement | PHI | Monroe | 59 min |
| Sep 18, 3:24 PM EDT | Special Weather Statement | PHI | Berks, Carbon | 51 min |
| Sep 18, 3:52 PM EDT | Special Weather Statement | PHI | Chester | 53 min |
| Sep 18, 4:05 PM EDT | Areal Flood Advisory | PHI | Berks, Lehigh | 55 min |
| Sep 18, 4:19 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester, Delaware, Montgomery | 56 min |
| Sep 18, 4:23 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Lehigh, Monroe, Northampton | 52 min |
| Sep 18, 4:26 PM EDT | Areal Flood Advisory | PHI | Bucks, Lehigh, Northampton | 3 hr |
| Sep 18, 4:35 PM EDT | Areal Flood Advisory | PHI | Bucks, Chester, Lehigh, Montgomery | 55 min |
| Sep 18, 5:01 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Chester, Delaware, Lehigh, Montgomery, Northampton and 1 more | 59 min |
| Sep 18, 5:12 PM EDT | Areal Flood Advisory | PHI | Bucks, Chester, Delaware, Montgomery | 63 min |
| Sep 18, 5:12 PM EDT | Severe Thunderstorm Warning | PHI | Delaware, Philadelphia | 78 min |
| Sep 18, 5:13 PM EDT | Severe Thunderstorm Warning | PHI | Monroe, Northampton | 62 min |
| Sep 18, 6:00 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Montgomery, Philadelphia | 60 min |
| Sep 18, 6:06 PM EDT | Areal Flood Advisory | PHI | Bucks, Montgomery, Philadelphia | 54 min |
| Sep 18, 6:19 PM EDT | Areal Flood Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 16 hr |
| Sep 18, 6:54 PM EDT | Areal Flood Advisory | PHI | Bucks | 111 min |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2012Every severe thunderstorm warning in 2012
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.