Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2012
Severe Thunderstorm Warning 102, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 18, 2012, 3:51 PM EDT for Berks County, Chester County, Montgomery County, Pennsylvania. It was in force for 28 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
- Jul 18, 2012, 3:51 PM EDT (19:51 UTC)
- Expired
- Jul 18, 2012, 4:19 PM EDT
- In force
- 28 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties Berks County, PA, Chester County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 107 km from the middle of the area, began a volume at 19:52 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 |
|---|---|---|---|
| Jul 18, 3:57 PM EDT | TSTM WND DMG | Douglass Twp, PA | TREE DOWN ON ROUTE 36 AND EDGE HILL ROAD |
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 |
|---|---|---|---|
| Jul 18, 12:41 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
The nearest sounding before it
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 7.9 hours before the alert went out and 104 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
- 884 J/kg
- Mixed-layer CIN
- -169 J/kg
- Mixed-layer LCL
- 1666 m above ground
- 0-6 km bulk shear
- 9 kt
- 0-1 km storm-relative helicity
- 4 m²/s²
- 0-3 km storm-relative helicity
- 10 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
808 WUUS51 KPHI 181951 SVRPHI PAC011-029-091-182030- /O.NEW.KPHI.SV.W.0102.120718T1951Z-120718T2030Z/ BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 351 PM EDT WED JUL 18 2012 THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... EAST CENTRAL BERKS COUNTY IN EASTERN PENNSYLVANIA... NORTH CENTRAL CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA... WESTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA... * UNTIL 430 PM EDT * AT 348 PM 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 6 MILES WEST OF BECHTELSVILLE TO 10 MILES NORTHWEST OF CEDARVILLE...OR ALONG A LINE EXTENDING FROM 11 MILES EAST OF READING TO 6 MILES EAST OF READING...AND MOVING SOUTHEAST AT 10 MPH. * SEVERE THUNDERSTORMS WILL BE NEAR... BECHTELSVILLE AROUND 410 PM EDT... 6 MILES SOUTHWEST OF BALLY AROUND 415 PM EDT... GILBERTSVILLE AROUND 425 PM EDT... POTTSTOWN...CEDARVILLE...7 MILES WEST OF SPRING MOUNT AND 7 MILES WEST OF GREEN LANE AROUND 430 PM EDT... PRECAUTIONARY/PREPAREDNESS ACTIONS... THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE IMMEDIATELY FOR DAMAGING WINDS...LARGE HAIL...AND DEADLY CLOUD TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER... PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS. IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS IMMEDIATELY! REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY LIGHTNING. && LAT...LON 4033 7536 4017 7557 4029 7586 4045 7573 TIME...MOT...LOC 1951Z 303DEG 10KT 4036 7573 4030 7581 $$ DRAG
2 follow-up statements
291 WWUS51 KPHI 182008 SVSPHI SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 408 PM EDT WED JUL 18 2012 PAC029-182018- /O.CAN.KPHI.SV.W.0102.000000T0000Z-120718T2030Z/ CHESTER PA- 408 PM EDT WED JUL 18 2012 ...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL CHESTER COUNTY IS CANCELLED... A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT WEDNESDAY EVENING FOR NORTHEAST NEW JERSEY. A SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 900 PM EDT WEDNESDAY EVENING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND EASTERN PENNSYLVANIA. LAT...LON 4035 7542 4024 7562 4033 7577 4043 7568 TIME...MOT...LOC 2008Z 266DEG 16KT 4036 7565 4033 7571 $$ PAC011-091-182030- /O.CON.KPHI.SV.W.0102.000000T0000Z-120718T2030Z/ BERKS PA-MONTGOMERY PA- 408 PM EDT WED JUL 18 2012 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT FOR NORTHWESTERN MONTGOMERY AND EAST CENTRAL BERKS COUNTIES... AT 405 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING POTENTIALLY DAMAGING WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM BECHTELSVILLE TO BOYERTOWN...OR ALONG A LINE EXTENDING FROM 14 MILES EAST OF READING TO 11 MILES EAST OF READING...MOVING EAST AT 20 MPH. THE STORMS WERE WEAKENING. SEVERE THUNDERSTORMS WILL BE NEAR... BALLY...POTTSTOWN...HALFWAY HOUSE AND BOYERTOWN BY 420 PM EDT... POTTSGROVE AND GILBERTSVILLE BY 425 PM EDT... 6 MILES WEST OF GREEN LANE BY 430 PM EDT... PRECAUTIONARY/PREPAREDNESS ACTIONS... A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT WEDNESDAY EVENING FOR NORTHEAST NEW JERSEY. A SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 900 PM EDT WEDNESDAY EVENING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND EASTERN PENNSYLVANIA. && LAT...LON 4035 7542 4024 7562 4033 7577 4043 7568 TIME...MOT...LOC 2008Z 266DEG 16KT 4036 7565 4033 7571 $$ DRAG
453 WWUS51 KPHI 182019 SVSPHI SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 419 PM EDT WED JUL 18 2012 PAC011-091-182028- /O.CAN.KPHI.SV.W.0102.000000T0000Z-120718T2030Z/ BERKS PA-MONTGOMERY PA- 419 PM EDT WED JUL 18 2012 ...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN MONTGOMERY AND EAST CENTRAL BERKS COUNTIES IS CANCELLED... A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT WEDNESDAY EVENING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND EASTERN PENNSYLVANIA. LAT...LON 4035 7542 4024 7562 4033 7577 4043 7568 TIME...MOT...LOC 2018Z 266DEG 16KT 4036 7559 4033 7565 $$ DRAG
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 18, 1:27 PM EDT | Special Weather Statement | PHI | Monroe | 33 min |
| Jul 18, 1:53 PM EDT | Special Weather Statement | PHI | Bucks | 37 min |
| Jul 18, 2:07 PM EDT | Special Weather Statement | PHI | Berks | 38 min |
| Jul 18, 2:12 PM EDT | Severe Thunderstorm Warning | PHI | Berks | 48 min |
| Jul 18, 2:15 PM EDT | Special Weather Statement | PHI | Monroe | 60 min |
| Jul 18, 2:23 PM EDT | Special Weather Statement | PHI | Northampton | 67 min |
| Jul 18, 2:43 PM EDT | Special Weather Statement | PHI | Berks, Lehigh | 47 min |
| Jul 18, 3:04 PM EDT | Special Weather Statement | PHI | Berks, Lehigh, Northampton | 41 min |
| Jul 18, 3:13 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Bucks, Lehigh, Northampton | 47 min |
| Jul 18, 3:26 PM EDT | Severe Thunderstorm Warning | PHI | Northampton | 49 min |
| Jul 18, 3:36 PM EDT | Special Weather Statement | PHI | Berks | 54 min |
| Jul 18, 3:43 PM EDT | Special Weather Statement | PHI | Carbon | 47 min |
| Jul 18, 3:52 PM EDT | Flash Flood Warning | PHI | Monroe, Northampton | 113 min |
| Jul 18, 4:22 PM EDT | Special Weather Statement | PHI | Bucks | 23 min |
| Jul 18, 4:28 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 32 min |
| Jul 18, 5:30 PM EDT | Special Weather Statement | PHI | Bucks | 60 min |
| Jul 18, 5:51 PM EDT | Special Weather Statement | PHI | Philadelphia | 54 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.