Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2011
Severe Thunderstorm Warning 271, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 19, 2011, 4:52 PM EDT for 5 counties in Pennsylvania. It was in force for 53 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
- Aug 19, 2011, 4:52 PM EDT (20:52 UTC)
- Expired
- Aug 19, 2011, 5:45 PM EDT
- In force
- 53 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties Berks County, PA, Bucks County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA
The radar
The Philadelphia radar (KDIX), 104 km from the middle of the area, began a volume at 20:53 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 |
|---|---|---|---|
| Aug 19, 5:21 PM EDT | HAIL 0.5 | Macungie, PA |
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 |
|---|---|---|---|
| Aug 19, 1:04 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
The nearest sounding before it
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 8.9 hours before the alert went out and 137 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
- 146 J/kg
- Mixed-layer CIN
- -154 J/kg
- Mixed-layer LCL
- 1250 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 359 m²/s²
- 0-3 km storm-relative helicity
- 370 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
967
WUUS51 KPHI 192052
SVRPHI
PAC011-017-077-091-095-192145-
/O.NEW.KPHI.SV.W.0271.110819T2052Z-110819T2145Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
452 PM EDT FRI AUG 19 2011
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
EAST CENTRAL BERKS COUNTY IN EASTERN PENNSYLVANIA...
SOUTHEASTERN LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
THIS INCLUDES THE CITY OF ALLENTOWN...
SOUTH CENTRAL NORTHAMPTON COUNTY IN EASTERN PENNSYLVANIA...
THIS INCLUDES THE CITY OF EASTON...
NORTHWESTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
NORTHWESTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
* UNTIL 545 PM EDT
* AT 449 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM CLAUSSVILLE TO TOPTON...OR
ALONG A LINE EXTENDING FROM 9 MILES WEST OF ALLENTOWN TO 13 MILES
NORTHEAST OF READING...AND MOVING EAST AT 10 MPH.
* SEVERE THUNDERSTORMS WILL BE NEAR...
BECHTELSVILLE AND ANCIENT OAKS AROUND 515 PM EDT...
BECHTELSVILLE AROUND 520 PM EDT...
GILBERTSVILLE AROUND 525 PM EDT...
ALLENTOWN AND BALLY AROUND 530 PM EDT...
ALLENTOWN AND EMMAUS AROUND 535 PM EDT...
ZIONSVILLE AROUND 540 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.
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 SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT FRIDAY
EVENING FOR NORTHERN DELAWARE AND NEW JERSEY AND EASTERN
PENNSYLVANIA.
&&
LAT...LON 4065 7520 4065 7521 4063 7520 4045 7517
4026 7530 4035 7579 4061 7565 4060 7554
4070 7521
TIME...MOT...LOC 2052Z 271DEG 10KT 4058 7563 4043 7572
$$
TFG1 follow-up statement
348
WWUS51 KPHI 192137
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
537 PM EDT FRI AUG 19 2011
PAC011-095-192147-
/O.CAN.KPHI.SV.W.0271.000000T0000Z-110819T2145Z/
BERKS PA-NORTHAMPTON PA-
537 PM EDT FRI AUG 19 2011
...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL NORTHAMPTON AND
EAST CENTRAL BERKS COUNTIES IS CANCELLED...
THE SEVERE THUNDERSTORM IS SOUTHEAST OF THE REGION.
PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT FRIDAY
EVENING FOR NORTHERN DELAWARE AND NEW JERSEY AND EASTERN
PENNSYLVANIA.
LAT...LON 4053 7528 4046 7528 4028 7540 4032 7561
4049 7550 4056 7538 4054 7535 4057 7529
TIME...MOT...LOC 2137Z 313DEG 13KT 4049 7547 4034 7556
$$
PAC017-077-091-192145-
/O.CON.KPHI.SV.W.0271.000000T0000Z-110819T2145Z/
MONTGOMERY PA-LEHIGH PA-BUCKS PA-
537 PM EDT FRI AUG 19 2011
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 PM EDT
FOR NORTHWESTERN BUCKS...SOUTHEASTERN LEHIGH AND NORTHWESTERN
MONTGOMERY COUNTIES...
AT 536 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER
SIZE HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THESE STORMS
WERE LOCATED ALONG A LINE EXTENDING FROM ZIONSVILLE TO RED HILL...OR
ALONG A LINE EXTENDING FROM 7 MILES SOUTH OF ALLENTOWN TO 17 MILES
SOUTH OF ALLENTOWN...MOVING SOUTHEAST AT 15 MPH.
SEVERE THUNDERSTORMS WILL BE NEAR...
RED HILL...GREEN LANE...COOPERSBURG AND TRUMBAUERSVILLE BY 545 PM
EDT...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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 SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT FRIDAY
EVENING FOR NORTHERN DELAWARE AND NEW JERSEY AND EASTERN
PENNSYLVANIA.
&&
LAT...LON 4053 7528 4046 7528 4028 7540 4032 7561
4049 7550 4056 7538 4054 7535 4057 7529
TIME...MOT...LOC 2137Z 313DEG 13KT 4049 7547 4034 7556
$$
TFGThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 18, 8:08 PM EDT | Special Weather Statement | PHI | Berks | 67 min |
| Aug 18, 8:26 PM EDT | Areal Flood Advisory | PHI | Bucks, Chester, Delaware, Montgomery, Philadelphia | 112 min |
| Aug 18, 8:31 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Montgomery | 59 min |
| Aug 18, 8:48 PM EDT | Special Weather Statement | PHI | Monroe | 57 min |
| Aug 18, 8:48 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 57 min |
| Aug 19, 12:02 AM EDT | Special Weather Statement | PHI | Chester | 58 min |
| Aug 19, 12:50 AM EDT | Special Weather Statement | PHI | Chester, Delaware | 40 min |
| Aug 19, 1:14 AM EDT | Areal Flood Advisory | PHI | Bucks, Chester, Delaware, Montgomery, Philadelphia | 3 hr |
| Aug 19, 1:31 AM EDT | Special Weather Statement | PHI | Delaware, Philadelphia | 59 min |
| Aug 19, 4:00 AM EDT | Areal Flood Warning | PHI | Delaware | 4 hr |
| Aug 19, 1:46 PM EDT | Severe Thunderstorm Warning | PHI | Monroe | 59 min |
| Aug 19, 2:35 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Monroe | 70 min |
| Aug 19, 2:38 PM EDT | Areal Flood Advisory | PHI | Carbon, Monroe | 3 hr |
| Aug 19, 2:57 PM EDT | Flash Flood Warning | PHI | Carbon, Monroe | 3 hr |
| Aug 19, 3:47 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Monroe | 58 min |
| Aug 19, 4:29 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 61 min |
| Aug 19, 4:32 PM EDT | Areal Flood Advisory | PHI | Berks, Lehigh, Northampton | 2 hr |
| Aug 19, 5:35 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 55 min |
| Aug 19, 5:39 PM EDT | Areal Flood Advisory | PHI | Chester, Delaware | 3 hr |
| Aug 19, 5:42 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Montgomery | 48 min |
| Aug 19, 5:45 PM EDT | Areal Flood Advisory | PHI | Bucks, Montgomery, Philadelphia | 3 hr |
| Aug 19, 5:59 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 80 min |
| Aug 19, 6:14 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Chester, Delaware, Montgomery, Philadelphia | 65 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.