Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2006
Severe Thunderstorm Warning 261, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 29, 2006, 2:53 PM EDT for Chester County, Montgomery County, Pennsylvania. It was in force for 52 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 29, 2006, 2:53 PM EDT (18:53 UTC)
- Expired
- Aug 29, 2006, 3:45 PM EDT
- In force
- 52 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Counties, with a storm outline in the text
Counties Chester County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 108 km from the middle of the area, began a volume at 18:56 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 29, 3:15 PM EDT | TSTM WND DMG | Pottsgrove, PA | WIRES REPORTED DOWN IN LOWER POTTSGROVE. |
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 29, 1:52 PM EDT | Tornado Watch | SPC | 6 hr |
The nearest sounding before it
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 6.9 hours before the alert went out and 90 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
- 21 J/kg
- Mixed-layer CIN
- -132 J/kg
- Mixed-layer LCL
- 934 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 98 m²/s²
- 0-3 km storm-relative helicity
- 185 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
000
WUUS51 KPHI 291854
SVRPHI
PAC029-091-291945-
/O.NEW.KPHI.SV.W.0261.060829T1853Z-060829T1945Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
253 PM EDT TUE AUG 29 2006
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
NORTH CENTRAL CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA
WEST CENTRAL MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA
* UNTIL 345 PM EDT
* AT 252 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED 10
MILES WEST OF POTTSTOWN...AND MOVING SOUTHEAST AT 20 MPH. DOPPLER
RADAR WAS INDICATING 60 TO 70 MPH OF WIND WITH THIS THUNDERSTORM
ALOFT.
* THE SEVERE THUNDERSTORM WILL BE NEAR...
POTTSTOWN BY 320 PM EDT...
PHOENIXVILLE BY 345 PM EDT...
A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. 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.
TORRENTIAL DOWNPOURS WILL ALSO ACCOMPANY THIS STORM AND POOR DRAINAGE
FLOODING WILL OCCUR.
LAT...LON 4028 7554 4023 7551 4017 7551 3999 7555
4009 7575 4017 7580 4018 7580 4025 7569
4029 7567
$$
TFG1 follow-up statement
000
WWUS51 KPHI 291904
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
303 PM EDT TUE AUG 29 2006
PAC029-091-291945-
/O.CON.KPHI.SV.W.0261.000000T0000Z-060829T1945Z/
CHESTER PA-MONTGOMERY PA-
303 PM EDT TUE AUG 29 2006
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM EDT
FOR WEST CENTRAL MONTGOMERY AND NOW INCLUDES ALL OF CHESTER COUNTY...
AT 300 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS
LOCATED NEAR KENILWORTH...AND MOVING SOUTHEAST AT 20 MPH.
A SECOND SEVERE STORM HAS FORMED JUST NORTHWEST OF OXFORD AND SHOWS
SOME ROTATION WITH IT ALOFT. THIS STORM WILL MOVE EAST AND PASS NEAR
WEST GROVE ABOUT 330 PM.
THE NORTHERN SEVERE THUNDERSTORM WILL BE NEAR...
KENILWORTH...SOUTH POTTSTOWN...POTTSTOWN AND STOWE BY 345 PM EDT...
A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. IF A TORNADO
IS SPOTTED... ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A STURDY
STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.
DOPPLER RADAR HAS INDICATED SOME WEAK ROTATION WITHIN THE OXFORD
STORM. WHILE NOT IMMEDIATELY LIKELY...A TORNADO MAY STILL DEVELOP. IF A
TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A
STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.
A TORNADO WATCH REMAINS IN EFFECT UNTIL 800 PM EDT TUESDAY EVENING
FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN NEW
JERSEY AND EASTERN PENNSYLVANIA.
LAT...LON 4027 7554 4022 7551 4016 7551 3998 7555
3975 7578 3974 7607 4016 7580 4017 7580
4024 7569 4028 7567
$$
TFGThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 29, 2:14 PM EDT | Severe Thunderstorm Warning | PHI | Berks | 61 min |
| Aug 29, 2:42 PM EDT | Flash Flood Warning | PHI | Berks | 3 hr |
| Aug 29, 3:37 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware, Montgomery, Philadelphia | 68 min |
| Aug 29, 3:39 PM EDT | Flash Flood Warning | PHI | Chester | 3 hr |
| Aug 29, 3:50 PM EDT | Flash Flood Warning | PHI | Montgomery | 3 hr |
| Aug 29, 4:15 PM EDT | Flash Flood Warning | PHI | Philadelphia | 3 hr |
| Aug 29, 5:43 PM EDT | Flash Flood Warning | PHI | Berks | 2 hr |
Nearby
Severe Thunderstorm Warnings in Pennsylvania, 2006Every severe thunderstorm warning in 2006
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.