Alert archive / Pennsylvania / Flash Flood Warnings in 2011
Flash Flood Warning 62, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 11, 2011, 9:00 PM EDT for Chester County, Pennsylvania. It was in force for 3 hr. 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 11, 2011, 9:00 PM EDT (01:00 UTC)
- Expired
- Sep 11, 2011, 11:31 PM EDT
- In force
- 3 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
County Chester County, PA
The radar
The Philadelphia radar (KDIX), 129 km from the middle of the area, began a volume at 01:01 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 nearest sounding before it
Washington/Dulle, VA (KIAD), launched 00:00Z, 1.0 hours before the alert went out and 173 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
- 420 J/kg
- Mixed-layer CIN
- -58 J/kg
- Mixed-layer LCL
- 1369 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- 144 m²/s²
- 0-3 km storm-relative helicity
- 126 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
942
WGUS51 KPHI 120100
FFWPHI
PAC029-120500-
/O.NEW.KPHI.FF.W.0062.110912T0100Z-110912T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
900 PM EDT SUN SEP 11 2011
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* FLASH FLOOD WARNING FOR...
WESTERN CHESTER COUNTY...
* UNTIL 100 AM EDT...
* AT 857 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
VERY HEAVY RAIN FROM A THUNDERSTORM MOVING INTO WESTERN CHESTER
COUNTY FROM LANCASTER COUNTY.
* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
COATESVILLE...DOWNINGTOWN...HONEY BROOK...PARKESBURG...COCHRANVILLE
AND GLENMOORE.
ADDITIONAL RAINFALL AMOUNTS OF AN INCH OR TWO ARE POSSIBLE IN THE
WARNED AREA.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
PLEASE REPORT FLOODING...HAIL OR WIND DAMAGE TO THE NATIONAL WEATHER
SERVICE BY CALLING TOLL FREE...1-877-633-6772.
&&
LAT...LON 3993 7600 3996 7600 4003 7595 4011 7595
4014 7590 4014 7588 4010 7564 3985 7579
3991 7602 3992 7601
$$
IOVINO2 follow-up statements
079
WGUS71 KPHI 120221
FFSPHI
FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1021 PM EDT SUN SEP 11 2011
PAC029-120500-
/O.CON.KPHI.FF.W.0062.000000T0000Z-110912T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHESTER PA-
1021 PM EDT SUN SEP 11 2011
...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 100 AM EDT FOR
WESTERN CHESTER COUNTY...
AT 1015 PM EDT...DOPPLER RADAR CONTINUED TO INDICATE SCATTERED
THUNDERSTORMS PRODUCING HEAVY RAIN OVER AND NEAR WESTERN CHESTER
COUNTY. RADAR INDICATED THAT OVER AN INCH OF RAIN HAD ALREADY FALLEN
FROM HONEY BROOK TO DOWNINGTOWN.
LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO HONEY
BROOK...COATESVILLE...GLENMOORE...PARKESBURG AND DOWNINGTOWN.
ADDITIONAL RAINFALL AMOUNTS OF UP TO AN INCH ARE POSSIBLE IN THE
WARNED AREA.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
IF YOU WILL BE DRIVING IN THE AREA, BE PREPARED FOR REDUCED
VISIBILITY DUE TO THE HEAVY RAIN. DO NOT DRIVE YOUR VEHICLE THROUGH
FLOOD WATERS. THE WATER MAY BE DEEPER THAN YOU THINK IT IS. YOU WILL
BE PUTTING YOURSELF IN DANGER AND YOU MAY DAMAGE YOUR VEHICLE.
PLEASE REPORT FLOODING...HAIL OR WIND DAMAGE BY CALLING YOUR LOCAL
LAW ENFORCEMENT OFFICIALS OR BY CALLING THE NATIONAL WEATHER SERVICE
TOLL FREE AT...1-877-633-6772.
&&
LAT...LON 3993 7600 3996 7600 4003 7595 4011 7595
4014 7590 4014 7588 4010 7564 3985 7579
3991 7602 3992 7601
$$
IOVINO085
WGUS71 KPHI 120331
FFSPHI
FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1131 PM EDT SUN SEP 11 2011
PAC029-120340-
/O.CAN.KPHI.FF.W.0062.000000T0000Z-110912T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHESTER PA-
1131 PM EDT SUN SEP 11 2011
...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR WESTERN CHESTER
COUNTY...
THE WATER FROM THIS EVENING'S HEAVY RAINFALL IS RECEDING AND IT NO
LONGER POSES A THREAT TO LIFE OR PROPERTY. THEREFORE...THE FLASH
FLOOD WARNING HAS BEEN CANCELLED.
LAT...LON 3993 7600 3996 7600 4003 7595 4011 7595
4014 7590 4014 7588 4010 7564 3985 7579
3991 7602 3992 7601
$$
IOVINOThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 11, 8:19 PM EDT | Flash Flood Warning | PHI | Berks | 3 hr |
| Sep 11, 8:46 PM EDT | Areal Flood Advisory | PHI | Chester | 3 hr |
| Sep 11, 9:14 PM EDT | Flash Flood Warning | PHI | Berks, Chester, Montgomery | 110 min |
| Sep 11, 9:14 PM EDT | Special Weather Statement | PHI | Berks, Chester, Lehigh, Montgomery | 61 min |
| Sep 11, 9:24 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 51 min |
| Sep 11, 9:34 PM EDT | Special Weather Statement | PHI | Philadelphia | 41 min |
| Sep 11, 9:54 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Montgomery | 51 min |
| Sep 11, 9:56 PM EDT | Flash Flood Warning | PHI | Bucks, Chester, Delaware, Montgomery, Philadelphia | 4 hr |
| Sep 11, 10:25 PM EDT | Special Weather Statement | PHI | Philadelphia | 65 min |
| Sep 11, 10:29 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware | 46 min |
| Sep 11, 10:44 PM EDT | Areal Flood Advisory | PHI | Chester | 107 min |
| Sep 11, 10:52 PM EDT | Special Weather Statement | PHI | Bucks, Delaware, Montgomery, Philadelphia | 83 min |
| Sep 11, 11:10 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Delaware, Philadelphia | 65 min |
| Sep 12, 11:05 AM EDT | Coastal Flood Statement | PHI | Delaware, Philadelphia | 6 hr |
Nearby
Flash Flood Warnings in Pennsylvania, 2011Every flash flood 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.