Alert archive / Pennsylvania / Flash Flood Warnings in 2008
Flash Flood Warning 34, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 9, 2008, 9:30 AM EDT for Chester County, Montgomery 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 9, 2008, 9:30 AM EDT (13:30 UTC)
- Expired
- Sep 9, 2008, 12:29 PM EDT
- In force
- 3 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Chester County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 109 km from the middle of the area, began a volume at 13:31 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
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 1.5 hours before the alert went out and 66 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
- 1988 J/kg
- Mixed-layer CIN
- -21 J/kg
- Mixed-layer LCL
- 557 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 118 m²/s²
- 0-3 km storm-relative helicity
- 109 m²/s²
- Significant tornado parameter
- 1.0
- Supercell composite
- 5.3
The text
As transmitted, in the capitals the NWS used until 2016.
000
WGUS51 KPHI 091330
FFWPHI
PAC029-091-091730-
/O.NEW.KPHI.FF.W.0034.080909T1330Z-080909T1730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
930 AM EDT TUE SEP 9 2008
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* FLASH FLOOD WARNING FOR...
CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
* UNTIL 130 PM EDT
* AT 924 AM...NATIONAL WEATHER SERVICE DOPPLER RADAR SHOWED
HEAVY RAIN, ASSOCIATED WITH THUNDERSTORMS, MOVING ACROSS THE
REGION. BETWEEN 0.75 AN 1.50 INCHES OF RAIN CAN BE EXPECTED WITH
THE HEAVIER STORMS IN ABOUT ONE HOUR.
* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO VALLEY
FORGE...PUGHTOWN...GLENMOORE...CHESTER SPRINGS...CEDARVILLE...
SPRING MOUNT...SOUDERTON...POTTSTOWN...PHOENIXVILLE...NORRISTOWN...
LANSDALE...KING OF PRUSSIA...HONEY BROOK...GILBERTSVILLE...
ELVERSON...EAST GREENVILLE AND COLLEGEVILLE
THE SOILS REMAIN VERY MOIST DUE TO THE 2.00 TO 4.00 INCHES OF RAIN
TROPICAL STORM HANNA PRODUCED ON SATURDAY. BECAUSE OF THIS, RUNOFF
FROM WITH THIS MORNINGS RAINFALL WILL BE GREATER THAN NORMAL.
A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.
LAT...LON 3973 7615 3978 7607 3988 7600 3992 7602
4004 7595 4011 7595 4025 7569 4044 7553
4023 7517 4005 7536 4007 7538 4004 7543
4003 7541 4000 7546 3999 7545 3987 7561
3984 7560 3984 7559 3982 7569 3972 7578
$$
KRUZDLO1 follow-up statement
000
WGUS71 KPHI 091629
FFSPHI
FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1229 PM EDT TUE SEP 9 2008
PAC029-091-091638-
/O.CAN.KPHI.FF.W.0034.000000T0000Z-080909T1730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHESTER PA-MONTGOMERY PA-
1229 PM EDT TUE SEP 9 2008
...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR MONTGOMERY AND
CHESTER COUNTIES...
HEAVY RAIN ASSOCIATED WITH THE LINE OF THUNDERSTORMS HAS ENDED.
WHILE SOME LIGHT RAIN WILL CONTINUE THIS AFTERNOON, EXCESSIVE
RUNOFF IS NO LONGER EXPECTED. FOR THIS REASON, THE NATIONAL WEATHER
SERVICE HAS CANCELLED THE FLASH FLOOD WARNING.
LAT...LON 3973 7615 3978 7607 3988 7600 3992 7602
4004 7595 4011 7595 4025 7569 4044 7553
4023 7517 4005 7536 4007 7538 4004 7543
4003 7541 4000 7546 3999 7545 3987 7561
3984 7560 3984 7559 3982 7569 3972 7578
$$
KRUZDLOThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 9, 8:40 AM EDT | Severe Thunderstorm Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 50 min |
| Sep 9, 8:51 AM EDT | Areal Flood Advisory | PHI | Berks, Lehigh | 3 hr |
| Sep 9, 8:51 AM EDT | Severe Thunderstorm Warning | PHI | Berks, Bucks, Carbon, Chester, Lehigh, Montgomery and 1 more | 39 min |
| Sep 9, 9:09 AM EDT | Areal Flood Advisory | PHI | Northampton | 3 hr |
| Sep 9, 9:21 AM EDT | Severe Thunderstorm Warning | PHI | Berks, Bucks, Chester, Delaware, Lehigh, Monroe and 3 more | 39 min |
| Sep 9, 9:41 AM EDT | Flash Flood Warning | PHI | Bucks | 3 hr |
| Sep 9, 9:59 AM EDT | Flash Flood Warning | PHI | Bucks, Delaware, Montgomery, Philadelphia | 3 hr |
| Sep 9, 10:57 AM EDT | Severe Thunderstorm Warning | PHI | Bucks | 48 min |
Nearby
Flash Flood Warnings in Pennsylvania, 2008Every flash flood warning in 2008
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.