Alert archive / Pennsylvania / Flash Flood Warnings in 2009
Flash Flood Warning 49, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 22, 2009, 6:03 AM EDT for Montgomery County, Philadelphia 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
- Aug 22, 2009, 6:03 AM EDT (10:03 UTC)
- Expired
- Aug 22, 2009, 8:44 AM EDT
- In force
- 3 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Montgomery County, PA, Philadelphia County, PA
The nearest sounding before it
Brookhaven, NY (KOKX), launched 00:00Z, 10.1 hours before the alert went out and 215 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
- 1483 J/kg
- Mixed-layer CIN
- -26 J/kg
- Mixed-layer LCL
- 764 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 99 m²/s²
- 0-3 km storm-relative helicity
- 120 m²/s²
- Significant tornado parameter
- 0.7
- Supercell composite
- 6.3
The text
As transmitted, in the capitals the NWS used until 2016.
000
WGUS51 KPHI 221003
FFWPHI
PAC091-101-221400-
/O.NEW.KPHI.FF.W.0049.090822T1003Z-090822T1400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
603 AM EDT SAT AUG 22 2009
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* FLASH FLOOD WARNING FOR...
SOUTHEASTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
WEST CENTRAL PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
* UNTIL 1000 AM EDT
* AT 550 AM EDT...HEAVY RAIN WAS ONCE AGAIN FALLING ACROSS THE
WISSAHICKON CREEK WATERSHED. THE WISSAHICKON CREEK GAGE, NEAR THE
BORDER OF MONTGOMERY AND PHILADELPHIA COUNTIES, HAS BEEN RISING
STEADILY THROUGH THE NIGHT. THE ADDITIONAL RAIN, THAT IS CURRENTLY
FALLING, IS EXPECTED TO PUSH WATER LEVELS ABOVE FLOOD STAGE.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
DO NOT ATTEMPT TO CROSS SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN
DEPTH BY FOOT OR BY AUTOMOBILE.
&&
LAT...LON 4021 7531 4024 7525 4013 7510 4010 7517
4003 7516 4001 7522
$$
KRUZDLO1 follow-up statement
000
WGUS71 KPHI 221244
FFSPHI
FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
844 AM EDT SAT AUG 22 2009
PAC091-101-221253-
/O.CAN.KPHI.FF.W.0049.000000T0000Z-090822T1400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
PHILADELPHIA PA-MONTGOMERY PA-
844 AM EDT SAT AUG 22 2009
...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR EAST CENTRAL
MONTGOMERY AND WEST CENTRAL PHILADELPHIA COUNTIES...
THE WISSAHICKON CREEK HAS CRESTED BELOW FLOOD STAGE AND IS NOW
FALLING.
LAT...LON 4021 7531 4024 7525 4013 7510 4010 7517
4003 7516 4001 7522
$$
TFGThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 21, 10:14 PM EDT | Areal Flood Advisory | PHI | Chester | 3 hr |
| Aug 21, 10:49 PM EDT | Flash Flood Warning | PHI | Chester | 55 min |
| Aug 22, 1:40 AM EDT | Areal Flood Advisory | PHI | Bucks, Montgomery, Philadelphia | 3 hr |
| Aug 22, 1:51 AM EDT | Flash Flood Warning | PHI | Montgomery, Philadelphia | 77 min |
| Aug 22, 6:21 PM EDT | Flash Flood Warning | PHI | Bucks, Northampton | 3 hr |
| Aug 22, 7:00 PM EDT | Flash Flood Warning | PHI | Bucks, Chester, Delaware, Montgomery, Philadelphia | 4 hr |
Nearby
Flash Flood Warnings in Pennsylvania, 2009Every flash flood warning in 2009
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.