Alert archive / Pennsylvania / Flash Flood Warnings in 2007
Flash Flood Warning 23, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 19, 2007, 11:34 PM EDT for Montgomery County, Pennsylvania. It took effect at Jun 19, 2007, 11:39 PM EDT. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Jun 19, 2007, 11:34 PM EDT (03:34 UTC)
- In effect from
- Jun 19, 2007, 11:39 PM EDT
- Expired
- Jun 20, 2007, 3:30 AM EDT
- In force
- 4 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Whole counties
County Montgomery County, PA
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 00:00Z, 3.6 hours before the alert went out and 224 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
- 1609 J/kg
- Mixed-layer CIN
- -60 J/kg
- Mixed-layer LCL
- 1522 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 86 m²/s²
- 0-3 km storm-relative helicity
- 89 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 WGUS51 KPHI 200339 FFWPHI PAC091-200730- BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1134 PM EDT TUE JUN 19 2007 THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A * FLASH FLOOD WARNING FOR... NORTHWESTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA... * UNTIL 330 AM EDT * AT 1130 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED VERY HEAVY RAIN FROM A THUNDERSTORM NEAR POTTSTOWN...OR ABOUT 15 MILES SOUTHEAST OF READING...MOVING NORTHEAST AT 35 MPH. OTHER STRONG THUNDERSTORMS WERE MOVING NORTHEAST FROM LANCASTER COUNTY. * LOCATIONS IN THE WARNED AREA THAT ARE LIKELY TO FLOOD INCLUDE BUT ARE NOT LIMITED TO SCHLEGEL RUN...SWAMP CREEK...AND MIDDLE CREEK. BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING. DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY. MOVE TO HIGHER GROUND. LAT...LON 4025 7568 4018 7555 4033 7536 4044 7552 $$ RPW
1 follow-up statement
000 WGUS71 KPHI 200617 FFSPHI FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 216 AM EDT WED JUN 20 2007 PAC091-200626- MONTGOMERY PA- 216 AM EDT WED JUN 20 2007 ...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR NORTHWESTERN MONTGOMERY COUNTY... HEAVY RAIN HAD MOVED EAST OF THE AREA AS OF 215 AM. ADDITIONAL SHOWERS AND THUNDERSTORMS ARE POSSIBLE OVERNIGHT, BUT THEY ARE NOT EXPECTED TO CAUSE ANY ADDITIONAL RISK OF FLOODING. LAT...LON 4025 7568 4018 7555 4033 7536 4044 7552 $$ MPD
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 19, 8:01 PM EDT | Severe Thunderstorm Warning | PHI | Lehigh, Northampton | 59 min |
| Jun 19, 8:18 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Montgomery | 57 min |
| Jun 19, 8:49 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 56 min |
| Jun 19, 11:14 PM EDT | Flash Flood Warning | PHI | Berks | 4 hr |
| Jun 19, 11:50 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Chester | 55 min |
Nearby
Flash Flood Warnings in Pennsylvania, 2007Every flash flood warning in 2007
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.