Alert archive / Pennsylvania / Flash Flood Warnings in 2007
Flash Flood Warning 10, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at May 12, 2007, 6:45 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 counties it named.
The facts
- Issued
- May 12, 2007, 6:45 PM EDT (22:45 UTC)
- Expired
- May 12, 2007, 9:45 PM EDT
- In force
- 3 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Whole counties
County Chester County, PA
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 10.8 hours before the alert went out and 182 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
- 192 J/kg
- Mixed-layer CIN
- -104 J/kg
- Mixed-layer LCL
- 1076 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 26 m²/s²
- 0-3 km storm-relative helicity
- 39 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted, in the capitals the NWS used until 2016.
000 WGUS51 KPHI 122247 FFWPHI PAC029-130145- BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 645 PM EDT SAT MAY 12 2007 THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A * FLASH FLOOD WARNING FOR... SOUTHERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA... * UNTIL 945 PM EDT * AT 644 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED FLASH FLOODING FROM A THUNDERSTORM THAT IS BUILDING BACKWARD OVER THE WARNED AREA NEAR WEST CHESTER. IN ADDITION, THERE ARE MORE THUNDERSTORMS WITH HEAVY RAIN ABOUT TO MOVE INTO SOUTHERN CHESTER COUNTY FROM LANCASTER COUNTY. STORM TOTAL ESTIMATES HAVE ALREADY EXCEEDED ONE INCH IN CENTRAL CHESTER COUNTY. * LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WEST CHESTER AND COATESVILLE EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS. MOST FLOOD RELATED DEATHS OCCUR IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS WATER COVERED BRIDGES...DIPS...OR LOW WATER CROSSINGS. NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL ONE...ON FOOT. TO ESCAPE RISING WATER MOVE UP TO HIGHER GROUND. LAT...LON 4001 7596 3975 7608 3975 7578 4000 7546 $$ TFG
2 follow-up statements
000 WGUS71 KPHI 122342 FFSPHI FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 740 PM EDT SAT MAY 12 2007 PAC029-130145- CHESTER PA- 740 PM EDT SAT MAY 12 2007 ...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 945 PM EDT FOR SOUTHERN CHESTER COUNTY... AT 735 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO INDICATE THUNDERSTORMS PRODUCING VERY HEAVY RAIN OVER THE WARNED AREA. THE THUNDERSTORMS THOUGH ARE WEAKENING AND WILL BE MOVING OUT OF THE WARNED AREA BY ABOUT 8 PM. LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WEST CHESTER...PARKESBURG...DOWNINGTOWN AND COATESVILLE ADDITIONAL RAINFALL AMOUNTS OF UP TO ONE INCH ARE POSSIBLE IN THE WARNED AREA. SO FAR DOPPLER RADAR ONE HOUR STORM TOTAL ESTIMATES HAVE EXCEEDED TWO INCHES IN WEST BRADFORD...NEWLIN...EAST BRADFORD AND POCOPSON TOWNSHIPS. EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL CREEKS AND STREAMS...UNDERPASSES. ADDITIONALLY...COUNTRY ROADS AND FARMLANDS ALONG THE IMMEDIATE BANKS OF CREEKS...STREAMS AND OTHER LOW LYING AREAS ARE SUBJECT TO FLOODING. DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY. MOVE TO HIGHER GROUND. LAT...LON 4001 7596 3975 7608 3975 7578 4000 7546 $$ TFG
000 WGUS71 KPHI 130122 FFSPHI FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 915 PM EDT SAT MAY 12 2007 PAC029-130145- CHESTER PA- 915 PM EDT SAT MAY 12 2007 ...A FLASH FLOOD WARNING WILL BE ALLOWED TO EXPIRE AT 945 PM EDT FOR SOUTHERN CHESTER COUNTY... AT 908 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THAT THE HEAVIEST RAIN HAS MOVED WELL EAST OF CHESTER COUNTY. DOPPLER RADAR STORM TOTAL ESTIMATES REACHED BETWEEN 3 AND 4 INCHES IN WEST BRADFORD...EAST BRADFORD AND POCOPSON TOWNSHIPS. LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WEST CHESTER...PARKESBURG...DOWNINGTOWN AND COATESVILLE DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. ONLY A FEW INCHES OF RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR VEHICLE. DO NOT DRIVE AROUND BARRICADES. LAT...LON 4001 7596 3975 7608 3975 7578 4000 7546 $$ TFG
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 12, 5:24 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 36 min |
| May 12, 6:31 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 59 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.