Alert archive / Pennsylvania / Flash Flood Warnings in 2012
Flash Flood Warning 48, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 3, 2012, 9:15 AM EDT for Chester County, Delaware County, Montgomery County, Pennsylvania. It was in force for 3 hr. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Sep 3, 2012, 9:15 AM EDT (13:15 UTC)
- Expired
- Sep 3, 2012, 12:15 PM EDT
- In force
- 3 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Chester County, PA, Delaware County, PA, Montgomery County, PA
The radar
The Philadelphia radar (KDIX), 97 km from the middle of the area, began a volume at 13:14 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Sep 3, 11:59 AM EDT | FLOOD | Birmingham Twp, PA | ROUTE 926 AND CREEK ROAD CLOSED DUE TO FLOODING. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 1.3 hours before the alert went out and 204 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
- 383 J/kg
- Mixed-layer CIN
- -34 J/kg
- Mixed-layer LCL
- 718 m above ground
- 0-6 km bulk shear
- 12 kt
- 0-1 km storm-relative helicity
- 77 m²/s²
- 0-3 km storm-relative helicity
- 86 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
714 WGUS51 KPHI 031315 FFWPHI PAC029-045-091-031615- /O.NEW.KPHI.FF.W.0048.120903T1315Z-120903T1615Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 915 AM EDT MON SEP 3 2012 THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A * FLASH FLOOD WARNING FOR... CENTRAL MONTGOMERY COUNTY... NORTHERN DELAWARE COUNTY... NORTHEASTERN CHESTER COUNTY... * UNTIL 1215 PM EDT... * AT 908 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED VERY HEAVY RAIN OVER NORTHEASTERN CHESTER...NORTHWESTERN DELAWARE COUNTIES...AND MOVING INTO CENTRAL MONTGOMERY. RAINFALL ESTIMATES OF AROUND 2 INCHES ARE OCCURING WITH THESE SHOWERS AND ARE MOVING OVER AREAS THAT RECIEVED FLOODING OVERNIGHT. * LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO COLLEGEVILLE...CONSHOHOCKEN...DOWNINGTOWN...KING OF PRUSSIA... LIONVILLE...MARSHALLTON...NORRISTOWN...PAOLI...PHOENIXVILLE... RADNOR TOWNSHIP...ROYERSFORD...TRAPPE...WEST CHESTER...CHESTER SPRINGS...CHEYNEY...GRADYVILLE...NEWTOWN SQUARE...VALLEY FORGE AND WESTTOWN. ADDITIONAL RAINFALL AMOUNTS OF ONE TO TWO INCHES ARE POSSIBLE IN THE WARNED AREA. PRECAUTIONARY/PREPAREDNESS ACTIONS... 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. NEVER ATTEMPT TO CROSS SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR IN AN AUTOMOBILE. TURN AROUND DON'T DROWN! PLEASE REPORT FLOODING...HAIL OR WIND DAMAGE TO THE NATIONAL WEATHER SERVICE BY CALLING TOLL FREE...1-877-633-6772. && LAT...LON 4028 7552 4002 7523 3984 7561 4001 7581 $$ ROBERTSON
1 follow-up statement
036 WGUS71 KPHI 031440 FFSPHI FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1040 AM EDT MON SEP 3 2012 PAC029-045-091-031615- /O.CON.KPHI.FF.W.0048.000000T0000Z-120903T1615Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ MONTGOMERY PA-DELAWARE PA-CHESTER PA- 1040 AM EDT MON SEP 3 2012 ...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1215 PM EDT FOR EASTERN CHESTER...NORTHERN DELAWARE AND CENTRAL MONTGOMERY COUNTIES... AT 1029 AM EDT...DOPPLER RADAR CONTINUES TO INDICATE HEAVY RAIN MOVING INTO EASTERN CHESTER...NORTHERN DELAWARE...AND CENTRAL MONTGOMERY COUNTIES. THESE AREAS HAVE ALREADY RECEIVED AN ESTIMATED THREE TO FOUR INCHES THIS MORNING AND HAD FLOODING OVERNIGHT. RAINFALL RATES WERE ON THE DECREASE AROUND 1030 AM. HOWEVER, THE THREAT OF FLASH FLOODING CONTINUES. SOME LOCATIONS MAY PICK UP ANOTHER INCH OR MORE OF RAIN. THE VALLEY CREEK AT VALLEY FORGE CONTINUES TO RISE AND MAY RISE ABOVE FLOOD STAGE. LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO BROOMALL... BRYN MAWR...COLLEGEVILLE...CONSHOHOCKEN...DOWNINGTOWN...KING OF PRUSSIA...LIONVILLE...MARSHALLTON...NORRISTOWN...PAOLI... PHOENIXVILLE...RADNOR TOWNSHIP...ROYERSFORD...TRAPPE...WEST CHESTER...CHESTER SPRINGS...CHEYNEY...CONCORDVILLE...GRADYVILLE... NEWTOWN SQUARE...TROUT LAKE...VALLEY FORGE AND WESTTOWN. PRECAUTIONARY/PREPAREDNESS ACTIONS... DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY. MOVE TO HIGHER GROUND. PLEASE REPORT FLOODING...HAIL OR WIND DAMAGE BY CALLING YOUR LOCAL LAW ENFORCEMENT OFFICIALS OR BY CALLING THE NATIONAL WEATHER SERVICE TOLL FREE AT...1-877-633-6772. && LAT...LON 4028 7552 4002 7523 3984 7561 4001 7581 $$ ROBERTSON
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 3, 12:24 AM EDT | Areal Flood Advisory | PHI | Chester, Delaware | 3 hr |
| Sep 3, 12:58 AM EDT | Flash Flood Warning | PHI | Chester, Delaware | 5 hr |
| Sep 3, 4:19 AM EDT | River Flood Warning | PHI | Delaware | 91 min |
| Sep 3, 4:44 AM EDT | Areal Flood Advisory | PHI | Chester, Montgomery | 3 hr |
| Sep 3, 6:24 AM EDT | Areal Flood Warning | PHI | Chester | 4 hr |
| Sep 3, 8:05 AM EDT | Areal Flood Advisory | PHI | Chester, Delaware, Montgomery, Philadelphia | 3 hr |
| Sep 3, 8:23 AM EDT | Flash Flood Warning | PHI | Delaware | 82 min |
| Sep 3, 10:28 AM EDT | Special Weather Statement | PHI | Philadelphia | 62 min |
| Sep 3, 11:14 AM EDT | Areal Flood Advisory | PHI | Bucks, Montgomery, Philadelphia | 2 hr |
| Sep 3, 12:04 PM EDT | Areal Flood Warning | PHI | Chester | 4 hr |
| Sep 3, 2:44 PM EDT | Areal Flood Advisory | PHI | Chester | 119 min |
| Sep 3, 3:00 PM EDT | Flash Flood Watch | PHI | Delaware, Philadelphia | 49 hr |
| Sep 3, 5:27 PM EDT | Areal Flood Warning | PHI | Delaware | 3 hr |
| Sep 3, 6:41 PM EDT | River Flood Warning | PHI | Delaware | 2 hr |
Nearby
Flash Flood Warnings in Pennsylvania, 2012Every flash flood warning in 2012
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.