Alert archive / Pennsylvania / Flash Flood Warnings in 2012
Flash Flood Warning 28, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 1, 2012, 6:08 PM EDT for Chester County, Montgomery County, Pennsylvania. It was in force for 2 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 1, 2012, 6:08 PM EDT (22:08 UTC)
- Expired
- Aug 1, 2012, 8:15 PM EDT
- In force
- 2 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), 96 km from the middle of the area, began a volume at 22:09 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, 10.1 hours before the alert went out and 102 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
- 897 J/kg
- Mixed-layer CIN
- -5 J/kg
- Mixed-layer LCL
- 643 m above ground
- 0-6 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- 16 m²/s²
- 0-3 km storm-relative helicity
- -2 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
144 WGUS51 KPHI 012208 FFWPHI PAC029-091-020200- /O.NEW.KPHI.FF.W.0028.120801T2208Z-120802T0200Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 608 PM EDT WED AUG 1 2012 THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A * FLASH FLOOD WARNING FOR... CENTRAL MONTGOMERY COUNTY... NORTHEASTERN CHESTER COUNTY... * UNTIL 1000 PM EDT... * AT 605 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED VERY HEAVY RAIN FROM A THUNDERSTORM OVER CENTRAL MONTGOMERY AND NORTHEASTERN CHESTER COUNTIES. DOPPLER RADAR INDICATES THAT AS MUCH AS TWO AND ONE-HALF INCHES OF RAIN HAS FALLEN SO FAR. ADDITIONAL RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE POSSIBLE IN THE WARNED AREA. PRECAUTIONARY/PREPAREDNESS ACTIONS... PLEASE REPORT FLOODING...HAIL OR WIND DAMAGE TO THE NATIONAL WEATHER SERVICE BY CALLING TOLL FREE...1-877-633-6772. && LAT...LON 4033 7535 4010 7537 4012 7565 4034 7562 $$ HAYES
2 follow-up statements
287 WGUS71 KPHI 012339 FFSPHI FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 739 PM EDT WED AUG 1 2012 PAC029-091-020200- /O.CON.KPHI.FF.W.0028.000000T0000Z-120802T0200Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ MONTGOMERY PA-CHESTER PA- 739 PM EDT WED AUG 1 2012 ...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1000 PM EDT FOR NORTHEASTERN CHESTER AND CENTRAL MONTGOMERY COUNTIES... AT 735 PM EDT...THE HEAVIEST RAIN HAS MOVED OUT OF THE AREA. HOWEVER...RUNOFF FROM THE EARLIER HEAVY RAIN IS STILL ALLOWING CREEKS AND STREAMS TO RISE. ADDITIONAL RUNOFF COULD PUSH SOME CREEKS AND STREAMS TO NEAR OR JUST ABOVE BANKFULL. PRECAUTIONARY/PREPAREDNESS ACTIONS... EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS. PLEASE REPORT FLOODING...HAIL OR WIND DAMAGE BY CALLING YOUR LOCAL LAW ENFORCEMENT OFFICIALS OR BY CALLING THE NATIONAL WEATHER SERVICE TOLL FREE AT...1-877-633-6772. && LAT...LON 4033 7535 4010 7537 4012 7565 4034 7562 $$ HAYES
098 WGUS71 KPHI 020015 FFSPHI FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 815 PM EDT WED AUG 1 2012 PAC029-091-020026- /O.CAN.KPHI.FF.W.0028.000000T0000Z-120802T0200Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ MONTGOMERY PA-CHESTER PA- 815 PM EDT WED AUG 1 2012 ...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR NORTHEASTERN CHESTER AND CENTRAL MONTGOMERY COUNTIES... THE WATERS FROM THE EARLIER HEAVY RAINS ARE RECEDING AND FLOOD WATERS NO LONGER POSE A THREAT TO LIFE OR PROPERTY. THEREFORE...THE FLASH FLOOD WARNING HAS BEEN CANCELLED. LAT...LON 4033 7535 4010 7537 4012 7565 4034 7562 $$ HAYES
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 31, 8:11 PM EDT | Special Weather Statement | PHI | Berks | 64 min |
| Jul 31, 9:12 PM EDT | Special Weather Statement | PHI | Berks, Lehigh | 63 min |
| Jul 31, 9:51 PM EDT | Coastal Flood Statement | PHI | Delaware, Philadelphia | 5 hr |
| Aug 1, 1:02 AM EDT | Special Weather Statement | PHI | Chester | 58 min |
| Aug 1, 2:03 PM EDT | Special Weather Statement | PHI | Chester | 57 min |
| Aug 1, 2:27 PM EDT | Special Weather Statement | PHI | Bucks | 63 min |
| Aug 1, 2:47 PM EDT | Areal Flood Advisory | PHI | Bucks | 3 hr |
| Aug 1, 3:03 PM EDT | Special Weather Statement | PHI | Monroe | 57 min |
| Aug 1, 3:31 PM EDT | Coastal Flood Statement | PHI | Delaware, Philadelphia | 11 hr |
| Aug 1, 3:35 PM EDT | Special Weather Statement | PHI | Philadelphia | 55 min |
| Aug 1, 4:07 PM EDT | Flash Flood Warning | PHI | Bucks, Montgomery | 3 hr |
| Aug 1, 4:16 PM EDT | Special Weather Statement | PHI | Carbon, Monroe | 59 min |
| Aug 1, 4:51 PM EDT | Areal Flood Advisory | PHI | Monroe | 36 min |
| Aug 1, 4:53 PM EDT | Special Weather Statement | PHI | Philadelphia | 67 min |
| Aug 1, 5:06 PM EDT | Areal Flood Advisory | PHI | Montgomery, Philadelphia | 12 min |
| Aug 1, 5:09 PM EDT | Flash Flood Warning | PHI | Montgomery, Philadelphia | 3 hr |
| Aug 1, 5:22 PM EDT | Flash Flood Warning | PHI | Monroe | 106 min |
| Aug 1, 5:34 PM EDT | Special Weather Statement | PHI | Carbon | 56 min |
| Aug 1, 5:43 PM EDT | Special Weather Statement | PHI | Delaware, Montgomery | 62 min |
| Aug 1, 5:46 PM EDT | Severe Thunderstorm Warning | PHI | Philadelphia | 31 min |
| Aug 1, 5:50 PM EDT | Special Weather Statement | PHI | Montgomery | 55 min |
| Aug 1, 5:53 PM EDT | Areal Flood Advisory | PHI | Carbon, Monroe | 100 min |
| Aug 1, 5:55 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Monroe, Northampton | 65 min |
| Aug 1, 6:16 PM EDT | Areal Flood Advisory | PHI | Philadelphia | 46 min |
| Aug 1, 6:22 PM EDT | Special Weather Statement | PHI | Lehigh | 53 min |
| Aug 1, 6:30 PM EDT | Areal Flood Advisory | PHI | Chester, Delaware | 64 min |
| Aug 1, 6:53 PM EDT | Areal Flood Advisory | PHI | Lehigh, Northampton | 69 min |
| Aug 1, 6:59 PM EDT | Special Weather Statement | PHI | Northampton | 61 min |
| Aug 1, 7:32 PM EDT | Special Weather Statement | PHI | Chester | 58 min |
| Aug 1, 7:49 PM EDT | Areal Flood Advisory | PHI | Chester | 52 min |
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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.