Alert archive / Pennsylvania / Areal Flood Warnings in 2011
Areal Flood Warning 46, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this areal flood warning at Aug 19, 2011, 8:03 PM EDT for Montgomery County, Philadelphia County, Pennsylvania. It was in force for 9 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 19, 2011, 8:03 PM EDT (00:03 UTC)
- Expired
- Aug 20, 2011, 4:44 AM EDT
- In force
- 9 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties Montgomery County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 74 km from the middle of the area, began a volume at 00:04 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
Brookhaven, NY (KOKX), launched 00:00Z, 0.1 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
- 962 J/kg
- Mixed-layer CIN
- -38 J/kg
- Mixed-layer LCL
- 961 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 15 m²/s²
- 0-3 km storm-relative helicity
- 50 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
948 WGUS41 KPHI 200003 FLWPHI BULLETIN - IMMEDIATE BROADCAST REQUESTED FLOOD WARNING NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 803 PM EDT FRI AUG 19 2011 PAC091-101-200600- /O.NEW.KPHI.FA.W.0046.110820T0003Z-110820T0600Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ PHILADELPHIA PA-MONTGOMERY PA- 803 PM EDT FRI AUG 19 2011 THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A * FLOOD WARNING FOR... WEST CENTRAL PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA... EASTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA... * UNTIL 200 AM EDT * AT 800 PM EDT...THE WISSAHICKON CREEK WAS RISING QUICKLY DUE TO THIS EVENING'S HEAVY RAINFALL. MINOR FLOODING IS ANTICIPATED ALONG THE CREEK INTO THE OVERNIGHT HOURS. SOME ROADWAY AND POOR DRAINAGE AREA FLOODING WAS ALSO REPORTED IN THE VICINITY. A FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR HAS BEEN REPORTED. ALL INTERESTED PARTIES SHOULD TAKE NECESSARY PRECAUTIONS. LAT...LON 4022 7517 3999 7518 4009 7532 4031 7532 $$ IOVINO
2 follow-up statements
890 WGUS41 KPHI 200550 FLWPHI BULLETIN - IMMEDIATE BROADCAST REQUESTED FLOOD WARNING NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 150 AM EDT SAT AUG 20 2011 PAC091-101-200900- /O.EXT.KPHI.FA.W.0046.000000T0000Z-110820T0900Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ PHILADELPHIA PA-MONTGOMERY PA- 150 AM EDT SAT AUG 20 2011 THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS EXTENDED THE * FLOOD WARNING FOR... WEST CENTRAL PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA... EASTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA... * UNTIL 500 AM EDT * AT 148 AM EDT...THE WISSAHICKON CREEK WAS STILL ABOVE FLOOD STAGE EARLY THIS MORNING. THE CREEK IS EXPECTED TO SLOWLY FALL DURING THE OVERNIGHT HOURS...DROPPING BELOW FLOOD STAGE TOWARD DAYBREAK. * MINOR FLOODING IS ANTICIPATED ALONG THE CREEK THROUGH THE OVERNIGHT HOURS. A FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR HAS BEEN REPORTED. STREAM RISES WILL BE SLOW AND FLASH FLOODING IS NOT EXPECTED. HOWEVER...ALL INTERESTED PARTIES SHOULD TAKE NECESSARY PRECAUTIONS IMMEDIATELY. LAT...LON 4022 7517 3999 7518 4009 7532 4031 7532 $$ HAYES
547 WGUS81 KPHI 200844 FLSPHI FLOOD STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 444 AM EDT SAT AUG 20 2011 PAC091-101-200854- /O.CAN.KPHI.FA.W.0046.000000T0000Z-110820T0900Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ PHILADELPHIA PA-MONTGOMERY PA- 444 AM EDT SAT AUG 20 2011 ...THE FLOOD WARNING HAS BEEN CANCELLED FOR EASTERN MONTGOMERY AND WEST CENTRAL PHILADELPHIA COUNTIES... LAT...LON 4022 7517 3999 7518 4009 7532 4031 7532 $$ HAYES
The office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 19, 8:54 PM EDT | Areal Flood Warning | PHI | Chester | 4 hr |
| Aug 19, 11:51 PM EDT | Areal Flood Warning | PHI | Montgomery, Philadelphia | 3 hr |
Nearby
Areal Flood Warnings in Pennsylvania, 2011Every areal flood warning in 2011
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.