Alert archive / Pennsylvania / Areal Flood Warnings in 2011
Areal Flood Warning 47, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this areal flood warning at Aug 19, 2011, 8:54 PM EDT for Chester County, Pennsylvania. 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 outline as issued.
The facts
- Issued
- Aug 19, 2011, 8:54 PM EDT (00:54 UTC)
- Expired
- Aug 20, 2011, 12:35 AM EDT
- In force
- 4 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
County Chester County, PA
The radar
The Philadelphia radar (KDIX), 90 km from the middle of the area, began a volume at 00:54 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
Washington/Dulle, VA (KIAD), launched 00:00Z, 0.9 hours before the alert went out and 207 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
- 1 J/kg
- Mixed-layer CIN
- -239 J/kg
- Mixed-layer LCL
- 1791 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- -22 m²/s²
- 0-3 km storm-relative helicity
- 23 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted, in the capitals the NWS used until 2016.
368
WGUS41 KPHI 200054
FLWPHI
BULLETIN - IMMEDIATE BROADCAST REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
854 PM EDT FRI AUG 19 2011
PAC029-200645-
/O.NEW.KPHI.FA.W.0047.110820T0054Z-110820T0645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHESTER PA-
854 PM EDT FRI AUG 19 2011
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* FLOOD WARNING FOR...
EAST CENTRAL CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
* UNTIL 245 AM EDT
* AT 850 PM EDT...VALLEY CREEK WAS RISING QUICKLY DUE TO THIS
EVENING'S HEAVY RAINFALL. MINOR FLOODING IS ANTICIPATED ALONG
THE CREEK INTO THE OVERNIGHT HOURS. THERE MAY ALSO BE SOME ROADWAY
AND POOR DRAINAGE AREA FLOODING IN THE VICINITY.
A FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR HAS BEEN
REPORTED. ALL INTERESTED PARTIES SHOULD TAKE NECESSARY PRECAUTIONS.
LAT...LON 4004 7556 4013 7548 4009 7545 4010 7543
4007 7541 4007 7537 4004 7543 4002 7542
4001 7545 4000 7546
$$
IOVINO1 follow-up statement
596
WGUS81 KPHI 200435
FLSPHI
FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1235 AM EDT SAT AUG 20 2011
PAC029-200442-
/O.CAN.KPHI.FA.W.0047.000000T0000Z-110820T0645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHESTER PA-
1235 AM EDT SAT AUG 20 2011
...THE FLOOD WARNING HAS BEEN CANCELLED FOR EAST CENTRAL CHESTER
COUNTY...
AT 1215 AM...THE VALLEY CREEK GAGE READ 5.7 FEET AND FALLING. FLOOD
STAGE IS 7.0 FEET. WITH LITTLE ADDITIONAL RAIN EXPECTED OVERNIGHT...
THE CREEK IS NOT EXPECTED TO REACH FLOOD STAGE...SO THE FLOOD
WARNING HAS BEEN CANCELLED.
LAT...LON 4004 7556 4013 7548 4009 7545 4010 7543
4007 7541 4007 7537 4004 7543 4002 7542
4001 7545 4000 7546
$$
HAYESThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 19, 8:03 PM EDT | Areal Flood Warning | PHI | Montgomery, Philadelphia | 9 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.