Alert archive / Pennsylvania / Areal Flood Warnings in 2011
Areal Flood Warning 48, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this areal flood warning at Aug 19, 2011, 11:51 PM EDT for Montgomery County, Philadelphia 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 outline as issued.
The facts
- Issued
- Aug 19, 2011, 11:51 PM EDT (03:51 UTC)
- Expired
- Aug 20, 2011, 3:13 AM EDT
- In force
- 3 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), 57 km from the middle of the area, began a volume at 03:52 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, 3.9 hours before the alert went out and 206 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.
336
WGUS41 KPHI 200351
FLWPHI
BULLETIN - IMMEDIATE BROADCAST REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1151 PM EDT FRI AUG 19 2011
PAC091-101-200745-
/O.NEW.KPHI.FA.W.0048.110820T0351Z-110820T0745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
PHILADELPHIA PA-MONTGOMERY PA-
1151 PM EDT FRI AUG 19 2011
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* FLOOD WARNING FOR...
NORTHEASTERN PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
SOUTHEASTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
* UNTIL 345 AM EDT
* AT 1150 PM EDT...THE RIVER GAGE ON THE PENNYPACK CREEK IN
PHILADELPHIA COUNTY WAS 7.25 FEET. FLOOD STAGE IS 7.0 FEET.
* MINOR FLOODING IS ANTICIPATED ALONG THE CREEK INTO 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.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLOODING IS OBSERVED ACT QUICKLY. MOVE UP TO
HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO
FLOODING WHEN WATER BEGINS RISING.
&&
LAT...LON 4011 7497 4001 7504 4001 7505 4000 7506
4002 7517 4019 7517
$$
HAYES1 follow-up statement
431
WGUS81 KPHI 200713
FLSPHI
FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
313 AM EDT SAT AUG 20 2011
PAC091-101-200723-
/O.CAN.KPHI.FA.W.0048.000000T0000Z-110820T0745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
PHILADELPHIA PA-MONTGOMERY PA-
313 AM EDT SAT AUG 20 2011
...THE FLOOD WARNING HAS BEEN CANCELLED FOR SOUTHEASTERN MONTGOMERY
AND NORTHEASTERN PHILADELPHIA COUNTIES...
THE PENNYPACK CREEK HAS DROPPED BELOW FLOOD STAGE. SINCE NO
ADDITIONAL RAIN IS EXPECTED...THE FLOOD WARNING HAS BEEN CANCELLED.
LAT...LON 4011 7497 4001 7504 4001 7505 4000 7506
4002 7517 4019 7517
$$
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, 8:54 PM EDT | Areal Flood Warning | PHI | Chester | 4 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.