Alert archive / Pennsylvania / Areal Flood Warnings in 2012

Areal Flood Warning 10, NWS Philadelphia/Mount Holly

June 2, 2012Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this areal flood warning at Jun 2, 2012, 2:45 AM EDT for Montgomery County, Pennsylvania. It was in force for 6 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
Jun 2, 2012, 2:45 AM EDT (06:45 UTC)
Expired
Jun 2, 2012, 8:45 AM EDT
In force
6 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

County Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 102 km from the middle of the area, began a volume at 06:46 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, 6.8 hours before the alert went out and 226 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.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 00:00Z on 2012-06-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 497 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2012-06-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 289 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
497 J/kg
Mixed-layer CIN
-25 J/kg
Mixed-layer LCL
621 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
289 m²/s²
0-3 km storm-relative helicity
334 m²/s²
Significant tornado parameter
0.9
Supercell composite
6.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

958 
WGUS41 KPHI 020645
FLWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
245 AM EDT SAT JUN 2 2012

PAC091-021245-
/O.NEW.KPHI.FA.W.0010.120602T0645Z-120602T1245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONTGOMERY PA-
245 AM EDT SAT JUN 2 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLOOD WARNING FOR...
  NORTHWESTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 845 AM EDT

* AT 245 AM EDT...MINOR FLOODING WAS OCCURRING ON THE UPPER PART OF
  THE PERKIOMEN CREEK. THE MINOR FLOODING WILL CONTINUE EARLY THIS
  MORNING WITH THE CREEK EXPECTED TO RETURN WITHIN ITS BANKS BY 845
  AM.

* WHILE RISES ARE EXPECTED ON THE LOWER PART OF THE PERKIOMEN CREEK 
  EARLY THIS MORNING, NO FLOODING IS ANTICIPATED THERE.

A FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR HAS BEEN REPORTED.

DO NOT DRIVE THROUGH FLOOD WATERS, THE WATER MAY BE DEEPER THAN YOU 
THINK IT IS.

LAT...LON 4044 7553 4033 7533 4022 7542 4033 7562

$$

IOVINO
1 follow-up statement
421 
WGUS81 KPHI 021244
FLSPHI

FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
844 AM EDT SAT JUN 2 2012

PAC091-021251-
/O.EXP.KPHI.FA.W.0010.000000T0000Z-120602T1245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONTGOMERY PA-
844 AM EDT SAT JUN 2 2012

...THE FLOOD WARNING WILL EXPIRE AT 845 AM EDT FOR NORTHWESTERN
MONTGOMERY COUNTY...

THE UPPER PART OF THE PERKIOMEN CREEK HAS RETURN WITHIN ITS 
BANKS...THEREFORE THE FLOOD WARNING WILL BE ALLOWED TO EXPIRE. 

THERE MAY STILL REMAIN WATER ON SOME LOCAL ROADWAYS OR LOW 
SPOTS...SO USE CAUTION WHILE DRIVING.

LAT...LON 4044 7553 4033 7533 4022 7542 4033 7562

$$

ROBERTSON

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 1, 8:46 PM EDTAreal Flood AdvisoryPHIChester, Delaware, Montgomery, Philadelphia5 hr
Jun 1, 8:58 PM EDTSpecial Weather StatementPHIBerks, Bucks, Lehigh, Montgomery, Northampton62 min
Jun 1, 9:03 PM EDTTornado WarningPHIBucks, Montgomery27 min
Jun 1, 10:01 PM EDTSpecial Weather StatementPHIBerks89 min
Jun 1, 11:04 PM EDTFlash Flood WarningPHIBerks, Lehigh, Montgomery4 hr
Jun 2, 12:26 AM EDTAreal Flood AdvisoryPHIBerks, Montgomery85 min
Jun 2, 1:12 AM EDTAreal Flood AdvisoryPHIMonroe3 hr
Jun 2, 11:28 AM EDTCoastal Flood AdvisoryPHIDelaware, Philadelphia15 hr

Nearby

Areal Flood Warnings in Pennsylvania, 2012Every areal 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.