Alert archive / Pennsylvania / Flash Flood Warnings in 2007

Flash Flood Warning 15, NWS Philadelphia/Mount Holly

May 31, 2007Lehigh County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at May 31, 2007, 11:27 PM EDT for Lehigh County, Pennsylvania. It was in force for 93 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
May 31, 2007, 11:27 PM EDT (03:27 UTC)
Expired
Jun 1, 2007, 1:00 AM EDT
In force
93 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Lehigh County, PA

The radar

The Philadelphia radar (KDIX), 125 km from the middle of the area, began a volume at 03:29 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, 3.5 hours before the alert went out and 231 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, Brookhaven, NY at 00:00Z on 2007-06-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 00:00Z on 2007-06-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 170 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1386 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
170 m²/s²
0-3 km storm-relative helicity
218 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
WGUS51 KPHI 010328
FFWPHI
PAC077-010500-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1127 PM EDT THU MAY 31 2007

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHWESTERN LEHIGH COUNTY IN EASTERN PENNSYLVANIA...

* UNTIL 100 AM EDT

* AT 1125 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR
  INDICATED VERY HEAVY RAINS FROM THUNDERSTORMS NEAR
  SCHNECKSVILLE...OR ABOUT 10 MILES WEST OF ALLENTOWN...MOVING
  SOUTHEAST AT 15 MPH.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL 
CREEKS AND STREAMS...URBAN AREAS...AND HIGHWAYS AND UNDERPASSES. 
ADDITIONALLY...COUNTRY ROADS AND FARMLANDS ALONG THE BANKS OF 
CREEKS...STREAMS AND OTHER LOW LYING AREAS ARE SUBJECT TO FLOODING.
THIS RAIN WILL BE IN ADDITION TO HEAVY RAIN WHICH OCCURRED EARLIER 
THIS EVENING.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH 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.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING. 
DO NOT ATTEMPT TO CROSS SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN 
DEPTH BY FOOT OR BY AUTOMOBILE.

LAT...LON 4068 7588 4057 7573 4067 7557 4077 7564

$$

JRP

The office that day

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

IssuedProductOfficeCountiesLasted
May 31, 8:19 PM EDTFlash Flood WarningPHIBerks, Lehigh116 min
May 31, 8:30 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh45 min
May 31, 8:50 PM EDTSevere Thunderstorm WarningPHILehigh40 min
May 31, 9:33 PM EDTSevere Thunderstorm WarningPHILehigh34 min
May 31, 9:50 PM EDTFlash Flood WarningPHILehigh3 hr
Jun 1, 2:36 PM EDTSevere Thunderstorm WarningPHIMonroe54 min
Jun 1, 3:37 PM EDTSevere Thunderstorm WarningPHIMonroe38 min
Jun 1, 3:53 PM EDTSevere Thunderstorm WarningPHINorthampton82 min
Jun 1, 4:24 PM EDTSevere Thunderstorm WarningPHIMonroe66 min
Jun 1, 4:31 PM EDTFlash Flood WarningPHIMonroe3 hr
Jun 1, 5:33 PM EDTSevere Thunderstorm WarningPHIBerks87 min
Jun 1, 6:00 PM EDTFlash Flood WarningPHIBerks3 hr
Jun 1, 6:39 PM EDTSevere Thunderstorm WarningPHILehigh58 min
Jun 1, 6:50 PM EDTSevere Thunderstorm WarningPHIBerks62 min
Jun 1, 7:02 PM EDTSevere Thunderstorm WarningPHIBucks88 min
Jun 1, 7:03 PM EDTFlash Flood WarningPHILehigh3 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2007Every flash flood warning in 2007

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.