Alert archive / Pennsylvania / Flash Flood Warnings in 2013

Flash Flood Warning 42, NWS Philadelphia/Mount Holly

July 22, 2013Berks County, Lehigh County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 22, 2013, 11:39 PM EDT for Berks County, Lehigh County, Pennsylvania. It was in force for 4 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 22, 2013, 11:39 PM EDT (03:39 UTC)
Expired: Jul 23, 2013, 3:45 AM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Berks County, PA, Lehigh County, PA

The radar

The Philadelphia radar (KDIX), 128 km from the middle of the area, began a volume at 03:39 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.

What was reported inside it

Time	Report	Where	Remark
Jul 23, 12:30 AM EDT	FLASH FLOOD	Wyomissing, PA	WYOMISSING CREEK QUICKLY OUT OF ITS BANKS. FLOODING REPORTED AT THE CAMBRIDGE COMMONS APARTMENT COMPLEX INCLUDING WATER INTO THE MAINTENANCE BUILDING.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 3.7 hours before the alert went out and 232 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1248 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1188 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 53 m²/s²
0-3 km storm-relative helicity: 74 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 2.5

Open this sounding in Storm Lab

The text

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

100 
WGUS51 KPHI 230339
FFWPHI
PAC011-077-230745-
/O.NEW.KPHI.FF.W.0042.130723T0339Z-130723T0745Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1139 PM EDT MON JUL 22 2013

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  BERKS COUNTY...
  LEHIGH COUNTY...

* UNTIL 345 AM EDT...

* AT 1135 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM OVER BERKS AND LEHIGH COUNTIES.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO ALLENTOWN
  AND READING.

DOPPLER RADAR ESTIMATES OF 2 TO 3 INCHES OF RAIN HAS FALLEN ACROSS 
PORTIONS OF THE AREA AND AN ADDITIONAL RAINFALL AMOUNTS 2 INCHES OR 
GREATER IS POSSIBLE IN THE WARNED AREA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. NEVER ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR IN AN
AUTOMOBILE. TURN AROUND DON'T DROWN!

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.

&&

LAT...LON 4067 7591 4078 7564 4079 7561 4074 7560
      4072 7556 4073 7554 4066 7548 4066 7546
      4060 7539 4057 7539 4044 7554 4024 7571
      4014 7589 4023 7603 4038 7622

$$

FORECASTER:

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 22, 9:19 PM EDT	Areal Flood Advisory	PHI	Carbon, Monroe	3 hr
Jul 22, 9:53 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh	3 hr
Jul 22, 11:09 PM EDT	Areal Flood Advisory	PHI	Berks, Chester	3 hr
Jul 23, 12:11 AM EDT	Special Weather Statement	PHI	Chester	94 min
Jul 23, 12:25 AM EDT	Flash Flood Warning	PHI	Chester	4 hr
Jul 23, 1:50 AM EDT	Areal Flood Advisory	PHI	Bucks, Delaware, Montgomery, Philadelphia	4 hr
Jul 23, 2:11 AM EDT	Flash Flood Warning	PHI	Bucks, Delaware, Montgomery, Philadelphia	4 hr
Jul 23, 3:49 AM EDT	Flash Flood Watch	PHI	Berks, Bucks, Chester, Delaware, Lehigh, Montgomery and 2 more	11 hr
Jul 23, 4:10 PM EDT	Special Weather Statement	PHI	Bucks, Delaware, Philadelphia	2 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2013 Every flash flood warning in 2013

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.