Alert archive / Pennsylvania / Flash Flood Warnings in 2013

Flash Flood Warning 63, NWS Philadelphia/Mount Holly

August 28, 2013Bucks County, Lehigh County, Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 28, 2013, 10:10 AM EDT for Bucks County, Lehigh County, Northampton County, Pennsylvania. It was in force for 3 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: Aug 28, 2013, 10:10 AM EDT (14:10 UTC)
Expired: Aug 28, 2013, 1:15 PM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Bucks County, PA, Lehigh County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 106 km from the middle of the area, began a volume at 14:13 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
Aug 28, 11:00 AM EDT	FLOOD	Allentown, PA	FLOODING ALONG ROUTE 309 CLOSED AN INTERSECTION.

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

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 2.2 hours before the alert went out and 135 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: 994 J/kg
Mixed-layer CIN: -34 J/kg
Mixed-layer LCL: 862 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 0 m²/s²
0-3 km storm-relative helicity: 40 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.3

Open this sounding in Storm Lab

The text

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

058 
WGUS51 KPHI 281410
FFWPHI
PAC017-077-095-281715-
/O.NEW.KPHI.FF.W.0063.130828T1410Z-130828T1715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1010 AM EDT WED AUG 28 2013

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHWESTERN BUCKS COUNTY...
  SOUTHEASTERN LEHIGH COUNTY...
  SOUTH CENTRAL NORTHAMPTON COUNTY...

* UNTIL 115 PM EDT...

* AT 1005 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM OVER NORTHWESTERN BUCKS...SOUTH
  CENTRAL NORTHAMPTON AND SOUTHEASTERN LEHIGH COUNTIES. OBSERVATIONS 
  SHOW THAT OVER 2 INCHES HAS ALREADY FALLEN IN PORTIONS OF SOUTHERN
  LEHIGH AND UPPER BUCKS COUNTY WITHIN THE PAST HOUR OR SO.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO ALLENTOWN, 
  QUAKERTOWN, COOPERSBURG.

ADDITIONAL RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE 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!

FLOODING IS OCCURRING OR IS IMMINENT. MOST FLOOD RELATED DEATHS OCCUR
IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS WATER COVERED BRIDGES...
DIPS...OR LOW WATER CROSSINGS. TURN AROUND...DON'T DROWN! NEVER TRY
TO CROSS A FLOWING STREAM...EVEN A SMALL ONE...ON FOOT. TO ESCAPE
RISING WATER MOVE UP TO HIGHER GROUND.

&&

LAT...LON 4052 7549 4066 7555 4071 7531 4058 7524
      4045 7520 4040 7541

$$

FORECASTER: HEAVENER

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 28, 9:23 AM EDT	Special Weather Statement	PHI	Lehigh	52 min
Aug 28, 9:34 AM EDT	Areal Flood Advisory	PHI	Bucks, Lehigh, Northampton	3 hr
Aug 28, 10:57 AM EDT	Areal Flood Advisory	PHI	Northampton	3 hr
Aug 28, 12:14 PM EDT	Special Weather Statement	PHI	Delaware, Montgomery, Philadelphia	61 min
Aug 28, 1:11 PM EDT	Areal Flood Warning	PHI	Philadelphia	4 hr
Aug 28, 1:25 PM EDT	Areal Flood Advisory	PHI	Delaware, Philadelphia	95 min

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.