Alert archive / Pennsylvania / Flash Flood Warnings in 2011

Flash Flood Warning 68, NWS Philadelphia/Mount Holly

September 28, 20114 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 28, 2011, 6:41 PM EDT for 4 counties in 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: Sep 28, 2011, 6:41 PM EDT (22:41 UTC)
Expired: Sep 28, 2011, 9:59 PM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Carbon County, PA, Lehigh County, PA, Monroe County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 121 km from the middle of the area, began a volume at 22:44 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
Sep 28, 8:15 PM EDT	FLASH FLOOD	Bath, PA	STREET FLOODING...WATER RESCUES BY LOCAL EMERGENCY CREWS

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, 10.7 hours before the alert went out and 171 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: 822 J/kg
Mixed-layer CIN: -16 J/kg
Mixed-layer LCL: 526 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 34 m²/s²
0-3 km storm-relative helicity: 65 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

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

558 
WGUS51 KPHI 282241
FFWPHI
PAC025-077-089-095-290245-
/O.NEW.KPHI.FF.W.0068.110928T2241Z-110929T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
641 PM EDT WED SEP 28 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL LEHIGH COUNTY...
  NORTHAMPTON COUNTY...
  EAST CENTRAL CARBON COUNTY...
  SOUTHERN MONROE COUNTY...

* UNTIL 1045 PM EDT...

* AT 640 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN FROM A CLUSTER OF SHOWERS AND THUNDERSTORMS OVER 
  EAST CENTRAL CARBON...EAST CENTRAL LEHIGH...NORTHAMPTON AND 
  SOUTHERN MONROE COUNTIES.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PLEASE REPORT FLOODING...HAIL OR WIND DAMAGE TO THE NATIONAL WEATHER
SERVICE BY CALLING TOLL FREE...1-877-633-6772.

&&

LAT...LON 4099 7512 4099 7514 4096 7514 4092 7510
      4083 7510 4077 7515 4078 7516 4074 7520
      4061 7522 4058 7526 4057 7557 4107 7557
      4110 7514

$$

HAYES

1 follow-up statement

095 
WGUS71 KPHI 290159
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
959 PM EDT WED SEP 28 2011

PAC025-077-089-095-290209-
/O.CAN.KPHI.FF.W.0068.000000T0000Z-110929T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LEHIGH PA-NORTHAMPTON PA-CARBON PA-MONROE PA-
959 PM EDT WED SEP 28 2011

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SOUTHERN MONROE...
EAST CENTRAL CARBON...NORTHAMPTON AND EAST CENTRAL LEHIGH COUNTIES...

THE HEAVIEST OF THE RAIN HAS EXITED THE AREA...BUT SMALL STREAM 
FLOODING IS EXPECTED INTO THE EARLY MORNING HOURS OF THURSDAY. THE 
FLASH FLOOD WARNING HAS BEEN REPLACED BY A FLOOD WARNING TO ACCOUNT 
FOR THE SMALL STREAM FLOODING.

LAT...LON 4099 7512 4099 7514 4096 7514 4092 7510
      4083 7510 4077 7515 4078 7516 4074 7520
      4061 7522 4058 7526 4057 7557 4107 7557
      4110 7514

$$

HAYES

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 27, 8:16 PM EDT	Areal Flood Warning	PHI	Carbon, Monroe	3 hr
Sep 27, 11:53 PM EDT	Coastal Flood Statement	PHI	Delaware, Philadelphia	4 hr
Sep 28, 1:54 AM EDT	Special Weather Statement	PHI	Bucks, Delaware, Lehigh, Monroe, Montgomery, Northampton and 1 more	51 min
Sep 28, 3:56 AM EDT	Flash Flood Watch	PHI	Berks, Carbon, Delaware, Lehigh, Monroe, Northampton and 1 more	39 hr
Sep 28, 4:38 AM EDT	Areal Flood Warning	PHI	Bucks	3 hr
Sep 28, 5:45 AM EDT	Special Weather Statement	PHI	Montgomery	60 min
Sep 28, 10:02 AM EDT	Coastal Flood Statement	PHI	Delaware, Philadelphia	8 hr
Sep 28, 11:15 AM EDT	Special Weather Statement	PHI	Berks	60 min
Sep 28, 12:24 PM EDT	Special Weather Statement	PHI	Lehigh	51 min
Sep 28, 3:20 PM EDT	Special Weather Statement	PHI	Chester, Delaware, Montgomery	55 min
Sep 28, 3:59 PM EDT	Special Weather Statement	PHI	Berks, Chester, Delaware, Montgomery	61 min
Sep 28, 4:21 PM EDT	Special Weather Statement	PHI	Carbon	54 min
Sep 28, 4:33 PM EDT	Areal Flood Advisory	PHI	Berks, Chester, Montgomery	2 hr
Sep 28, 4:36 PM EDT	Flash Flood Warning	PHI	Berks, Chester	3 hr
Sep 28, 4:48 PM EDT	Special Weather Statement	PHI	Northampton	57 min
Sep 28, 4:59 PM EDT	Areal Flood Advisory	PHI	Bucks, Northampton	3 hr
Sep 28, 5:02 PM EDT	Special Weather Statement	PHI	Berks, Lehigh	58 min
Sep 28, 5:12 PM EDT	Special Weather Statement	PHI	Lehigh	63 min
Sep 28, 5:29 PM EDT	Special Weather Statement	PHI	Carbon	61 min
Sep 28, 5:32 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Carbon, Lehigh, Northampton	58 min
Sep 28, 5:42 PM EDT	Areal Flood Advisory	PHI	Berks, Bucks, Carbon, Lehigh, Monroe, Montgomery and 1 more	3 hr
Sep 28, 6:31 PM EDT	Special Weather Statement	PHI	Northampton	59 min
Sep 28, 6:35 PM EDT	Areal Flood Warning	PHI	Bucks	2 hr
Sep 28, 7:44 PM EDT	Areal Flood Warning	PHI	Chester	3 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2011 Every flash 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.