Alert archive / Pennsylvania / Flash Flood Warnings in 2009

Flash Flood Warning 5, NWS Philadelphia/Mount Holly

June 9, 2009Berks County, Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 9, 2009, 2:20 PM EDT for Berks County, Chester County, Pennsylvania. It was in force for 3 hr. 2 reports 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: Jun 9, 2009, 2:20 PM EDT (18:20 UTC)
Expired: Jun 9, 2009, 5:05 PM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Berks County, PA, Chester County, PA

The radar

The Philadelphia radar (KDIX), 130 km from the middle of the area, began a volume at 18:21 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
Jun 9, 2:55 PM EDT	FLOOD	3 Sw Birdsboro, PA	ROADS FLOODED IN MORGANTOWN.
Jun 9, 3:00 PM EDT	HEAVY RAIN 0	2 W Elverson, PA	1.50 INCHES OF RAIN IN THE LAST HOUR.

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, 6.3 hours before the alert went out and 66 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: 1272 J/kg
Mixed-layer CIN: -67 J/kg
Mixed-layer LCL: 804 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 87 m²/s²
0-3 km storm-relative helicity: 108 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 1.9

Open this sounding in Storm Lab

The text

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

000 
WGUS51 KPHI 091820
FFWPHI
PAC011-029-092215-
/O.NEW.KPHI.FF.W.0005.090609T1820Z-090609T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
220 PM EDT TUE JUN 9 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL BERKS COUNTY IN EASTERN PENNSYLVANIA...
  NORTHWESTERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 615 PM EDT

* AT 218 PM EDT...NATIONAL WEATHER SERVICE RADAR SHOWED VERY HEAVY RAIN 
  FROM A THUNDERSTORM OVER THE WARNED AREA. THE THUNDERSTORM WAS 
  NEARLY STATIONARY.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO BIRDSBORO

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

&&

LAT...LON 3993 7600 3999 7599 4003 7595 4011 7595
      4014 7590 4020 7598 4027 7597 4031 7569
      3988 7573 3987 7600 3992 7601

$$

RNS

1 follow-up statement

000 
WGUS71 KPHI 092105
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
505 PM EDT TUE JUN 9 2009

PAC011-029-092114-
/O.CAN.KPHI.FF.W.0005.000000T0000Z-090609T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHESTER PA-BERKS PA-
505 PM EDT TUE JUN 9 2009

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SOUTH CENTRAL BERKS
AND NORTHWESTERN CHESTER COUNTIES...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM EDT
TUESDAY EVENING FOR NORTHEASTERN PENNSYLVANIA.

THE HEAVY RAIN HAS MOVED OUT OF THE AREA.

LAT...LON 3993 7600 3999 7599 4003 7595 4011 7595
      4014 7590 4020 7598 4027 7597 4031 7569
      3988 7573 3987 7600 3992 7601

$$

RNS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 9, 4:17 AM EDT	Dense Fog Advisory	PHI		5 hr
Jun 9, 5:38 AM EDT	Severe Thunderstorm Warning	PHI	Berks	67 min
Jun 9, 7:20 AM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	55 min
Jun 9, 8:00 AM EDT	Severe Thunderstorm Warning	PHI	Delaware, Philadelphia	60 min
Jun 9, 8:06 AM EDT	Severe Thunderstorm Warning	PHI	Philadelphia	54 min
Jun 9, 8:20 AM EDT	Areal Flood Advisory	PHI	Delaware, Montgomery, Philadelphia	3 hr
Jun 9, 8:42 AM EDT	Areal Flood Advisory	PHI	Bucks	3 hr
Jun 9, 9:56 AM EDT	Flash Flood Warning	PHI	Chester	105 min
Jun 9, 1:49 PM EDT	Flash Flood Watch	PHI	Delaware, Philadelphia	5 hr
Jun 9, 2:24 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	66 min
Jun 9, 2:59 PM EDT	Tornado Warning	PHI	Chester	32 min
Jun 9, 3:08 PM EDT	Tornado Warning	PHI	Chester	28 min
Jun 9, 3:14 PM EDT	Tornado Warning	PHI	Chester	46 min
Jun 9, 3:29 PM EDT	Severe Thunderstorm Warning	PHI	Chester	61 min

Nearby

Flash Flood Warnings in Pennsylvania, 2009 Every flash flood warning in 2009

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.