Alert archive / Pennsylvania / Flash Flood Warnings in 2011

Flash Flood Warning 53, NWS State College, PA

September 9, 20116 counties in Pennsylvania

NWS State College, PA issued this flash flood warning at Sep 9, 2011, 11:09 PM EDT for 6 counties in 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: Sep 9, 2011, 11:09 PM EDT (03:09 UTC)
Expired: Sep 10, 2011, 3:00 AM EDT
In force: 4 hr
Issued by: NWS State College, PA
Area: Storm-based polygon
Flood severity: None

Counties Dauphin County, PA, Montour County, PA, Northumberland County, PA, Schuylkill County, PA, Snyder County, PA, Union County, PA

The radar

The State College radar (KCCX), 99 km from the middle of the area, began a volume at 03:08 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 10, 12:41 AM EDT	FLASH FLOOD	Herndon, PA	FLASH FLOODING IN HERNDON AND REBUCK.

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, 3.2 hours before the alert went out and 210 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: 134 J/kg
Mixed-layer CIN: -79 J/kg
Mixed-layer LCL: 1385 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 14 m²/s²
0-3 km storm-relative helicity: 72 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

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

487 
WGUS51 KCTP 100309
FFWCTP
PAC043-093-097-107-109-119-100700-
/O.NEW.KCTP.FF.W.0053.110910T0309Z-110910T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1109 PM EDT FRI SEP 9 2011

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHERN DAUPHIN COUNTY...
  SOUTHERN MONTOUR COUNTY...
  WEST CENTRAL SCHUYLKILL COUNTY...
  SNYDER COUNTY...
  UNION COUNTY...
  NORTHUMBERLAND COUNTY...

* UNTIL 300 AM EDT...

* AT 1054 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR ESTIMATES
  AND RAIN GAGE REPORTS INDICATED VERY HEAVY RAIN FROM THUNDERSTORMS
  ALONG A LINE EXTENDING FROM WEIKERT TO MEISERVILLE TO LYKENS...OR
  ALONG A LINE EXTENDING FROM 10 MILES SOUTHWEST OF MIFFLINBURG TO
  9 MILES SOUTHWEST OF SELINSGROVE TO ELIZABETHVILLE. THE LINE OF 
  THUNDERSTORMS WAS MOVING NORTHEAST AT 10 MPH. RADAR RAINFALL
  ESTIMATES OF 1.00 TO 1.75 INCHES OCCURRED OVER THE PAST HOUR FROM 
  NEAR MCCLURE TO MCALISTERVILLE...THOMPSONTOWN AND RICHFIELD...AND 
  RAINFALL AMOUNTS OF UP TO 2 INCHES ARE EXPECTED ACROSS MUCH OF THE
  WARNED AREA OVER THE NEXT FEW HOURS.   

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO DANVILLE...
  SELINSGROVE...KULPMONT...MILTON...MOUNT CARMEL...NORTHUMBERLAND...
  SHAMOKIN...SUNBURY...LEWISBURG AND MIFFLINBURG.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4078 7629 4047 7669 4043 7694 4057 7699
      4064 7694 4064 7700 4068 7704 4068 7708
      4079 7715 4081 7736 4083 7736 4107 7713
      4109 7698 4115 7696 4104 7668 4095 7654
      4082 7650 4083 7641 4078 7638

$$

FORECASTER: LAMBERT

The office that day

Everything else NWS State College, PA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 9, 8:19 PM EDT	Flash Flood Warning	CTP	Blair, Cambria, Centre, Clearfield, Huntingdon, Juniata and 2 more	3 hr
Sep 9, 8:31 PM EDT	Special Weather Statement	CTP	Juniata, Mifflin, Perry	59 min
Sep 9, 9:32 PM EDT	Special Weather Statement	CTP	Juniata, Perry	58 min
Sep 9, 10:08 PM EDT	Flash Flood Warning	CTP	Juniata, Mifflin, Perry, Snyder	3 hr
Sep 9, 10:41 PM EDT	River Flood Warning	CTP	Blair, Huntingdon	15 hr
Sep 9, 10:41 PM EDT	River Flood Warning	CTP	Blair, Huntingdon	6 hr
Sep 9, 10:41 PM EDT	River Flood Warning	CTP	Perry	15 hr
Sep 9, 11:42 PM EDT	Areal Flood Advisory	CTP	Elk	78 min
Sep 10, 12:32 AM EDT	Flash Flood Warning Emergency	CTP	Columbia, Lycoming, Montour, Northumberland, Schuylkill	5 hr
Sep 10, 12:57 AM EDT	Areal Flood Warning	CTP	Juniata, Mifflin, Perry, Snyder	6 hr
Sep 10, 1:14 AM EDT	Special Weather Statement	CTP	Warren	46 min
Sep 10, 4:01 AM EDT	Areal Flood Advisory	CTP	Elk, McKean, Warren	3 hr
Sep 10, 6:51 AM EDT	Areal Flood Advisory	CTP	Cambria, Cameron, Clearfield, Elk, McKean, Warren	3 hr
Sep 10, 9:02 AM EDT	Flash Flood Warning	CTP	Cambria, Clearfield	4 hr
Sep 10, 4:40 PM EDT	Areal Flood Advisory	CTP	Adams, Cumberland, Franklin, Huntingdon, Juniata, Mifflin and 2 more	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.