Alert archive / Pennsylvania / Flash Flood Warnings in 2011

Flash Flood Warning 47, NWS State College, PA

September 9, 20114 counties in Pennsylvania

NWS State College, PA issued this flash flood warning at Sep 9, 2011, 2:50 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 9, 2011, 2:50 PM EDT (18:50 UTC)
Expired: Sep 9, 2011, 5:45 PM EDT
In force: 3 hr
Issued by: NWS State College, PA
Area: Storm-based polygon
Flood severity: None

Counties Adams County, PA, Cumberland County, PA, Franklin County, PA, Fulton County, PA

The radar

The State College radar (KCCX), 105 km from the middle of the area, began a volume at 18:53 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 9, 5:45 PM EDT	FLASH FLOOD	Greencastle, PA	SPOTTER REPORTED WATER OVER HIGHWAY 16...SIGNIFICANT FLASH FLOODING IN GREENCASTLE.

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 12:00Z, 6.8 hours before the alert went out and 120 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: 881 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 484 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 44 m²/s²
0-3 km storm-relative helicity: 80 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

652 
WGUS51 KCTP 091850
FFWCTP
PAC001-041-055-057-092145-
/O.NEW.KCTP.FF.W.0047.110909T1850Z-110909T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  ADAMS COUNTY...
  SOUTHWESTERN CUMBERLAND COUNTY...
  FRANKLIN COUNTY...
  FULTON COUNTY...

* UNTIL 545 PM EDT...

* AT 244 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM SHOWERS AND THUNDERSTORMS MOVING INTO AND
  THROUGH ADAMS AND FRANKLIN COUNTIES. THAT RAIN SHOULD CONTINUE TO
  MOVE TO THE NORTHWEST. THE HEAVY RAIN WILL CAUSE NUMEROUS STREAMS
  AND CREEKS TO FLOOD RAPIDLY.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  CHAMBERSBURG...GREENCASTLE...WAYNESBORO...SHIPPENSBURG AND
  GETTYSBURG.

ADDITIONAL RAINFALL AMOUNTS OF AN INCH TO AN INCH AND A HALF 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!

&&

LAT...LON 4001 7820 4006 7818 4009 7820 4016 7813
      4013 7806 4010 7792 4006 7786 4012 7781
      4007 7714 4001 7701 3986 7695 3983 7700
      3972 7700 3972 7838

$$

FORECASTER: DANGELO

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 9, 2:55 AM EDT	Areal Flood Warning	CTP	Adams, Cumberland, Perry	6 hr
Sep 9, 9:18 AM EDT	Areal Flood Warning	CTP	Dauphin, Lancaster, Lebanon, York	8 hr
Sep 9, 11:44 AM EDT	Areal Flood Advisory	CTP	Bedford, Cambria, Somerset	2 hr
Sep 9, 1:42 PM EDT	Areal Flood Advisory	CTP	Adams	108 min
Sep 9, 2:35 PM EDT	Flash Flood Warning	CTP	Bedford, Cambria, Somerset	3 hr
Sep 9, 4:27 PM EDT	Areal Flood Advisory	CTP	McKean, Potter, Warren	3 hr
Sep 9, 5:30 PM EDT	Flash Flood Warning	CTP	Bedford, Blair, Cumberland, Franklin, Fulton, Huntingdon	3 hr
Sep 9, 6:07 PM EDT	Flash Flood Warning	CTP	Adams, Blair, Cumberland, Franklin, Huntingdon, Juniata and 2 more	3 hr
Sep 9, 6:54 PM EDT	Flash Flood Warning	CTP	Bedford, Blair, Cambria, Clearfield	3 hr
Sep 9, 7:06 PM EDT	Areal Flood Advisory	CTP	Elk	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.