Alert archive / Pennsylvania / Flash Flood Warnings in 2017

Flash Flood Warning 18, NWS State College, PA

July 28, 20175 counties in Pennsylvania

NWS State College, PA issued this flash flood warning at Jul 28, 2017, 9:46 PM EDT for 5 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: Jul 28, 2017, 9:46 PM EDT (01:46 UTC)
Expired: Jul 29, 2017, 12:45 AM EDT
In force: 3 hr
Issued by: NWS State College, PA
Area: Storm-based polygon
Flood severity: None

Counties Blair County, PA, Cambria County, PA, Centre County, PA, Clearfield County, PA, Huntingdon County, PA

The radar

The State College radar (KCCX), 28 km from the middle of the area, began a volume at 01:48 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
Jul 28, 11:15 PM EDT	FLASH FLOOD	Coalport, PA	NUMEROUS BASEMENTS FLOODED. POWER OUT DUE TO TREES COLLAPSING ONTO WIRES.

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

The nearest sounding before it

Pittsburgh, PA (KAGC), launched 00:00Z, 1.8 hours before the alert went out and 169 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: 732 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 801 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: -24 m²/s²
0-3 km storm-relative helicity: 28 m²/s²
Significant tornado parameter: -0.1
Supercell composite: -0.5

Open this sounding in Storm Lab

The text

As transmitted.

091 
WGUS51 KCTP 290146
FFWCTP
PAC013-021-027-033-061-290445-
/O.NEW.KCTP.FF.W.0018.170729T0146Z-170729T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service State College PA
946 PM EDT FRI JUL 28 2017

The National Weather Service in State College PA has issued a

* Flash Flood Warning for...
  Southwestern Clearfield County in central Pennsylvania...
  Northern Huntingdon County in central Pennsylvania...
  Southwestern Centre County in central Pennsylvania...
  Northeastern Blair County in central Pennsylvania...
  Northeastern Cambria County in central Pennsylvania...

* Until 1245 AM EDT.

* At 943 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area.  Up to 4 inches of rain has 
  already fallen during the past 3 hours on Pine grove Mountain just 
  to the south of State College, with similar amounts falling near 
  the Clearfield...Cambria County border. Flash flooding is expected 
  to begin shortly. 

* Some locations that will experience flooding include...
  State College, Tyrone, Altoona, Whipple Dam State Park, Pine Grove
  Mills, Houserville, Northern Cambria, Bellwood, Osceola Mills and
  Spruce Creek.

Additional rainfall amounts of 1 to 2 inches is likely in the warned 
area between 945 pm and midnight.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

Please report flooding to your local law enforcement agency when you
can do so safely.

&&

LAT...LON 4072 7880 4090 7881 4082 7767 4075 7764
      4073 7768 4068 7770 4068 7768 4063 7777
      4056 7783 4054 7846 4062 7885

$$

Lambert

1 follow-up statement

651 
WGUS71 KCTP 290347
FFSCTP

Flash Flood Statement
National Weather Service State College PA
1147 PM EDT FRI JUL 28 2017

PAC013-021-027-033-061-290445-
/O.CON.KCTP.FF.W.0018.000000T0000Z-170729T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clearfield PA-Huntingdon PA-Centre PA-Blair PA-Cambria PA-
1147 PM EDT FRI JUL 28 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1245 AM EDT FOR
SOUTHWESTERN CLEARFIELD...NORTHERN HUNTINGDON...SOUTHWESTERN
CENTRE...NORTHEASTERN BLAIR AND NORTHEASTERN CAMBRIA COUNTIES...

At 1141 PM EDT, Doppler radar indicated a nearly stationary area of 
moderate to heavy rain with a few embedded thunderstorms over the 
warned area. Widespread rainfall amounts of 1 to 2 inches have 
already occurred over the past several hours, with a few locations 
across Southern Clearfield County and Northern Huntingdon County 
receiving as much as 4 inches. 

Although rainfall rates have gradually decreased over the past 1 to 
2 hours, localized Flash flooding is still expected.

Some locations that will experience flooding include...
State College, Tyrone, Altoona, Whipple Dam State Park, Pine Grove
Mills, Houserville, Northern Cambria, Bellwood, Osceola Mills and
Spruce Creek.

Additional rainfall amounts of one half of an inch to one inch 
are possible in the warned area between 1145 pm and 1245 am Saturday.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles. Be especially cautious at night when it is 
harder to recognize the dangers of flooding.

Please report flooding to your local law enforcement agency when you
can do so safely.

&&

LAT...LON 4072 7880 4090 7881 4082 7767 4075 7764
      4073 7768 4068 7770 4068 7768 4063 7777
      4056 7783 4054 7846 4062 7885

$$

Lambert

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 28, 8:25 PM EDT	Areal Flood Advisory	CTP	Adams, Bedford, Blair, Cambria, Centre, Clearfield and 9 more	3 hr
Jul 28, 9:28 PM EDT	Areal Flood Advisory	CTP	Lancaster, Lebanon	2 hr
Jul 28, 10:09 PM EDT	Flash Flood Warning	CTP	Cumberland, Franklin, Fulton, Huntingdon, Juniata, Mifflin and 1 more	3 hr
Jul 28, 11:33 PM EDT	Areal Flood Advisory	CTP	Adams, Lancaster, York	3 hr
Jul 29, 5:06 AM EDT	Areal Flood Advisory	CTP	Somerset	3 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2017 Every flash flood warning in 2017

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.