Alert archive / Pennsylvania / Flash Flood Watches in 2011

Flash Flood Watch 9, NWS Pittsburgh, PA

September 9, 20117 counties in Pennsylvania

NWS Pittsburgh, PA issued this flash flood watch at Sep 9, 2011, 8:33 PM EDT for 7 counties in Pennsylvania. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued: Sep 9, 2011, 8:33 PM EDT (00:33 UTC)
Expired: Sep 10, 2011, 3:14 AM EDT
In force: 7 hr
Issued by: NWS Pittsburgh, PA
Flood severity: None

Counties Armstrong County, PA, Butler County, PA, Clarion County, PA, Forest County, PA, Jefferson County, PA, Mercer County, PA, Venango County, PA

The radar

The Pittsburgh radar (KPBZ), 90 km from the middle of the area, began a volume at 00:36 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.

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 00:00Z, 0.6 hours before the alert went out and 96 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: 1080 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 555 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: -39 m²/s²
0-3 km storm-relative helicity: 21 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Pittsburgh, PA wrote its last area forecast discussion before this flash flood watch went out at Sep 9, 8:21 PM EDT, 12 minutes earlier.

Area forecast discussion, Sep 9, 8:21 PM EDT, 12 minutes before

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Hazardous weather outlook, Sep 9, 8:29 PM EDT, 4 minutes before

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In the hours before

Special weather statement, Sep 9, 8:23 PM EDT, 10 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 9, 8:23 PM EDT	Special Weather Statement	PBZ	Armstrong, Indiana, Jefferson	52 min
Sep 9, 9:25 PM EDT	Special Weather Statement	PBZ	Armstrong, Indiana, Jefferson	50 min
Sep 10, 8:35 AM EDT	Special Weather Statement	PBZ	Indiana	55 min
Sep 10, 9:12 AM EDT	Areal Flood Advisory	PBZ	Indiana, Jefferson	3 hr
Sep 10, 10:48 AM EDT	Areal Flood Warning	PBZ	Armstrong, Clarion, Indiana, Jefferson	4 hr
Sep 10, 4:38 PM EDT	Special Weather Statement	PBZ	Allegheny	52 min
Sep 10, 5:35 PM EDT	Special Weather Statement	PBZ	Westmoreland	55 min
Sep 10, 5:03 PM EDT	Special Weather Statement	PBZ	Brooke	57 min

Nearby

Flash Flood Watches in Pennsylvania, 2011 Every flash flood watch 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.