Alert archive / Pennsylvania / Flash Flood Watches in 2012

Flash Flood Watch 5, NWS Pittsburgh, PA

July 27, 20128 counties in Pennsylvania

NWS Pittsburgh, PA issued this flash flood watch at Jul 27, 2012, 3:21 PM EDT for 8 counties in Pennsylvania. It took effect at Jul 27, 2012, 6:00 PM EDT. It was in force for 10 hr.

The area

The counties it named.

The facts

Issued: Jul 27, 2012, 3:21 PM EDT (19:21 UTC)
In effect from: Jul 27, 2012, 6:00 PM EDT
Expired: Jul 28, 2012, 4:00 AM EDT
In force: 10 hr
Issued by: NWS Pittsburgh, PA
Flood severity: None

Counties Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Butler County, PA, Clarion County, PA, Fayette County, PA, Jefferson County, PA, Westmoreland County, PA

The radar

The Pittsburgh radar (KPBZ), 50 km from the middle of the area, began a volume at 19:22 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 12:00Z, 7.4 hours before the alert went out and 48 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: 224 J/kg
Mixed-layer CIN: -27 J/kg
Mixed-layer LCL: 670 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: -19 m²/s²
0-3 km storm-relative helicity: 35 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

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 Jul 27, 1:32 PM EDT, 1 hour 49 minutes earlier.

Area forecast discussion, Jul 27, 1:32 PM EDT, 1 hour 49 minutes before

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Hazardous weather outlook, Jul 27, 4:29 AM EDT, 10 hours 52 minutes before

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In the hours before

Local storm report, Jul 27, 10:14 AM EDT, 5 hours 7 minutes before

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Local storm report, Jul 27, 10:19 AM EDT, 5 hours 2 minutes before

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Local storm report, Jul 27, 10:20 AM EDT, 5 hours 1 minute before

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Special weather statement, Jul 27, 1:08 PM EDT, 2 hours 13 minutes before

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Special weather statement, Jul 27, 1:36 PM EDT, 1 hour 45 minutes before

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Special weather statement, Jul 27, 3:07 PM EDT, 14 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
Jul 26, 8:09 PM EDT	Special Weather Statement	PBZ	Butler, Lawrence, Mercer	66 min
Jul 26, 10:08 PM EDT	Areal Flood Warning	PBZ	Indiana	11 hr
Jul 27, 1:08 PM EDT	Special Weather Statement	PBZ	Butler	37 min
Jul 27, 1:36 PM EDT	Special Weather Statement	PBZ	Forest, Venango	39 min
Jul 27, 3:07 PM EDT	Special Weather Statement	PBZ	Jefferson	38 min
Jul 27, 3:35 PM EDT	Special Weather Statement	PBZ	Beaver	40 min
Jul 27, 4:20 PM EDT	Special Weather Statement	PBZ	Armstrong	40 min
Jul 27, 4:37 PM EDT	Special Weather Statement	PBZ	Washington	38 min
Jul 27, 5:03 PM EDT	Special Weather Statement	PBZ	Armstrong, Indiana	57 min
Jul 27, 5:19 PM EDT	Special Weather Statement	PBZ	Washington	41 min
Jul 27, 6:26 PM EDT	Special Weather Statement	PBZ	Armstrong, Butler, Clarion, Jefferson	64 min
Jul 27, 3:44 PM EDT	Special Weather Statement	PBZ	Belmont, Guernsey	46 min
Jul 27, 4:30 PM EDT	Special Weather Statement	PBZ	Belmont	45 min
Jul 27, 6:01 PM EDT	Special Weather Statement	PBZ	Noble	44 min
Jul 27, 6:44 PM EDT	Special Weather Statement	PBZ	Monroe, Noble	46 min
Jul 26, 8:30 PM EDT	Special Weather Statement	PBZ	Tucker	45 min

Nearby

Flash Flood Watches in Pennsylvania, 2012 Every flash flood watch in 2012

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.