Alert archive / Pennsylvania / Flash Flood Watches in 2007

Flash Flood Watch 1, NWS Pittsburgh, PA

July 19, 200712 counties in Pennsylvania; 11 counties in Ohio; 6 counties in West Virginia

NWS Pittsburgh, PA issued this flash flood watch at Jul 19, 2007, 3:40 AM EDT for 12 counties in Pennsylvania; 11 counties in Ohio; 6 counties in West Virginia. It was in force for 17 hr.

The area

The counties it named.

The facts

Issued: Jul 19, 2007, 3:40 AM EDT (07:40 UTC)
Expired: Jul 19, 2007, 9:05 PM EDT
In force: 17 hr
Issued by: NWS Pittsburgh, PA
Flood severity: None

All 29 counties

Belmont County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Guernsey County, OH, Harrison County, OH, Jefferson County, OH, Monroe County, OH, Muskingum County, OH, Noble County, OH, Tuscarawas County, OH, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Butler County, PA, Clarion County, PA, Forest County, PA, Greene County, PA, Jefferson County, PA, Lawrence County, PA, Mercer County, PA, Venango County, PA, Washington County, PA, Brooke County, WV, Hancock County, WV, Marion County, WV, Marshall County, WV, Ohio County, WV, Wetzel County, WV

The radar

The Pittsburgh radar (KPBZ), 29 km from the middle of the area, began a volume at 07:40 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, 7.7 hours before the alert went out and 37 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: 412 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 1031 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 38 m²/s²
0-3 km storm-relative helicity: 97 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

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 18, 2:29 PM EDT, 13 hours 11 minutes earlier.

Area forecast discussion, Jul 18, 2:29 PM EDT, 13 hours 11 minutes before

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Hazardous weather outlook, Jul 18, 4:09 AM EDT, 23 hours 31 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 19, 2:00 AM EDT	Severe Thunderstorm Warning	PBZ	Jefferson	30 min
Jul 19, 3:21 AM EDT	Flash Flood Warning	PBZ	Coshocton	6 hr

Nearby

Flash Flood Watches in Pennsylvania, 2007 Flash Flood Watches in Ohio, 2007 Flash Flood Watches in West Virginia, 2007 Every flash flood watch in 2007

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.