Alert archive / Pennsylvania / Flood Watches in 2011

Flood Watch 7, NWS Pittsburgh, PA

May 18, 20115 counties in Pennsylvania; 5 counties in West Virginia

NWS Pittsburgh, PA issued this flood watch at May 18, 2011, 2:41 AM EDT for 5 counties in Pennsylvania; 5 counties in West Virginia. It was in force for 16 hr.

The area

The counties it named.

The facts

Issued: May 18, 2011, 2:41 AM EDT (06:41 UTC)
Expired: May 18, 2011, 6:33 PM EDT
In force: 16 hr
Issued by: NWS Pittsburgh, PA
Flood severity: None

Counties Allegheny County, PA, Fayette County, PA, Greene County, PA, Washington County, PA, Westmoreland County, PA, Brooke County, WV, Marion County, WV, Marshall County, WV, Ohio County, WV, Wetzel County, WV

The radar

The Pittsburgh radar (KPBZ), 58 km from the middle of the area, began a volume at 06:41 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 6.7 hours before the alert went out and 270 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: 503 J/kg
Mixed-layer CIN: -8 J/kg
Mixed-layer LCL: 868 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 127 m²/s²
0-3 km storm-relative helicity: 159 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.4

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this 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 flood watch went out at May 18, 1:49 AM EDT, 52 minutes earlier.

Area forecast discussion, May 18, 1:49 AM EDT, 52 minutes before

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Hazardous weather outlook, May 17, 8:58 PM EDT, 5 hours 43 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
May 17, 10:02 PM EDT	River Flood Advisory	PBZ	Allegheny	64 hr
May 18, 7:25 AM EDT	Special Weather Statement	PBZ	Allegheny, Lawrence, Westmoreland	50 min
May 18, 11:56 AM EDT	Special Weather Statement	PBZ	Allegheny	49 min
May 18, 12:51 PM EDT	Special Weather Statement	PBZ	Beaver	39 min
May 18, 1:21 PM EDT	Special Weather Statement	PBZ	Greene	39 min
May 18, 1:32 PM EDT	Special Weather Statement	PBZ	Butler, Lawrence	43 min
May 18, 1:37 PM EDT	Severe Thunderstorm Warning	PBZ	Greene	53 min
May 18, 1:51 PM EDT	Special Weather Statement	PBZ	Allegheny, Westmoreland	54 min
May 18, 2:12 PM EDT	Areal Flood Warning	PBZ	Westmoreland	4 hr
May 18, 2:27 PM EDT	Severe Thunderstorm Warning	PBZ	Greene, Washington	48 min
May 18, 2:34 PM EDT	Special Weather Statement	PBZ	Mercer	56 min
May 18, 2:53 PM EDT	Severe Thunderstorm Warning	PBZ	Washington	52 min
May 18, 2:58 PM EDT	Flash Flood Warning	PBZ	Greene	62 min
May 18, 3:45 PM EDT	Areal Flood Advisory	PBZ	Washington	3 hr
May 18, 4:34 PM EDT	Special Weather Statement	PBZ	Allegheny	41 min
May 18, 4:38 PM EDT	Special Weather Statement	PBZ	Allegheny	37 min
May 18, 5:15 PM EDT	Special Weather Statement	PBZ	Butler, Lawrence	45 min
May 18, 6:07 PM EDT	Special Weather Statement	PBZ	Lawrence	38 min
May 18, 2:26 PM EDT	Special Weather Statement	PBZ	Jefferson	49 min
May 18, 2:32 PM EDT	Severe Thunderstorm Warning	PBZ	Carroll, Columbiana, Jefferson	43 min
May 18, 5:19 PM EDT	Special Weather Statement	PBZ	Belmont, Harrison	41 min
May 18, 5:44 PM EDT	Special Weather Statement	PBZ	Carroll	31 min
May 18, 6:03 PM EDT	Special Weather Statement	PBZ	Belmont	42 min

Nearby

Flood Watches in Pennsylvania, 2011 Flood Watches in West Virginia, 2011 Every 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.