Alert archive / Pennsylvania / Flash Flood Watches in 2009

Flash Flood Watch 4, NWS State College, PA

July 26, 20099 counties in Pennsylvania

NWS State College, PA issued this flash flood watch at Jul 26, 2009, 3:40 AM EDT for 9 counties in Pennsylvania. It took effect at Jul 26, 2009, 12:00 PM EDT. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued: Jul 26, 2009, 3:40 AM EDT (07:40 UTC)
In effect from: Jul 26, 2009, 12:00 PM EDT
Expired: Jul 26, 2009, 7:59 PM EDT
In force: 8 hr
Issued by: NWS State College, PA
Flood severity: None

Counties Adams County, PA, Cumberland County, PA, Dauphin County, PA, Franklin County, PA, Lancaster County, PA, Lebanon County, PA, Perry County, PA, Schuylkill County, PA, York County, PA

The radar

The State College radar (KCCX), 125 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 7.7 hours before the alert went out and 146 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: 754 J/kg
Mixed-layer CIN: -69 J/kg
Mixed-layer LCL: 1179 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 207 m²/s²
0-3 km storm-relative helicity: 220 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 4.1

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 State College, PA wrote its last area forecast discussion before this flash flood watch went out at Jul 26, 1:57 AM EDT, 1 hour 43 minutes earlier.

Area forecast discussion, Jul 26, 1:57 AM EDT, 1 hour 43 minutes before

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Hazardous weather outlook, Jul 25, 8:04 PM EDT, 7 hours 36 minutes before

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In the hours before

Special weather statement, Jul 26, 12:28 AM EDT, 3 hours 12 minutes before

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Special weather statement, Jul 26, 2:13 AM EDT, 1 hour 27 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 26, 12:28 AM EDT	Special Weather Statement	CTP	Adams	62 min
Jul 26, 2:13 AM EDT	Special Weather Statement	CTP	Lancaster	17 min
Jul 26, 2:11 PM EDT	Special Weather Statement	CTP	Clinton	34 min
Jul 26, 2:39 PM EDT	Special Weather Statement	CTP	Tioga	36 min
Jul 26, 3:46 PM EDT	Special Weather Statement	CTP	Lycoming	29 min
Jul 26, 4:17 PM EDT	Special Weather Statement	CTP	Sullivan	28 min
Jul 26, 4:51 PM EDT	Special Weather Statement	CTP	York	24 min
Jul 26, 5:35 PM EDT	Special Weather Statement	CTP	Lancaster	25 min
Jul 26, 6:11 PM EDT	Special Weather Statement	CTP	Lancaster	19 min
Jul 26, 6:16 PM EDT	Special Weather Statement	CTP	Lancaster	29 min
Jul 26, 6:41 PM EDT	Special Weather Statement	CTP	Lancaster	34 min
Jul 26, 7:02 PM EDT	Special Weather Statement	CTP	Warren	28 min
Jul 26, 7:30 PM EDT	Special Weather Statement	CTP	Lancaster	45 min

Nearby

Flash Flood Watches in Pennsylvania, 2009 Every flash flood watch in 2009

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.