Alert archive / Pennsylvania / Tornado Watches in 2013

Tornado Watch 133

April 19, 201336 counties in Pennsylvania

The Storm Prediction Center issued this tornado watch at Apr 19, 2013, 3:55 PM EDT for 36 counties in Pennsylvania. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Apr 19, 2013, 3:55 PM EDT (19:55 UTC)
Expired
Apr 19, 2013, 9:27 PM EDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt
All 36 counties

Adams County, PA, Berks County, PA, Bradford County, PA, Carbon County, PA, Centre County, PA, Chester County, PA, Clinton County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Juniata County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Lycoming County, PA, Mifflin County, PA, Monroe County, PA, Montour County, PA, Northampton County, PA, Northumberland County, PA, Perry County, PA, Pike County, PA, Schuylkill County, PA, Snyder County, PA, Sullivan County, PA, Susquehanna County, PA, Tioga County, PA, Union County, PA, Wayne County, PA, Wyoming County, PA, York County, PA

The radar

The State College radar (KCCX), 93 km from the middle of the area, began a volume at 19:57 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
5%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

11 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Apr 19, 4:10 PM EDTSevere Thunderstorm WarningCTPBedford, Blair, Centre, Clearfield, Clinton, Huntingdon and 4 more80 min
Apr 19, 5:37 PM EDTSevere Thunderstorm WarningBGMBradford38 min
Apr 19, 6:14 PM EDTSevere Thunderstorm WarningBGMBradford46 min
Apr 19, 6:22 PM EDTSevere Thunderstorm WarningCTPColumbia, Dauphin, Juniata, Lebanon, Lycoming, Montour and 5 more83 min
Apr 19, 6:27 PM EDTTornado WarningBGMBradford, Susquehanna33 min
Apr 19, 6:39 PM EDTSevere Thunderstorm WarningCTPAdams, Cumberland, Dauphin, Lancaster, Lebanon, York81 min
Apr 19, 6:50 PM EDTSevere Thunderstorm WarningBGMBradford, Lackawanna, Luzerne, Susquehanna, Wyoming40 min
Apr 19, 6:58 PM EDTTornado WarningBGMBradford, Susquehanna62 min
Apr 19, 7:29 PM EDTSevere Thunderstorm WarningBGMLackawanna, Luzerne, Pike, Susquehanna, Wayne, Wyoming61 min
Apr 19, 7:45 PM EDTSevere Thunderstorm WarningPHICarbon45 min
Apr 19, 8:06 PM EDTSevere Thunderstorm WarningBGMPike, Wayne54 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 7.9 hours before the alert went out and 193 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-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2013-04-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 16 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2013-04-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 215 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
16 J/kg
Mixed-layer CIN
-37 J/kg
Mixed-layer LCL
705 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
215 m²/s²
0-3 km storm-relative helicity
226 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 19, 1:27 PM EDTMesoscale DiscussionSPCAdams, Chester, Lancaster, York63 min
Apr 19, 3:36 PM EDTMesoscale DiscussionSPCAdams, Berks, Bradford, Carbon, Chester, Columbia and 25 more54 min
Apr 19, 6:02 PM EDTMesoscale DiscussionSPCAdams, Berks, Bradford, Carbon, Chester, Columbia and 21 more58 min
Apr 19, 7:12 PM EDTMesoscale DiscussionSPCBucks, Delaware, Montgomery, Philadelphia93 min

Nearby

Tornado Watches in Pennsylvania, 2013Every tornado watch in 2013

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.