Alert archive / Pennsylvania / Severe Thunderstorm Watches in 2013

Severe Thunderstorm Watch 558

November 1, 20134 states

The Storm Prediction Center issued this severe thunderstorm watch at Nov 1, 2013, 4:17 AM EDT for 4 states. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Nov 1, 2013, 4:17 AM EDT (08:17 UTC)
Expired
Nov 1, 2013, 8:30 AM EDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt
All 52 counties

Allegany County, MD, Carroll County, MD, Frederick County, MD, Washington County, MD, Adams County, PA, Bedford County, PA, Blair County, PA, Cambria County, PA, Cameron County, PA, Centre County, PA, Clearfield County, PA, Clinton County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Elk County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Juniata County, PA, Lancaster County, PA, Lebanon County, PA, Lycoming County, PA, McKean County, PA, Mifflin County, PA, Montour County, PA, Northumberland County, PA, Perry County, PA, Potter County, PA, Schuylkill County, PA, Snyder County, PA, Somerset County, PA, Sullivan County, PA, Tioga County, PA, Union County, PA, York County, PA, City of Harrisonburg, VA, City of Winchester, VA, Clarke County, VA, Frederick County, VA, Loudoun County, VA, Rockingham County, VA, Shenandoah County, VA, Warren County, VA, Berkeley County, WV, Grant County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Mineral County, WV, Morgan County, WV, Pendleton County, WV

The radar

The State College radar (KCCX), 46 km from the middle of the area, began a volume at 08:17 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
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
50%
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
Nov 1, 4:22 AM EDTSevere Thunderstorm WarningCTPCameron, Clinton, Elk, McKean, Potter53 min
Nov 1, 4:27 AM EDTSevere Thunderstorm WarningLWXAllegany63 min
Nov 1, 4:59 AM EDTSevere Thunderstorm WarningCTPBedford, Blair, Cambria, Cameron, Centre, Clearfield and 6 more61 min
Nov 1, 5:13 AM EDTSevere Thunderstorm WarningCTPCameron, Clinton, Lycoming, Potter, Tioga62 min
Nov 1, 5:28 AM EDTSevere Thunderstorm WarningLWXAllegany, Washington62 min
Nov 1, 5:38 AM EDTSevere Thunderstorm WarningCTPAdams, Centre, Clinton, Cumberland, Dauphin, Franklin and 11 more52 min
Nov 1, 6:00 AM EDTSevere Thunderstorm WarningCTPLycoming, Tioga45 min
Nov 1, 6:16 AM EDTSevere Thunderstorm WarningLWXFrederick, Washington44 min
Nov 1, 6:29 AM EDTSevere Thunderstorm WarningCTPAdams, Columbia, Cumberland, Dauphin, Franklin, Juniata and 11 more61 min
Nov 1, 7:35 AM EDTSevere Thunderstorm WarningCTPLancaster, York55 min
Nov 1, 7:39 AM EDTSevere Thunderstorm WarningLWXBaltimore, Carroll, Harford51 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

Pittsburgh, PA (KAGC), launched 00:00Z, 8.3 hours before the alert went out and 167 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, Pittsburgh, PA at 00:00Z on 2013-11-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Pittsburgh, PA at 00:00Z on 2013-11-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 817 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
643 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
817 m²/s²
0-3 km storm-relative helicity
902 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
Nov 1, 12:46 AM EDTSevere Thunderstorm WatchSPCGarrett5 hr
Nov 1, 3:37 AM EDTMesoscale DiscussionSPCAllegany, Carroll, Frederick, Garrett, Washington83 min
Nov 1, 5:41 AM EDTMesoscale DiscussionSPCCarroll, Washington94 min
Oct 31, 10:09 PM EDTSevere Thunderstorm WatchSPCCrawford, Erie6 hr
Nov 1, 12:39 AM EDTMesoscale DiscussionSPCCrawford96 min
Nov 1, 6:25 AM EDTSevere Thunderstorm WatchSPCBerks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more5 hr
Nov 1, 8:34 AM EDTMesoscale DiscussionSPCBucks, Chester, Delaware, Montgomery, Northampton, Philadelphia86 min

Nearby

Severe Thunderstorm Watches in Pennsylvania, 2013Severe Thunderstorm Watches in Virginia, 2013Severe Thunderstorm Watches in West Virginia, 2013Every severe thunderstorm 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.