Alert archive / Pennsylvania / Severe Thunderstorm Watches in 2015

Severe Thunderstorm Watch 372

June 30, 20155 states

The Storm Prediction Center issued this severe thunderstorm watch at Jun 30, 2015, 1:21 PM EDT for 5 states. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Jun 30, 2015, 1:21 PM EDT (17:21 UTC)
Expired: Jun 30, 2015, 8:00 PM EDT
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 80 counties

Kent County, DE, New Castle County, DE, Anne Arundel County, MD, Baltimore County, MD, Caroline County, MD, Carroll County, MD, Cecil County, MD, City of Baltimore, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Queen Anne's County, MD, Talbot County, MD, Washington County, MD, Camden County, NJ, Cumberland County, NJ, Essex County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Morris County, NJ, Passaic County, NJ, Salem County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Orange County, NY, Sullivan County, NY, Adams County, PA, Bedford County, PA, Berks County, PA, Blair County, PA, Bradford County, PA, Bucks County, PA, Cambria County, PA, Cameron County, PA, Carbon County, PA, Centre County, PA, Chester County, PA, Clearfield County, PA, Clinton County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Delaware County, PA, Elk 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, McKean County, PA, Mifflin County, PA, Monroe County, PA, Montgomery County, PA, Montour County, PA, Northampton County, PA, Northumberland County, PA, Perry County, PA, Philadelphia County, PA, Pike County, PA, Potter County, PA, Schuylkill County, PA, Snyder County, PA, Somerset County, PA, Sullivan County, PA, Susquehanna County, PA, Tioga County, PA, Union County, PA, Warren County, PA, Wayne County, PA, Wyoming County, PA, York County, PA

The radar

The State College radar (KCCX), 87 km from the middle of the area, began a volume at 17:22 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: 20%
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: 50%
One or more hailstones of 2 inches or more: 30%
Six or more combined severe hail and wind reports: 70%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jun 30, 1:48 PM EDT	Flash Flood Warning	PHI	Berks	4 hr
Jun 30, 1:54 PM EDT	Severe Thunderstorm Warning	CTP	Lancaster, York	66 min
Jun 30, 2:00 PM EDT	Tornado Warning	PHI	Berks, Chester	30 min
Jun 30, 2:05 PM EDT	Tornado Warning	CTP	Lancaster	25 min
Jun 30, 2:05 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Carbon, Lehigh, Monroe, Northampton	55 min
Jun 30, 2:13 PM EDT	Tornado Warning	PHI	Lehigh	32 min
Jun 30, 2:15 PM EDT	Severe Thunderstorm Warning	LWX	Harford	34 min
Jun 30, 2:26 PM EDT	Flash Flood Warning	CTP	Lancaster, York	3 hr
Jun 30, 2:34 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	56 min
Jun 30, 2:41 PM EDT	Severe Thunderstorm Warning	PHI	Cecil	49 min
Jun 30, 2:42 PM EDT	Tornado Warning	PHI	Lehigh, Northampton	33 min
Jun 30, 2:52 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery	38 min
Jun 30, 2:55 PM EDT	Flash Flood Warning	PHI	Berks, Lehigh, Northampton	4 hr
Jun 30, 3:00 PM EDT	Severe Thunderstorm Warning	PHI	Warren	60 min
Jun 30, 3:07 PM EDT	Severe Thunderstorm Warning	CTP	Mifflin, Snyder, Union	53 min
Jun 30, 3:14 PM EDT	Severe Thunderstorm Warning	LWX	Anne Arundel, Baltimore, Harford	46 min
Jun 30, 3:22 PM EDT	Tornado Warning	PHI	Chester, Delaware, Montgomery	23 min
Jun 30, 3:25 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	37 min
Jun 30, 3:28 PM EDT	Tornado Warning	CTP	Snyder, Union	47 min
Jun 30, 3:43 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	47 min
Jun 30, 3:45 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	45 min
Jun 30, 3:47 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Morris, Sussex, Warren	43 min
Jun 30, 3:51 PM EDT	Flash Flood Warning	LWX	Harford	114 min
Jun 30, 3:58 PM EDT	Flash Flood Warning	CTP	Schuylkill	3 hr
Jun 30, 4:05 PM EDT	Severe Thunderstorm Warning	CTP	Columbia, Montour, Northumberland	55 min
Jun 30, 4:24 PM EDT	Severe Thunderstorm Warning	CTP	Schuylkill	66 min
Jun 30, 4:32 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Kent, Queen Anne's, Talbot	43 min
Jun 30, 4:43 PM EDT	Severe Thunderstorm Warning	CTP	Lancaster, Lebanon	77 min
Jun 30, 6:03 PM EDT	Flash Flood Warning	PHI	Carbon, Monroe	11 hr
Jun 30, 6:28 PM EDT	Severe Thunderstorm Warning	PHI	Sussex, Warren	47 min
Jun 30, 7:13 PM EDT	Severe Thunderstorm Warning	PHI	Sussex, Warren	62 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 5.4 hours before the alert went out and 179 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: 600 J/kg
Mixed-layer CIN: -45 J/kg
Mixed-layer LCL: 728 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 128 m²/s²
0-3 km storm-relative helicity: 128 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 2.9

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 30, 12:31 PM EDT	Mesoscale Discussion	SPC	New Castle	2 hr
Jun 30, 4:15 PM EDT	Mesoscale Discussion	SPC	Kent, New Castle	2 hr
Jun 30, 12:58 PM EDT	Severe Thunderstorm Watch	SPC	Garrett	8 hr
Jun 30, 1:38 PM EDT	Mesoscale Discussion	SPC	Charles, Saint Mary's	3 hr
Jun 30, 2:22 PM EDT	Severe Thunderstorm Watch	SPC	Allegany, Calvert, Charles, Montgomery, Prince George's, Saint Mary's	7 hr
Jun 30, 3:34 PM EDT	Severe Thunderstorm Watch	SPC	Dorchester	6 hr
Jun 30, 3:48 PM EDT	Mesoscale Discussion	SPC	Allegany, Garrett, Washington	117 min
Jun 30, 7:38 PM EDT	Mesoscale Discussion	SPC	Allegany, Garrett	67 min
Jun 30, 2:57 PM EDT	Mesoscale Discussion	SPC	Warren	63 min
Jun 30, 3:18 PM EDT	Mesoscale Discussion	SPC	Allegany, Cayuga, Chemung, Chenango, Cortland, Livingston and 8 more	2 hr
Jun 30, 12:03 PM EDT	Mesoscale Discussion	SPC	Allegheny, Beaver, Greene, Lawrence, Washington	2 hr
Jun 30, 12:55 PM EDT	Mesoscale Discussion	SPC	Boone, Clay, Fayette, Greenbrier, Hardy, Kanawha and 15 more	3 hr
Jun 30, 1:37 PM EDT	Severe Thunderstorm Watch	SPC	Boone, Braxton, Cabell, Calhoun, Clay, Fayette and 17 more	7 hr
Jun 30, 7:08 PM EDT	Mesoscale Discussion	SPC	Boone, Braxton, Cabell, Calhoun, Clay, Fayette and 14 more	67 min

Nearby

Severe Thunderstorm Watches in Pennsylvania, 2015 Severe Thunderstorm Watches in Maryland, 2015 Severe Thunderstorm Watches in New Jersey, 2015 Every severe thunderstorm watch in 2015

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.