Alert archive / Pennsylvania / Mesoscale Discussions in 2013

Mesoscale Discussion 540

April 19, 2013Broome County, New York; 27 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at Apr 19, 2013, 6:02 PM EDT for Broome County, New York; 27 counties in Pennsylvania. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued
Apr 19, 2013, 6:02 PM EDT (22:02 UTC)
Expired
Apr 19, 2013, 7:00 PM EDT
In force
58 min
Issued by
the Storm Prediction Center
All 28 counties

Broome County, NY, Adams County, PA, Berks County, PA, Bradford County, PA, Carbon County, PA, Chester County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne 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, Union County, PA, Wayne County, PA, Wyoming County, PA, York County, PA

The radar

The State College radar (KCCX), 141 km from the middle of the area, began a volume at 22:05 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 12:00Z, 10.0 hours before the alert went out and 222 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

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 19, 3:55 PM EDTTornado WatchSPCSullivan6 hr
Apr 19, 4:45 PM EDTMesoscale DiscussionSPCBroome, Cayuga, Chemung, Chenango, Cortland, Delaware and 15 more60 min
Apr 19, 7:12 PM EDTMesoscale DiscussionSPCBronx, Kings, New York, Orange, Putnam, Queens and 3 more93 min
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

Nearby

Mesoscale Discussions in Pennsylvania, 2013Mesoscale Discussions in New York, 2013Every mesoscale discussion 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.