Alert archive / Maryland / Mesoscale Discussions in 2016

Mesoscale Discussion 1073

June 28, 20169 counties in Maryland; 5 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at Jun 28, 2016, 3:49 PM EDT for 9 counties in Maryland; 5 counties in Pennsylvania. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued: Jun 28, 2016, 3:49 PM EDT (19:49 UTC)
Expired: Jun 28, 2016, 4:45 PM EDT
In force: 56 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Baltimore County, MD, Carroll County, MD, Cecil County, MD, City of Baltimore, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Montgomery County, MD, Prince George's County, MD, Berks County, PA, Chester County, PA, Lancaster County, PA, Lehigh County, PA, York County, PA

The radar

The Sterling radar (KLWX), 112 km from the middle of the area, began a volume at 19:51 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 305Jun 28, 4:10 PM EDT

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 7.8 hours before the alert went out and 109 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: 341 J/kg
Mixed-layer CIN: -73 J/kg
Mixed-layer LCL: 1019 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: -39 m²/s²
0-3 km storm-relative helicity: 70 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.4

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 28, 4:09 PM EDT	Severe Thunderstorm Watch	SPC	Anne Arundel, Baltimore, Carroll, Cecil, Charles, Frederick and 8 more	7 hr
Jun 28, 7:16 PM EDT	Mesoscale Discussion	SPC	Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 9 more	59 min
Jun 28, 1:09 PM EDT	Mesoscale Discussion	SPC	Bradford, Carbon, Clinton, Columbia, Lackawanna, Luzerne and 11 more	66 min

Nearby

Mesoscale Discussions in Maryland, 2016 Mesoscale Discussions in Pennsylvania, 2016 Every mesoscale discussion in 2016

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.