Alert archive / Maryland / Mesoscale Discussions in 2020

Mesoscale Discussion 1671

September 2, 20205 states

The Storm Prediction Center issued this mesoscale discussion at Sep 2, 2020, 8:20 PM EDT for 5 states. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued: Sep 2, 2020, 8:20 PM EDT (00:20 UTC)
Expired: Sep 2, 2020, 10:15 PM EDT
In force: 115 min
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 484

All 30 counties

Kent County, DE, New Castle County, DE, Anne Arundel County, MD, Baltimore County, MD, Caroline County, MD, Cecil County, MD, City of Baltimore, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Talbot County, MD, Camden County, NJ, Cumberland County, NJ, Gloucester County, NJ, Salem County, NJ, Berks County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Lancaster County, PA, Montgomery County, PA, Philadelphia County, PA, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, Fairfax County, VA

The radar

The Dover AFB radar (KDOX), 96 km from the middle of the area, began a volume at 00:20 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

Wallops Is Stn, VA (KWAL), launched 00:00Z, 0.3 hours before the alert went out and 178 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: 928 J/kg
Mixed-layer CIN: -62 J/kg
Mixed-layer LCL: 889 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 64 m²/s²
0-3 km storm-relative helicity: 99 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 2.0

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
Sep 3, 3:06 PM EDT	Mesoscale Discussion	SPC	Kent, New Castle, Sussex	114 min
Sep 3, 3:42 PM EDT	Tornado Watch	SPC	Kent, New Castle, Sussex	6 hr
Sep 3, 6:18 PM EDT	Mesoscale Discussion	SPC	Kent, Sussex	117 min

Nearby

Mesoscale Discussions in Maryland, 2020 Mesoscale Discussions in Pennsylvania, 2020 Mesoscale Discussions in Virginia, 2020 Every mesoscale discussion in 2020

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.