Alert archive / Maryland / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 101, NWS Baltimore/Washington

June 10, 2020Harford County, Maryland

NWS Baltimore/Washington issued this severe thunderstorm warning at Jun 10, 2020, 9:49 PM EDT for Harford County, Maryland. It was in force for 41 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jun 10, 2020, 9:49 PM EDT (01:49 UTC)
Expired: Jun 10, 2020, 10:30 PM EDT
In force: 41 min
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Harford County, MD

The radar

The Dover AFB radar (KDOX), 108 km from the middle of the area, began a volume at 01:51 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 nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 1.8 hours before the alert went out and 115 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: 2039 J/kg
Mixed-layer CIN: -33 J/kg
Mixed-layer LCL: 808 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 127 m²/s²
0-3 km storm-relative helicity: 188 m²/s²
Significant tornado parameter: 1.3
Supercell composite: 7.2

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Baltimore/Washington wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 10, 9:10 PM EDT, 39 minutes earlier.

Area forecast discussion, Jun 10, 9:10 PM EDT, 39 minutes before

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Hazardous weather outlook, Jun 10, 9:32 PM EDT, 17 minutes before

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In the hours before

Local storm report, Jun 10, 7:47 PM EDT, 2 hours 2 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
747 PM EDT WED JUN 10 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0727 PM     TSTM WND DMG     1 NNW DICKERSON         39.24N  77.43W
06/10/2020                   FREDERICK          MD   TRAINED SPOTTER

            TREE DOWN ON POWERLINES

&&

EVENT NUMBER LWX2001196

SMZ

Local storm report, Jun 10, 8:04 PM EDT, 1 hour 45 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
804 PM EDT WED JUN 10 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0724 PM     NON-TSTM WND DMG DICKERSON               39.22N  77.42W
06/10/2020                   MONTGOMERY         MD   911 CALL CENTER

            TREE AND BRANCHES DOWN ON WIRES IN THE 22100 BLOCK OF
            MD-28/DICKERSON ROAD NEAR DICKERSON.

&&

EVENT NUMBER LWX2001197

DH

Local storm report, Jun 10, 8:09 PM EDT, 1 hour 40 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
809 PM EDT WED JUN 10 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0724 PM     TSTM WND DMG     DICKERSON               39.22N  77.42W
06/10/2020                   MONTGOMERY         MD   911 CALL CENTER

            TREE AND BRANCHES DOWN ON WIRES IN THE 22100 BLOCK OF
            MD-28/DICKERSON ROAD NEAR DICKERSON.

&&

CORRECTED EVENT

EVENT NUMBER LWX2001197

DH

Local storm report, Jun 10, 8:11 PM EDT, 1 hour 38 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
811 PM EDT WED JUN 10 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0800 PM     TSTM WND DMG     KENSINGTON              39.03N  77.07W
06/10/2020                   MONTGOMERY         MD   911 CALL CENTER

            MULTIPLE REPORTS OF TREES AND WIRES DOWN IN THE
            KENSINGTON AREA.

&&

EVENT NUMBER LWX2001198

DH

Local storm report, Jun 10, 8:16 PM EDT, 1 hour 33 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
816 PM EDT WED JUN 10 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0754 PM     MARINE TSTM WIND 2 SE COBB ISLAND        38.24N  76.83W
06/10/2020  M39 MPH          ANZ537             MD   BUOY

&&

EVENT NUMBER LWX2001199

DH

Local storm report, Jun 10, 8:29 PM EDT, 1 hour 20 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
829 PM EDT WED JUN 10 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0757 PM     TSTM WND DMG     2 NE GREEN VALLEY       39.37N  77.22W
06/10/2020                   FREDERICK          MD   DEPT OF HIGHWAYS

            TREE DOWN ON I-70 NEAR MILE MARKER 65.

&&

EVENT NUMBER LWX2001200

DH

The office that day

Everything else NWS Baltimore/Washington issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 11, 12:53 AM EDT	Areal Flood Warning	LWX	Culpeper, Fairfax, Fauquier, Loudoun, Prince William	4 hr
Jun 11, 10:59 AM EDT	Special Marine Warning	LWX		32 min
Jun 10, 10:06 PM EDT	Severe Thunderstorm Warning	LWX	Carroll, Frederick, Howard, Montgomery	24 min
Jun 10, 10:24 PM EDT	Severe Thunderstorm Warning	LWX	Baltimore, Carroll, Frederick	26 min
Jun 11, 1:44 AM EDT	Coastal Flood Advisory	LWX	Anne Arundel	10 hr

Nearby

Severe Thunderstorm Warnings in Maryland, 2020 Every severe thunderstorm warning 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.