Alert archive / Maryland / Flash Flood Warnings in 2013

Flash Flood Warning 47, NWS Baltimore/Washington

June 18, 2013Calvert County, Maryland

NWS Baltimore/Washington issued this flash flood warning at Jun 18, 2013, 4:51 PM EDT for Calvert County, Maryland. It was in force for 3 hr. 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 18, 2013, 4:51 PM EDT (20:51 UTC)
Expired: Jun 18, 2013, 7:45 PM EDT
In force: 3 hr
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon
Flood severity: None

County Calvert County, MD

The radar

The Sterling radar (KLWX), 96 km from the middle of the area, began a volume at 20:53 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 8.9 hours before the alert went out and 110 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: 811 J/kg
Mixed-layer CIN: -63 J/kg
Mixed-layer LCL: 833 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 34 m²/s²
0-3 km storm-relative helicity: 89 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.3

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood 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 flash flood warning went out at Jun 18, 3:39 PM EDT, 1 hour 12 minutes earlier.

Area forecast discussion, Jun 18, 3:39 PM EDT, 1 hour 12 minutes before

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Hazardous weather outlook, Jun 18, 3:21 PM EDT, 1 hour 30 minutes before

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In the hours before

Local storm report, Jun 18, 4:31 PM EDT, 20 minutes before

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Local storm report, Jun 18, 4:35 PM EDT, 16 minutes before

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Local storm report, Jun 18, 4:38 PM EDT, 13 minutes before

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Local storm report, Jun 18, 4:44 PM EDT, 7 minutes before

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Local storm report, Jun 18, 4:45 PM EDT, 6 minutes before

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Local storm report, Jun 18, 4:51 PM EDT, 0 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 17, 8:15 PM EDT	Flash Flood Warning	LWX	Albemarle, Augusta, Nelson, City of Charlottesville, City of Staunton, City of Waynesboro	3 hr
Jun 17, 10:53 PM EDT	Areal Flood Warning	LWX	Albemarle, Augusta, Nelson, Rockingham, City of Charlottesville, City of Staunton and 1 more	6 hr
Jun 18, 3:54 AM EDT	Flash Flood Watch	LWX	Arlington, Clarke, Culpeper, Fairfax, Fauquier, Frederick and 21 more	13 hr
Jun 18, 1:05 PM EDT	Areal Flood Warning	LWX	Albemarle, Nelson	6 hr
Jun 18, 1:29 PM EDT	Areal Flood Warning	LWX	Frederick, City of Winchester	6 hr
Jun 18, 1:37 PM EDT	Flash Flood Warning	LWX	Greene, Madison, Orange	3 hr
Jun 18, 2:56 PM EDT	Special Marine Warning	LWX		94 min
Jun 18, 4:29 PM EDT	Special Marine Warning	LWX		91 min
Jun 18, 5:54 PM EDT	Special Marine Warning	LWX		66 min
Jun 18, 1:58 PM EDT	Flash Flood Warning	LWX	Anne Arundel, Calvert, Charles, Prince George's	3 hr

Nearby

Flash Flood Warnings in Maryland, 2013 Every flash flood warning 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.