Alert archive / Virginia / Flash Flood Warnings in 2003

Flash Flood Warning 137, NWS Baltimore/Washington

September 23, 2003Fairfax County, City of Fairfax, Virginia; Montgomery County, Maryland

NWS Baltimore/Washington issued this flash flood warning at Sep 23, 2003, 5:43 AM EDT for Fairfax County, City of Fairfax, Virginia; Montgomery County, Maryland. It was in force for 2 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: Sep 23, 2003, 5:43 AM EDT (09:43 UTC)
Expired: Sep 23, 2003, 7:45 AM EDT
In force: 2 hr
Issued by: NWS Baltimore/Washington
Area: Counties, with a storm outline in the text

Counties Montgomery County, MD, City of Fairfax, VA, Fairfax County, VA

The radar

The Sterling radar (KLWX), 20 km from the middle of the area, began a volume at 09:42 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, 9.7 hours before the alert went out and 12 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: 7 J/kg
Mixed-layer CIN: -42 J/kg
Mixed-layer LCL: 918 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 281 m²/s²
0-3 km storm-relative helicity: 400 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

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 Sep 23, 3:50 AM EDT, 1 hour 53 minutes earlier.

Area forecast discussion, Sep 23, 3:50 AM EDT, 1 hour 53 minutes before

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Hazardous weather outlook, Sep 23, 5:12 AM EDT, 31 minutes before

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In the hours before

Local storm report, Sep 23, 3:33 AM EDT, 2 hours 10 minutes before

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Local storm report, Sep 23, 4:00 AM EDT, 1 hour 43 minutes before

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Local storm report, Sep 23, 5:30 AM EDT, 13 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
Sep 23, 1:13 AM EDT	Flash Flood Warning	LWX	Fauquier	3 hr
Sep 23, 1:37 AM EDT	Flash Flood Warning	LWX	Loudoun	3 hr
Sep 23, 1:49 AM EDT	Flash Flood Warning	LWX	Clarke, Warren	3 hr
Sep 23, 4:25 AM EDT	Flash Flood Warning	LWX	Clarke, Fauquier, Loudoun, Warren	3 hr
Sep 23, 7:06 AM EDT	Special Marine Warning	LWX		114 min
Sep 23, 2:25 AM EDT	Flash Flood Warning	LWX	Carroll	3 hr
Sep 23, 2:43 AM EDT	Flash Flood Warning	LWX	Montgomery	3 hr
Sep 23, 5:15 AM EDT	Flash Flood Warning	LWX	Carroll	3 hr

Nearby

Flash Flood Warnings in Virginia, 2003 Flash Flood Warnings in Maryland, 2003 Every flash flood warning in 2003

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.