Alert archive / Virginia / Flash Flood Warnings in 2013

Flash Flood Warning 70, NWS Baltimore/Washington

July 20, 2013Albemarle County, Virginia

NWS Baltimore/Washington issued this flash flood warning at Jul 20, 2013, 4:45 PM EDT for Albemarle County, Virginia. It was in force for 4 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: Jul 20, 2013, 4:45 PM EDT (20:45 UTC)
Expired: Jul 20, 2013, 8:45 PM EDT
In force: 4 hr
Issued by: NWS Baltimore/Washington
Area: Storm-based polygon
Flood severity: None

County Albemarle County, VA

The radar

The Sterling radar (KLWX), 141 km from the middle of the area, began a volume at 20:47 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

Roanoke, VA (KRNK), launched 12:00Z, 8.8 hours before the alert went out and 124 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: 1163 J/kg
Mixed-layer CIN: -14 J/kg
Mixed-layer LCL: 555 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 44 m²/s²
0-3 km storm-relative helicity: 46 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 Jul 20, 2:28 PM EDT, 2 hours 17 minutes earlier.

Area forecast discussion, Jul 20, 2:28 PM EDT, 2 hours 17 minutes before

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Hazardous weather outlook, Jul 20, 1:12 PM EDT, 3 hours 33 minutes before

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In the hours before

Local storm report, Jul 20, 2:23 PM EDT, 2 hours 22 minutes before

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Local storm report, Jul 20, 2:29 PM EDT, 2 hours 16 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
229 PM EDT SAT JUL 20 2013

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

0358 PM     TSTM WND DMG     MILAM                   38.81N  79.10W
07/19/2013                   HARDY              WV   EMERGENCY MNGR

            TREE DOWN ON SOUTH FORK RD.

&&

CORRECTED EVENT TIME

EVENT NUMBER LWX1300680

GMS

Local storm report, Jul 20, 2:37 PM EDT, 2 hours 8 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
237 PM EDT SAT JUL 20 2013

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

0349 PM     HAIL             W FRANKLIN              38.64N  79.33W
07/19/2013  E0.75 INCH       PENDLETON          WV   TRAINED SPOTTER

&&

EVENT NUMBER LWX1300681

GMS

Local storm report, Jul 20, 3:13 PM EDT, 1 hour 32 minutes before

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Local storm report, Jul 20, 4:31 PM EDT, 14 minutes before

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Local storm report, Jul 20, 4:37 PM EDT, 8 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
437 PM EDT SAT JUL 20 2013

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

0412 PM     TSTM WND DMG     4 N KEENE               37.92N  78.55W
07/20/2013                   ALBEMARLE          VA   PUBLIC

            TWO TREES DOWN ON STATE HWY 20 NEAR WALTON MIDDLE
            SCHOOL

&&

EVENT NUMBER LWX1300684

KCS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 19, 9:25 PM EDT	Heat Advisory	LWX	Arlington, City of Alexandria, City of Falls Church	21 hr
Jul 20, 3:56 PM EDT	Severe Thunderstorm Warning	LWX	Albemarle	49 min
Jul 20, 4:38 PM EDT	Severe Thunderstorm Warning	LWX	Albemarle, Nelson	52 min
Jul 20, 6:15 PM EDT	Severe Thunderstorm Warning	LWX	Augusta, City of Staunton, City of Waynesboro	45 min
Jul 20, 7:59 PM EDT	Small Craft Advisory	LWX		10 hr
Jul 20, 12:28 PM EDT	Severe Thunderstorm Warning	LWX	Frederick, Washington	47 min

Nearby

Flash Flood Warnings in Virginia, 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.