Alert archive / Virginia / Flash Flood Warnings in 2011

Flash Flood Warning 52, NWS Blacksburg, VA

July 7, 2011Halifax County, Virginia

NWS Blacksburg, VA issued this flash flood warning at Jul 7, 2011, 4:53 PM EDT for Halifax County, Virginia. 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 outline as issued.

The facts

Issued
Jul 7, 2011, 4:53 PM EDT (20:53 UTC)
Expired
Jul 7, 2011, 7:57 PM EDT
In force
3 hr
Issued by
NWS Blacksburg, VA
Area
Storm-based polygon
Flood severity
None

County Halifax County, VA

The radar

The Raleigh/Durham radar (KRAX), 112 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

Roanoke, VA (KRNK), launched 12:00Z, 8.9 hours before the alert went out and 93 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-pSkew-T log-p diagram, Roanoke, VA at 12:00Z on 2011-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 113 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Roanoke, VA at 12:00Z on 2011-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
113 J/kg
Mixed-layer CIN
-87 J/kg
Mixed-layer LCL
1046 m above ground
0-6 km bulk shear
3 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
5 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

821 
WGUS51 KRNK 072053
FFWRNK
VAC083-080245-
/O.NEW.KRNK.FF.W.0052.110707T2053Z-110708T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE BLACKSBURG VA
453 PM EDT THU JUL 7 2011

THE NATIONAL WEATHER SERVICE IN BLACKSBURG HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN HALIFAX COUNTY IN SOUTH CENTRAL VIRGINIA

* UNTIL 1045 PM EDT.

* AT 448 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN FROM A STATIONARY THUNDERSTORM OVER THE WARNED     
  AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO STAUNTON
  RIVER STATE PARK...SOUTH BOSTON...SCOTTSBURG...HALIFAX AND DRYBURG.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF 1 TO 3 INCHES ARE POSSIBLE IN THE 
WARNED AREA. AROUND 2 INCHES OF RAIN HAS ALREADY FALLEN.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

PLEASE RELAY ANY REPORTS OF FLOODING INCLUDING MUDSLIDES...OR ROAD
CLOSURES TO THE NATIONAL WEATHER SERVICE IN BLACKSBURG BY CALLING
TOLL FREE...1...8 6 6...2 1 5...4 3 2 4. DELAYED REPORTS ARE WELCOME.

&&

LAT...LON 3663 7855 3663 7858 3669 7865 3669 7867
      3665 7870 3658 7871 3656 7873 3654 7872
      3654 7908 3685 7897 3679 7869 3671 7867
      3670 7864 3668 7863

$$
2 follow-up statements
718 
WGUS71 KRNK 072224
FFSRNK

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BLACKSBURG VA
624 PM EDT THU JUL 7 2011

VAC083-080245-
/O.CON.KRNK.FF.W.0052.000000T0000Z-110708T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HALIFAX VA-
624 PM EDT THU JUL 7 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM EDT FOR
SOUTHEASTERN HALIFAX COUNTY...

AT 620 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE AROUND 3 INCHES OF RAIN FROM THUNDERSTORMS IN A FEW HOURS. 

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO 
TURBEVILLE AND ALTON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

ADDITIONAL RAINFALL AMOUNTS OF ABOUT AN INCH ARE POSSIBLE IN THE 
WARNED AREA.

PLEASE RELAY ANY REPORTS OF FLOODING INCLUDING MUDSLIDES...OR ROAD
CLOSURES TO THE NATIONAL WEATHER SERVICE IN BLACKSBURG BY CALLING
TOLL FREE...1...8 6 6...2 1 5...4 3 2 4. DELAYED REPORTS ARE WELCOME.

&&

LAT...LON 3663 7855 3663 7858 3669 7865 3669 7867
      3665 7870 3658 7871 3656 7873 3654 7872
      3654 7908 3685 7897 3679 7869 3671 7867
      3670 7864 3668 7863

$$
085 
WGUS71 KRNK 072357
FFSRNK

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BLACKSBURG VA
757 PM EDT THU JUL 7 2011

VAC083-080008-
/O.CAN.KRNK.FF.W.0052.000000T0000Z-110708T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
HALIFAX VA-
757 PM EDT THU JUL 7 2011

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SOUTHEASTERN
HALIFAX COUNTY...

HEAVY RAIN HAS ENDED OVER THE WARNED AREA...THUS THE FLASH FLOOD 
WARNING HAS BEEN CANCELLED.

LAT...LON 3663 7855 3663 7858 3669 7865 3669 7867
      3665 7870 3658 7871 3656 7873 3654 7872
      3654 7908 3685 7897 3679 7869 3671 7867
      3670 7864 3668 7863

$$

The office that day

Everything else NWS Blacksburg, VA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 7, 2:04 PM EDTSpecial Weather StatementRNKGrayson56 min
Jul 7, 2:57 PM EDTSpecial Weather StatementRNKCity of Galax33 min
Jul 7, 3:21 PM EDTSpecial Weather StatementRNKCharlotte39 min
Jul 7, 3:27 PM EDTSevere Thunderstorm WarningRNKCharlotte38 min
Jul 7, 4:22 PM EDTSpecial Weather StatementRNKHalifax53 min
Jul 7, 4:38 PM EDTSpecial Weather StatementRNKPulaski37 min
Jul 7, 5:04 PM EDTFlash Flood WarningRNKPulaski3 hr
Jul 7, 5:52 PM EDTSpecial Weather StatementRNKSmyth38 min
Jul 7, 5:59 PM EDTSpecial Weather StatementRNKCarroll31 min
Jul 7, 6:07 PM EDTSevere Thunderstorm WarningRNKCarroll23 min
Jul 7, 7:02 PM EDTSpecial Weather StatementRNKCity of Danville28 min
Jul 7, 7:36 PM EDTSpecial Weather StatementRNKCity of Martinsville54 min

Nearby

Flash Flood Warnings in Virginia, 2011Every flash flood warning in 2011

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.