Alert archive / Virginia / Flash Flood Watches in 2015

Flash Flood Watch 12, NWS Blacksburg, VA

December 24, 201526 counties in Virginia; 4 counties in West Virginia

NWS Blacksburg, VA issued this flash flood watch at Dec 24, 2015, 2:33 PM EST for 26 counties in Virginia; 4 counties in West Virginia. It took effect at Dec 25, 2015, 12:00 AM EST. It was in force for 22 hr.

The area

The counties it named.

The facts

Issued: Dec 24, 2015, 2:33 PM EST (19:33 UTC)
In effect from: Dec 25, 2015, 12:00 AM EST
Expired: Dec 25, 2015, 9:59 PM EST
In force: 22 hr
Issued by: NWS Blacksburg, VA
Flood severity: None

All 30 counties

Alleghany County, VA, Amherst County, VA, Appomattox County, VA, Bath County, VA, Bedford County, VA, Bland County, VA, Botetourt County, VA, Buckingham County, VA, Campbell County, VA, City of Buena Vista, VA, City of Covington, VA, City of Lexington, VA, City of Lynchburg, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, Craig County, VA, Floyd County, VA, Franklin County, VA, Giles County, VA, Montgomery County, VA, Pulaski County, VA, Roanoke County, VA, Rockbridge County, VA, Tazewell County, VA, Wythe County, VA, Greenbrier County, WV, Mercer County, WV, Monroe County, WV, Summers County, WV

The radar

The Roanoke radar (KFCX), 48 km from the middle of the area, began a volume at 19:36 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, 7.6 hours before the alert went out and 55 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: 207 J/kg
Mixed-layer CIN: -33 J/kg
Mixed-layer LCL: 460 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 448 m²/s²
0-3 km storm-relative helicity: 468 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 2.3

Open this sounding in Storm Lab

What forecasters said that day

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

NWS Blacksburg, VA wrote its last area forecast discussion before this flash flood watch went out at Dec 24, 1:27 PM EST, 1 hour 6 minutes earlier.

Area forecast discussion, Dec 24, 1:27 PM EST, 1 hour 6 minutes before

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Hazardous weather outlook, Dec 24, 4:31 AM EST, 10 hours 2 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BLACKSBURG VA
431 AM EST THU DEC 24 2015

VAZ007-010>014-017>020-022>024-033>035-045>047-WVZ042>044-507-508-
250945-
TAZEWELL-BLAND-GILES-WYTHE-PULASKI-MONTGOMERY-FLOYD-CRAIG-
ALLEGHANY VA-BATH-ROANOKE-BOTETOURT-ROCKBRIDGE-FRANKLIN-BEDFORD-
AMHERST-CAMPBELL-APPOMATTOX-BUCKINGHAM-MERCER-SUMMERS-MONROE-
EASTERN GREENBRIER-WESTERN GREENBRIER-
431 AM EST THU DEC 24 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL VIRGINIA...SOUTH
CENTRAL VIRGINIA...SOUTHWEST VIRGINIA...WEST CENTRAL VIRGINIA AND
SOUTHEAST WEST VIRGINIA.

.DAY ONE...TODAY AND TONIGHT.

SHOWERS AND THUNDERSTORMS WITH LOCALLY HEAVY RAIN ARE EXPECTED
TODAY. SOME STORMS MAY ALSO PRODUCE STRONG GUSTY WINDS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

NCZ001>006-018>020-VAZ009-015-016-032-043-044-058-059-250945-
ASHE-ALLEGHANY NC-SURRY-STOKES-ROCKINGHAM-CASWELL-WATAUGA-WILKES-
YADKIN-SMYTH-GRAYSON-CARROLL-PATRICK-HENRY-PITTSYLVANIA-HALIFAX-
CHARLOTTE-
431 AM EST THU DEC 24 2015

...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL NORTH
CAROLINA...NORTHWEST NORTH CAROLINA...SOUTH CENTRAL VIRGINIA AND
SOUTHWEST VIRGINIA.

.DAY ONE...TODAY AND TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   FLASH FLOOD WATCH.

ALSO...SOME THUNDERSTORMS TODAY MAY PRODUCE STRONG GUSTY WINDS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

In the hours before

Special weather statement, Dec 24, 10:29 AM EST, 4 hours 4 minutes before

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Local storm report, Dec 24, 10:37 AM EST, 3 hours 56 minutes before

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Local storm report, Dec 24, 12:33 PM EST, 2 hours before

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Local storm report, Dec 24, 12:51 PM EST, 1 hour 42 minutes before

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Special weather statement, Dec 24, 2:02 PM EST, 31 minutes before

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Special weather statement, Dec 24, 2:30 PM EST, 3 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 23, 8:22 PM EST	River Flood Warning	RNK	Halifax	4 days
Dec 24, 3:23 AM EST	River Flood Warning	RNK	Charlotte, Halifax	55 hr
Dec 24, 4:06 AM EST	Flash Flood Watch	RNK	Carroll, Charlotte, Grayson, Halifax, Henry, Patrick and 5 more	42 hr
Dec 24, 5:45 AM EST	Special Weather Statement	RNK	Carroll, Grayson, Wythe	45 min
Dec 24, 7:33 AM EST	Special Weather Statement	RNK	Charlotte, Halifax, Pittsylvania, City of Danville	57 min
Dec 24, 7:47 AM EST	Flash Flood Warning	RNK	Grayson	6 hr
Dec 24, 8:51 AM EST	Flash Flood Warning	RNK	Charlotte, Halifax	6 hr
Dec 24, 9:01 AM EST	River Flood Warning	RNK	Pittsylvania, City of Danville	49 hr
Dec 24, 9:01 AM EST	River Flood Warning	RNK	Halifax	72 hr
Dec 24, 10:21 AM EST	Areal Flood Advisory	RNK	City of Danville	3 hr
Dec 24, 10:29 AM EST	Special Weather Statement	RNK	Charlotte, Halifax, City of Danville	61 min
Dec 24, 11:47 AM EST	Areal Flood Warning	RNK	Pittsylvania, City of Danville	9 hr
Dec 24, 2:30 PM EST	Special Weather Statement	RNK	City of Danville	30 min
Dec 24, 2:45 PM EST	Areal Flood Warning	RNK	Charlotte, Halifax	9 hr
Dec 24, 7:57 AM EST	Special Weather Statement	RNK	Wilkes	63 min
Dec 24, 9:49 AM EST	Areal Flood Advisory	RNK	Ashe, Watauga	6 hr
Dec 24, 2:02 PM EST	Special Weather Statement	RNK	Rockingham	28 min

Nearby

Flash Flood Watches in Virginia, 2015 Flash Flood Watches in West Virginia, 2015 Every flash flood watch in 2015

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.