Alert archive / Tennessee / Flash Flood Watches in 2009

Flash Flood Watch 3, NWS Nashville, TN

May 16, 200925 counties in Tennessee

NWS Nashville, TN issued this flash flood watch at May 16, 2009, 11:27 AM CDT for 25 counties in Tennessee. It took effect at May 16, 2009, 1:00 PM CDT. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued: May 16, 2009, 11:27 AM CDT (16:27 UTC)
In effect from: May 16, 2009, 1:00 PM CDT
Expired: May 16, 2009, 9:25 PM CDT
In force: 8 hr
Issued by: NWS Nashville, TN
Flood severity: None

All 25 counties

Bedford County, TN, Cannon County, TN, Coffee County, TN, Cumberland County, TN, Davidson County, TN, DeKalb County, TN, Fentress County, TN, Giles County, TN, Grundy County, TN, Jackson County, TN, Lawrence County, TN, Lewis County, TN, Marshall County, TN, Maury County, TN, Overton County, TN, Pickett County, TN, Putnam County, TN, Rutherford County, TN, Smith County, TN, Van Buren County, TN, Warren County, TN, Wayne County, TN, White County, TN, Williamson County, TN, Wilson County, TN

The radar

The Nashville radar (KOHX), 58 km from the middle of the area, began a volume at 16:26 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

Nashville Metro, TN (KBNA), launched 12:00Z, 4.5 hours before the alert went out and 51 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: 1150 J/kg
Mixed-layer CIN: -44 J/kg
Mixed-layer LCL: 703 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 109 m²/s²
0-3 km storm-relative helicity: 129 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 watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Nashville, TN wrote its last area forecast discussion before this flash flood watch went out at May 16, 11:13 AM CDT, 14 minutes earlier.

Area forecast discussion, May 16, 11:13 AM CDT, 14 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
1113 AM CDT SAT MAY 16 2009

.MESO UPDATE...
BROKEN LINE OF STORMS FORMING ALONG COLD FRONT IN NW CORNER OF
MIDSTATE. HEATING ACR SOUTH/EAST MID TN IS EXPECTED TO GENERATE
1500-2500 J/KG B/L CAPES AHEAD OF FRONT. LOW SHEAR EVENT.

INSTAB AND LIFT ENOUGH FOR SOME HAIL. BUT LARGER CONCERN IS FOR
HEAVY RAINFALL IN SOUTH/EAST MID TN. WL POST A FLASH FLOOD WATCH
THIS AFTERNOON AND TONIGHT FOR THESE AREA...AND INCLUDE METRO
NASHVILLE. 1-3 INCHES OF RAINFALL POSSIBLE.

&&

.PREV DISCUSSION... /ISSUED 455 AM CDT SAT MAY 16 2009/

MESOSCALE UPDATE 02...
SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP ACROSS WESTERN
MIDDLE TN FROM THE TENNESSEE RIVER TO ABOUT 50 MILES EAST OF THE
TENNESSEE RIVER. THIS REMAINS AN AREA OF RATHER STEEP MID-LEVEL
LAPSE RATES ON THE ORDER OF 7 DEGS CELSIUS PER KM. ALSO...VWP OFF
OHX DOPPLER SHOWS 40 KT LOW LEVEL JET WHICH HAS STRENGTHENED OVER
THE LAST HOUR WORKING ACROSS THIS AREA. ALSO OF CONCERN AT THIS TIME
IS OUTFLOW BOUNDARY DROPPING SOUTHEAST OUT OF WESTERN KY AND INTO
NORTHWEST MIDDLE TN DURING THE NEXT HOUR. THIS BOUNDARY MOST
LIKELY WILL ACT TO INCREASE COVERAGE ALONG WITH TSTM INTENSITIES
THAT MAY LEAD TO LOCALLY HEAVY RAINFALL. 1 TO 2 INCH RAINFALL
AMOUNTS COULD OCCUR WITHIN AN HR WHICH WOULD LEAD TO SWOLLEN
CREEKS AND STREAMS.

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR TNZ011-027-028-
030>034-058>066-075-077>080-093>095.

&&

04

Hazardous weather outlook, May 16, 5:17 AM CDT, 6 hours 10 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NASHVILLE TN
517 AM CDT SAT MAY 16 2009

TNZ005>011-022>034-056>066-075-077>080-093>095-171030-
STEWART-MONTGOMERY-ROBERTSON-SUMNER-MACON-CLAY-PICKETT-BENTON-
HOUSTON-HUMPHREYS-DICKSON-CHEATHAM-DAVIDSON-WILSON-TROUSDALE-
SMITH-JACKSON-PUTNAM-OVERTON-FENTRESS-PERRY-HICKMAN-LEWIS-
WILLIAMSON-MAURY-MARSHALL-RUTHERFORD-CANNON-DEKALB-WHITE-
CUMBERLAND-BEDFORD-COFFEE-WARREN-GRUNDY-VAN BUREN-WAYNE-LAWRENCE-
GILES-
517 AM CDT SAT MAY 16 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MIDDLE TENNESSEE.

.DAY ONE...TONIGHT

STRONG TO LOCALLY SEVERE THUNDERSTORMS ARE POSSIBLE TODAY AND THIS
EVENING. GUSTY WIND AND PEA TO MARBLE SIZED HAIL WILL BE THE MAIN
THREAT. LOCALLY HEAVY RAIN MAY ALSO OCCUR...WHICH MAY LEAD TO STANDING
WATER ON ROADWAYS AND MINOR FLOODING.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

DUE TO THE BRIEF AND ISOLATED NATURE OF POSSIBLE SEVERE WEATHER...
SPOTTER ACTIVATION IS NOT ANTICIPATED.

07

In the hours before

Special weather statement, May 16, 6:40 AM CDT, 4 hours 47 minutes before

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Local storm report, May 16, 9:55 AM CDT, 1 hour 32 minutes before

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE NASHVILLE TN
955 AM CDT SAT MAY 16 2009

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

1123 AM     HAIL             8 S JAMESTOWN           36.32N 84.94W
05/15/2009  M1.00 INCH       FENTRESS           TN   LAW ENFORCEMENT

            ONE INCH HAIL WAS REPORTED.

0200 PM     TSTM WND DMG     BYRDSTOWN               36.57N 85.13W
05/15/2009                   PICKETT            TN   LAW ENFORCEMENT

            PENNY SIZE HAIL AND TREES DOWN

0217 PM     HAIL             2 S MURFREESBORO        35.82N 86.39W
05/15/2009  E0.88 INCH       RUTHERFORD         TN   TRAINED SPOTTER

            NICKEL SIZE HAIL ALONG HWY 231 SOUTH

0217 PM     HAIL             5 S LAWRENCEBURG        35.17N 87.34W
05/15/2009  E0.50 INCH       LAWRENCE           TN   TRAINED SPOTTER

            DIME SIZE HAIL REPORTED BY SPOTTER NEAR LEOME

0225 PM     TSTM WND DMG     3 SW SMITHVILLE         35.93N 85.86W
05/15/2009                   DEKALB             TN   LAW ENFORCEMENT

            SEVERAL TREES BLOWN DOWN

0227 PM     HAIL             MURFREESBORO            35.85N 86.39W
05/15/2009  E1.00 INCH       RUTHERFORD         TN   TRAINED SPOTTER

            NEAR I-24 AND CHURCH STREET

0231 PM     HAIL             SPENCER                 35.74N 85.46W
05/15/2009  E0.75 INCH       VAN BUREN          TN   LAW ENFORCEMENT

            PENNY HAIL IN SPENCER

0240 PM     HAIL             SPARTA                  35.93N 85.47W
05/15/2009  E1.00 INCH       WHITE              TN   EMERGENCY MNGR

            IN SPARTA

0505 PM     HAIL             NASHVILLE               36.17N 86.78W
05/15/2009  E1.00 INCH       DAVIDSON           TN   TRAINED SPOTTER

            MURFREESBORO PIKE AREA NICKEL TO QUARTER SIZE

0510 PM     HAIL             NASHVILLE               36.17N 86.78W
05/15/2009  E0.88 INCH       DAVIDSON           TN   TRAINED SPOTTER

            I-24 AT BRILEY PKWY

0514 PM     HAIL             2 SE NASHVILLE          36.15N 86.76W
05/15/2009  E0.50 INCH       DAVIDSON           TN   TRAINED SPOTTER

            DIME SIZE HAIL REPORTED AT MURFREESBORO ROAD AND KERMIT
            DRIVE.

0553 PM     HAIL             1 N NASHVILLE           36.19N 86.78W
05/15/2009  E0.75 INCH       DAVIDSON           TN   PUBLIC

            PENNY SIZE HAIL REPORTED BY THE PUBLIC ON BRICK CHURCH
            LANE NEAR INTERSECTION WITH KNIGHT ROAD.

&&

JBW

The office that day

Everything else NWS Nashville, TN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 16, 8:51 AM CDT	River Flood Advisory	OHX	Decatur, Hardin, Perry, Wayne	22 hr
May 16, 12:15 PM CDT	Severe Thunderstorm Warning	OHX	Perry	45 min
May 16, 12:49 PM CDT	Severe Thunderstorm Warning	OHX	Cheatham, Davidson, Robertson	26 min
May 16, 1:49 PM CDT	Severe Thunderstorm Warning	OHX	Williamson	56 min
May 16, 2:04 PM CDT	Severe Thunderstorm Warning	OHX	Maury	26 min
May 16, 2:13 PM CDT	Flash Flood Warning	OHX	Perry	3 hr
May 16, 2:16 PM CDT	Severe Thunderstorm Warning	OHX	Lewis, Maury	29 min
May 16, 2:35 PM CDT	Severe Thunderstorm Warning	OHX	Rutherford	25 min
May 16, 2:38 PM CDT	Severe Thunderstorm Warning	OHX	Smith, Trousdale, Wilson	22 min
May 16, 2:59 PM CDT	Severe Thunderstorm Warning	OHX	Putnam	31 min
May 16, 3:01 PM CDT	Severe Thunderstorm Warning	OHX	Clay, Jackson	29 min
May 16, 3:13 PM CDT	Severe Thunderstorm Warning	OHX	Jackson, Overton, Putnam	32 min

Nearby

Flash Flood Watches in Tennessee, 2009 Every flash flood watch in 2009

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.