Alert archive / Tennessee / Severe Thunderstorm Warnings in 2006

Severe Thunderstorm Warning 80, NWS Huntsville, AL

April 20, 2006Franklin County, Tennessee

NWS Huntsville, AL issued this severe thunderstorm warning at Apr 20, 2006, 8:04 PM CDT for Franklin County, Tennessee. It was in force for 35 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Apr 20, 2006, 8:04 PM CDT (01:04 UTC)
Expired
Apr 20, 2006, 8:39 PM CDT
In force
35 min
Issued by
NWS Huntsville, AL
Area
Counties, with a storm outline in the text

County Franklin County, TN

The radar

The Northeast Alabama radar (KHTX), 25 km from the middle of the area, began a volume at 01:06 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 00:00Z, 1.1 hours before the alert went out and 118 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, Nashville Metro, TN at 00:00Z on 2006-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 135 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Nashville Metro, TN at 00:00Z on 2006-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 7 square meters per square second.19395878Sfc1 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
135 J/kg
Mixed-layer CIN
-81 J/kg
Mixed-layer LCL
1065 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
7 m²/s²
0-3 km storm-relative helicity
-5 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

Open this sounding in Storm Lab

What forecasters said that day

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

NWS Huntsville, AL wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 20, 3:20 PM CDT, 4 hours 44 minutes earlier.

Area forecast discussion, Apr 20, 3:20 PM CDT, 4 hours 44 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
320 PM CDT THU APR 20 2006

.DISCUSSION...
BIG PICTURE WISE...THE INFRARED/WATER VAPOR SATELLITE LOOP INDICATED
A QUASI-STATIONARY UPPER LOW PINWHEELING OVER WESTERN MINNESOTA...
WITH A SERIES OF UPPER LEVEL DISTURBANCES POISED TO MOVE UNDER IT
TOWARD THE TENN AND OHIO VALLEY THROUGH FRIDAY. FOR THE PRESENT...
ACTIVE SHOWERS AND T-STORMS CONTINUE FROM WEST TEXAS (ASSOCIATED WITH
AN UPPER DISTURBANCE) WITH OTHER CONVECTION HOLDING ITS OWN ACROSS NE
TEXAS...AND OUR EARLIER CONVECTION EXITING THE CUMBERLAND PLATEAU.
3 PM TEMPS HAVE WARMED INTO THE UPPER 70S TO LOWER 80S. AREA CAPES OF
2000-3000 J/KG WERE NOTED...WITH HIGHER VALUES TOWARD MORE SUNNY
CENTRAL ALABAMA...AND 0-3KM HELICITIES REMAINING BELOW 100 M/S.

A FEW HOURS OF QUIET WEATHER STORM WISE HAVE CAME TO AN END...AS
ATMOSPHERIC INSTABILITIES AND STORM POTENTIAL CRANK UP AGAIN. AN
UPPER LEVEL SHORT WAVE EARLIER...ALONG WITH MORE THAN A FEW BOUNDARY
INTERACTIONS AND INSTABILITY HELPED GET SHOWERS AND THUNDERSTORMS
GOING EARLY. SEVERE T-STORM WATCH #221 REMAINS IN EFFECT FOR ALL OF
THE HUNTSVILLE FORECAST AREA THROUGH 7 PM. UPWARD VERTICAL MOTION
PRECEDING A MESOSCALE CONVECTIVE VORT WILL HELP GET MORE SHOWERS AND
STORMS GOING FOR THIS PORTION OF THE TENNESSEE VALLEY THE REMAINDER
OF THIS AFTERNOON AND TONIGHT.

FOR TONIGHT AND TOMORROW...THE APPROACH OF THE UPPER SYSTEM AND
BETTER CONVERGENCE WILL BRING A GOOD CHANCE OF SHOWERS AND STORMS...
SOME SEVERE FOR THE TENN VALLEY. AS IN TODAY...MAIN THREATS ARE HAIL
AND STRONG WINDS. HAVE KEEP LIKELY POPS GOING FOR TONIGHT IN THIS
REGARD. FOR FRIDAY...A MORE UNSTABLE ATMOSPHERE...AND THE APPROACH OF
A COLD FRONT WILL CONTINUE A SEVERE WEATHER THREAT. INCREASING SHEAR
WILL BRING A BETTER CHANCE FOR ISOLATED TORNADO DEVELOPMENT IN THE
STRONGEST STORMS. THE COLD FRONT SHOULD MOVE ACROSS THE VALLEY AFTER
MIDNIGHT SAT...AND REACH NE ALABAMA BEFORE NOON SAT. ITS PASSAGE WILL
TAPER THE CHANCES OF RAIN. WITH A FEW DAYS THIS WEEK AROUND 90...HIGH
TEMPS IN THE MID 70S SAT WILL FEEL A TAD ON THE COOL SIDE.

DRY WEATHER SHOULD CONTINUE THROUGH SUNDAY. HOWEVER...A RETURN SURGE
OF MOISTURE WILL BRING ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS TO
THE VALLEY...ESPECIALLY FOR THE MIDDLE OF NEXT WEEK. THROUGH THAT
TIME...TEMPS WILL RANGE IN THE 70S WITH MORE CLOUDS THAN SUNSHINE
THIS PERIOD. NORTHERN HEMISPHERE BLOCKING AND MEDIUM RANGE MODEL
INCONSISTENCY CONTINUE...SO NO BIG CHANGES EXCEPT TEMPS FOR NEXT WEEK.

&&

.PRELIMINARY POINT TEMPS/POPS...
HUNTSVILLE    63  78  55  76 /  60  80  70  10
SHOALS        63  77  54  77 /  60  80  60  10
CULLMAN       63  80  56  77 /  60  80  70  10
FAYETTEVILLE  62  77  54  76 /  60  80  70  10
FORT PAYNE    62  79  56  76 /  60  80  80  20

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

RSB
Hazardous weather outlook, Apr 20, 12:40 PM CDT, 7 hours 24 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1240 PM CDT THU APR 20 2006

ALZ001>010-016-TNZ076-096-097-210230-
COLBERT-CULLMAN-DE KALB-FRANKLIN AL-FRANKLIN TN-JACKSON-LAUDERDALE-
LAWRENCE-LIMESTONE-LINCOLN-MADISON-MARSHALL-MOORE-MORGAN-
1240 PM CDT THU APR 20 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH ALABAMA AND PORTIONS
OF SOUTHERN MIDDLE TENNESSEE.

.DAY ONE...THROUGH TONIGHT...

SCATTERED TO NUMEROUS THUNDERSTORMS WILL DEVELOP THROUGHOUT THE
AFTERNOON AND EVENING HOURS AS UPPER LEVEL ENERGY MOVES THROUGH
AND INTERACTS WITH A VERY UNSTABLE AIR MASS. SOME OF THESE
THUNDERSTORMS MAY BECOME SEVERE WITH LARGE HAIL AND DAMAGING WINDS
BEING THE MAIN THREATS.  LOCALLY HEAVY RAINFALL WILL ALSO BE A
POSSIBILITY DUE TO THE SLOW MOVEMENT OF THE THUNDERSTORMS.

THUNDERSTORMS WILL GRADUALLY DIMINISH IN COVERAGE AND INTENSITY
OVERNIGHT...ALTHOUGH AN ISOLATED STRONG TO SEVERE STORM OR TWO
CANNOT BE RULED OUT.

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

A COLD FRONT WILL MOVE IN FROM THE WEST ON FRIDAY ALONG WITH A
STRONG UPPER TROUGH. THAT COMBINATION WILL RESULT IN MORE
THUNDERSTORM COVERAGE OVER THE AREA...AND A SLIGHT RISK OF SEVERE
THUNDERSTORMS WITH DAMAGING WINDS AND ISOLATED TORNADOES THE MAIN
THREATS. THE ACTIVITY COULD EXTEND WELL INTO THE EVENING...THEN
DIMINISH OVERNIGHT AND EARLY SATURDAY AS THE FRONT MOVES THROUGH.

.SPOTTER CALL TO ACTION STATEMENT...

ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT PERSONNEL
MAY BE NECESSARY AT TIMES THROUGH FRIDAY.

In the hours before

Local storm report, Apr 20, 4:56 PM CDT, 3 hours 8 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
456 PM CDT THU APR 20 2006

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

0442 PM     HAIL             MENTONE                 34.58N 85.59W
04/20/2006  E0.88 INCH       DEKALB             AL   EMERGENCY MNGR

&&

DJN
Special weather statement, Apr 20, 5:14 PM CDT, 2 hours 50 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
514 PM CDT THU APR 20 2006

ALZ008-202245-
MARSHALL-
514 PM CDT THU APR 20 2006

...SIGNIFICANT WEATHER ALERT FOR SOUTHERN MARSHALL COUNTY UNTIL 545
PM CDT...

AT 505 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM NEAR ALBERTVILLE...MOVING EAST AT 5 MPH.

DIME SIZE HAIL...FREQUENT LIGHTNING...AND WINDS UP TO 40 MPH ARE
EXPECTED WITH THIS STORM.

* LOCATIONS IN OR NEAR THE PATH INCLUDE...
  ALBERTVILLE.
  BOAZ.
  HUSTLEVILLE.
  MCVILLE.

REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO THE
STORM TO BE STRUCK BY LIGHTNING. SEEK SAFE SHELTER IMMEDIATELY.

CBD
Local storm report, Apr 20, 5:57 PM CDT, 2 hours 7 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
557 PM CDT THU APR 20 2006

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

0511 PM     HAIL             ALBERTVILLE             34.26N 86.21W
04/20/2006  E0.50 INCH       MARSHALL           AL   EMERGENCY MNGR

0524 PM     HAIL             BOAZ                    34.20N 86.16W
04/20/2006  E0.50 INCH       MARSHALL           AL   EMERGENCY MNGR

0548 PM     HAIL             HOLLY POND              34.17N 86.62W
04/20/2006  M0.88 INCH       CULLMAN            AL   AMATEUR RADIO

&&

RSB
Local storm report, Apr 20, 5:59 PM CDT, 2 hours 5 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
559 PM CDT THU APR 20 2006

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

0536 PM     HAIL             HOLLY POND              34.17N 86.62W
04/20/2006  E1.00 INCH       CULLMAN            AL   EMERGENCY MNGR

            NICKEL TO QUARTER SIZED HAIL

&&

RSB
Local storm report, Apr 20, 6:44 PM CDT, 1 hour 20 minutes before
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Local storm report, Apr 20, 7:13 PM CDT, 51 minutes before
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The office that day

Everything else NWS Huntsville, AL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 20, 7:36 PM CDTSevere Thunderstorm WarningHUNJackson39 min
Apr 20, 7:44 PM CDTSevere Thunderstorm WarningHUNMadison31 min
Apr 21, 12:49 AM CDTSevere Thunderstorm WarningHUNLimestone41 min
Apr 21, 2:43 AM CDTSevere Thunderstorm WarningHUNCullman62 min
Apr 21, 3:10 AM CDTSevere Thunderstorm WarningHUNMarshall53 min
Apr 21, 3:43 AM CDTSevere Thunderstorm WarningHUNJackson33 min
Apr 21, 4:00 AM CDTFlash Flood WatchHUNCullman, DeKalb, Marshall21 hr
Apr 21, 4:43 AM CDTSevere Thunderstorm WarningHUNMarshall27 min
Apr 21, 5:02 AM CDTSevere Thunderstorm WarningHUNJackson43 min
Apr 21, 5:09 AM CDTSevere Thunderstorm WarningHUNMadison21 min
Apr 21, 5:37 AM CDTSevere Thunderstorm WarningHUNMorgan38 min
Apr 21, 6:15 AM CDTSevere Thunderstorm WarningHUNMorgan45 min
Apr 21, 6:21 AM CDTSevere Thunderstorm WarningHUNMorgan39 min
Apr 21, 6:34 AM CDTSevere Thunderstorm WarningHUNMadison41 min
Apr 21, 7:01 AM CDTSevere Thunderstorm WarningHUNLimestone29 min
Apr 21, 3:18 PM CDTSevere Thunderstorm WarningHUNJackson18 min
Apr 21, 3:20 PM CDTSevere Thunderstorm WarningHUNJackson, Madison40 min
Apr 21, 3:26 PM CDTSevere Thunderstorm WarningHUNDeKalb49 min
Apr 21, 3:55 PM CDTSevere Thunderstorm WarningHUNJackson35 min
Apr 21, 4:15 PM CDTSevere Thunderstorm WarningHUNDeKalb15 min
Apr 21, 4:30 PM CDTSevere Thunderstorm WarningHUNJackson15 min
Apr 21, 5:36 PM CDTSevere Thunderstorm WarningHUNMarshall24 min
Apr 21, 6:40 PM CDTSevere Thunderstorm WarningHUNDeKalb35 min

Nearby

Severe Thunderstorm Warnings in Tennessee, 2006Every severe thunderstorm warning in 2006

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.