Alert archive / Alabama / Tornado Warnings in 2017

Tornado Warning 13, NWS Huntsville, AL

December 23, 2017Colbert County, Alabama

NWS Huntsville, AL issued this tornado warning at Dec 23, 2017, 5:17 AM CST for Colbert County, Alabama. It was in force for 28 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Dec 23, 2017, 5:17 AM CST (11:17 UTC)
Expired: Dec 23, 2017, 5:45 AM CST
In force: 28 min
Issued by: NWS Huntsville, AL
Area: Storm-based polygon
Tornado: Radar indicated

County Colbert County, AL

The radar

The Columbus AFB radar (KGWX), 89 km from the middle of the area, began a volume at 11:20 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

Little Rock, AR (KBYH), launched 00:00Z, 11.3 hours before the alert went out and 181 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 455 m above ground
0-6 km bulk shear: 81 kt
0-1 km storm-relative helicity: 289 m²/s²
0-3 km storm-relative helicity: 372 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

120 
WFUS54 KHUN 231117
TORHUN
ALC033-231145-
/O.NEW.KHUN.TO.W.0013.171223T1117Z-171223T1145Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Huntsville AL
517 AM CST SAT DEC 23 2017

The National Weather Service in Huntsville Alabama has issued a

* Tornado Warning for...
  Southwestern Colbert County in northwestern Alabama...

* Until 545 AM CST

* At 517 AM CST, severe thunderstorms capable of producing both
  tornadoes and extensive straight line wind damage were located 7
  miles south of Cherokee, or 10 miles east of Tishomingo State Park,
  moving east at 35 mph.

  HAZARD...Tornado. 

  SOURCE...Radar indicated rotation. 

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely. 

* This tornadic thunderstorm will remain over mainly rural areas of
  southwestern Colbert County, including the following locations: Red
  Rock, Posey Loop, Mynot, Mt Hester and Srygley Church.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 3458 8809 3473 8810 3473 8782 3458 8780
TIME...MOT...LOC 1117Z 270DEG 31KT 3464 8800 

TORNADO...RADAR INDICATED
HAIL...<.75

$$

70/DD

1 follow-up statement

251 
WWUS54 KHUN 231137
SVSHUN

Severe Weather Statement
National Weather Service Huntsville AL
537 AM CST SAT DEC 23 2017

ALC033-231146-
/O.EXP.KHUN.TO.W.0013.000000T0000Z-171223T1145Z/
Colbert AL-
537 AM CST SAT DEC 23 2017

...THE TORNADO WARNING FOR SOUTHWESTERN COLBERT COUNTY WILL EXPIRE AT
545 AM CST...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.  However gusty winds are still possible with
this thunderstorm.

Remember, a Severe Thunderstorm Warning still remains in effect for 
this area until 600 AM CST.

LAT...LON 3458 8809 3473 8810 3473 8782 3458 8780
TIME...MOT...LOC 1136Z 270DEG 31KT 3464 8781 

$$

70/DD

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 23, 5:01 AM CST	Severe Thunderstorm Warning	HUN	Colbert, Franklin, Lauderdale	29 min
Dec 23, 5:31 AM CST	Severe Thunderstorm Warning	HUN	Colbert, Franklin, Lauderdale	29 min
Dec 23, 6:00 AM CST	Special Weather Statement	HUN	Lawrence	30 min
Dec 23, 6:30 AM CST	Special Weather Statement	HUN	Limestone	30 min
Dec 23, 7:33 AM CST	Special Weather Statement	HUN	Cullman	27 min
Dec 23, 7:36 AM CST	Special Weather Statement	HUN	Madison	24 min
Dec 23, 9:16 AM CST	Special Weather Statement	HUN	DeKalb, Jackson, Marshall	74 min
Dec 23, 10:36 AM CST	Special Weather Statement	HUN	DeKalb	24 min

Nearby

Tornado Warnings in Alabama, 2017 Every tornado warning in 2017 Tornadoes in 2017

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.