Alert archive / Florida / Tornado Warnings in 2018

Tornado Warning 10, NWS Miami, FL

December 20, 2018Collier County, Florida

NWS Miami, FL issued this tornado warning at Dec 20, 2018, 2:46 PM EST for Collier County, Florida. It was in force for 29 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 20, 2018, 2:46 PM EST (19:46 UTC)
Expired
Dec 20, 2018, 3:15 PM EST
In force
29 min
Issued by
NWS Miami, FL
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

County Collier County, FL

The radar

The Miami radar (KAMX), 112 km from the middle of the area, began a volume at 19:49 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Dec 20, 2:15 PM ESTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Miami, FL (KMFL), launched 12:00Z, 7.8 hours before the alert went out and 120 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, Miami, FL at 12:00Z on 2018-12-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 343 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, Miami, FL at 12:00Z on 2018-12-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 262 square meters per square second.1939587897Sfc1 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
343 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
787 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
262 m²/s²
0-3 km storm-relative helicity
271 m²/s²
Significant tornado parameter
0.6
Supercell composite
4.1

Open this sounding in Storm Lab

The text

As transmitted.

668 
WFUS52 KMFL 201946
TORMFL
FLC021-202015-
/O.NEW.KMFL.TO.W.0010.181220T1946Z-181220T2015Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Miami FL
246 PM EST THU DEC 20 2018

The National Weather Service in Miami has issued a

* Tornado Warning for...
  South central Collier County in southwestern Florida...

* Until 315 PM EST.
    
* At 245 PM EST, a severe thunderstorm capable of producing a large 
  waterspout and capable of producing a tornado was located 7 miles 
  southeast of Royal Palm Hammock, or 8 miles west of Everglades 
  City, moving northeast at 45 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Expect damage to mobile homes, roofs, and vehicles. Tree 
           damage is likely.

* Locations impacted include...
  Port Of The Island and Cape Romano Aquatic Preserve. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to an interior room on the lowest floor of a
sturdy building. Avoid windows. If you are outdoors, in a mobile
home, or in a vehicle, move to the closest substantial shelter and
protect yourself from flying debris.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Miami. You can also share your report with NWS Miami on Facebook and
Twitter.

&&

LAT...LON 2587 8145 2586 8151 2591 8158 2599 8150
      2593 8140
TIME...MOT...LOC 1945Z 235DEG 40KT 2591 8151 

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

$$

AR

The office that day

Everything else NWS Miami, FL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 20, 4:09 AM ESTGale WarningMFL48 hr
Dec 20, 4:40 AM ESTCoastal Flood StatementMFLCollier7 hr
Dec 20, 4:40 AM ESTRip Current StatementMFLBroward, Collier, Miami-Dade, Palm Beach59 hr
Dec 20, 4:40 AM ESTHigh Surf AdvisoryMFLCollier59 hr
Dec 20, 6:48 AM ESTSpecial Weather StatementMFLBroward27 min
Dec 20, 7:13 AM ESTSpecial Weather StatementMFLBroward32 min
Dec 20, 7:42 AM ESTSpecial Weather StatementMFLPalm Beach33 min
Dec 20, 8:03 AM ESTSpecial Marine WarningMFL27 min
Dec 20, 8:24 AM ESTSpecial Marine WarningMFL37 min
Dec 20, 11:35 AM ESTCoastal Flood StatementMFLMonroe40 hr
Dec 20, 11:35 AM ESTCoastal Flood AdvisoryMFLCollier40 hr
Dec 20, 12:33 PM ESTSpecial Marine WarningMFL57 min
Dec 20, 1:23 PM ESTSpecial Weather StatementMFLCollier, Glades, Hendry52 min
Dec 20, 1:35 PM ESTTornado WarningMFLGlades, Hendry25 min
Dec 20, 1:45 PM ESTSevere Thunderstorm WarningMFLCollier45 min
Dec 20, 1:51 PM ESTSpecial Marine WarningMFL54 min
Dec 20, 1:58 PM ESTSpecial Marine WarningMFL62 min
Dec 20, 2:21 PM ESTSpecial Weather StatementMFLCollier, Glades, Hendry54 min
Dec 20, 2:44 PM ESTSpecial Weather StatementMFLPalm Beach46 min
Dec 20, 2:53 PM ESTSpecial Marine WarningMFL67 min
Dec 20, 3:13 PM ESTSpecial Weather StatementMFLCollier, Hendry62 min
Dec 20, 3:52 PM ESTWind AdvisoryMFLBroward, Collier, Glades, Hendry, Miami-Dade, Monroe and 1 more28 hr
Dec 20, 5:44 PM ESTSpecial Marine WarningMFL46 min
Dec 20, 5:48 PM ESTSpecial Weather StatementMFLMonroe42 min
Dec 20, 6:28 PM ESTSpecial Weather StatementMFLMiami-Dade62 min

Nearby

Tornado Warnings in Florida, 2018Every tornado warning in 2018Tornadoes in 2018

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.