Alert archive / Florida / Tornado Warnings in 2018

Tornado Warning 13, NWS Melbourne, FL

December 20, 2018Seminole County, Volusia County, Florida

NWS Melbourne, FL issued this tornado warning at Dec 20, 2018, 10:46 AM EST for Seminole County, Volusia 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, 10:46 AM EST (15:46 UTC)
Expired
Dec 20, 2018, 11:15 AM EST
In force
29 min
Issued by
NWS Melbourne, FL
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.0 in

Counties Seminole County, FL, Volusia County, FL

The radar

The Melbourne radar (KMLB), 85 km from the middle of the area, began a volume at 15:46 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, 7:55 AM ESTTornado WatchSPC7 hr

The nearest sounding before it

Cape Canaveral, FL (KXMR), launched 12:00Z, 3.8 hours before the alert went out and 66 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, Cape Canaveral, FL at 12:00Z on 2018-12-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 326 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, Cape Canaveral, FL at 12:00Z on 2018-12-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 174 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
326 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
778 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
174 m²/s²
0-3 km storm-relative helicity
231 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.4

Open this sounding in Storm Lab

The text

As transmitted.

827 
WFUS52 KMLB 201546
TORMLB
FLC117-127-201615-
/O.NEW.KMLB.TO.W.0013.181220T1546Z-181220T1615Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Melbourne FL
1046 AM EST THU DEC 20 2018

The National Weather Service in Melbourne has issued a

* Tornado Warning for...
  Northeastern Seminole County in east central Florida...
  Southeastern Volusia County in east central Florida...

* Until 1115 AM EST.

* At 1046 AM EST, severe thunderstorms capable of producing both 
  tornadoes and straight line wind damage were located over Geneva, 
  moving northeast at 45 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
  northeastern Seminole and southeastern Volusia Counties, including
  the following locations... Lake Harney.

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.

This cluster of thunderstorms is capable of producing tornadoes and
widespread significant wind damage. Do not wait to see or hear the
tornado. For your protection move to an interior room on the lowest
floor of a building.

&&

LAT...LON 2868 8109 2871 8119 2897 8111 2890 8088
TIME...MOT...LOC 1546Z 209DEG 40KT 2875 8111 

TORNADO...RADAR INDICATED
HAIL...0.00IN

$$

Rodriguez
1 follow-up statement
665 
WWUS52 KMLB 201605
SVSMLB

Severe Weather Statement
National Weather Service Melbourne FL
1105 AM EST THU DEC 20 2018

FLC117-201614-
/O.CAN.KMLB.TO.W.0013.000000T0000Z-181220T1615Z/
Seminole FL-
1105 AM EST THU DEC 20 2018

...THE TORNADO WARNING FOR NORTHEASTERN SEMINOLE COUNTY IS
CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 400 PM EST for east central
Florida.

LAT...LON 2877 8101 2881 8106 2887 8103 2895 8104
      2890 8088
TIME...MOT...LOC 1604Z 209DEG 40KT 2893 8100 

$$

FLC127-201615-
/O.CON.KMLB.TO.W.0013.000000T0000Z-181220T1615Z/
Volusia FL-
1105 AM EST THU DEC 20 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1115 AM EST FOR
SOUTHEASTERN VOLUSIA COUNTY...

At 1104 AM EST, a severe squall line capable of producing both 
tornadoes and straight line wind damage was located from near 
Edgewater to Farmton, moving northeast at 45 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
southeastern Volusia County.

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.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

This cluster of thunderstorms is capable of producing tornadoes and
widespread significant wind damage. Do not wait to see or hear the
tornado. For your protection move to an interior room on the lowest
floor of a building.

&&

LAT...LON 2877 8101 2881 8106 2887 8103 2895 8104
      2890 8088
TIME...MOT...LOC 1604Z 209DEG 40KT 2893 8100 

TORNADO...RADAR INDICATED
HAIL...0.00IN

$$

Cristaldi

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 20, 3:46 AM ESTGale WarningMLB48 hr
Dec 20, 4:12 AM ESTBeach Hazards StatementMLBVolusia14 hr
Dec 20, 4:15 AM ESTLake Wind AdvisoryMLBOkeechobee, Orange, Osceola, Seminole, Volusia14 hr
Dec 20, 8:17 AM ESTSpecial Weather StatementMLBLake58 min
Dec 20, 8:23 AM ESTTornado WarningMLBLake, Orange22 min
Dec 20, 9:14 AM ESTSpecial Weather StatementMLBOrange, Seminole, Volusia61 min
Dec 20, 9:25 AM ESTTornado WarningMLBOrange35 min
Dec 20, 9:37 AM ESTSpecial Marine WarningMLB3 hr
Dec 20, 10:00 AM ESTAreal Flood AdvisoryMLBLake, Orange, Osceola, Seminole, Volusia2 hr
Dec 20, 10:18 AM ESTSpecial Weather StatementMLBOrange, Seminole, Volusia57 min
Dec 20, 11:01 AM ESTTornado WarningMLBVolusia29 min
Dec 20, 11:24 AM ESTTornado WarningMLBVolusia19 min
Dec 20, 11:35 AM ESTSevere Thunderstorm WarningMLBBrevard, Orange, Osceola, Seminole, Volusia55 min
Dec 20, 12:02 PM ESTTornado WarningMLBBrevard, Seminole, Volusia28 min
Dec 20, 12:21 PM ESTAreal Flood AdvisoryMLBBrevard, Lake, Orange, Osceola, Seminole, Volusia3 hr
Dec 20, 12:25 PM ESTSpecial Marine WarningMLB110 min
Dec 20, 12:33 PM ESTSevere Thunderstorm WarningMLBBrevard, Seminole, Volusia27 min
Dec 20, 12:57 PM ESTSevere Thunderstorm WarningMLBBrevard, Orange, Osceola63 min
Dec 20, 1:42 PM ESTSpecial Weather StatementMLBOkeechobee48 min
Dec 20, 2:02 PM ESTSpecial Marine WarningMLB3 hr
Dec 20, 2:05 PM ESTSpecial Weather StatementMLBBrevard25 min
Dec 20, 2:19 PM ESTSpecial Marine WarningMLB3 hr
Dec 20, 2:25 PM ESTSevere Thunderstorm WarningMLBBrevard27 min
Dec 20, 2:59 PM ESTSpecial Weather StatementMLBIndian River, Martin, Saint Lucie61 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.