Alert archive / Florida / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 16, NWS Melbourne, FL

April 20, 20124 counties in Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Apr 20, 2012, 6:36 PM EDT for 4 counties in Florida. It was in force for 54 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: Apr 20, 2012, 6:36 PM EDT (22:36 UTC)
Expired: Apr 20, 2012, 7:30 PM EDT
In force: 54 min
Issued by: NWS Melbourne, FL
Area: Storm-based polygon

Counties Brevard County, FL, Orange County, FL, Seminole County, FL, Volusia County, FL

The radar

The Melbourne radar (KMLB), 65 km from the middle of the area, began a volume at 22:40 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

Cape Canaveral, FL (KXMR), launched 12:00Z, 10.6 hours before the alert went out and 45 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: 414 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 861 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 3 m²/s²
0-3 km storm-relative helicity: 22 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

484 
WUUS52 KMLB 202236
SVRMLB
FLC009-095-117-127-202330-
/O.NEW.KMLB.SV.W.0016.120420T2236Z-120420T2330Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
636 PM EDT FRI APR 20 2012

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHWESTERN BREVARD COUNTY IN FLORIDA
  ORANGE COUNTY IN FLORIDA
  SEMINOLE COUNTY IN FLORIDA
  SOUTHEASTERN VOLUSIA COUNTY IN FLORIDA

* UNTIL 730 PM EDT.

* AT 635 PM EDT...TRAINED WEATHER SPOTTERS REPORTED A SEVERE
  THUNDERSTORM CAPABLE PRODUCING WINDS NEAR 60 MPH AND COIN
  SIZE HAIL. THIS STORM WAS LOCATED NEAR LONGWOOD AND MOVING
  SOUTHEAST AT 15 MPH. OTHER STORMS WERE INTENSIFYING EAST TO 
  GENEVA AND  LAKE HARNEY.

* OTHER LOCATIONS IN THE WARNING INCLUDE...BUT ARE NOT LIMITED 
  TO...WEKIVA SPRINGS...ALTAMONTE SPRINGS...MAITLAND...LONGWOOD... 
  LAKE MARY...OAK HILL...CANAVERAL GROVES...SCOTTSMOOR...OVIEDO...
  MIMS...
 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS IN EXCESS OF 58 MILES AN
HOUR AND OR LARGE DESTRUCTIVE HAIL. FREQUENT TO EXCESSIVE LIGHTNING
AND VERY HEAVY RAIN WILL ALSO BE POSSIBLE. IF THE STORM APPROACHES
YOU...SEEK SHELTER IN AN ENCLOSED BUILDING ON THE LOWEST FLOOR. KEEP
AWAY FROM WINDOWS.

&&

LAT...LON 2875 8153 2889 8080 2885 8081 2875 8079
      2877 8084 2866 8082 2866 8079 2870 8078
      2869 8078 2860 8077 2862 8079 2860 8080
      2856 8079 2853 8076 2851 8077 2831 8073
      2852 8156
TIME...MOT...LOC 2233Z 278DEG 6KT 2865 8145

$$


52

1 follow-up statement

033 
WWUS52 KMLB 202324
SVSMLB

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MELBOURNE FL
724 PM EDT FRI APR 20 2012

FLC009-095-117-127-202333-
/O.EXP.KMLB.SV.W.0016.000000T0000Z-120420T2330Z/
SEMINOLE-ORANGE-VOLUSIA-BREVARD-
724 PM EDT FRI APR 20 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN BREVARD...
SOUTHEASTERN VOLUSIA...ORANGE AND SEMINOLE COUNTIES WILL EXPIRE AT
730 PM EDT...

THE SEVERE STORM THAT PROMPTED THE WARNING HAD WEAKENED AND EXITED
THE WARNING AREA...THUS THE WARNING HAS BEEN ALLOWED TO EXPIRE.

LAT...LON 2875 8153 2889 8080 2885 8081 2875 8079
      2877 8084 2866 8082 2866 8079 2870 8078
      2869 8078 2860 8077 2862 8079 2860 8080
      2856 8079 2853 8076 2851 8077 2831 8073
      2852 8156
TIME...MOT...LOC 2323Z 278DEG 6KT 2864 8136

$$


52

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 20, 3:06 PM EDT	Severe Thunderstorm Warning	MLB	Lake, Orange	38 min
Apr 20, 3:56 PM EDT	Special Weather Statement	MLB	Lake, Orange, Osceola, Seminole	64 min
Apr 20, 4:08 PM EDT	Severe Thunderstorm Warning	MLB	Indian River	67 min
Apr 20, 4:09 PM EDT	Severe Thunderstorm Warning	MLB	Orange, Osceola	66 min
Apr 20, 4:15 PM EDT	Special Marine Warning	MLB		2 hr
Apr 20, 4:19 PM EDT	Special Weather Statement	MLB	Martin	41 min
Apr 20, 4:22 PM EDT	Severe Thunderstorm Warning	MLB	Osceola	53 min
Apr 20, 4:29 PM EDT	Special Weather Statement	MLB	Volusia	61 min
Apr 20, 4:35 PM EDT	Severe Thunderstorm Warning	MLB	Volusia	55 min
Apr 20, 4:43 PM EDT	Severe Thunderstorm Warning	MLB	Okeechobee	62 min
Apr 20, 5:04 PM EDT	Severe Thunderstorm Warning	MLB	Lake, Volusia	56 min
Apr 20, 5:20 PM EDT	Special Weather Statement	MLB	Indian River	40 min
Apr 20, 5:34 PM EDT	Special Marine Warning	MLB		116 min
Apr 20, 5:34 PM EDT	Severe Thunderstorm Warning	MLB	Brevard, Osceola	56 min
Apr 20, 5:39 PM EDT	Severe Thunderstorm Warning	MLB	Indian River, Saint Lucie	66 min
Apr 20, 5:59 PM EDT	Special Marine Warning	MLB		2 hr
Apr 20, 6:49 PM EDT	Special Weather Statement	MLB	Martin	56 min
Apr 20, 7:37 PM EDT	Special Weather Statement	MLB	Brevard	53 min
Apr 20, 7:49 PM EDT	Special Marine Warning	MLB		41 min

Nearby

Severe Thunderstorm Warnings in Florida, 2012 Every severe thunderstorm warning in 2012

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.