Alert archive / Florida / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 11, NWS Melbourne, FL

April 20, 2012Volusia County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Apr 20, 2012, 4:35 PM EDT for Volusia County, Florida. It was in force for 55 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Apr 20, 2012, 4:35 PM EDT (20:35 UTC)
Expired: Apr 20, 2012, 5:30 PM EDT
In force: 55 min
Issued by: NWS Melbourne, FL
Area: Storm-based polygon

County Volusia County, FL

The radar

The Melbourne radar (KMLB), 135 km from the middle of the area, began a volume at 20:37 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.

What was reported inside it

Time	Report	Where	Remark
Apr 20, 4:50 PM EDT	HAIL 1.25	4 N Barberville, FL	BUCKLE ROAD AND STATE ROAD 40. QUARTER HAIL AT 440 PM, UP TO HALF DOLLAR AT 448 PM.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Cape Canaveral, FL (KXMR), launched 12:00Z, 8.6 hours before the alert went out and 111 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.

768 
WUUS52 KMLB 202035
SVRMLB
FLC127-202130-
/O.NEW.KMLB.SV.W.0011.120420T2035Z-120420T2130Z/

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

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  VOLUSIA COUNTY IN FLORIDA

* UNTIL 530 PM EDT.

* AT 433 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  BARBERVILLE...AND MOVING EAST AT 15 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE...BUT ARE NOT LIMITED
  TO...DE LEON SPRINGS...DE LAND...ORMOND BY THE SEA...ORMOND
  BEACH...HOLLY HILL AND DAYTONA BEACH

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 2901 8090 2903 8141 2906 8145 2909 8146
      2910 8147 2928 8155 2932 8142 2927 8141
      2927 8116 2941 8116 2943 8111
TIME...MOT...LOC 2034Z 259DEG 18KT 2920 8138

$$


52

1 follow-up statement

926 
WWUS52 KMLB 202122
SVSMLB

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

FLC127-202132-
/O.EXP.KMLB.SV.W.0011.000000T0000Z-120420T2130Z/
VOLUSIA-
522 PM EDT FRI APR 20 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN VOLUSIA COUNTY WILL
EXPIRE AT 530 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 2901 8090 2903 8141 2906 8145 2909 8146
      2910 8147 2928 8155 2932 8142 2927 8141
      2927 8116 2941 8116 2943 8111
TIME...MOT...LOC 2122Z 259DEG 18KT 2925 8111

$$


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, 4:43 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, 6:36 PM EDT	Severe Thunderstorm Warning	MLB	Brevard, Orange, Seminole, Volusia	54 min
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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.