Alert archive / Florida / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 29, NWS Melbourne, FL

April 28, 2011Okeechobee County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Apr 28, 2011, 6:54 PM EDT for Okeechobee County, Florida. It was in force for 51 min. 7 reports 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 28, 2011, 6:54 PM EDT (22:54 UTC)
Expired: Apr 28, 2011, 7:45 PM EDT
In force: 51 min
Issued by: NWS Melbourne, FL
Area: Storm-based polygon

County Okeechobee County, FL

The radar

The Melbourne radar (KMLB), 102 km from the middle of the area, began a volume at 22:56 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 28, 7:05 PM EDT	HAIL 2.75	3 S Okeechobee, FL	REPORT OF BASEBALL SIZE HAIL SOUTH OF CITY OF OKEECHOBEE. REPORT RELAYED BY WFO MIAMI.
Apr 28, 7:10 PM EDT	HAIL 1.75	3 S Okeechobee, FL
Apr 28, 7:10 PM EDT	HAIL 2.75	3 S Okeechobee, FL	REPORT OF BASEBALL SIZE HAIL SOUTH OF CITY OF OKEECHOBEE. REPORT RELAYED BY WFO MIAMI.
Apr 28, 7:15 PM EDT	HAIL 1	2 Sse Okeechobee, FL
Apr 28, 7:15 PM EDT	HAIL 2.5	3 S Okeechobee, FL
Apr 28, 7:26 PM EDT	HAIL 2.5	3 S Okeechobee, FL
Apr 28, 7:34 PM EDT	HAIL 2.75	3 S Okeechobee, FL	REPORT OF BASEBALL SIZE HAIL SOUTH OF CITY OF OKEECHOBEE. REPORT RELAYED BY WFO MIAMI.

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, 10.9 hours before the alert went out and 144 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: 671 J/kg
Mixed-layer CIN: -81 J/kg
Mixed-layer LCL: 1082 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 34 m²/s²
0-3 km storm-relative helicity: 46 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

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

480 
WUUS52 KMLB 282254
SVRMLB
FLC093-282345-
/O.NEW.KMLB.SV.W.0029.110428T2254Z-110428T2345Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
654 PM EDT THU APR 28 2011

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN OKEECHOBEE COUNTY IN FLORIDA

* UNTIL 745 PM EDT.

* AT 648 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED 
  A SEVERE THUNDERSTORM CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING 
  WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED NEAR OKEE TANTIE 
  STATE PARK...OR 8 MILES SOUTH OF OKEECHOBEE...AND MOVING NORTHEAST 
  AT 15 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE...BUT ARE NOT LIMITED TO...
  TAYLOR CREEK AND FOUR SEASONS ESTATES

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 2718 8075 2720 8080 2720 8082 2715 8086
      2714 8087 2716 8088 2721 8095 2741 8074
      2726 8068 2713 8068
TIME...MOT...LOC 2254Z 231DEG 20KT 2714 8084

$$
RL

1 follow-up statement

343 
WWUS52 KMLB 282317
SVSMLB

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MELBOURNE FL
717 PM EDT THU APR 28 2011

FLC093-282345-
/O.CON.KMLB.SV.W.0029.000000T0000Z-110428T2345Z/
OKEECHOBEE-
717 PM EDT THU APR 28 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR SOUTHEASTERN OKEECHOBEE COUNTY...

AT 713 PM EDT...TRAINED WEATHER SPOTTERS REPORTED A SEVERE 
THUNDERSTORM PRODUCING QUARTER SIZE HAIL.  THIS STORM WAS LOCATED 6 
MILES SOUTHEAST OF OKEECHOBEE...MOVING NORTHEAST AT 25 MPH.

THE SEVERE THUNDERSTORM WILL OTHERWISE REMAIN OVER MAINLY RURAL AREAS
OF THE INDICATED COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING DESTRUCTIVE WINDS AND LARGE
DAMAGING HAIL. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY
AWAY FROM WINDOWS!

&&

LAT...LON 2718 8075 2720 8080 2720 8082 2715 8086
      2714 8087 2716 8088 2721 8095 2741 8074
      2726 8068 2713 8068
TIME...MOT...LOC 2316Z 231DEG 20KT 2722 8073

$$

67

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 28, 3:14 PM EDT	Special Weather Statement	MLB	Volusia	46 min
Apr 28, 3:30 PM EDT	Special Marine Warning	MLB		110 min
Apr 28, 4:11 PM EDT	Severe Thunderstorm Warning	MLB	Indian River, Saint Lucie	24 min
Apr 28, 5:44 PM EDT	Special Weather Statement	MLB	Okeechobee, Osceola	61 min
Apr 28, 6:18 PM EDT	Special Weather Statement	MLB	Brevard, Indian River	57 min
Apr 28, 6:37 PM EDT	Special Marine Warning	MLB		53 min
Apr 28, 6:48 PM EDT	Severe Thunderstorm Warning	MLB	Brevard	42 min
Apr 28, 7:52 PM EDT	Special Weather Statement	MLB	Saint Lucie	38 min

Nearby

Severe Thunderstorm Warnings in Florida, 2011 Every severe thunderstorm warning in 2011

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.