Alert archive / Florida / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 15, NWS Melbourne, FL

April 20, 2012Indian River County, Saint Lucie County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Apr 20, 2012, 5:39 PM EDT for Indian River County, Saint Lucie County, Florida. It was in force for 66 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, 5:39 PM EDT (21:39 UTC)
Expired
Apr 20, 2012, 6:45 PM EDT
In force
66 min
Issued by
NWS Melbourne, FL
Area
Storm-based polygon

Counties Indian River County, FL, Saint Lucie County, FL

The radar

The Melbourne radar (KMLB), 80 km from the middle of the area, began a volume at 21:38 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, 9.7 hours before the alert went out and 115 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 2012-04-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 414 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 2012-04-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 3 square meters per square second.193958Sfc1 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
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.

037 
WUUS52 KMLB 202139
SVRMLB
FLC061-111-202245-
/O.NEW.KMLB.SV.W.0015.120420T2139Z-120420T2245Z/

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

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN INDIAN RIVER COUNTY IN FLORIDA
  NORTHERN ST. LUCIE COUNTY IN FLORIDA

* UNTIL 645 PM EDT.

* AT 533 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR   
VERO BEACH HIGHLANDS...OR NEAR INDRIO...AND MOVING SOUTHEAST AT 10 
MPH.
 
OTHER STRONG STORMS...POSSIBLY BECOMING SEVERE...WERE FORMING IN 
NORTH-CENTRAL AND NORTHWEST SAINT LUCIE COUNTY.

* OTHER LOCATIONS IN THE WARNING INCLUDE...BUT ARE NOT LIMITED TO...
  SOUTH BEACH...SAINT LUCIE VILLAGE...QUEENS COVE...FORT PIERCE...
  WHITE CITY...FORT PIERCE INLET...INDIAN RIVER ESTATES AND SAINT
  LUCIE NUCLEAR PLANT

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.

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY! LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

&&

LAT...LON 2734 8023 2735 8027 2739 8027 2745 8031
      2736 8027 2740 8066 2743 8068 2755 8061
      2763 8035 2759 8031 2755 8031
TIME...MOT...LOC 2138Z 289DEG 8KT 2756 8035

$$

SEDLOCK
2 follow-up statements
060 
WWUS52 KMLB 202211
SVSMLB

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

FLC061-202218-
/O.CAN.KMLB.SV.W.0015.000000T0000Z-120420T2245Z/
INDIAN RIVER-
611 PM EDT FRI APR 20 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN INDIAN RIVER
COUNTY IS CANCELLED...

LAT...LON 2735 8027 2739 8027 2745 8031 2742 8031
      2737 8028 2736 8028 2740 8066 2744 8068
      2755 8061 2756 8031 2734 8023
TIME...MOT...LOC 2208Z 293DEG 10KT 2750 8028

$$

FLC111-202245-
/O.CON.KMLB.SV.W.0015.000000T0000Z-120420T2245Z/
ST. LUCIE-
611 PM EDT FRI APR 20 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM EDT
FOR NORTHERN ST. LUCIE COUNTY...

AT 603 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO
DETECT A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED NEAR PEPPER BEACH PARK...OR NEAR FORT PIERCE INLET...MOVING
SOUTHEAST AT 10 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO FORT
PIERCE OCEAN PARK...SURFSIDE PARK...COLLINS PARK ESTATES...INDIAN
RIVER ESTATES...FREDERICK DOUGLASS PARK AND SAINT LUCIE NUCLEAR PLANT

OTHER STRONG STORMS WERE ALSO ACROSS NORTH-CENTRAL AND WESTERN 
OSCEOLA COUNTY. THESE STRENGTHENING CELLS...TOO...CONTAIN TORRENTIAL 
RAINFALL...SMALL HAIL...GUSTY WINDS AND FREQUENT CLOUD TO GROUND 
LIGHTNING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY! LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

&&

LAT...LON 2735 8027 2739 8027 2745 8031 2742 8031
      2737 8028 2736 8028 2740 8066 2744 8068
      2755 8061 2756 8031 2734 8023
TIME...MOT...LOC 2208Z 293DEG 10KT 2750 8028

$$

SEDLOCK
797 
WWUS52 KMLB 202241
SVSMLB

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

FLC111-202249-
/O.EXP.KMLB.SV.W.0015.000000T0000Z-120420T2245Z/
ST. LUCIE-
641 PM EDT FRI APR 20 2012

...THE SEVERE THUNDERSTORM WARNING FOR ST. LUCIE COUNTY WILL BE 
ALLOWED TO EXPIRE AT 645 PM EDT...

THE SEVERE STORM THAT PROMPTED THE WARNING HAD MOVED OFF THE EAST 
COAST...WHILE OTHER STRONG STORMS ARE STILL ONGOING OVER CENTRAL AND 
SOUTHERN SAINT LUCIE COUNTY.

STRONG GUSTY WINDS 40 TO 50 MPH...SMALL COIN SIZE HAIL...TORRENTIAL 
RAINS AND FREQUENT LIGHTNING WILL REMAIN POSSIBLE OVER THE NEXT HOUR.

LAT...LON 2735 8027 2739 8027 2745 8031 2742 8031
      2737 8028 2736 8028 2740 8066 2744 8068
      2755 8061 2756 8031 2734 8023
TIME...MOT...LOC 2239Z 293DEG 10KT 2747 8019

$$

SEDLOCK

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 20, 3:06 PM EDTSevere Thunderstorm WarningMLBLake, Orange38 min
Apr 20, 3:56 PM EDTSpecial Weather StatementMLBLake, Orange, Osceola, Seminole64 min
Apr 20, 4:08 PM EDTSevere Thunderstorm WarningMLBIndian River67 min
Apr 20, 4:09 PM EDTSevere Thunderstorm WarningMLBOrange, Osceola66 min
Apr 20, 4:15 PM EDTSpecial Marine WarningMLB2 hr
Apr 20, 4:19 PM EDTSpecial Weather StatementMLBMartin41 min
Apr 20, 4:22 PM EDTSevere Thunderstorm WarningMLBOsceola53 min
Apr 20, 4:29 PM EDTSpecial Weather StatementMLBVolusia61 min
Apr 20, 4:35 PM EDTSevere Thunderstorm WarningMLBVolusia55 min
Apr 20, 4:43 PM EDTSevere Thunderstorm WarningMLBOkeechobee62 min
Apr 20, 5:04 PM EDTSevere Thunderstorm WarningMLBLake, Volusia56 min
Apr 20, 5:20 PM EDTSpecial Weather StatementMLBIndian River40 min
Apr 20, 5:34 PM EDTSpecial Marine WarningMLB116 min
Apr 20, 5:34 PM EDTSevere Thunderstorm WarningMLBBrevard, Osceola56 min
Apr 20, 5:59 PM EDTSpecial Marine WarningMLB2 hr
Apr 20, 6:36 PM EDTSevere Thunderstorm WarningMLBBrevard, Orange, Seminole, Volusia54 min
Apr 20, 6:49 PM EDTSpecial Weather StatementMLBMartin56 min
Apr 20, 7:37 PM EDTSpecial Weather StatementMLBBrevard53 min
Apr 20, 7:49 PM EDTSpecial Marine WarningMLB41 min

Nearby

Severe Thunderstorm Warnings in Florida, 2012Every 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.