Alert archive / Florida / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 8, NWS Melbourne, FL

April 11, 2021Lake County, Orange County, Osceola County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Apr 11, 2021, 12:23 PM EDT for Lake County, Orange County, Osceola County, Florida. It was in force for 52 min. 5 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 11, 2021, 12:23 PM EDT (16:23 UTC)
Expired
Apr 11, 2021, 1:15 PM EDT
In force
52 min
Issued by
NWS Melbourne, FL
Area
Storm-based polygon
Hail
0.75 in
Wind
70.0 mph

Counties Lake County, FL, Orange County, FL, Osceola County, FL

The radar

The Melbourne radar (KMLB), 85 km from the middle of the area, began a volume at 16:26 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

TimeReportWhereRemark
Apr 11, 12:31 PM EDTTSTM WND GST 447 Nw Loughman, FLMESONET STATION EW2910 DAVENPORT.
Apr 11, 12:40 PM EDTHAIL 0.755 Sw Celebration, FLTRAINED SPOTTER REPORTS PENNY SIZE HAIL NEAR LAKE WILSON ROAD AND CR-532.
Apr 11, 12:42 PM EDTTSTM WND GST 46Kissimmee Airport, FLAWOS AT KISSIMMEE GATEWAY MEASURED A PEAK WIND GUST OF 40KT OR 46MPH FROM THE WNW.
Apr 11, 12:54 PM EDTTSTM WND GST 46Orlando International A, FLASOS AT ORLANDO INTERNATIONAL MEASURED A PEAK WIND GUST OF 40KT OR 46MPH FROM THE NNW.
Apr 11, 1:15 PM EDTTSTM WND GST 476 Sse West Lake Toho, FLSFWMD STATION ON THE SOUTH EDGE OF LAKE TOHO MEASURED A PEAK WIND GUST OF 47MPH.

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Apr 11, 8:15 AM EDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Cape Canaveral, FL (KXMR), launched 12:00Z, 4.4 hours before the alert went out and 101 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 2021-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 449 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Cape Canaveral, FL at 12:00Z on 2021-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 202 square meters per square second.1939587897Sfc1 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
449 J/kg
Mixed-layer CIN
-181 J/kg
Mixed-layer LCL
1002 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
202 m²/s²
0-3 km storm-relative helicity
199 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

As transmitted.

720 
WUUS52 KMLB 111623
SVRMLB
FLC069-095-097-111715-
/O.NEW.KMLB.SV.W.0008.210411T1623Z-210411T1715Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Melbourne FL
1223 PM EDT Sun Apr 11 2021

The National Weather Service in Melbourne has issued a

* Severe Thunderstorm Warning for...
  South central Lake County in east central Florida...
  Southwestern Orange County in east central Florida...
  Northwestern Osceola County in east central Florida...

* Until 115 PM EDT.

* At 1223 PM EDT, a severe thunderstorm was located over Four
  Corners, or near Celebration, moving east at 60 mph.

  HAZARD...70 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings.

* Locations impacted include...
  Orlando, Kissimmee, Apopka, Ocoee and Winter Garden. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 2869 8169 2862 8133 2817 8116 2807 8135
      2808 8135 2809 8145 2805 8143 2804 8146
      2814 8145 2814 8152 2820 8152 2826 8156
      2826 8166 2835 8166 2836 8181
TIME...MOT...LOC 1623Z 253DEG 50KT 2830 8162 

HAIL...0.75IN
WIND...70MPH
 
$$

Smith
2 follow-up statements
325 
WWUS52 KMLB 111645
SVSMLB

Severe Weather Statement
National Weather Service Melbourne FL
1245 PM EDT Sun Apr 11 2021

FLC069-111654-
/O.CAN.KMLB.SV.W.0008.000000T0000Z-210411T1715Z/
Lake FL-
1245 PM EDT Sun Apr 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL LAKE COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 400 PM EDT for
east central Florida.

LAT...LON 2862 8157 2862 8133 2817 8116 2807 8135
      2808 8135 2809 8145 2805 8143 2804 8146
      2814 8145 2814 8152 2820 8152 2826 8156
TIME...MOT...LOC 1644Z 253DEG 50KT 2839 8129 

$$

FLC095-097-111715-
/O.CON.KMLB.SV.W.0008.000000T0000Z-210411T1715Z/
Orange FL-Osceola FL-
1245 PM EDT Sun Apr 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 115 PM EDT
FOR SOUTHWESTERN ORANGE AND NORTHWESTERN OSCEOLA COUNTIES...

At 1244 PM EDT, a severe thunderstorm was located near Orlando
International Airport, moving east at 60 mph.

HAZARD...70 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
Orlando, Kissimmee, Ocoee, Winter Garden and Saint Cloud. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 2862 8157 2862 8133 2817 8116 2807 8135
      2808 8135 2809 8145 2805 8143 2804 8146
      2814 8145 2814 8152 2820 8152 2826 8156
TIME...MOT...LOC 1644Z 253DEG 50KT 2839 8129 

HAIL...0.75IN
WIND...70MPH
 
$$

Smith
144 
WWUS52 KMLB 111705
SVSMLB

Severe Weather Statement
National Weather Service Melbourne FL
105 PM EDT Sun Apr 11 2021

FLC095-097-111715-
/O.EXP.KMLB.SV.W.0008.000000T0000Z-210411T1715Z/
Orange FL-Osceola FL-
105 PM EDT Sun Apr 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN ORANGE AND
NORTHWESTERN OSCEOLA COUNTIES WILL EXPIRE AT 115 PM EDT...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.

A Severe Thunderstorm Watch remains in effect until 400 PM EDT for
east central Florida.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Melbourne.

LAT...LON 2862 8157 2862 8133 2817 8116 2807 8135
      2808 8135 2809 8145 2805 8143 2804 8146
      2814 8145 2814 8152 2820 8152 2826 8156
TIME...MOT...LOC 1705Z 253DEG 50KT 2847 8099 

$$

Smith

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 11, 4:31 AM EDTSpecial Weather StatementMLBFlagler44 min
Apr 11, 7:38 AM EDTSpecial Marine WarningMLB2 hr
Apr 11, 7:43 AM EDTSpecial Weather StatementMLBVolusia62 min
Apr 11, 8:45 AM EDTSpecial Weather StatementMLBVolusia45 min
Apr 11, 9:19 AM EDTSpecial Marine WarningMLB26 min
Apr 11, 9:45 AM EDTSpecial Weather StatementMLBLake60 min
Apr 11, 10:35 AM EDTSevere Thunderstorm WarningMLBOrange, Seminole23 min
Apr 11, 10:56 AM EDTSevere Thunderstorm WarningMLBSeminole, Volusia30 min
Apr 11, 11:01 AM EDTSpecial Weather StatementMLBLake44 min
Apr 11, 11:05 AM EDTSpecial Weather StatementMLBSeminole10 min
Apr 11, 11:29 AM EDTSpecial Marine WarningMLB2 hr
Apr 11, 11:31 AM EDTSpecial Weather StatementMLBSeminole, Volusia44 min
Apr 11, 11:39 AM EDTSpecial Weather StatementMLBLake, Orange66 min
Apr 11, 11:45 AM EDTSpecial Weather StatementMLBVolusia60 min
Apr 11, 12:39 PM EDTSpecial Weather StatementMLBBrevard, Osceola66 min
Apr 11, 1:04 PM EDTSpecial Weather StatementMLBSeminole41 min
Apr 11, 1:08 PM EDTSpecial Marine WarningMLB3 hr
Apr 11, 1:13 PM EDTSpecial Weather StatementMLBIndian River, Okeechobee62 min
Apr 11, 1:55 PM EDTSevere Thunderstorm WarningMLBBrevard, Indian River36 min
Apr 11, 2:11 PM EDTSpecial Weather StatementMLBIndian River, Martin, Okeechobee, Saint Lucie94 min
Apr 11, 2:17 PM EDTSevere Thunderstorm WarningMLBIndian River, Martin, Okeechobee, Saint Lucie58 min

Nearby

Severe Thunderstorm Warnings in Florida, 2021Every severe thunderstorm warning in 2021

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.