Alert archive / Florida / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 6, NWS Melbourne, FL

April 11, 2021Orange County, Seminole County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Apr 11, 2021, 10:35 AM EDT for Orange County, Seminole County, Florida. It was in force for 23 min. 23 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, 10:35 AM EDT (14:35 UTC)
Expired: Apr 11, 2021, 10:58 AM EDT
In force: 23 min
Issued by: NWS Melbourne, FL
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Orange County, FL, Seminole County, FL

The radar

The Melbourne radar (KMLB), 90 km from the middle of the area, began a volume at 14:35 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 11, 10:40 AM EDT	HAIL 1	5 S Altamonte Springs, FL	LOCAL BROADCAST MEDIA REPORTS HAIL UP TO QUARTER SIZE NEAR THE DUBSDREAD GOLF COURSE NEAR COLLEGE PARK.
Apr 11, 10:42 AM EDT	HAIL 1	4 S Altamonte Springs, FL	LOCAL BROADCAST MEDIA REPORTS QUARTER SIZE HAIL IN ALTAMONTE.
Apr 11, 10:42 AM EDT	HAIL 1.25	Winter Park, FL	PUBLIC REPORTS HALF DOLLAR SIZED HAIL IN WINTER PARK. TIME ESTIMATED FROM RADAR.
Apr 11, 10:42 AM EDT	HAIL 1.75	Winter Park, FL	PUBLIC REPORTS QUARTER TO GOLFBALL SIZED HAIL IN WINTER PARK.
Apr 11, 10:43 AM EDT	HAIL 0.7	Casselberry, FL	PUBLIC REPORTS DIME SIZED HAIL IN CASSELBERRY
Apr 11, 10:45 AM EDT	HAIL 0.88	Maitland, FL	TRAINED SPOTTER REPORTS NICKEL SIZED HAIL IN MAITLAND.
Apr 11, 10:45 AM EDT	HAIL 1	4 Se Altamonte Springs, FL	A TRAINED SPOTTER REPORTED NICKEL TO QUARTER SIZED HAIL IN MAITLAND NEAR SENECA TRAIL AND HORATIO AVENUE.
Apr 11, 10:48 AM EDT	HAIL 0.7	5 N Azalea Park, FL	TRAINED SPOTTER REPORTS DIME SIZED HAIL IN WINTER PARK.
Apr 11, 10:48 AM EDT	HAIL 1.25	1 Nne Goldenrod, FL	PUBLIC REPORTS HALF DOLLAR SIZED HAIL NEAR GOLDENROD.
Apr 11, 10:49 AM EDT	HAIL 1.75	5 Nne Azalea Park, FL	EM REPORTS GOLF BALL SIZED HAIL NEAR SR-426 AND TUSKAWILLA ROAD.
Apr 11, 10:50 AM EDT	HAIL 0.7	1 S Altamonte Springs, FL	PUBLIC REPORTS DIME SIZED HAIL IN MAITLAND.
Apr 11, 10:50 AM EDT	HAIL 0.7	Casselberry, FL	PUBLIC REPORTS DIME SIZE HAIL NEAR CASSELBERRY.
Apr 11, 10:50 AM EDT	HAIL 1	5 E Altamonte Springs, FL	A TRAINED SPOTTER REPORTED QUARTER SIZED HAIL NEAR CASSELBERRY.
Apr 11, 10:50 AM EDT	HAIL 1	5 Ese Altamonte Springs, FL	TRAINED SPOTTER REPORTS QUARTER SIZED HAIL.
Apr 11, 10:50 AM EDT	HAIL 2	5 Ese Casselberry, FL	TRAINED SPOTTER REPORTS 2 INCH HAIL IN OVIEDO.
Apr 11, 10:51 AM EDT	HAIL 0.88	6 E Casselberry, FL	TRAINED SPOTTER REPORTS NICKEL SIZED HAIL NEAR SR-417 AND RED BUG LAKE ROAD.
Apr 11, 10:51 AM EDT	HAIL 1	4 E Goldenrod, FL	PUBLIC REPORTS AT LEAST QUARTER SIZED HAIL NEAR UCF.
Apr 11, 10:52 AM EDT	HAIL 0.7	5 N Azalea Park, FL	PUBLIC REPORTS DIME SIZED HAIL IN AZALEA PARK NEAR GOLDENROD.
Apr 11, 10:54 AM EDT	HAIL 0.88	Casselberry, FL	PUBLIC REPORTS DIME TO NICKEL SIZED HAIL IN CASSELBERRY.
Apr 11, 10:54 AM EDT	HAIL 2	4 Ese Casselberry, FL	TRAINED SPOTTER REPORTS 2-INCH HAIL NEAR THE INTERSECTION OF PUBLIX ROAD AND BROOKS LANE IN OVIEDO.
Apr 11, 10:58 AM EDT	HAIL 0.88	2 E Casselberry, FL	TRAINED SPOTTER REPORTS NICKEL SIZE HAIL NEAR CASSELBERRY.
Apr 11, 11:00 AM EDT	HAIL 1	3 Ese Casselberry, FL	LOCAL BROADCAST MEDIA RELAYED A REPORT OF QUARTER SIZED HAIL NEAR RED BUG LAKE RD AND DODD ROAD IN WINTER SPRINGS.
Apr 11, 11:00 AM EDT	HAIL 1	Winter Park, FL	TRAINED SPOTTER REPORTS QUARTER SIZED HAIL IN WINTER PARK.

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.

Issued	Product	Office	Lasted
Apr 11, 8:15 AM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Cape Canaveral, FL (KXMR), launched 12:00Z, 2.6 hours before the alert went out and 88 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: 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.

092 
WUUS52 KMLB 111435
SVRMLB
FLC095-117-111515-
/O.NEW.KMLB.SV.W.0006.210411T1435Z-210411T1515Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Melbourne FL
1035 AM EDT Sun Apr 11 2021

The National Weather Service in Melbourne has issued a

* Severe Thunderstorm Warning for...
  Southwestern Seminole County in east central Florida...
  Northwestern Orange County in east central Florida...

* Until 1115 AM EDT.

* At 1035 AM EDT, a severe thunderstorm was located over Fairview
  Shores, or over College Park, moving northeast at 35 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2849 8141 2858 8157 2879 8141 2861 8116
TIME...MOT...LOC 1435Z 236DEG 32KT 2858 8142 

HAIL...1.00IN
WIND...60MPH
 
$$

Smith

2 follow-up statements

762 
WWUS52 KMLB 111446
SVSMLB

Severe Weather Statement
National Weather Service Melbourne FL
1046 AM EDT Sun Apr 11 2021

FLC095-117-111515-
/O.CON.KMLB.SV.W.0006.000000T0000Z-210411T1515Z/
Seminole FL-Orange FL-
1046 AM EDT Sun Apr 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1115 AM EDT
FOR SOUTHWESTERN SEMINOLE AND CENTRAL ORANGE COUNTIES...

At 1046 AM EDT, a severe thunderstorm was located over Fern Park, or
over Casselberry, moving northeast at 35 mph.

HAZARD...Golf ball size hail and 60 mph wind gusts.

SOURCE...Public.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
Orlando, Altamonte Springs, Oviedo, Winter Springs and Winter Park. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2852 8138 2859 8146 2878 8139 2861 8116
TIME...MOT...LOC 1446Z 236DEG 32KT 2864 8133 

HAIL...1.75IN
WIND...60MPH
 
$$

Smith

021 
WWUS52 KMLB 111458
SVSMLB

Severe Weather Statement
National Weather Service Melbourne FL
1058 AM EDT Sun Apr 11 2021

FLC095-117-111507-
/O.CAN.KMLB.SV.W.0006.000000T0000Z-210411T1515Z/
Seminole FL-Orange FL-
1058 AM EDT Sun Apr 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN SEMINOLE AND
CENTRAL ORANGE COUNTIES IS CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.  However heavy rain is
still possible with this thunderstorm.

A Severe Thunderstorm Warning still remains in effect for south 
central Seminole County until 1145 AM.

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

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

LAT...LON 2852 8138 2859 8146 2878 8139 2861 8116
TIME...MOT...LOC 1455Z 236DEG 32KT 2870 8123 

$$

Smith

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 11, 4:31 AM EDT	Special Weather Statement	MLB	Flagler	44 min
Apr 11, 7:38 AM EDT	Special Marine Warning	MLB		2 hr
Apr 11, 7:43 AM EDT	Special Weather Statement	MLB	Volusia	62 min
Apr 11, 8:45 AM EDT	Special Weather Statement	MLB	Volusia	45 min
Apr 11, 9:19 AM EDT	Special Marine Warning	MLB		26 min
Apr 11, 9:45 AM EDT	Special Weather Statement	MLB	Lake	60 min
Apr 11, 10:56 AM EDT	Severe Thunderstorm Warning	MLB	Seminole, Volusia	30 min
Apr 11, 11:01 AM EDT	Special Weather Statement	MLB	Lake	44 min
Apr 11, 11:05 AM EDT	Special Weather Statement	MLB	Seminole	10 min
Apr 11, 11:29 AM EDT	Special Marine Warning	MLB		2 hr
Apr 11, 11:31 AM EDT	Special Weather Statement	MLB	Seminole, Volusia	44 min
Apr 11, 11:39 AM EDT	Special Weather Statement	MLB	Lake, Orange	66 min
Apr 11, 11:45 AM EDT	Special Weather Statement	MLB	Volusia	60 min
Apr 11, 12:23 PM EDT	Severe Thunderstorm Warning	MLB	Lake, Orange, Osceola	52 min
Apr 11, 12:39 PM EDT	Special Weather Statement	MLB	Brevard, Osceola	66 min
Apr 11, 1:04 PM EDT	Special Weather Statement	MLB	Seminole	41 min
Apr 11, 1:08 PM EDT	Special Marine Warning	MLB		3 hr
Apr 11, 1:13 PM EDT	Special Weather Statement	MLB	Indian River, Okeechobee	62 min
Apr 11, 1:55 PM EDT	Severe Thunderstorm Warning	MLB	Brevard, Indian River	36 min
Apr 11, 2:11 PM EDT	Special Weather Statement	MLB	Indian River, Martin, Okeechobee, Saint Lucie	94 min
Apr 11, 2:17 PM EDT	Severe Thunderstorm Warning	MLB	Indian River, Martin, Okeechobee, Saint Lucie	58 min

Nearby

Severe Thunderstorm Warnings in Florida, 2021 Every 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.