Alert archive / Florida / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 7, NWS Melbourne, FL

April 11, 2021Seminole County, Volusia County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Apr 11, 2021, 10:56 AM EDT for Seminole County, Volusia County, Florida. It was in force for 30 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, 10:56 AM EDT (14:56 UTC)
Expired: Apr 11, 2021, 11:26 AM EDT
In force: 30 min
Issued by: NWS Melbourne, FL
Area: Storm-based polygon
Hail: 1.75 in
Wind: 60.0 mph

Counties Seminole County, FL, Volusia County, FL

The radar

The Melbourne radar (KMLB), 85 km from the middle of the area, began a volume at 14:55 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, 10:57 AM EDT	HAIL 0.88	6 W Chuluota, FL	PUBLIC REPORTS NICKEL SIZED HAIL IN CHULUOTA.
Apr 11, 10:58 AM EDT	HAIL 0.88	2 E Casselberry, FL	TRAINED SPOTTER REPORTS NICKEL SIZE HAIL NEAR CASSELBERRY.
Apr 11, 10:58 AM EDT	HAIL 1	5 W Chuluota, FL	TRAINED SPOTTER REPORTS QUARTER SIZED HAIL ON PROVIDENCE LANE IN OVIEDO.
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, 11:03 AM EDT	HAIL 1.5	3 Wnw Chuluota, FL	PUBLIC REPORTS PING PONG TO NEARLY GOLF BALL SIZED HAIL IN OVIEDO.

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, 2.9 hours before the alert went out and 68 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.

404 
WUUS52 KMLB 111456
SVRMLB
FLC117-127-111545-
/O.NEW.KMLB.SV.W.0007.210411T1456Z-210411T1545Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Melbourne FL
1056 AM EDT Sun Apr 11 2021

The National Weather Service in Melbourne has issued a

* Severe Thunderstorm Warning for...
  Eastern Seminole County in east central Florida...
  South central Volusia County in east central Florida...

* Until 1145 AM EDT.

* At 1056 AM EDT, a severe thunderstorm was located over Oviedo,
  moving northeast at 45 mph.

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

  SOURCE...Emergency management.

  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...
  Sanford, Oviedo, Winter Springs, Casselberry and Chuluota. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2893 8107 2878 8097 2862 8097 2861 8129
      2867 8134
TIME...MOT...LOC 1456Z 246DEG 38KT 2866 8119 

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

Smith

2 follow-up statements

642 
WWUS52 KMLB 111513
SVSMLB

Severe Weather Statement
National Weather Service Melbourne FL
1113 AM EDT Sun Apr 11 2021

FLC117-127-111545-
/O.CON.KMLB.SV.W.0007.000000T0000Z-210411T1545Z/
Seminole FL-Volusia FL-
1113 AM EDT Sun Apr 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1145 AM EDT
FOR EASTERN SEMINOLE AND SOUTH CENTRAL VOLUSIA COUNTIES...

At 1112 AM EDT, a severe thunderstorm was located near Maytown, or
near Geneva, moving northeast at 45 mph.

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

SOURCE...Emergency management.

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...
Oviedo, Winter Springs, Chuluota, Lake Jessup and Geneva. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Melbourne.

&&

LAT...LON 2878 8097 2862 8097 2861 8129 2869 8129
      2888 8103
TIME...MOT...LOC 1512Z 246DEG 38KT 2873 8101 

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

Smith

487 
WWUS52 KMLB 111526
SVSMLB

Severe Weather Statement
National Weather Service Melbourne FL
1126 AM EDT Sun Apr 11 2021

FLC117-127-111536-
/O.CAN.KMLB.SV.W.0007.000000T0000Z-210411T1545Z/
Seminole FL-Volusia FL-
1126 AM EDT Sun Apr 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN SEMINOLE AND SOUTH
CENTRAL VOLUSIA COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.  However gusty winds and
heavy rain are still possible with this thunderstorm.

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 2878 8097 2862 8097 2861 8129 2869 8129
      2888 8103
TIME...MOT...LOC 1525Z 246DEG 38KT 2879 8085 

$$

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, 10:35 AM EDT	Severe Thunderstorm Warning	MLB	Orange, Seminole	23 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.