Alert archive / Florida / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 12, NWS Melbourne, FL

April 25, 2021Lake County, Seminole County, Volusia County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Apr 25, 2021, 8:39 AM EDT for Lake County, Seminole County, Volusia County, Florida. It was in force for 36 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 25, 2021, 8:39 AM EDT (12:39 UTC)
Expired
Apr 25, 2021, 9:15 AM EDT
In force
36 min
Issued by
NWS Melbourne, FL
Area
Storm-based polygon
Tornado
Possible
Hail
0.75 in
Wind
60.0 mph

Counties Lake County, FL, Seminole County, FL, Volusia County, FL

The radar

The Melbourne radar (KMLB), 114 km from the middle of the area, began a volume at 12:41 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, 0.7 hours before the alert went out and 103 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 2021-04-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1032 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 2021-04-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 177 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
1032 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
717 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
177 m²/s²
0-3 km storm-relative helicity
171 m²/s²
Significant tornado parameter
1.0
Supercell composite
5.3

Open this sounding in Storm Lab

The text

As transmitted.

227 
WUUS52 KMLB 251239
SVRMLB
FLC069-117-127-251315-
/O.NEW.KMLB.SV.W.0012.210425T1239Z-210425T1315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Melbourne FL
839 AM EDT Sun Apr 25 2021

The National Weather Service in Melbourne has issued a

* Severe Thunderstorm Warning for...
  Northwestern Seminole County in east central Florida...
  East central Lake County in east central Florida...
  Central Volusia County in east central Florida...

* Until 915 AM EDT.

* At 838 AM EDT, a severe thunderstorm was located near Paisley,
  moving east at 30 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Deltona, Sanford, Lake Mary, Orange City and Cassia. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2898 8158 2896 8119 2875 8136 2877 8142
      2878 8142 2878 8145 2886 8165
TIME...MOT...LOC 1238Z 282DEG 27KT 2891 8156 

TORNADO...POSSIBLE
HAIL...0.75IN
WIND...60MPH
 
$$

Combs
2 follow-up statements
541 
WWUS52 KMLB 251254
SVSMLB

Severe Weather Statement
National Weather Service Melbourne FL
854 AM EDT Sun Apr 25 2021

FLC069-117-127-251315-
/O.CON.KMLB.SV.W.0012.000000T0000Z-210425T1315Z/
Seminole FL-Lake FL-Volusia FL-
854 AM EDT Sun Apr 25 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 AM EDT
FOR NORTHWESTERN SEMINOLE...EAST CENTRAL LAKE AND CENTRAL VOLUSIA
COUNTIES...

At 854 AM EDT, a severe thunderstorm was located over Cassia, moving
east at 30 mph.

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

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Deltona, Sanford, Lake Mary, Orange City and Cassia. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2896 8119 2875 8136 2877 8139 2878 8142
      2878 8145 2885 8163 2898 8154
TIME...MOT...LOC 1254Z 282DEG 27KT 2888 8142 

TORNADO...POSSIBLE
HAIL...0.75IN
WIND...60MPH
 
$$

Combs
006 
WWUS52 KMLB 251307
SVSMLB

Severe Weather Statement
National Weather Service Melbourne FL
907 AM EDT Sun Apr 25 2021

FLC069-117-127-251316-
/O.EXP.KMLB.SV.W.0012.000000T0000Z-210425T1315Z/
Seminole FL-Lake FL-Volusia FL-
907 AM EDT Sun Apr 25 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN SEMINOLE...EAST
CENTRAL LAKE AND CENTRAL VOLUSIA COUNTIES WILL EXPIRE AT 915 AM
EDT...
                
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 will be allowed to expire.  However gusty 
winds, frequent lightning, and heavy rain are still possible with 
this thunderstorm.

LAT...LON 2896 8119 2875 8136 2877 8139 2878 8142
      2878 8145 2885 8163 2898 8154
TIME...MOT...LOC 1306Z 283DEG 19KT 2887 8139 

$$

Combs

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 25, 6:52 AM EDTSpecial Marine WarningMLB53 min
Apr 25, 6:56 AM EDTSpecial Weather StatementMLBFlagler34 min
Apr 25, 7:31 AM EDTSpecial Weather StatementMLBLake59 min
Apr 25, 8:30 AM EDTSpecial Weather StatementMLBLake30 min
Apr 25, 9:28 AM EDTSpecial Weather StatementMLBSeminole32 min
Apr 25, 9:44 AM EDTSevere Thunderstorm WarningMLBBrevard, Seminole, Volusia46 min
Apr 25, 10:04 AM EDTSpecial Marine WarningMLB56 min
Apr 25, 12:13 PM EDTSpecial Weather StatementMLBBrevard32 min
Apr 25, 12:54 PM EDTSpecial Weather StatementMLBBrevard36 min
Apr 25, 12:57 PM EDTSpecial Marine WarningMLB63 min
Apr 25, 4:33 PM EDTSpecial Marine WarningMLB57 min
Apr 25, 7:22 PM EDTSpecial Marine WarningMLB53 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.