Alert archive / Florida / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 36, NWS Melbourne, FL

August 23, 2021Okeechobee County, Saint Lucie County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Aug 23, 2021, 5:51 PM EDT for Okeechobee County, Saint Lucie County, Florida. It was in force for 20 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: Aug 23, 2021, 5:51 PM EDT (21:51 UTC)
Expired: Aug 23, 2021, 6:11 PM EDT
In force: 20 min
Issued by: NWS Melbourne, FL
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Okeechobee County, FL, Saint Lucie County, FL

The radar

The Melbourne radar (KMLB), 81 km from the middle of the area, began a volume at 21:51 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, 9.9 hours before the alert went out and 121 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: 1015 J/kg
Mixed-layer CIN: -62 J/kg
Mixed-layer LCL: 1056 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 1 m²/s²
0-3 km storm-relative helicity: -6 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

303 
WUUS52 KMLB 232151
SVRMLB
FLC093-111-232230-
/O.NEW.KMLB.SV.W.0036.210823T2151Z-210823T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Melbourne FL
551 PM EDT Mon Aug 23 2021

The National Weather Service in Melbourne has issued a

* Severe Thunderstorm Warning for...
  Western St. Lucie County in east central Florida... 
  East central Okeechobee County in east central Florida...

* Until 630 PM EDT.

* At 551 PM EDT, a severe thunderstorm was located 11 miles northeast
  of Four Seasons Estates, or 14 miles northeast of Treasure Island,
  moving north at 15 mph.

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

  SOURCE...Radar indicated.

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

* This severe thunderstorm will remain over mainly rural areas of
  northwestern St. Lucie and east central Okeechobee Counties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Frequent cloud to ground lightning is occurring with this storm. 
Move indoors immediately. Lightning is one of nature's leading 
killers. Remember, if you can hear thunder, you are close enough to 
be struck by lightning.

&&

LAT...LON 2728 8066 2751 8083 2756 8057 2730 8055
TIME...MOT...LOC 2151Z 162DEG 14KT 2738 8065 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Kelly

1 follow-up statement

128 
WWUS52 KMLB 232211
SVSMLB

Severe Weather Statement
National Weather Service Melbourne FL
611 PM EDT Mon Aug 23 2021

FLC093-111-232221-
/O.CAN.KMLB.SV.W.0036.000000T0000Z-210823T2230Z/
St. Lucie FL-Okeechobee FL-
611 PM EDT Mon Aug 23 2021

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN ST. LUCIE AND EAST 
CENTRAL OKEECHOBEE 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 these thunderstorms.

LAT...LON 2728 8066 2751 8083 2756 8057 2730 8055
TIME...MOT...LOC 2209Z 162DEG 14KT 2745 8068 

$$

Kelly

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 23, 2:34 PM EDT	Special Weather Statement	MLB	Lake	41 min
Aug 23, 3:05 PM EDT	Special Weather Statement	MLB	Volusia	40 min
Aug 23, 5:41 PM EDT	Special Weather Statement	MLB	Okeechobee	49 min
Aug 23, 6:30 PM EDT	Special Weather Statement	MLB	Indian River	45 min
Aug 23, 7:07 PM EDT	Special Weather Statement	MLB	Brevard	38 min
Aug 23, 7:24 PM EDT	Special Marine Warning	MLB		96 min
Aug 23, 7:38 PM EDT	Special Weather Statement	MLB	Indian River	37 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.