Alert archive / Florida / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 21, NWS Melbourne, FL

April 24, 2018Martin County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Apr 24, 2018, 1:55 PM EDT for Martin County, Florida. It was in force for 50 min. 3 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 24, 2018, 1:55 PM EDT (17:55 UTC)
Expired: Apr 24, 2018, 2:45 PM EDT
In force: 50 min
Issued by: NWS Melbourne, FL
Area: Storm-based polygon
Hail: 0.88 in
Wind: 60.0 mph

County Martin County, FL

The radar

The Melbourne radar (KMLB), 130 km from the middle of the area, began a volume at 17:56 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 24, 2:19 PM EDT	TSTM WND GST 41	2 Sw Hobe Sound, FL	WEATHERFLOW SITE IN HOBE SOUND XHOB MEASURED A PEAK WIND GUST OF 41 MPH /36 KNOTS
Apr 24, 2:19 PM EDT	TSTM WND GST 51	1 Se Hobe Sound, FL	WEATHERBUG SITE AT HOBE SOUND MCRF1 MEASURED A PEAK WIND GUST OF 51 MPH / 44 KNOTS.
Apr 24, 2:25 PM EDT	HAIL 1	Hobe Sound, FL	TRAINED SPOTTER REPORTED QUARTER SIZE AND LARGER HAIL IN HOBE SOUND.

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

The nearest sounding before it

Miami, FL (KMFL), launched 12:00Z, 5.9 hours before the alert went out and 133 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: 694 J/kg
Mixed-layer CIN: -35 J/kg
Mixed-layer LCL: 910 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 48 m²/s²
0-3 km storm-relative helicity: 115 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 2.0

Open this sounding in Storm Lab

The text

As transmitted.

282 
WUUS52 KMLB 241755
SVRMLB
FLC085-241845-
/O.NEW.KMLB.SV.W.0021.180424T1755Z-180424T1845Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Melbourne FL
155 PM EDT TUE APR 24 2018

The National Weather Service in Melbourne has issued a

* Severe Thunderstorm Warning for...
  Southeastern Martin County in east central Florida...

* Until 245 PM EDT

* At 154 PM EDT, a severe thunderstorm was located 8 miles north of
  North County Airport, or 10 miles southwest of Hobe Sound, moving
  northeast at 20 mph.

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

  SOURCE...Radar indicated. 

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

* Locations impacted include...
  Tequesta, Jupiter Island, Hobe Sound, Port Salerno and Hobe Sound
  Beach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2696 8032 2697 8033 2714 8022 2716 8015
      2697 8008 2697 8014 2696 8014
TIME...MOT...LOC 1754Z 223DEG 18KT 2697 8026 

HAIL...0.88IN
WIND...60MPH
 
$$

DWS

2 follow-up statements

198 
WWUS52 KMLB 241807
SVSMLB

Severe Weather Statement
National Weather Service Melbourne FL
207 PM EDT TUE APR 24 2018

FLC085-241845-
/O.CON.KMLB.SV.W.0021.000000T0000Z-180424T1845Z/
Martin FL-
207 PM EDT TUE APR 24 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 245 PM EDT
FOR SOUTHEASTERN MARTIN COUNTY...

At 206 PM EDT, a severe thunderstorm was located near Jonathan
Dickinson State Park, or near Hobe Sound, moving northeast at 20 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...
Tequesta, Jupiter Island, Hobe Sound, Port Salerno and Hobe Sound
Beach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows.

&&

LAT...LON 2697 8014 2696 8014 2696 8026 2706 8027
      2714 8022 2716 8015 2697 8008
TIME...MOT...LOC 1806Z 223DEG 18KT 2701 8021 

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

DWS

638 
WWUS52 KMLB 241820
SVSMLB

Severe Weather Statement
National Weather Service Melbourne FL
220 PM EDT TUE APR 24 2018

FLC085-241845-
/O.CON.KMLB.SV.W.0021.000000T0000Z-180424T1845Z/
Martin FL-
220 PM EDT TUE APR 24 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 245 PM EDT
FOR SOUTHEASTERN MARTIN COUNTY...

At 219 PM EDT, a severe thunderstorm was located over Hobe Sound
Beach, or over Hobe Sound, moving northeast at 25 mph.

HAZARD...60 mph wind gusts and half dollar size hail. 

SOURCE...Radar indicated. 

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

Locations impacted include...
Tequesta, Jupiter Island, Hobe Sound, Port Salerno and Hobe Sound
Beach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows.

&&

LAT...LON 2697 8014 2696 8014 2696 8026 2706 8027
      2714 8022 2716 8015 2697 8008
TIME...MOT...LOC 1819Z 231DEG 20KT 2705 8012 

HAIL...1.25IN
WIND...60MPH
 
$$

Sedlock

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 24, 12:01 PM EDT	Special Weather Statement	MLB	Martin, Saint Lucie	59 min
Apr 24, 12:26 PM EDT	Special Marine Warning	MLB		64 min
Apr 24, 12:36 PM EDT	Severe Thunderstorm Warning	MLB	Saint Lucie	27 min
Apr 24, 12:47 PM EDT	Special Marine Warning	MLB		43 min
Apr 24, 1:00 PM EDT	Special Weather Statement	MLB	Martin, Saint Lucie	45 min
Apr 24, 1:31 PM EDT	Severe Thunderstorm Warning	MLB	Martin, Saint Lucie	59 min
Apr 24, 1:34 PM EDT	Special Marine Warning	MLB		56 min
Apr 24, 1:49 PM EDT	Special Weather Statement	MLB	Martin	41 min
Apr 24, 1:57 PM EDT	Special Marine Warning	MLB		63 min
Apr 24, 2:08 PM EDT	Severe Thunderstorm Warning	MLB	Saint Lucie	52 min
Apr 24, 2:12 PM EDT	Severe Thunderstorm Warning	MLB	Martin, Saint Lucie	34 min
Apr 24, 2:16 PM EDT	Tornado Warning	MLB	Martin	29 min
Apr 24, 2:25 PM EDT	Special Marine Warning	MLB		2 hr
Apr 24, 2:40 PM EDT	Severe Thunderstorm Warning	MLB	Martin	50 min
Apr 24, 5:49 PM EDT	Special Weather Statement	MLB	Martin	41 min

Nearby

Severe Thunderstorm Warnings in Florida, 2018 Every severe thunderstorm warning in 2018

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.