Alert archive / Florida / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 57, NWS Miami, FL

August 12, 2021Broward County, Miami-Dade County, Florida

NWS Miami, FL issued this severe thunderstorm warning at Aug 12, 2021, 4:43 PM EDT for Broward County, Miami-Dade County, Florida. It was in force for 32 min. 1 report 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
Aug 12, 2021, 4:43 PM EDT (20:43 UTC)
Expired
Aug 12, 2021, 5:15 PM EDT
In force
32 min
Issued by
NWS Miami, FL
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Broward County, FL, Miami-Dade County, FL

The radar

The Miami radar (KAMX), 42 km from the middle of the area, began a volume at 20:43 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

TimeReportWhereRemark
Aug 12, 4:59 PM EDTMARINE TSTM WIND 401 S North Miami Beach, FLWEATHER FLOW STATION XNMI REPORTED A WIND GUSTS OF 40 MPH FROM A THUNDERSTORM.

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, 8.7 hours before the alert went out and 17 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, Miami, FL at 12:00Z on 2021-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1357 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, Miami, FL at 12:00Z on 2021-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 square meters per square second.1939Sfc1 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
1357 J/kg
Mixed-layer CIN
-28 J/kg
Mixed-layer LCL
1074 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
-4 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

241 
WUUS52 KMFL 122043
SVRMFL
FLC011-086-122115-
/O.NEW.KMFL.SV.W.0057.210812T2043Z-210812T2115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Miami FL
443 PM EDT Thu Aug 12 2021

The National Weather Service in Miami has issued a

* Severe Thunderstorm Warning for...
  Northern Miami-Dade County in southeastern Florida...
  Southern Broward County in southeastern Florida...

* Until 515 PM EDT.

* At 442 PM EDT, severe thunderstorms were located along a line
  extending from 12 miles east of Port Everglades to near Surfside,
  moving southwest at 25 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Miami, Hialeah, Pembroke Pines, Hollywood and Miramar. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2579 8005 2574 8039 2595 8031 2609 8011
      2610 8004
TIME...MOT...LOC 2042Z 066DEG 23KT 2604 7994 2587 8008 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

BAXTER
1 follow-up statement
790 
WWUS52 KMFL 122105
SVSMFL

Severe Weather Statement
National Weather Service Miami FL
505 PM EDT Thu Aug 12 2021

FLC011-086-122115-
/O.EXP.KMFL.SV.W.0057.000000T0000Z-210812T2115Z/
Miami-Dade FL-Broward FL-
505 PM EDT Thu Aug 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN MIAMI-DADE AND
SOUTHERN BROWARD COUNTIES WILL EXPIRE AT 515 PM EDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with these thunderstorms.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Miami. You can also share your report with NWS Miami on
Facebook and Twitter.

LAT...LON 2579 8005 2574 8039 2595 8031 2609 8011
      2610 8004
TIME...MOT...LOC 2105Z 066DEG 23KT 2598 8008 2581 8022 

$$

BAXTER

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 2:48 PM EDTSpecial Marine WarningMFL42 min
Aug 12, 3:23 PM EDTSpecial Marine WarningMFL35 min
Aug 12, 4:19 PM EDTSpecial Marine WarningMFL41 min
Aug 12, 4:27 PM EDTSpecial Weather StatementMFLMiami-Dade63 min
Aug 12, 4:42 PM EDTSpecial Marine WarningMFL63 min
Aug 12, 4:56 PM EDTTropical Storm WatchMFLCollier, Miami-Dade, Monroe30 hr
Aug 12, 7:02 PM EDTSpecial Marine WarningMFL43 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.