Alert archive / Florida / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 1, NWS Key West, FL

August 28, 2021Monroe County, Florida

NWS Key West, FL issued this severe thunderstorm warning at Aug 28, 2021, 1:27 AM EDT for Monroe County, Florida. It was in force for 14 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 28, 2021, 1:27 AM EDT (05:27 UTC)
Expired: Aug 28, 2021, 1:41 AM EDT
In force: 14 min
Issued by: NWS Key West, FL
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

County Monroe County, FL

What was reported inside it

Time	Report	Where	Remark
Aug 28, 1:28 AM EDT	MARINE TSTM WIND 53	5 Wsw Boca Chica Channe, FL	AN EAST-SOUTHEAST WIND GUST OF 46 KTS, OR 53 MPH, WAS RECORDED BY THE FLORIDA KEYS NWS RSOIS AROUND 128 AM EDT.

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

The nearest sounding before it

Key West, FL (KEYW), launched 00:00Z, 5.5 hours before the alert went out and 7 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: 900 J/kg
Mixed-layer CIN: -16 J/kg
Mixed-layer LCL: 843 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 138 m²/s²
0-3 km storm-relative helicity: 154 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.1

Open this sounding in Storm Lab

The text

As transmitted.

999 
WUUS52 KKEY 280527
SVRKEY
FLC087-280600-
/O.NEW.KKEY.SV.W.0001.210828T0527Z-210828T0600Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Key West FL
127 AM EDT Sat Aug 28 2021

The National Weather Service in Key West has issued a

* Severe Thunderstorm Warning for...
  Lower Keys in Monroe County in Florida...

* Until 200 AM EDT.

* At 126 AM EDT, a severe thunderstorm was located over Key Haven, or
  over Key West, moving northwest at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Key West, Boca Chica Channel Bridge, Boca Chica, Fleming Key, Key
  Haven and Sunset Key.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2452 8179 2459 8186 2459 8184 2463 8181
      2467 8179 2470 8174 2454 8167 2453 8172
TIME...MOT...LOC 0526Z 148DEG 33KT 2456 8175 

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

$$

CLR

1 follow-up statement

581 
WWUS52 KKEY 280541
SVSKEY

Severe Weather Statement
National Weather Service Key West FL
141 AM EDT Sat Aug 28 2021

FLC087-280550-
/O.CAN.KKEY.SV.W.0001.000000T0000Z-210828T0600Z/
Lower Keys in Monroe FL-
141 AM EDT Sat Aug 28 2021

...THE SEVERE THUNDERSTORM WARNING FOR LOWER KEYS IN MONROE COUNTY IS
CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Key West.

LAT...LON 2452 8179 2459 8186 2459 8184 2463 8181
      2467 8179 2470 8174 2454 8167 2453 8172
TIME...MOT...LOC 0539Z 148DEG 33KT 2468 8183 

$$

CLR

The office that day

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

Issued	Product	Office	Lasted
Aug 27, 11:43 PM EDT	Special Marine Warning	KEY	62 min
Aug 27, 11:45 PM EDT	Special Marine Warning	KEY	35 min
Aug 28, 12:19 AM EDT	Special Marine Warning	KEY	56 min
Aug 28, 12:45 AM EDT	Special Marine Warning	KEY	60 min
Aug 28, 9:30 AM EDT	Special Marine Warning	KEY	60 min
Aug 28, 10:28 AM EDT	Special Marine Warning	KEY	62 min
Aug 28, 11:27 AM EDT	Special Marine Warning	KEY	29 min
Aug 28, 1:17 PM EDT	Special Marine Warning	KEY	58 min
Aug 28, 6:00 PM EDT	Special Marine Warning	KEY	60 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.