Alert archive / Florida / Tornado Warnings in 2017

Tornado Warning 2, NWS Key West, FL

September 9, 2017Monroe County, Florida

NWS Key West, FL issued this tornado warning at Sep 9, 2017, 5:56 PM EDT for Monroe County, Florida. It was in force for 49 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: Sep 9, 2017, 5:56 PM EDT (21:56 UTC)
Expired: Sep 9, 2017, 6:45 PM EDT
In force: 49 min
Issued by: NWS Key West, FL
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.0 in

County Monroe County, FL

The radar

The Key West radar (KBYX), 17 km from the middle of the area, began a volume at 21:59 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Sep 9, 12:09 PM EDT	Tornado Watch	SPC	12 hr

The nearest sounding before it

Key West, FL (KEYW), launched 12:00Z, 9.9 hours before the alert went out and 21 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: 429 J/kg
Mixed-layer CIN: -63 J/kg
Mixed-layer LCL: 1024 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 41 m²/s²
0-3 km storm-relative helicity: 54 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

923 
WFUS52 KKEY 092156
TORKEY
FLC087-092245-
/O.NEW.KKEY.TO.W.0002.170909T2156Z-170909T2245Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Key West FL
556 PM EDT SAT SEP 9 2017

The National Weather Service in Key West has issued a

* Tornado Warning for...
  Lower Keys in Monroe County in Florida...

* Until 645 PM EDT
    
* At 554 PM EDT, a severe thunderstorm capable of producing a tornado
  was located 9 miles northwest of Pidgeon Key, or 9 miles northwest 
  of Seven Mile Bridge, moving west-southwest at 60 mph. Brief 
  tornadoes may occur over the course of the next 45 minutes.

  HAZARD...Tornado. 

  SOURCE...Radar indicated rotation. 

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely. 

* Locations impacted include...
  Key West, Bahia Honda Channel Bridge, Big Coppitt Key, Boca Chica
  Channel Bridge, Niles Channel Bridge, Spanish Harbor Channel
  Bridge, Boca Chica, West End Of Seven Mile Bridge, Saddlebunch Keys
  and Sunset Key.

This includes US 1 between mile markers 0 and 40. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 2453 8186 2460 8195 2462 8190 2458 8184
      2467 8180 2472 8166 2470 8162 2475 8161
      2482 8144 2479 8135 2481 8128 2477 8125
      2470 8127 2470 8120 2474 8114 2461 8133
      2461 8143 2458 8146 2460 8151 2452 8174
TIME...MOT...LOC 2154Z 068DEG 52KT 2482 8124 

TORNADO...RADAR INDICATED
HAIL...0.00IN

$$

MCLOVIN

2 follow-up statements

493 
WWUS52 KKEY 092230
SVSKEY

Severe Weather Statement
National Weather Service Key West FL
630 PM EDT SAT SEP 9 2017

FLC087-092245-
/O.CON.KKEY.TO.W.0002.000000T0000Z-170909T2245Z/
Lower Keys in Monroe FL-
630 PM EDT SAT SEP 9 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM EDT FOR LOWER
KEYS IN MONROE COUNTY...
    
At 630 PM EDT, a severe thunderstorm capable of producing a tornado 
was located near Saddlebunch Keys, or 7 miles north of Big Coppitt 
Key, moving southwest at 60 mph. Brief   tornadoes may occur over 
the course of the next 15 minutes.

HAZARD...Tornado. 

SOURCE...Radar indicated rotation. 

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely. 

Locations impacted include...
Key West, Bahia Honda Channel Bridge, Big Coppitt Key, Boca Chica
Channel Bridge, Niles Channel Bridge, Spanish Harbor Channel Bridge,
Boca Chica, West End Of Seven Mile Bridge, Saddlebunch Keys and
Sunset Key.

This includes US 1 between mile markers 0 and 40. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 2453 8186 2460 8195 2462 8190 2459 8189
      2458 8184 2467 8179 2472 8166 2470 8162
      2475 8160 2482 8144 2479 8135 2481 8128
      2477 8125 2470 8127 2469 8121 2461 8133
      2461 8143 2458 8146 2460 8152 2452 8174
TIME...MOT...LOC 2228Z 062DEG 51KT 2470 8164 

TORNADO...RADAR INDICATED
HAIL...0.00IN

$$

MCLOVIN

853 
WWUS52 KKEY 092241
SVSKEY

Severe Weather Statement
National Weather Service Key West FL
641 PM EDT SAT SEP 9 2017

FLC087-092250-
/O.EXP.KKEY.TO.W.0002.000000T0000Z-170909T2245Z/
Lower Keys in Monroe FL-
641 PM EDT SAT SEP 9 2017

...THE TORNADO WARNING FOR LOWER KEYS IN MONROE COUNTY WILL EXPIRE AT
645 PM EDT...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.

A tornado watch remains in effect until midnight EDT for Florida.

LAT...LON 2453 8186 2460 8195 2462 8190 2459 8189
      2458 8184 2467 8179 2472 8166 2470 8162
      2475 8160 2482 8144 2479 8135 2481 8128
      2477 8125 2470 8127 2469 8121 2461 8133
      2461 8143 2458 8146 2460 8152 2452 8174
TIME...MOT...LOC 2240Z 068DEG 52KT 2463 8182 

$$

MCLOVIN

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 9, 12:02 AM EDT	Special Weather Statement	KEY		58 min
Sep 9, 1:06 AM EDT	Special Weather Statement	KEY		54 min
Sep 9, 7:50 AM EDT	Special Weather Statement	KEY		85 min
Sep 9, 2:46 PM EDT	Special Weather Statement	KEY		59 min
Sep 9, 5:34 PM EDT	Tornado Warning	KEY	Monroe	26 min
Sep 9, 7:07 PM EDT	Tornado Warning	KEY	Monroe	23 min

Nearby

Tornado Warnings in Florida, 2017 Every tornado warning in 2017 Tornadoes in 2017

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.