Alert archive / Florida / Extreme Wind Warnings in 2017

Extreme Wind Warning 1, NWS Key West, FL

September 10, 2017Monroe County, Florida

NWS Key West, FL issued this extreme wind warning at Sep 10, 2017, 6:20 AM EDT for Monroe County, Florida. It was in force for 3 hr. 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 10, 2017, 6:20 AM EDT (10:20 UTC)
Expired
Sep 10, 2017, 9:15 AM EDT
In force
3 hr
Issued by
NWS Key West, FL
Area
Storm-based polygon

County Monroe County, FL

The radar

The Key West radar (KBYX), 24 km from the middle of the area, began a volume at 10:20 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

Key West, FL (KEYW), launched 00:00Z, 10.3 hours before the alert went out and 27 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, Key West, FL at 00:00Z on 2017-09-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Key West, FL at 00:00Z on 2017-09-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -28 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1148 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
-28 m²/s²
0-3 km storm-relative helicity
74 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

779 
WFUS52 KKEY 101020
EWWKEY
FLC087-101315-
/O.NEW.KKEY.EW.W.0001.170910T1020Z-170910T1315Z/

BULLETIN - EAS ACTIVATION REQUESTED
Extreme Wind Warning
National Weather Service Key West FL
620 AM EDT SUN SEP 10 2017

The National Weather Service in Key West has issued a

* Extreme Wind Warning for...
  Lower Keys in Monroe County in Florida...

* Until 915 AM EDT

* At 617 AM EDT, National Weather Service Doppler radar indicated 
  extreme winds, associated with the eyewall of Hurricane Irma, were 
  moving into the Lower Keys.  

  This is an extremely dangerous and life-threatening situation!

* 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...

Treat these imminent extreme winds as if a tornado was approaching 
and move immediately to the safe room in your shelter. Take action 
now to protect your life! YOU SHOULD ALREADY BE TAKING COVER!

&&

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

LAT...LON 2453 8184 2464 8181 2472 8167 2470 8162
      2476 8160 2478 8154 2481 8150 2480 8138
      2479 8135 2480 8129 2474 8126 2470 8127
      2471 8124 2468 8121 2461 8135 2460 8141
      2461 8143 2460 8144 2459 8154 2455 8163
TIME...MOT...LOC 1017Z 180DEG 0KT 2467 8157 

$$

CLR
1 follow-up statement
681 
WWUS52 KKEY 101208
SVSKEY

Severe Weather Statement
National Weather Service Key West FL
808 AM EDT SUN SEP 10 2017

FLC087-101315-
/O.CON.KKEY.EW.W.0001.000000T0000Z-170910T1315Z/
Lower Keys in Monroe FL-
808 AM EDT SUN SEP 10 2017

...AN EXTREME WIND WARNING REMAINS IN EFFECT UNTIL 915 AM EDT FOR
LOWER KEYS IN MONROE COUNTY...

At 800 AM EDT, National Weather Service Doppler radar indicated 
extreme winds, associated with the northern eyewall of Hurricane 
Irma, were moving across and just north of the Lower Keys. 

If you happen to be in the Lower Keys, it is very likely that 
sensible weather conditions will diminish significantly...namely the 
winds and rainfall. DO NOT BE FOOLED BY THIS. As Irma continues to 
move northward, winds over the next hour will shift from the exact 
opposite direction, and will likely do so very violently and with 
little to no time to react. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Treat these imminent extreme winds as if a tornado was approaching 
and stay in the safe room of your shelter. Continue to use whatever 
you have to protect yourself from flying debris: pillows, 
mattresses, blankets, helmets, etc.

DO NOT GO OUTSIDE. Remain sheltered in place and hunkered down. 

This is an extremely dangerous and life-threatening situation!
  
This includes US 1 between mile markers 0 and 40. 

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

LAT...LON 2453 8184 2464 8181 2472 8167 2470 8162
      2476 8160 2478 8154 2481 8150 2480 8138
      2479 8135 2480 8129 2474 8126 2470 8127
      2471 8124 2468 8121 2461 8135 2460 8141
      2461 8143 2460 8144 2459 8154 2455 8163
TIME...MOT...LOC 1156Z 180DEG 0KT 2467 8157 

$$

04

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 10, 9:21 AM EDTExtreme Wind WarningKEYMonroe114 min
Sep 10, 11:15 AM EDTSpecial Weather StatementKEY90 min
Sep 10, 4:06 PM EDTSpecial Weather StatementKEY84 min
Sep 10, 6:21 PM EDTSpecial Weather StatementKEYMiami-Dade54 min

Nearby

Extreme Wind Warnings in Florida, 2017Every extreme wind warning 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.