Alert archive / Florida / Special Marine Warnings in 2019

Special Marine Warning 310, NWS Key West, FL

September 13, 2019

NWS Key West, FL issued this special marine warning at Sep 13, 2019, 9:37 PM EDT. It was in force for 53 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 13, 2019, 9:37 PM EDT (01:37 UTC)
Expired
Sep 13, 2019, 10:30 PM EDT
In force
53 min
Issued by
NWS Key West, FL
Area
Storm-based polygon
Hail
0.0 in
Wind
34.0 mph

The radar

The Key West radar (KBYX), 138 km from the middle of the area, began a volume at 01:39 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, 1.6 hours before the alert went out and 137 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 2019-09-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1861 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, Key West, FL at 00:00Z on 2019-09-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -70 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
1861 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
965 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
-70 m²/s²
0-3 km storm-relative helicity
-45 m²/s²
Significant tornado parameter
-0.3
Supercell composite
-2.7

Open this sounding in Storm Lab

The text

As transmitted.

023 
WHUS52 KKEY 140137
SMWKEY
GMZ034-055-075-140230-
/O.NEW.KKEY.MA.W.0310.190914T0137Z-190914T0230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Key West FL
937 PM EDT Fri Sep 13 2019

The National Weather Service in Key West has issued a

* Special Marine Warning for...
  Straits of Florida from Halfmoon Shoal to 20 nm west of Dry
  Tortugas out 60 nm...
  Gulf of Mexico including Dry Tortugas and Rebecca Shoal Channel...

* Until 1030 PM EDT.

* At 937 PM EDT, showers and isolated thunderstorms with gusty winds 
  were located along a line extending from 12 nm west of W Tower to 
  22 nm southwest of Twenty-Eight Foot Shoal Light, moving west at 
  25 knots.

  HAZARD...Wind gusts 34 knots or greater.

  SOURCE...National Weather Service Meteorologist.

  IMPACT...Expect wind gusts in excess of 34 knots, suddenly higher 
           waves, frequent lightning, and heavy downpours.

* Locations in the warning include...
  Rebecca Shoal Light, Dry Tortugas, Pulaski Shoal Light, Tortugas
  Ecological Reserve South, Dry Tortugas Light, Tortugas Ecological
  Reserve North and Fort Jefferson.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare for wind gusts in excess of 34 knots, steep and fast-building
seas, frequent lightning strikes, and blinding downpours. Stay low or
go below, and make sure all on board are wearing life jackets.

&&

LAT...LON 2461 8328 2480 8323 2495 8318 2502 8313
      2502 8251 2408 8248 2398 8327 2410 8329
TIME...MOT...LOC 0137Z 081DEG 26KT 2499 8294 2409 8259 

HAIL...0.00IN
WIND...>34KTS

$$

Jacobson

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 13, 8:00 PM EDTSpecial Marine WarningKEY45 min
Sep 13, 8:04 PM EDTSpecial Marine WarningKEY56 min
Sep 13, 8:40 PM EDTSpecial Marine WarningKEY27 min
Sep 13, 8:45 PM EDTSpecial Marine WarningKEY60 min
Sep 13, 10:23 PM EDTSpecial Marine WarningKEY67 min
Sep 14, 5:05 AM EDTSpecial Marine WarningKEY55 min
Sep 14, 6:14 AM EDTSpecial Marine WarningKEY61 min
Sep 14, 6:48 AM EDTSpecial Marine WarningKEY46 min
Sep 14, 7:09 AM EDTSpecial Marine WarningKEY33 min

Nearby

Special Marine Warnings in Florida, 2019Every special marine warning in 2019

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.