Alert archive / Florida / Special Marine Warnings in 2017

Special Marine Warning 310, NWS Miami, FL

November 24, 2017

NWS Miami, FL issued this special marine warning at Nov 24, 2017, 1:27 AM EST. It was in force for 33 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: Nov 24, 2017, 1:27 AM EST (06:27 UTC)
Expired: Nov 24, 2017, 2:00 AM EST
In force: 33 min
Issued by: NWS Miami, FL
Area: Storm-based polygon
Hail: 0.0 in
Wind: 34.0 mph

The radar

The Key West radar (KBYX), 121 km from the middle of the area, began a volume at 06:27 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, 6.5 hours before the alert went out and 125 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: 1852 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 737 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 18 m²/s²
0-3 km storm-relative helicity: 54 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.8

Open this sounding in Storm Lab

The text

As transmitted.

765 
WHUS52 KMFL 240627
SMWMFL
GMZ656-657-676-240700-
/O.NEW.KMFL.MA.W.0310.171124T0627Z-171124T0700Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SPECIAL MARINE WARNING
NATIONAL WEATHER SERVICE MIAMI FL
127 AM EST FRI NOV 24 2017

THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A

* SPECIAL MARINE WARNING FOR...
  COASTAL WATERS FROM CHOKOLOSKEE TO BONITA BEACH FL OUT 20 NM...
  COASTAL WATERS FROM EAST CAPE SABLE TO CHOKOLOSKEE FL OUT 20 NM...
  WATERS FROM CHOKOLOSKEE TO BONITA BEACH FL FROM 20 TO 60 NM...

* UNTIL 200 AM EST

* AT 126 AM EST...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING
  WATERSPOUTS WAS LOCATED 8 NM WEST OF CAPE ROMANO...OR 8 NM
  SOUTHWEST OF MARCO ISLAND...MOVING NORTHEAST AT 20 KNOTS.

  HAZARD...WATERSPOUTS AND WIND GUSTS 34 KNOTS OR GREATER. 

  SOURCE...RADAR INDICATED. 

  IMPACT...WATERSPOUTS CAN QUICKLY FORM AND CAPSIZE BOATS...DAMAGE 
           VESSELS AND CREATE SUDDENLY HIGHER WAVES. MAKE SURE ALL 
           ON BOARD ARE IN A SECURE LOCATION AND WEARING LIFE 
           JACKETS.  EXPECT WIND GUSTS IN EXCESS OF 34 
           KNOTS...SUDDENLY HIGHER WAVES...FREQUENT LIGHTNING AND 
           HEAVY DOWNPOURS. MAKE SURE ALL ON BOARD ARE WEARING LIFE 
           JACKETS. 

* LOCATIONS IMPACTED INCLUDE...
  CAPE ROMANO...MARCO ISLAND AND D TOWER. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FREQUENT LIGHTNING IS OCCURRING WITH THIS STORM. IF CAUGHT ON THE
OPEN WATER STAY BELOW DECK IF POSSIBLE...KEEP AWAY FROM UNGROUNDED
METAL OBJECTS.

&&

LAT...LON 2581 8210 2606 8174 2565 8139 2559 8158
      2553 8181 2556 8187 2558 8192 2560 8194
      2560 8197
TIME...MOT...LOC 0626Z 240DEG 22KT 2583 8183 

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

$$

67

The office that day

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

Issued	Product	Office	Counties	Lasted
Nov 23, 11:51 PM EST	Special Marine Warning	MFL		54 min
Nov 24, 12:44 AM EST	Special Marine Warning	MFL		46 min
Nov 24, 1:30 AM EST	Special Weather Statement	MFL	Collier	60 min

Nearby

Special Marine Warnings in Florida, 2017 Every special marine 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.