Alert archive / Florida / Special Marine Warnings in 2012

Special Marine Warning 21, NWS Miami, FL

April 6, 2012

NWS Miami, FL issued this special marine warning at Apr 6, 2012, 9:09 AM EDT. It was in force for 51 min. 3 reports 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
Apr 6, 2012, 9:09 AM EDT (13:09 UTC)
Expired
Apr 6, 2012, 10:00 AM EDT
In force
51 min
Issued by
NWS Miami, FL
Area
Storm-based polygon

The radar

The Miami radar (KAMX), 164 km from the middle of the area, began a volume at 13:12 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.

What was reported inside it

TimeReportWhereRemark
Apr 6, 9:47 AM EDTTSTM WND GST 47Naples, FLTHE NAPLES MUNICIPAL AIRPORT...APF...RECORDED A WIND GUST TO 47 MPH...OR 41 KNOTS...DURING A THUNDERSTORM.
Apr 6, 9:50 AM EDTHAIL 0.75Naples, FL
Apr 6, 9:55 AM EDTHAIL 1Naples, FL

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

The nearest sounding before it

Miami, FL (KMFL), launched 12:00Z, 1.2 hours before the alert went out and 169 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, Miami, FL at 12:00Z on 2012-04-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2930 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Miami, FL at 12:00Z on 2012-04-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 167 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
2930 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
478 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
167 m²/s²
0-3 km storm-relative helicity
257 m²/s²
Significant tornado parameter
3.7
Supercell composite
16.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

071 
WHUS52 KMFL 061309
SMWMFL
GMZ656-061400-
/O.NEW.KMFL.MA.W.0021.120406T1309Z-120406T1400Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SPECIAL MARINE WARNING
NATIONAL WEATHER SERVICE MIAMI FL
909 AM EDT FRI APR 6 2012

THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A

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

* UNTIL 1000 AM EDT

* AT 907 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  THUNDERSTORM...CAPABLE OF PRODUCING STRONG WINDS OF 34 KNOTS OR
  GREATER...ABOUT 17 NM WEST OF NAPLES...MOVING EAST AT 30 KNOTS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

AS THUNDERSTORMS MOVE OVER THE WATER...BOATERS CAN EXPECT STRONG
GUSTY WINDS...HIGH WAVES...DANGEROUS LIGHTNING...AND HEAVY RAIN. MOVE
TO SAFE HARBOR OR STAY CLOSE TO SHORE UNTIL THE STORM PASSES. IF
CAUGHT ON THE OPEN WATER...MAKE SURE ALL SAFETY GEAR IS AVAILABLE AND
LIFE JACKETS ARE BEING WORN BY YOU AND YOUR CREW.

&&

LAT...LON 2623 8205 2629 8182 2626 8183 2622 8181
      2617 8181 2614 8178 2607 8179 2602 8173
      2601 8173 2590 8208 2599 8213 2610 8214
      2611 8220 2615 8228
TIME...MOT...LOC 1308Z 256DEG 29KT 2610 8212

$$

AK
1 follow-up statement
342 
FZUS72 KMFL 061350
MWSMFL

MARINE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MIAMI FL
950 AM EDT FRI APR 6 2012

GMZ656-061400-
/O.EXP.KMFL.MA.W.0021.000000T0000Z-120406T1400Z/
950 AM EDT FRI APR 6 2012

...SPECIAL MARINE WARNING WILL EXPIRE AT 1000 AM EDT...

THE AFFECTED AREA WAS...
  COASTAL WATERS FROM CHOKOLOSKEE TO BONITA BEACH FL OUT 20 NM

DOPPLER RADAR INDICATED THAT THE STORM THAT PROMPTED THE SPECIAL 
MARINE WARNING HAD MOVED INLAND AND THEREFORE THE SPECIAL MARINE 
WARNING WILL EXPIRE AT 1000 AM EDT.

LAT...LON 2623 8205 2629 8182 2626 8183 2622 8181
      2617 8181 2614 8178 2607 8179 2602 8173
      2601 8173 2590 8208 2599 8213 2610 8214
      2611 8220 2615 8228
TIME...MOT...LOC 1350Z 256DEG 29KT 2618 8175

$$

AK

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 6, 9:29 AM EDTSpecial Marine WarningMFL46 min
Apr 6, 9:48 AM EDTSpecial Weather StatementMFLCollier42 min
Apr 6, 9:53 AM EDTSevere Thunderstorm WarningMFLCollier, Hendry37 min
Apr 6, 10:12 AM EDTSpecial Marine WarningMFL33 min
Apr 6, 10:13 AM EDTSpecial Weather StatementMFLCollier32 min
Apr 6, 10:50 AM EDTSpecial Marine WarningMFL55 min
Apr 6, 11:18 AM EDTSpecial Marine WarningMFL57 min
Apr 6, 11:21 AM EDTSpecial Weather StatementMFLCollier24 min
Apr 6, 11:39 AM EDTSpecial Weather StatementMFLBroward36 min
Apr 6, 11:46 AM EDTSevere Thunderstorm WarningMFLBroward, Palm Beach12 min
Apr 6, 11:51 AM EDTSpecial Marine WarningMFL43 min
Apr 6, 1:00 PM EDTSpecial Weather StatementMFLBroward30 min
Apr 6, 1:29 PM EDTSpecial Weather StatementMFLBroward31 min
Apr 6, 1:39 PM EDTSevere Thunderstorm WarningMFLBroward, Miami-Dade17 min
Apr 6, 1:42 PM EDTSpecial Marine WarningMFL33 min
Apr 6, 1:58 PM EDTSpecial Marine WarningMFL62 min
Apr 6, 2:56 PM EDTSpecial Marine WarningMFL64 min
Apr 6, 3:36 PM EDTSpecial Marine WarningMFL39 min
Apr 6, 4:00 PM EDTSpecial Marine WarningMFL45 min
Apr 6, 4:13 PM EDTSmall Craft AdvisoryMFL48 hr

Nearby

Special Marine Warnings in Florida, 2012Every special marine warning in 2012

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; radar from the NEXRAD Level II archive.