Alert archive / Florida / Special Marine Warnings in 2021

Special Marine Warning 252, NWS Key West, FL

October 28, 2021

NWS Key West, FL issued this special marine warning at Oct 28, 2021, 7:13 PM EDT. It was in force for 62 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
Oct 28, 2021, 7:13 PM EDT (23:13 UTC)
Expired
Oct 28, 2021, 8:15 PM EDT
In force
62 min
Issued by
NWS Key West, FL
Area
Storm-based polygon
Hail
0.0 in
Wind
34.0 mph

The radar

The Miami radar (KAMX), 143 km from the middle of the area, began a volume at 23:13 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

Miami, FL (KMFL), launched 12:00Z, 11.2 hours before the alert went out and 162 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 2021-10-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1570 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, Miami, FL at 12:00Z on 2021-10-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 68 square meters per square second.193958Sfc1 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
1570 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
724 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
68 m²/s²
0-3 km storm-relative helicity
118 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.6

Open this sounding in Storm Lab

The text

As transmitted.

528 
WHUS52 KKEY 282313
SMWKEY
GMZ072-290015-
/O.NEW.KKEY.MA.W.0252.211028T2313Z-211029T0015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Key West FL
713 PM EDT Thu Oct 28 2021

The National Weather Service in Key West has issued a

* Special Marine Warning for...
  Straits of Florida from Ocean Reef to Craig Key 20 to 60 nm out...

* Until 815 PM EDT.

* At 712 PM EDT, a strong thunderstorm was located 18 nm northeast of
  Elbow Cay, moving northeast 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.

* The strong thunderstorm will remain over mainly open waters.

LAT...LON 2443 7967 2408 8009 2425 8029 2474 8018
TIME...MOT...LOC 2312Z 227DEG 28KT 2423 8014 

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

$$

KR
2 follow-up statements
184 
FZUS72 KKEY 282345
MWSKEY

Marine Weather Statement
National Weather Service Key West FL
745 PM EDT Thu Oct 28 2021

GMZ072-290015-
/O.CON.KKEY.MA.W.0252.000000T0000Z-211029T0015Z/
745 PM EDT Thu Oct 28 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 815 PM EDT...

For the following areas...
Straits of Florida from Ocean Reef to Craig Key 20 to 60 nm out...

At 745 PM EDT, a strong thunderstorm was located 23 nm southeast of
Floyd's Wall Northeast, moving northeast 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.

The strong thunderstorm will remain over mainly open waters.

LAT...LON 2443 7967 2408 8009 2425 8029 2474 8018
TIME...MOT...LOC 2345Z 227DEG 28KT 2441 7993 

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

$$

KR
756 
FZUS72 KKEY 290014
MWSKEY

Marine Weather Statement
National Weather Service Key West FL
814 PM EDT Thu Oct 28 2021

GMZ072-290021-
/O.EXP.KKEY.MA.W.0252.000000T0000Z-211029T0015Z/
814 PM EDT Thu Oct 28 2021

...THE SPECIAL MARINE WARNING WILL EXPIRE AT 815 PM EDT...


LAT...LON 2443 7967 2408 8009 2425 8029 2474 8018
TIME...MOT...LOC 0011Z 227DEG 28KT 2454 7978 

$$

KR

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 28, 4:21 PM EDTSmall Craft AdvisoryKEY60 hr
Oct 28, 5:09 PM EDTSpecial Marine WarningKEY96 min
Oct 28, 6:49 PM EDTSpecial Marine WarningKEY25 min

Nearby

Special Marine Warnings in Florida, 2021Every special marine warning in 2021

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.