Alert archive / Florida / Special Marine Warnings in 2021

Special Marine Warning 21, NWS Tampa Bay, FL

February 15, 2021

NWS Tampa Bay, FL issued this special marine warning at Feb 15, 2021, 8:26 PM EST. It was in force for 94 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
Feb 15, 2021, 8:26 PM EST (01:26 UTC)
Expired
Feb 15, 2021, 10:00 PM EST
In force
94 min
Issued by
NWS Tampa Bay, FL
Area
Storm-based polygon
Hail
0.0 in
Wind
40.0 mph

The radar

The Tampa radar (KTBW), 111 km from the middle of the area, began a volume at 01:30 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

Tampa Bay, FL (KTBW), launched 00:00Z, 1.4 hours before the alert went out and 111 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, Tampa Bay, FL at 00:00Z on 2021-02-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1356 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, Tampa Bay, FL at 00:00Z on 2021-02-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 197 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
1356 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
856 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
197 m²/s²
0-3 km storm-relative helicity
225 m²/s²
Significant tornado parameter
1.4
Supercell composite
7.7

Open this sounding in Storm Lab

The text

As transmitted.

431 
WHUS52 KTBW 160126
SMWTBW
GMZ850-853-870-873-160300-
/O.NEW.KTBW.MA.W.0021.210216T0126Z-210216T0300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Tampa Bay Area Ruskin FL
826 PM EST Mon Feb 15 2021

The National Weather Service in Ruskin has issued a

* Special Marine Warning for...
  Coastal waters from Englewood to Tarpon Springs FL out 20 NM...
  Coastal waters from Tarpon Springs to Suwannee River FL out 20
  NM...
  Waters from Englewood to Tarpon Springs FL out 20 to 60 NM...
  Waters from Tarpon Springs to Suwannee River FL out 20 to 60 NM...

* Until 1000 PM EST.

* At 825 PM EST, severe thunderstorms capable of producing
  waterspouts were located along a line extending from near
  Yankeetown to 50 nm west of Indian Rocks Beach, moving east at 20
  knots.

  HAZARD...Waterspouts and wind gusts to 40 knots.

  SOURCE...Radar.

  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...
  Ozello, Crystal River, Hernando Beach, Clearwater Pass, Port
  Richey, Anclote Key, Indian Shore Reef, Bayport, Tarpon Springs,
  Yankeetown, Aripeka and Dunedin.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor immediately as gusty winds and high waves are
expected.

&&

LAT...LON 2915 8274 2890 8257 2854 8257 2812 8274
      2777 8294 2771 8374 2803 8377 2923 8292
      2924 8274
TIME...MOT...LOC 0125Z 257DEG 19KT 2907 8285 2777 8378 

WATERSPOUT...POSSIBLE
HAIL...0.00IN
WIND...40KTS

$$

TBW

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 15, 7:16 PM ESTSpecial Weather StatementTBWLevy59 min
Feb 15, 8:10 PM ESTSpecial Weather StatementTBWLevy50 min
Feb 15, 8:28 PM ESTSpecial Weather StatementTBWCitrus, Hernando47 min
Feb 15, 9:24 PM ESTSpecial Marine WarningTBW96 min
Feb 16, 3:18 AM ESTRip Current StatementTBWCharlotte, Hillsborough, Lee, Manatee, Pinellas, Sarasota34 hr

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.