Skip Navigation Link   weather.gov
NOAA logo - Click to go to the NOAA homepage National Weather Service Forecast Office   NWS logo - Click to go to the NWS homepage
NWS Office, Melbourne, Florida
 
   
Hazard Map Threat Levels Safety & Impact
Graphical Hazardous Weather Outlook
Waterspout Threat

The "Waterspout Hazard Map" depicts the local threat of waterspouts for specified marine areas.  It is largely based on the likelihood that waterspouts will occur, combined with the anticipated strength of the most intense waterspout.   

Waterspout Threat Level

Threat Level Descriptions

Extreme

"An Extreme Threat to Life and Property Aboard Small Marine Craft from Waterspouts."

Within 12 miles of a marine location, a moderate likelihood or greater (16% probability or greater) of a significant tornadic waterspout.  See description below.  

AND/OR...a  high likelihood or greater (26% probability or greater) of a tornadic waterspout.  See description below.  

AND/OR...a  very high likelihood (36% or greater) of a waterspout.  See description below.  

High

"A High Threat to Life and Property Aboard Small Marine Craft from Waterspouts."

Within 12 miles of a marine location, a low likelihood (6% to 15% probability) of a significant tornadic waterspout.  See description below.  

AND/OR...a moderate likelihood (16% to 25% probability) of a tornadic waterspout.  See description below.  

AND/OR...a high likelihood (26% to 35% probability) of a waterspout.  See description below.  

Moderate

"A Moderate Threat to Life and Property Aboard Small Marine Craft from Waterspouts."

Within 12 miles of a marine location, a very low likelihood (2% to 5% probability) of a significant tornadic waterspout.  See description below.  

AND/OR...a low likelihood (6% to 15% probability) of a tornadic waterspout.  See description below.  

AND/OR...a moderate likelihood (16% to 25% probability) of a waterspout.  See description below.  

Low

"A Low Threat to Life and Property Aboard Small Marine Craft from Waterspouts."

Within 12 miles of a marine location, a very low likelihood (2% to 5% probability) of a tornadic waterspout.  See description below.  

AND/OR...a low likelihood (6% to 15% probability) of a waterspout.  See description below.  

Very Low
" A Very Low Threat to Life and Property Aboard Small Marine Craft from Waterspouts."

Within 12 miles of a marine location, a very low likelihood (2% to 5% probability) of a waterspout.  See description below.  

Non-Threatening
" No Discernable Threat to Life and Property Aboard Marine Vessels from Waterspouts."

Within 12 miles of a marine location, environmental conditions do not support waterspouts.   

Note: Waterspouts form over (or move across) the coastal waters or intracoastal waters and become a hazard for small craft.  They are treated as tornadoes over water.  There are two type of waterspouts: "fair weather" and "tornadic".  Fair weather waterspouts are usually weaker, move slowly, and may not be associated with a thunderstorm.  Tornadic waterspouts form within developing thunderstorms, or severe thunderstorms, and move much faster while being more intense.  

Waterspout - A fair weather waterspout of F0 tornado intensity (73 mph or less; 63 knots or less). 

Tornadic Waterspout - A waterspout associated with a developing thunderstorm, or severe thunderstorm, of F0 to F1 intensity (74 mph to 112 mph; 64 knots to 97 knots).

Significant Tornadic Waterspout - A waterspout associated with a severe thunderstorm of F2 intensity or greater (113 mph or greater; 98 knots or greater).


 National Weather Service
 Melbourne, Florida
 421 Croton Road
 Melbourne, Florida 32935
 Page last modified: May 27, 2005
Disclaimer

Privacy Policy

Graphical Hazardous Weather Outlook
Version 2.0 - March, 2004
WFO Melbourne, Florida

SKYWARN Tornado Severe Hail Lightning Severe Wind (Flash) Flood River Flood Excessive Heat Excessive Cold High Wind Dense Fog / Smoke Wildfire Rip Current Coastal Flood waterspout Wind and Sea (Marine) Thunderstorm Gust Click for General Description