| HOME | ARCHIVES | FORECASTS | IMAGERY | ABOUT NHC | RECONNAISSANCE |

Tropical Depression TWENTY-ONE-E (Text)


Home   Public Adv   Fcst Adv   Discussion   Wind Probs   Graphics   Archive  

Hurr Wind Prob  50kt Wind Prob  TS Wind Prob  Warnings and 3-Day Cone  Warnings and 5-Day Cone 
1-2-3 Rule Wind Swath 

Mariners' 1-2-3 Rule

About this product:

The Mariners' 1-2-3 Rule, or "Danger area", is indicated by shading. The 1-2-3 Rule, commonly taught to mariners, refers to the rounded long-term NHC forecast errors of 100-200-300 nautical miles at 24-48-72 hours, respectively. The contour defining the shaded area is constructed by accounting for those errors and then broadened further to reflect the maximum tropical storm force (34 knot) wind radii forecast at each of those times by the NHC. The NHC does not warrant that avoiding these danger areas will eliminate the risk of harm from tropical cyclones.

Users operating in the vicinity of these systems are advised to continually monitor the latest Forecast/Advisories from the NHC and proceed at their own risk. Areas are also shaded for systems in which NHC forecasters believe there is an adequate chance of tropical cyclone formation within the next 48 hours.


Standard version of this page

Alternate Formats
About Alternates - E-Mail Advisories - RSS Feeds

Cyclone Forecasts
Latest Advisory - Past Advisories - About Advisories

Marine Forecasts
Latest Products - About Marine Products

Tools & Data
Satellite Imagery - US Weather Radar - Aircraft Recon - Local Data Archive - Forecast Verification - Deadliest/Costliest/Most Intense

Learn About Hurricanes
Storm Names Wind Scale - Prepare - Climatology - NHC Glossary - NHC Acronyms - Frequently Asked Questions - AOML Hurricane-Research Division

About Us
About NHC - Mission/Vision - Other NCEP Centers - NHC Staff - Visitor Information - NHC Library

Contact Us


NOAA/ National Weather Service
National Centers for Environmental Prediction
National Hurricane Center
11691 SW 17th Street
Miami, Florida, 33165-2149 USA
nhcwebmaster@noaa.gov
Disclaimer
Privacy Policy
Credits
About Us
Glossary
Career Opportunities
Page last modified: Thursday, 30-Oct-2014 14:27:16 UTC