Info on currently active tropical cyclones:

NRL tropical cyclone page
National Hurricane Center
Joint Typhoon Warning Center
CIMMS tropical cyclones
RAMMB active tropical cyclones
Weather underground

Seasonal forecasts:

Met Office
Laboratory for Atmospheric Research, Hong Kong for West Pac and Australian region

Model forecasts:

Genesis potential fields
NCEP model analyses and forecasts
other models
Penn State
Wright-Weather tracks

Derived products:

Tropical cyclone formation probabilities
Maximum potential intensity
QuikSCAT storm page
ASCAT winds
KAC R/D interactive mapping

Ocean energy:

Ocean heat content
Tropical cyclone heat potential

Aircraft recon:

tropicalatlantic
NHC

Region specific information:

North Atlantic:

Ocean heat content
Ocean obs
Gulf obs

Northwest Pacific:

Ocean heat content

Central north Pacific:

Central Pacific Hurricane Center

Northeast Pacific:

Ocean heat content

South Atlantic:

SST

Southern Pacific:

Fiji Meteorological Service
Australia Bureau of Meteorology

Southern Indian Ocean:

Meteo France - Reunion

Forums:

Storm2K

Archives:

UNISYS