anti trades prevailing winds west east middle latitudes degrees latitude originate high pressure areas horse latitudes tend poles steer extratropical cyclones general manner tropical cyclones cross subtropical ridge axis increased westerly flow winds predominantly southwest northwest strongest southern hemisphere times pressure lower poles weakest hemisphere pressures higher poles particularly strong areas land absent land flow pattern making current north south oriented slowing strongest westerly winds middle latitudes come degrees latitude play important role carrying warm waters winds western coasts continents especially southern hemisphere vast oceanic behaviour earth non rotating planet solar heating cause winds mid latitudes blow direction away subtropical ridge effect caused rotation earth causes winds steer right expected left expected winds tend blow southwest tend northwest pressures lower poles strength increases effect warming mid latitudes occurs arctic positive winter low pressure near poles stronger summer negative pressures higher poles flow blowing direction pole equator brings cold air mid latitudes year vary strength polar cyclone cyclone reaches maximum intensity winter increase strength cyclone reaches weakest intensity summer weaken example impact dust originating desert combine spread large distances eastward north_america particularly strong especially land middle latitudes cause progression west east winds slow southern hemisphere stormy cloudy conditions usual refer furious fifties according varying degrees latitude impact ocean currents persistent winds west east sides subtropical ridges located atlantic pacific oceans ocean currents driven similar manner currents weaker differences strength hemisphere process western intensification causes currents western boundary ocean basin stronger eastern boundary ocean western ocean currents transport warm tropical water polar regions ships crossing oceans taken advantage ocean currents centuries ocean current flows west east antarctica dominant circulation feature approximately largest ocean current northern hemisphere led development strong cyclones types base atmosphere ocean japanese black tide strong western boundary current western north pacific_ocean similar contributed depth ocean storms region extratropical cyclones extratropical cyclone scale low pressure weather system tropical polar characteristics connected fronts horizontal temperature point known zones extratropical refers fact type cyclone generally occurs outside tropics middle latitudes planet steer system generally west east systems described mid latitude cyclones area formation post tropical cyclones extratropical transition occurred described depressions lows weather forecasters general public everyday phenomena anti cyclones drive weather earth extratropical cyclones classified form zones temperature gradient late life cycle temperature distribution cyclone fairly uniform radius center low pressure extratropical cyclone transform subtropical storm tropical cyclone warm waters develops central convection core causes temperature near centers fade interaction tropical cyclones tropical cyclone crosses subtropical ridge axis normally break high pressure area caused system traversing general track high pressure area significantly winds moving general low pressure area north cyclone track strongly easterly component cyclone begun entering typhoon moving pacific_ocean asia example offshore japan north northeast typhoon encounters southwesterly winds blowing northeastward low pressure system passing china siberia tropical cyclones eventually forced northeast extratropical cyclones manner west east north subtropical ridge example tropical cyclone typhoon took similar trajectory
Westerlies