Typhoon Genevieve started Process_start to gradually weaken Cause_change_of_strength at noon on August 8 , and stronger vertical wind shear provided by a TUTT cell began Process_start to weaken Cause_change_of_strength the system further on August 9 .

Dry air , westerly wind shear , and upwelling of cold waters prevented Preventing_or_letting further intensification over the next 24 hours .

Epsilon continually defied Agree_or_refuse_to_act forecasts , at first due Causation to an unexpected loop to the southwest , and later due Causation to retaining Preserving its strength Cause_change_of_strength despite cold waters and strong wind shear .

Stronger wind shear caused Causation rapid weakening Cause_change_of_strength , and the storm Catastrophe could no longer be classified Check as a tropical cyclone late on December 8 .

It maintained this intensity for about 12 hours before an increase Cause_change_of_position_on_a_scale in wind shear induced its weakening Cause_change_of_strength by 3 January .

Later on December 20 , wind shear in the region increased Cause_change_of_position_on_a_scale , causing the system to weaken .

With low wind shear and a surge in the monsoon trough , the storm Catastrophe intensified Cause_change_of_position_on_a_scale while meandering over open waters .

over the following days , the hurricane 's winds fluctuated Motion as wind shear impeded significant development hindering it from becoming potentially dangerous .

Once this shear lightened on June 24 , the storm rapidly intensified Cause_change_of_strength to attain its peak strength with winds of 160 mph ( 260 km/h ) and an estimated barometric pressure of 921 mbar ( hPa ; 27.2 inHg ) .

Not long after reaching this strength , wind shear increased Cause_change_of_position_on_a_scale and the system entered Arriving a dry , stable environment .

over an area of warm sea surface temperatures , it was able to quickly strengthen Cause_change_of_strength to peak winds of 50 mph ( 85 km/h ) , through wind shear prevented much further development .

An approaching Arriving trough over the central United States induced Causation high wind shear over Sandy as it traversed Motion_directional the Bahamas , causing Causation the hurricane to weaken Cause_change_of_strength to a tropical storm while turning Becoming more northeastward .

The southern part of the trough detached , causing Causation the shear to decrease Cause_change_of_position_on_a_scale late on October 28 and allowing Preventing_or_letting Sandy to regain Earnings_and_losses strength .

After reaching Arriving Category 2 status on the Saffir-Simpson scale , Tomas quickly weakened Cause_change_of_strength to a tropical storm in the central Caribbean Sea , due to strong wind shear and dry air .

Increasing wind shear led to Causation the center becoming devoid of convection and the system eventually weakened Cause_change_of_strength to a tropical depression on August 13 .

Beginning on September 19 , Fran encountered Hostile_encounter strong wind shear , which contributed to further weakening .

However , strong wind shear pulled Motion the system apart , with visible imagery confirming the system 's degeneration into a depression with a fully exposed low-level circulation .

Slow weakening Cause_change_of_strength continued as Ma-on succumbed Death to the effects of high wind shear .

Initially subtropical , the storm slowly acquired Getting tropical characteristics as it tracked Self_motion across warmer sea surface temperatures and within an environment of decreasing Cause_change_of_position_on_a_scale vertical wind shear .

The hurricane reached Arriving peak winds of , but weakened Cause_change_of_strength subsequently due to wind shear .

The storm Catastrophe gradually drifted Motion southwestward and later southward under low wind shear , strengthening Cause_change_of_strength enough to be assigned Choosing the name `` Bobby '' by the Australian Bureau of Meteorology ( BoM ) .

the american national weather service stated Statement that an unexpected rise in wind shear kept Preventing_or_letting the system from intensifying much further before reaching guam .

Hostile wind shear then prompted Causation rapid weakening Cause_change_of_position_on_a_scale of the cyclone Catastrophe .

After becoming Becoming disorganized due Causation to wind shear from a nearby upper-level low , Mitch quickly intensified Cause_change_of_strength in response Response to improving Cause_to_make_progress conditions which included Cause_to_be_included warm waters and good outflow .

After peaking Cause_change_of_position_on_a_scale in intensity , increasing southeasterly vertical wind shear induced Causation a trend of rapid weakening on the storm Catastrophe .