Tropical Disturbance 11F subsequently developed to the southwest of Nadi, Fiji during January 29 . The system lay to the east of an upper level trough of low pressure within an area of high vertical windshear.
22.
On December 9, RSMC Nadi reported that Tropical Disturbance 05F had developed to the east of an upper level trough, in an area of moderate to high vertical windshear about to the northeast of Nadi, Fiji.
23.
Bellingham's proximity to the Fraser River valley occasionally subjects it to a harsh winter weather pattern ( termed a'north-Easter') wherein an upper level trough drives cold Arctic air from the Canadian interior southwesterly through the Fraser River Canyon.
24.
During its weakening phase, Cyclone Percy passed south of Tropical Depression 20S . Pulled by an upper level trough, Percy swung to the east, passing Tropical Depression 24S in the process, before being caught up by another trough.
25.
During December 29, after the system had stalled Zoe started to move towards the southeast in response to the strengthening steering flow, provided by an upper level trough of low pressure and a baroclinic system near New Caledonia.
26.
During 10 January, Rewa's remnants moved out of the South Pacific basin and back into the Australian region while starting to re-intensify into a tropical cyclone, as a mid to upper level trough over eastern Australia increased in size.
27.
The Ga type is characterized by an upper level trough in the central and eastern part of the United States which steers the newly formed wave north and northeast over the western side of the Appalachians accompanied by widespread precipitation to the north.
28.
This wind often precedes following a cold front passage across Argentina and tends to occur when a low pressure system brings heavy rain to the Chilean side, and when an upper level trough allows the winds to pass over the Andes to descend downwards.
29.
This wind often occurs before the passage of a cold front across Argentina, and tends to occur when a low pressure system brings heavy rain to the Chilean side, and when an upper level trough allows the winds to pass over the Andes to descend downwards.
30.
However, because it did not have the " classical characteristics of a tropical cyclone ", it was treated as a tropical depression by the BoM and the FMS . Over the next couple of days, in response to an upper level trough of low pressure weakening, the depression slowly weakened further, while accelerating to towards the southeast.
