Tag Archives: Gilma

Minimal Tropical Storm Gilma Forms Well East of Hawaii

Minimal Tropical Storm Gilma formed well east of Hawaii on Friday.  A scatterometer on a polar orbiting satellite indicated that there were winds to tropical storm force near former Tropical Depression Eight-E and the National Hurricane Center named the system Tropical Storm Gilma.  At 11:00 a.m. EDT on Friday the center of Tropical Storm Gilma was located at latitude 14.9°N and longitude 128.4°W which put it about 1825 miles (2935 km) east of South Point, Hawaii.  Gilma was moving toward the west-northwest at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1006 mb.

The circulation of Tropical Storm Gilma was poorly organized.  There was a distinct low level center of circulation.  However, the stronger thunderstorms were occurring in bands east of the center.  Bands in the western half of the circulation consisted primarily of low clouds and showers.  A large upper level trough was located west of Tropical Storm Gilma.  The trough was producing strong northwesterly winds which were blowing across the top of the circulation.  Those winds were producing significant vertical wind shear and they were probably the reason why the stronger thunderstorms were occurring east of the center of circulation.

Tropical Storm Gilma will move through an environment unfavorable for intensification during the weekend.  Gilma will move over water where the Sea Surface Temperature is near 28°C.  However, the upper level trough will continue to produce significant vertical wind shear.  Gilma is likely to weaken to a depression and it could dissipate if the upper level winds blow the top of the circulation east of the low level center.

Tropical Storm Gilma will move south of a subtropical high pressure system over the Eastern North Pacific.  The strong wind shear will mean that Gilma will be steered by the winds lower in the atmosphere.  Those winds will push Gilma in a general westerly or west-northwesterly direction.