Thursday, September 11, 2008

Thursday 11 am Ike Discussion

Vortex Data Messages Thursday

And the 11 am Ike Discussion

A historical note from the Pacific. Ike’s eye and surface wind speed activity, although not perfectly paralleling “the PI storm” probably is very close. The Pacific storm [PI for now] occurred the Western Pacific in 1969 and plagued flight crews throughout its life.

It started as the “Double Eye Dumbbell storm” that persisted in having a figure 8 eye with a small lens shaped cusp between two distinct and equally powerful eyes. Navy flight crews called this eye memory.

In this case the two eyes were persistent and rotated around each other and a mid point. This required skill to fix. Which one do you choose? Ike has presented a very small eye and an oblong eye at times.

At any rate this Pacific storm had central pressure well down to the 900 MB level and probably a little below. It had presented this unique eye feature from its first development of a West wind and cut off circulation.

The very unique thing it did was to move over the mountains of the Philippines and get sheared off. Then the oblong eye had unusual surface presentation of a 40 mile by 80-mile eye but with a huge area of high winds outside the large rotating eye. In this storm the upper level circulation was never able to build back down to the surface.

This sounds very similar to what happened to Ike and the ideas mentioned by the 11 AM Thursday discussion of the low pressure “not yet” being transported to the surface. Ike went over most of Cuba and it’s mountains. Storm dynamics of this shearing effect of the mountains are acting like a “memory” to Ike and restricting its transport of higher speed upper level winds to the surface.

Ike is a different storm and has presented at times a very small storm. The surface pressure in the eye and the aircraft tracks and Vortex Data Messages need to be watched closely. Hurricanes and Typhoons don’t read the textbook.


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