Thursday, July 28, 2011

Tropical Storm Don: July 28, Update B

Hmm… something funny is going on. Either my crystal ball needs a good scrubbing and the satellite images I’m look at are all wrong, or the NHC isn’t looking at what I’m looking at. I know they have been flying planes through TS Don, but the latest discussion says:
“DATA FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT SHOWED THE CENTRAL PRESSURE RISING TO 1005 MB...WHILE THE AIRCRAFT WINDS SUPPORTED AN INITIAL INTENSITY OF 40 KT.”

A rising central pressure? 40 knots translates to about 46 mph (1 knot = 1.15 mph). Unfortunately there is no direct high-resolution satellite pass of winds in this section of the Gulf available (to me) at the moment, and there are no buoys or other observations (because why would we need those?), so we have to rely on what the data collected by the plane shows and also on the images of this storm from the GOES satellite. The last NHC advisory had the storm center at 24.9N, 91.3W, moving NW at 16mph. The images attached here are the IR and visible satellite images that I grabbed an hour and a half or so after the last advisory.



If someone can see how the center is a little northwest of 24.9N and 91.3W (I marked an approximate location with a red dot on the visible image), then please let me know because to me it looks a little on the edge of the system. Either I need new glasses (quite likely ;-) ), or the plane is going through the wrong part of the storm which is why they are detecting an increase in pressure – but that doesn’t seem likely either, which is why I’m a bit befuddled.

There is a bit of wind shear (5-10 knots) but convection in this storm has progressively got stronger during the day, as you can see from the large red and bit of grey in the IR image. If they are correct, then landfall will be tomorrow night in the Corpus Christi area (as the current forecast center of cone line shows), however the bulk of the bad weather will be south of that.

I’ll stop by later and see if our opinions line up – I’ll have had a glass of wine by then, so I might be able to see things more clearly! ;-)

Ciao,
J.

Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm

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DISCLAIMER:These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.
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