8:30 AM 18 Aug 2007 Update
The latest recon shows about the same windspeed as in the advisory, and the pressure down to 926mb, and since the next two or three days are going to be critical for the ultimate mainland landfall location, I'm sure there is a lot of "no it's moving more north-- no it's moving more west" type of observations, which are always interesting...

Intense Hurricanes with eyes like Dean tend to wobble around like a spinning top, and it's hard to gauge if something is a trend, or a wobble. The SSD satellites with the forecast track overlays are helpful here, but I think bare minimum is a 4 frame change to really see if something is a wobble or a true movement.

Track is not the only variable, forward speed is as well, so it's important to watch the changes in forward speed as it affects the eventual movement of the system. It appears the latest model runs initialized the Upper Level Low over Florida too weak, so what this means for the track is uncertain at this time.

This shows the official forecast track from 5AM, vs the actual position of Hurricane Dean at 8:30AM. Click the image to go to the latest animation (Check the "Trop Pts" Box to see the track overlay)

7:30AM EDT 18 August 2007 Update
Dean has strenghtened a bit overnight to just shy of Category 5 strength, with 150MPH winds.

Dean is at a high enough intensity to start being affected by hard to time eyewall replacement cycles and other less understood elements of very extreme hurricanes. However that said, it still hasn't reached the warmest waters of the Caribbean yet, and may strengthen further. It is likely to weaken and strengthen some in cycles as it maintains this intensity for a bit.

The National Hurricane Center hasn't really changed the forecast track at all in the past two days, and continues it on the generally just slightly north of west motion into the Yucatan and eventually into Northern Mexico, however there is still some wildcards in the future track, especially as it approaches 85west, but the NHC's track makes the most sense at this time.

Jamaica will have until tonight before effects from dean start showing up, and the worst of it on Sunday.

9:35PM EDT 17 August 2007 Update
Recon has found 145 MPH winds, making Dean now a stronger Category 4 hurricane. Minimum pressure is now 936 mb. Dean is still strengthening.

Jamaica... For comparison, hurricane gilbert in 1988 had135MPH winds when it hit Jamaica.

Original Update
Recon Aircraft found a pressure of 946 mb and flight level winds of 146 knots, which estimated down to the surface represents about a 135MPH Hurricane, crossing into Category 4 terrirtory.

Dean has strengthened very rapidly today from a category 2 in the morning, to a category 3 in the afternoon, to a
category 4 at 8PM. Jamaica is the next target, dean would likely make its closest approach to Jamaica Sunday afternoon. Please take this one seriously Jamaica, it may not brush by like Emily did a few years ago. and very well may be stronger when it does.

After that, the Caymans may have to deal with this system. Then the Yucatan is now looking like a target, models have shifted back again (Well the GFDL did), it is still far enough out that it's worth watching for anyone in the Gulf and Caribbean though. Dean may have more surprises to come.

See Clark's blog below this article for more on the future of Hurricane Dean.

Event Related Links:

Jamaican Radio (106 Power)
Go Jamaica Hurricane Dean Watch
Jamaica Gleaner (Jamaican Newspaper)
Jamaican StormCarib Reports
Jamaican Meteorological Service
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Guantanamo Bay, Cuba Radar
Martinique Radar Animation Recording
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