Normandy wrote:Evening Thoughts,
Im going to write a lot about this, because in the last 24 hours Hurricane Dean has threatened to become one of the most devastaing, intense, and deadliest hurricanes we have seen. Since sparing the islands (and I say sparing because what it is now and what it was then are two totally different beasts) Dean has bombed into a borderline Category 5 storms. The 154kt Flight level winds, if using proper reduction, suggests 160 mph surface winds...However cloudtops have warmed and that reduction isn't appropriate for this situation. Regardless, Dean is well on its way to Category 5.
TRACK
This is important....very important.....and even MORE important because Dean is forecasted to hit in 4 days. I will first explain my reasoning by posting the GFS 500 mb analysis for the following days:
http://weather.unisys.com/gfs/init/gfs_500_init.htmlIll go by a step by step analysis of the relationship between Dean and the crucial ULL that will ultimately determine who gets leveled by this monster. If you want just open the link in a new window and follow along with the images.
Initial: Correctly places the ULL in the SW Carribean sea, as Dean starts to clear PR to the south. Notice Erin's remnants still remain in N Texas (this is more important than you think).
12 HR: Moves the ULL slightly to the FL Peninsula. Dean, at this point (per NHC), should be just south of the DR. The distance between the two lessens, and at this point Dean should be moving WNW and feeling the weakness being induced by this ULL. Notice Erin is STILL over Texas and actually is deeper now than yesterday.
24 Hr: Moves the ULL a great deal W and places it due south of the FL Panhandle. That means this ULL moves all the way from the Bahamas from when these runs were initialized (About an hour ago) to due south of the panhandle....a distance of about 400 miles. To due this, the ULL will need to have an average speed of 16 mph from this time till 3 AM EST Sunday (If my math is correct). Looking at the WV, that ULL is not going to move that far in this amount of time. Dean, at this point, should be starting to clear Haiti and making its move towards Jamaica. Even if the GFS run pans out, the distance between these two systems (Dean and the ULL) is narrowed further. At this point, Dean should be moving WNW and should have more of a northerly component then 12 hrs prior.
36 Hr: Moves the ULL another 200 miles in 12 hours (meaning that the ULL would need to average 16 mph....much more feasible). At this point, Dean would be over or near Jamaica, probably just passing it. The distance between the two holds steady. At this point, Dean should still be moving WNW. Oh and btw, Erin is STILL over N Texas.
48 Hr: ULL moves more, but thats not the important thing. This is the first time we see Dean's location according to the model. Notice its near the Eastern portions of N Cuba. According to the NHC track, Dean should be near or over Grand Cayman island. Not only is the GFS apparently moving this ULL too fast, its moving Dean to slow. This is the first time it becomes apparant that the GFS is out to lunch.
60 Hr: ULL is approaching the Lower Texas coast, Dean approaches Grand Cayman island. According to the NHC track, Dean should be nearing the Yucatan at this point. Again, the GFS is far too slow with Dean. Oh, and Erin is still there.
What does this mean? If the GFS were even right, Dean would be much further west in tandem with this ULL...so its incorrectly assessing the speeds of one, if not BOTH weather systems (Dean and the ULL).
Here is my analysis of how I think this situation plays out:
- 24 Hr -
I can't fathom the ULL moving that much in the next 24 hours, and it seems reasonable that by this time tomorrow the ULL over the Bahamas will be on the western Florida coast, not due south of the Panhandle. For this reason, Dean should begin to show a northerly component to his motion rather soon....and by tom morning Dean's due westward motion SHOULD be done with, and a heading of 285-295 should commence. This puts jamaica right in the crosshairs, and likely will suffer a direct strike from a Category 5 Hurricane Dean. Dean and the ULL should gain proximity, and Dean should begin being ventilated by the ULL and it should feel the weakeness it is producing.
- 48 Hr -
Dean should be approaching Grand Cayman Island, and the ULL should be somewhere south of MS. The proximity between the two should begin to lessen further, and at this point Dean might get sheared by the ULL, but I won't call for shearing of Dean just yet. At this point, Dean should be moving wnw at a heading of 295 or so due to the proximity to the ULL and the weakness it is producing. Also, Erin remains in N Texas and seems to be creating a weakness in the ridge over the SE US over central texas. These two weather systems in tandem, should produce a weakness sufficient enough to bring Dean just north of Cozumel and near the tip of the Yucatan peninsula. A strike on Cuba is not likely, but its more plausible to me then a strike near Belize. A path through the Yucatan Channel is plausible as well. I feel that Grand Cayman will encounter the eye of Dean, and Dean will likely be a Category 3 hurricane at this point (due to weakening because of Jamaica).
- 60 Hr -
By now, Dean should be entering the GOM. At this point in time, the ULL should be somewhere south of LA and approaching the TX coast. Dean should be right behind it, and at this point imo, Dean should be moving at a heading of 305-315 and should be feeling the weakness left in the ridge by not only the ULL, but Erin's remnants. This weakness should be sufficient enough to set Dean on a course for Texas. The exact landfall location is not very clear, but anywhere from Brownsville to Galveston looks likely. I can't see this moving anyhwere south of this area due to the poor timing that the GFS shows with the ULL and Dean (And even with this poor time it brings the storm near Brownsville. By this time, Dean will be about 24 hours from nearing the coast. At this time, my greatest risk for landfall in Texas is Matagorda Bay. It should be noted that the strength, and more importantly, the size of Dean could change this thinking. If Dean explodes to Katrina sized, the effects of the weakness would probably be more pronounced.
INTENSITY
Pretty straightforward for the next 24-48 Hours. Dean is going to become a monster....somewhere along the lines of 140 kt within the next day. Fluctations in intensity from that point will be caused by internal dynamics. It is possible that Dean becomes even stronger (150-160kt) as it is passing over high THCP and blazing SST's....add that in with a amazing upper air environment and Dean is set to become not only strong, but legendary. Jamaica will likely be facing the wrath of a true Category 5 cyclone, with winds on the order of 140-150 kts. Interaction with Haiti could alter Dean a bit, but I dont think it will approach it close enough to have any long term effects. Jamaica, quite possibly, will be totally destroyed by Dean, and loss of life in the DR/Haiti and Jamaica could reach 1000+. Very, very, very troubling scenario unfolding here....It should be noted that the last major hurricane to go over Jamaica was Gilbert (Cat3)....this will be far stronger....and subsequently, far more devastating. After Jamaica, Dean should weaken but still retain major hurricane status due too fast forward speed. After this, Dean should further strengthen (although interaction with the ULL could induce shear). Residents of the Grand Cayman should prepare for a major cane, and resident of the Yucatan should do the same. Intensity in the gulf is too far out to have much confidence, but a major strike is likely.
The GFS, despite its shift north, still is just not handling the important weather systems vital to steering Dean. The GFDL seems to have a MUCH better handle. If I were in Houston, Matagorda, Corpus, or Brownsville.....I would be making preparations. Preparations include: Gathering goods, gas, supplies. People in these areas also should prepare to evacuate. At this point, here are my percentages for strike:
Haiti/DR: 40% (So high because the H-force winds of Dean will still rake the southern shors)
Jamaica: 90%
Cozumel: 60%
Cancun: 75%
Isle of Youth: 50%
Caymans: 80%
These averages should be separate as they are FAR out.
Tampico: 20%
Brownsvile: 50%
Corpus: 70%
Houston: 50%
Folks......this is going to be terrble. Pray for those in Jamaica.
