MikeCAdministrator
(Admin)
Wed Jul 06 2005 10:06 PM
Hurricane Dennis in the Caribbean

9:50AM Update - July 7th
Dennis has made a northwestern jog over the last few hours and now it is likely to pass slightly north of Jamaica, as the NHC forecasted. Some of the model guidance has trended to the east again, we'll watch for persistence with the trends. If this persists it will force the keys to be under a watch tomorrow.



7:45AM Update - July 7th
Hurricane Dennis is now up to 105MPH Winds as it moves toward Jamaica. It is possible for it to reach Category 3 before nearing Jamaica.

7:00AM Update - July 7th
No real changes this morning, pressures are still dropping on Dennis, and tge windspeed is up, probably up some more at the 8AM advisory.

The future track hasn't changed much, still moving it into the gulf, west of the Florida peninsula and up toward the western panhandle toward New Orleans area, very similar to Hurricane Ivan's track last year. There is still a chance of varience in the late track, but trends seem to be settling on here for now.

How Dennis affects Jamaica, whether it passes north, south, or directy over the island, is still up for grabs. Jaimaica's mountainous interaction with the storm seems to do odd things (see ivan) so it'll be something to watch as it approaches there. People in Jamaica need to be prepared already.


Other places will still want to keep a watch through the weekend.

10:40PM Update
The Cayman Islands are now under a hurricane warning. Winds are up to 85MPH. Not much change on future track, or the certainty of it in the future. One good thing is that toward the end of the storm's path wind shear is forecast to increase, which may weaken the storm before landfall.

Additionally, another wave have come off the African coast, but for sanity's sake we won't mention that much more for a while unless something occurs. It's too early for long trackers, but you never know with this season.

8:45PM Update (Clark)
A slowing from 20mph down to 13mph, gradually over time, is more indicative of the system actually slowing down and not wobbles in the storm's path. It's reached an area where the steering currents are not as strong as they were towards the east; this motion should continue for another day or so before accelerating just slightly. However, any slowing and/or any hint of the storm becoming elongated north-south are prime indicators of a northward turn either in progress or about to occur.



Don't have time for a full update, but will leave you all with this: watch the shortwave current moving SE over central Kansas. It, coupled with the weak vortex near Dallas, are going to be the prime factors that influence Dennis to move north -- or not move north -- over the coming days. If the Kansas vortex continues to dive southward, the trough behind Cindy is going to become more amplified and likely capture Dennis before the models are predicting; the Dallas vortex may help this occur. If it begins to move towards the east, with the flow, Dennis should continue on a NW path to landfall in Louisiana. There is impetus for both scenarios to occur, but which one actually plays out remains to be seen. Right now, I would begin to believe the former rather than the latter, based off of synoptic trends and looking upstream over the northern Rockies, but there is some indication for the latter to occur as well.

The subtropical ridge is a bit weaker today than it was yesterday, though is pinched in the eastern Gulf by the remnants of Cindy's circulation. It extends to the Yucutan on its southern/southwestern extent, but only to Cedar Key, FL on the northern/northwestern side of things. These shortwaves should help keep the former in place and influence the latter; how much of this occurs will determine where the storm goes. Dennis bumping into it may play a role as well. There's still the chance of it slowing/stalling in the SE Gulf in 3-4 days, particularly if it gets caught outside of the influence of the ridge and the shortwave troughs, but I still don't consider it likely.

Do feel pretty confident, however, in saying that the GFS & UKMET are definitely on the west side of things, and the Canadian model is on the east side of things (though it is too fast). Slight ridging appears to be building over the intermountain western U.S., which would imply slight troughing along the east coast and a more northerly track for the storm, but again -- it's all about how much of an impact it has on Dennis. I can say, though, that as long as this giant upper low sits over the Pacific northwest of Hawaii, the pattern isn't going to shift greatly for awhile. Not exactly the greatest news for down the line into the season, though it'll likely weaken/break out before too long (just off of climatological factors alone).

Original Update
Dennis has now become a Hurricane, with 80MPH winds, expected to strengthen more over the next day or so as it gets closer to Jamaica. The current forecast track takes the center barely just north of Jamaica, but close enough to be felt. Folks there should prepare as if it may strike directly. Hurricane Warnings are up there.

After that, it will approach the Caymans and Cross over Cuba and likely enter the Gulf. Things are still somewhat uncertain after that, and the cone of error is large. But current model trends suggest the big Benda and Florida panhandle and points west toward New Orleans with the highest threat on Monday. However it may come close enough to the Florida Keys to cause concern there this weekend, and the cone still includes the west coast of Florida, so do not rule those out quite yet.

Bottom line is we still don't have a clear grasp of the storm 3 days out or so.



Do not focus on the line in the above maps, the storm is large and the cone of error that far out is even larger! I know those of you who had to deal with Ivan last year do not like that map.

Event Related Links

Monroe County/Florida Keys Emergency Management Bulletins

StormCarib hurricane reports from observers in the Islands - Jamaican StormCarib Reports
Caribbean Island Weather Reports
Jamaican Meteorological Service

Guantanamo Bay, Cuba Radar
Florida Keys Long Range Radar Loop

Dennis
Animated Model Plot of Dennis
Model Plot Graphic from the South Florida Water Management District of Dennis
Dennis Spaghetti Model from boatus
Weather Underground Model Plots for Dennis
Quikskat Image of Dennis

Floater Satellite (Visible) of Dennis with Storm Track Overlays

RAMSDIS high speed visible Floater of Dennis

Forecast Discussions for (Show All Locations):
Tampa. Mobile Bay,
New Orleans, Key West, Tallahassee.
Melbourne




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