Hurricane Dean

[Iceberg]

GFDL has a Texas CAT 5 hit again for the 12Z.

Sat pic.

Lots of good pics

[Thunder Snow]

thanks

[Calrissian]

OK... I'm just going to record the stream if the opportunity arises, and then I can take all the screendumps I like at my leisure! lol

Does anybody know if we're likely to see another pass of dean or a replay of the earlier one from the nasa video stream?

there was another pass just earlier, but they didn't cover it.

NASA-TV will replay that earlier pass video throughout the evening, since the mainstream media often do have an interest in such things.

---

As for Dean, he does seem stuck at the moment, but then, nothing increases in strength without pausing from time to time.

The warmest seas are still yet to come for Dean. Even if he drops to Cat'3, there is massive potencial once past Jamaica for him to bomb to a crazy new record low pressure.

The models are very closely saying the same thing that the 5-7 day track is broad NNW, but we are still a long way out, and I personally expect to see the natural tendency for the storm to start pulling more northward within a day or so. Even today we've seen the track a little north of the models.

Looks like Jamaica - if its hit, will fare worse on the north side.

Calrissian: 200ft underground in the nuclear bunker. (if only)

[Gray-Wolf]

I think that each time he pauses (for an eye wall replacement cycle) not only will his forward speed drop off but he'll have one of those trachiodal wobbles and nudge his direction a few more degrees N.

If the 'Florida Low' also helps in the 'steering' of Dean then the 'Texas hit' that GFDL propose may come in from a direction they are not yet proposing.

Lots of action flowing off Africa at 35w right now too. See where that takes us in 3 days time.

[Blackie]

If Dean hits Jamaica hard and keeps heading west, how will that impact the Cayman Islands? I haven't heard any mention of them in the firing line, but on that track I am sure they would be. And Grand Cayman is only just back on its feet after getting a pasting from Ivan.

[crimsone]

Thank heavens for that... no sign of a replay on the live stream, but it's not nessecary

Anybody who missed the ISS pass of Dean can see it here... http://www.nasa.gov/multimedia/videogallery/index.html

It's not quite as clear as it was on the live feed though... the video is a bit bright which obscures the details.

Edited August 18, 2007 by crimsone

[Gray-Wolf]

Thanks Crimsone. Just the thought of watching a 'cane realtime from space is mindblowing!!!

[kold weather]

Dean still looking extremely good though heat content doesn't seem to be quite high enough just now to get it to cat-5, though I'd say over the next 3-6hrs it stands a very good chance. The thing that will save this from an eyewall replacement cycle lasting all that long if it does try is the fact that its heading into ever more impressive heat cotnent and so to maintain the structure its got continues to be possible and indeed it can keep going.

I think its on the verge of an EWRC but right now the eye still looks pretty clear bar a thin layer of cloud...pressure rise to 929mbs up from 924mbs also supports the idea though the eye looks a touchbetter again now.

Still I don't think there is any doubting Dean looks utterly stunning on Vis.imagery right now, its not every day you see a hurricane look as strong as dean is right now, right now its close to peaking out at top strength in the waters its in now...once it gets into the W.caribbean the waters easily support anything from another 20-40mph stronger then it is now and if it can keep the current structure it'll go sub-900mbs.

I suspect that we could well have a cat-5 very shortly. Pressure rise earlier occured as the NW section of the eyewall weakened in an attempt at starting an EWRC. My theory is its since moved over higher heat content again which can support further development again. Indeed Dean looks the best its ever had with its inner core growing quite nicely and indeed its coverage now reminds me a lot of Allen and Gilbert at the same stage, yet another reason to suggest this could reach legendary status (top 10 storngest ever)

Eye is going to come close to Haiti and the northern quadrant may become slightly disrupted which may lead to strength levelling off around 6-9hrs time but by that time it could have easily reached towards the lower limits anyway. Looking at the short term track Haiti could wlel see the northern eyewall and could also see hurricane force winds sustained on the far SE. Dean is currently running north of its forecast track again which suggests the ULL may be a touch stronger then ezxpected allowing a more northerly route, the GFDL did go for this though it was too extreme in its NW motion. This WNW motion may just spare Jamaica the very worst of the hurricane with the N.quadrant maybe heading just to the north, its not easy to tell right now however.

Finally just to bring up a conversation from before, 880mbs isn't impossible in the Atlantic though it would require the loop current and utterly perfect condtions. Katrina moved over with very good, but not exactly perfect condtions (hence why it got the squashed look) and I think had it perfect condtions it could have gone down to 890-880mbs and i wouldn't evn rule out sub-880. The only other palce that can go sub-900mbs is where Dean is heading, the NW Cairbbean. IF Dean come sin on the back of an EWRC we really shouldn't rule out a sub-900mbs. I'd say the chances are just 5-10% right now BUT Wilma, Gilbert and Allen all done it under similar condtions...indeed Allen and Gilbert have taken nearly the exact same track as well to Dean. Wilma may not be the best example mind you a spressure ion the Caribbean were way below normal which allowed a lower pressure in the core.

Anyway a really exciting, if slightly worrying hurricane Dean is, certainly makes up for the lack of noteable storms in 06...

Edited August 18, 2007 by kold weather

[Paranoid]

Will we get an update at 9pm on the strength of the storm?

[crimsone]

at 10pm BST the next advisory will be with us

[kold weather]

Dean is heading roughly WNW but is wobbling its way north and west in a sort of stair-stepping fashion. Models are forecasting just south of Jamaica right now. (though some are slightly further north, all makes a big difference for the island) IMO its a touch north of the track over the last 12hrs and I think this will continue. It probably won't make much difference to Jamaica other then they may be in either the north or south eyewalls and in theory while the north is stronger in a cat-4/5 the south is still going to pack a very powerful punch indeed.

By the way the long range forecast is still uncertain. Models take it into Mexico with the GFDL only major model going into Texas and the GFS nesembles do seem 50-50 as for a Texas hit or Mexico. IMO I'm calling for a very close hit to the same point of Erin's landfall, maybe a shade to the south but probably within 50 miles. Allen is a very close match in terms of track and Gilbert and Emily are also pretty close, tohugh Emily maybe a touch too far south.

Long range strength also extremely difficult to gauge. Given Dean is growing in size with every hour it may not do that bad over but the eye is stil lfairly small which would suggest it could weaken quite a lot over land. Obviously the exact track is going to play a role. Heat content suggests this could get back upto 135-150mph though whether or not it does will depend on how badly the core is disrupted on its track over the Yucatan. I'd suspect something around the 125-135mph mark but can't rule out a higher strength. If it goes a little further north lie the GFDL then heat contetnt supports something close to 145-160mph mark..but once again thats if its got a good inner core already and perfect condtions. Dean may have a ndisrupted core from land tracking.

Edited August 18, 2007 by kold weather

[Iceberg]

He looks better now than he has done all day tbh, He could well have abandonned his outer wall and quit an ERC for now.

Recon not for awhile yet...

Edited August 18, 2007 by Iceberg

[biffvernon]

Still in the 'cool' water. It's a degree warmer past Jamaica and two degrees warmer the other side of Yukatan.

[kold weather]

latest advisory still has Dan at 130kts. Given no new data it would be wise to hold fire even though as Iceberg has said it does look stunning right now. Dvorak still shows outerwall is present though not fuly formed yet with the inner eyewlal open on the western side it appears however I'd like to see microwave sat.imagery to get a better idea if thats a true reflection.

Track has Dean heading directly over Jamaica though Dean is wobbling a lot around its cylonic motion and is stair-stepping its way on a general WNW motion. Haiti IMO looks like it could come very close to the eyewall, esp the developing outer eyewall which could cause some extreme damage and landslides could cause deaths to 100's if not 1000's like Jeanne did in 04. If anything track may take Dean just north of Jamaica but its very much wobble watch right now. If Dean gets to close to Haiti then strengthening will stop as it interacts with the mountions.

By the way every signle model/ensemble run now hit Yucatan, tohugh they still vary on exactly where they have DEan hitting, most are centered just south of Cancun but there are some 100 miles south and a few clipping Yucatan. Beyond that and most still hit Texas but then again the track at the motion is about 5 degrees close to the north then the models thought, though that may not continue. For tcc weho is going to the NE Yucatan it doesn't look good, even the NHC are stll going for a 160mph landfalling hurricane, and the NHC may well be under-estimating its peak strength.

Iceberg when is the next recon??

Edited August 18, 2007 by kold weather

[crimsone]

1. HURRICANE DEAN
	  FLIGHT ONE					  FLIGHT TWO
	  A. 18/1200,1800Z				A. 19/0000, 0600Z
	  B. AFXXX 0604A DEAN			 B. AFXXX 0704A DEAN
	  C. 18/1000Z					 C. 18/2200Z
	  D. 15.8N 69.0W				  D. 16.7N 72.3W
	  E. 18/1100Z TO 18/1800Z		 E. 18/2300Z TO 19/0600Z
	  F. SFC TO 10,000 FT			 F. SFC TO 10,000FT

If my interpretation is right, it'll be taking off in about an hour. (I never did find a legend for reading the plan of the day)

edit:... oddly enough, I just found one... http://www.nhc.noaa.gov/aboutreconpod.shtml

Edited August 18, 2007 by crimsone

[kold weather]

Okay, this one may be worth staying up for, who is going to join me (probably!)

I should mention, Jamaica is going to take a very big blow, even if it for some reason weakens we are still looking at extremely severe damage. based on its current foward speed of 17mph landfall of Dean should be in about 32hrs time, though of course in truth Dean could yet speed up or slow down. If it hits as a 150mph it presently is then we are looking at some truely historic damage t othe island, the strongest system to directly hit to my knowleadge is Gilbert and hit as a high end cat-3 becoming cat-4 while exiting the island.

also lest us forget the Cayman islands, given the heat content in that region of the Caribbean and the fact past hurricanes have really powered up in that region I think if Dean comes close to the eyewalls of Dean there wil lbe severe damage to the islands.

Looking at some really extreme damage and probably some horrid pictures come Monday afternoon of the damag eleft by Dean and expect quite a few deaths, even though the island should be well prepared hopefully Haiti may not fare so well.

[Iceberg]

Next Recon starts at midnight (11Z) add a further hour to get in position so from 1.00am onwards I would have thought.

I'll catch up in the morning I think, Good luck hope everybody see's something.

[crimsone]

"C" is the departure time, while "A" is the invest time... does that not mean that the recon takes off at 2200z, starts taking readings sometime before 0000z (perhaps at 2300z)?, and then takes a fix on the center at 0000z?

As you can probably tell, I'm confused as ever! lol

Edited August 18, 2007 by crimsone

[kold weather]

There wil lbe readings I suspect as soo as it takes off, there normally is but its not gonig to go down to flight level till 2300z and lasting till 0600z from the looks of it, though I'm not too wlel versed in reading that.

Anyway Dean's eye looks like its clearing back out again so can only assume pressure is starting to drop again. I don't think Dean actually went through an EWRC and instead seemed to try and go for it but once it hit even higher heat contents it seemed to not need to go through an eyewall replacement and instead could keep deepening without needing to contract the eye further in to sustain development. I suspect recon may go and find a 160mph cat-5 with central pressure dwon to about 920mbs providing the eye doesn't cloud over again. cloud tops are warming still but thats exopected given the temps should be reaching their max present that far west, the cloud tops should start to cool down again soon in the eyewall.

We'll find out in a few hours whether Dean has made it to cat-5 or not, based on tonights images though it looks an extremely impressive hurricane at any rate and does have a cat-5 'look' to it, if there is such a thing!

By the way worth saying that Dean has grown in size over the last 12hrs and is now a large hurricane, now as huge as some of the big boys of 05 but its getting there. Dean is remining me more and more of Allen and also more so now of Gilbert in terms of track and heading, though worth remembering Gilbert wasn't as strong as Dean is right at the time it hit Jamaica, indeed it was just becoming a category-3 so in that regard Dean is on a Gilbert track, indeed its pretty much bang on at the moment and the forecast is for that to continue, but quite close to the deadly Allen in terms of strength, so a sort of fusion between the two, both went sub-900mbs eventually.

Edited August 18, 2007 by kold weather

[SnowBear]

Ahhhh, let me see,

Take off time is C, which is always in Zulu time or GMT. As we are in BST, add one hour to the Zulu time to get the time in our current BST.

EG: C. 18/1000Z

On the 18th, flight takes off at 1000Z or 11.00am BST.

A is the projected invest/fix time for the centre of an invest or fix for an eye in a hurricane. It gives a projected first and last invest/fixes of that mission.

EG: A. 18/1200,1800Z

First invest/fix targeted for 1200Z, last one of the mission is 1800Z

E gives the time the mission will be in the target zone of the storm system.

EG: E. 18/1100Z TO 18/1800Z

In this particular mission the plane will be in the vicinity of the sotrm from 1100Z to 1800Z, note it takes 30 minutes from becoming on station to first invest/fix as noted in A, and the last invest/fix is right at the end of the mission before heading home.

F Is projected flight level for the mission at the target area

EG F. SFC TO 10,000 FT

In this case from the surface to 10,000 foot depending on winds found and conditions met.

Edited August 18, 2007 by SnowBear

[kold weather]

looking at the vis.imagery which may be one of the last decent quality one tonight it shows the eye has cleared very nicely with signs of the mesovortices in the eye (Stadium effect as well, telltale cat-5 feature!!!) though without great quality imagery it hard to tell. If this is not a cat-5 I'll be surprised based on it current look, the only slight thing that may prevent it from being quite as strong as it looks is the cloud tops aren't all that cold however other then that i can't really see any reason why Dean has gotten stronger since last recon found a central pressure of 929-930mbs, I suspect pressure is now dropping away again heading towards the deepest the current heat content supports and previous history shows which should be around the 910mbs mark---which would be close to Allen's bottomned out pressure in that part of the Caribbean, I don't think it would go lower then that but you can never rule out anything. 160-165mph max winds will be most likely found, I'll be surprised if its not gotten any stronger.

Not sure if it'll be quite that low of course but recon could find a stronger hurricane when it gets there barring an EWRC. However right now the eyewall is showing some intense convecton again and is stronger where it had previously weaker on the NW side which is a good infdication that Dean is now getting stronger and given soon the sun will be going down the upper temps should drop a little which should allow even greater convection, this stronger convection may wlel be an indication of this as well as an indicator that Dean is going to be a category-5 tonight when recon reaches the hurricane.

By the way if Dean does hit Jamaica as the forecast track shows then it will likely be the strongest hurricane they've had in at least a 150 years, in that regards Dean will truely be a historic hurricane. Gilbert hit as a developing cat-3/4 but dean is a step above what Gilbert was at this stage and given what i'm seeing on the Sat.Imagery if it come sin anything close to as powerful as it is now the island is going to be in some severe trouble, the only good thing is that if it does deepen tonight its going to have a hard time keeping it up as its going to go through a slightly lower heat content region about 12hrs time, that may just be enough to force it into an eyewall replacement cycle given its probable pressure at the time but its very 50-50.

Recon is now reporting back info by the way:

http://asp1.sbs.ohio-state.edu/text/tropic...tic/URNT15.KNHC

Currently heading towards the region Dean is in, still only at 66W so should be another 30 mins before we get more useful info about Dean's outer bands and the strength of the winds Dean has over that period.

Edited August 18, 2007 by kold weather

[Gray-Wolf]

He seems to now be swinging south of the updated storm track points (by a eye at least....that was 10mls wasn't it?) so, though always west wards, he seems to 'throw himself off balance' from time to time even before he encounters the disturbance that the 'Florida (now Gulf) Low' places upon him.

Maybe I just can't stand the thought of an uncomplicated, straight travelling 'cane that just ploughs into north Mexico and dies!!!

By the way K.W. did you note , on the GFDL model run, the storm that clobbered SW Florida just as Dean was dying in the hills of Mexico?

Edited August 18, 2007 by Gray-Wolf

[moochops]

Have been looking at weather forecasts for Jamaica over the coming days and some sites seem to be oblivious that Dean is around - http://www.bbc.co.uk/weather/5day.shtml?world=0298

[kold weather]

Well its taking 2-3hrs wobbles tothe NW then back to the west as it sort of wobbles around the complicated upper level pattern to the north.

The more I see of Dean, the more impressed I am, DR/Haiti must be getting lots of rain right now and probably already getting tropical storm sustained/hurricane force gusts, i'll bet there could be quit a few dead people on that island once the hurricane moves away sadly, landslides will be a real threat.. We'll see what Dean is like soon from recon but as I keep saying its got all the cat-5 signs...

I feel so sorry for the people of Jamaica, stronest hurricane hit in a very long time and could well be cat-5 unless it undergoes a EWRC, tohugh timing may just be on the island side as Dean may not hold that sort of strength for the length of time required but even if it is undergoing EWRC at the time of landflal this looks beastly strong it really does, in fact maybe even historically strong and I really don't use that lightly.

Hurricane warning will likely be issued early tomorrow morning for the Cayman islands, they may also get the northern eyewall on its current track.

Edited August 18, 2007 by kold weather

[Paranoid]

Tommorows weather in Kingston, light winds and showers, 31c. Slight chance of apocalypse later in the day...

You do have to hand it to people in Jamaica. All the vidoes i've seen on the news show them calmly preparing for the storm. If this was Britain we'd probably be running around screaming right now.

Edited August 18, 2007 by Paranoid