Tropical Depression Chris

[kold weather]

Very intresting Snowbear, looks like it works on juding how high the clouds are (By how cold they are) then converting that to what you'd expect in rainfall terms.

One other thing I did forget to note in my last few posts is how the tropical cyclone is moving constantly further north then wha tthe NHC are showing it. I have my doubts that it would strike Cuba given its already about 50 miles further north then what was expected 12hrs ago at this same point!

models are generally tracking this system too far south and the NHC will probably have to adjust the systems track to take it through the floirda straights and into the gulf.

By the way, even if this storm does just become a wave again, don't rule it out because it will find much more favorable condtions in the gulf of Mexico and could well re-form there into tropical storm Chris again even if it dies away over the next 12hrs, so something to watch even if Chris does die away and of course while that is looking increasingly like a possiblty I'm still not ruling out Chris completely if it can just keep that LLC ticking for the enxt 12-18hrs then it should get something of a moisture boost which may hel pspark off more storms even if they do get sheared pretty fast, because in its current state Chris won't last much longer.

[kold weather]

Okay going to do another breif update because ther eis another convective flare-up on its SE which will probably sustain it for another 6-12hrs even if the convective flare-up is already starting to be sheared. It's going to need to keep these flare-ups going for the next 24-36hrs while its in unfavorable condtions.

Prehaps even more intresting is that the intensity models are starting to gain a trend for re-strengthening Chris again, with some bringing it back upto hurricane status again. Reasoning is the same as my last few posts, the western ULL moves out of the way and is replaced by a ridge feature as the ULL to its NNW dives SW out of the way by 48hrs. Dry air should lessen as well and inflow should improve as the inflow moves back over the moist seas.

As I've said all along, IF it can survive int othe gulf its gonna have much better condtions there but its gonna still have a hard time to survive the next 24-36hrs given the inflow disruption and NNE shear from the ULL. For what its worth the NHc now goes for 50kts by 120hrs but notes this may be conservative. As amazing as this sounds its not beyond possiblty that Chris will become a hurricane much further down the line, despite the fact that its barely a tropical depression right now as the LLC is looking elongated N-S at the moment, still looks like a circulation is present but only just ,then again thats what 24hrs of constant high shear does I suppose!

Certainly can't rule that out though despite the short term propsects for chris looking extremely bad, still Chris is a fighter and it does have the positive of the loop currentand the gulf stream to come...

what a horror this system has been to forecast, certainly up ther ewith Epsilon in terms of ability to keep its strength up against all the odds!

[crimsone]

what a horror this system has been to forecast, certainly up ther ewith Epsilon in terms of ability to keep its strength up against all the odds!

I'll believe that comparison when I see the forcasters making jokey comments about it at the end of advisories again

[kold weather]

Well we aren't quite at this stage yet i suppose crimsone.

Still Td chris doesn't look done yet. While the LLC has further weakened and may wel now be open (if it is then its just a tropical wave...) however intrestingly as predicted there has been a convective blow-up on the southern side of the system. While its being sheared still pretty badly it does seem like the inflow has started to become better established again, remember what happened last night when the uinflow emerged back over the sea, well the same sort of thing is happening now. There is still plenty of dry air on the western side of the system (been there for the last 36hrs) however now with a stronger inflow the eastern side has perked up quite abit as you'd expect, like sparking a line of gas with a match.

Well Chris certainly is an impressive fighter, with some new deep sheared convection to the south of the center, a better inflow and moister air on its eastern side, with convection spreading up the eastern side (The more moist air that is!) Chris isn't quite dead yet, this is the third time its looked dead and has started to come back!

Recon should be intresting, may find pressure has dropped a touch and higher winds again in that large flare-up, could even find Ts winds in there but I'd guess probably not unless that mass gains more coverage.

If it doesn't hit Cuba and the LLC survives just a little longer (with the new flare-up, thats possible for sure.) then Chris could find itslef in a very intresting situation. when it reaches the gulf.

[garylaverick]

Could somebody point me in the direction of where to get this info, i'm interested in watching these system but don't know where to look for say satellite, charts, etc.

[SnowBear]

Hiya Gary

Probably the best place to start with is the US official Hurricane Centre, which is here http://www.nhc.noaa.gov/ (on the left, Get Storm Info > Satellite|Radar) and pick up the other links as we post them while tracking, there is a links page at the top of the Extreme weather worldwide / international weather watch section too.

[kold weather]

Recon presently in Chris and is finding some increased winds from last recon, highest flight level winds of 36kts:

1749 2200N 07140W 01524 0092 115 034 166 162 036 01651 0000000000

Still only about 30kts at the surface which is what the NHC has it at right now however with the convective mass growing close to the center I wouldn't be suprised to see 40-43kt reading in there somewhere in that big mass, esp considering 36kts was found in the bare NE quadrant away from the deep convection on that SE section which should be investigated shortly. Going to also be intresting to see if the recent increase in convection also means a reduction in pressure, I don't think it wil ljust yet but its a possiblty.

This convective burst may just come in the nick of time in term sof saving Chris because the LLC is clearly becoming elongated and very hard to track on the NHC sat loops, its probably still there but just very hard to track right now, the increase in convection though is just what this system needs. Gosh what an intresting system this one is, every time its close to death bang goes another mas sof convection on that eastern side, i swear it knows what its doing!

[markp1980]

Is this the start of the hurricane season?

What month does it start?

Do you think this year is going to be as active as the last 2 years?

[P.K.]

Is this the start of the hurricane season?

What month does it start?

Do you think this year is going to be as active as the last 2 years?

1st June to the end of November for the North Atlantic

It is going to be very hard for it to be as active as last year. As active as 2004 is certainly possible though.

[kold weather]

Presence of LLC has been confirmed by recon about 15mins ago by the vortex message, mind you the southern section is very weak, indeed near the LLC generally only 2-6kts of wind was found which suggests the LLC is on its last legs unless it strengthens again. Still for now the 36kts and confimred west wind should be enough to keep Chris as a 30kt tropical depression.

Also one other thing to note, convection has really increased in quadrants, WV imagery shows a lot of moisture being dragged southwards towards Chris along with the shear:

http://www.ssd.noaa.gov/goes/flt/t1/sloop-wv.html

ULL is clearly evident as wel lto the east of Chris which is still inflicting shear but for now the increased moisture is keeping Chris alive.

(ps, as P.K said, it's next to impossible to reach 2005 numbers,2004 is more then possible given we are 2 storms ahead at this stage.)

[Gray-Wolf]

EDIT: Oops, I see, that's the other ULL trawling up Florida at the mo'.

I've only just looked at the 'big picture' and seen the interface between the two ULL's. Poor Chris has survived one heck of a blow from the NE (the wind arrows look like the image of the blasts the North wind has coming out of his mouth on old maps!!) He now is on the 'far side' of the upper level wind tunnel so I guess ,if he keeps his circulation ,we'll see what we will see.

Edited August 4, 2006 by Gray-Wolf

[wolves78]

ZCZC MIATCDAT3 ALL

TTAA00 KNHC DDHHMM

TROPICAL DEPRESSION CHRIS DISCUSSION NUMBER 17

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032006

500 PM EDT FRI AUG 04 2006

THE CIRCULATION HAS BECOME BROAD AND POORLY-DEFINED WITHIN THE PAST

SEVERAL HOURS AND THE RECONNAISSANCE AIRCRAFT HAD A DIFFICULT TIME

FINDING THE CENTER AT 850 MB. DROPSONDES NEAR THE ESTIMATED 850 MB

CENTER INDICATED LIGHT WESTERLY SURFACE WINDS AND ADVISORIES WILL

CONTINUE. FLIGHT LEVEL WINDS OF 30-36 KT WERE OBSERVED WELL TO THE

NORTHEAST OF CENTER...AND THE INITIAL INTENSITY WILL REMAIN 30 KT

BASED ON THESE WINDS AND AN EARLIER 30 KT SYNOPTIC OBSERVATION FROM

GRAND TURK.

NORTH-NORTHEASTERLY SHEAR CONTINUES TO DISRUPT ANY CONVECTION

TRYING TO FORM NEAR THE CENTER. GIVEN THAT THE CIRCULATION IS

WEAKER THAN IT WAS 12 HOURS AGO...THE INTENSITY FORECAST WILL NOT

INDICATE RESTRENGTHING BACK TO TROPICAL STORM STATUS PRIOR TO

NEARING THE NORTH COAST OF CUBA. INSTEAD IT WILL WAIT UNTIL THE

SYSTEM ENTERS THE GULF OF MEXICO IN 2-3 DAYS. THE INTENSITY

FORECAST FOLLOWS THE TRENDS OF THE SHIPS AND GFDL MODELS

CLOSELY...BUT SHOWS LESS STRENGTHENING NEAR THE END OF THE FORECAST

PERIOD. IT SHOULD BE NOTED THAT THE INTENSITY FORECAST IS HIGHLY

CONTINGENT ON CHRIS MAINTAINING A CLOSED CIRCULATION...WHICH MAY

NOT HAPPEN.

THE INITIAL MOTION IS ESTIMATED AT 280/10 KT. THE TRACK FORECAST

REASONING REMAINS UNCHANGED AS CHRIS IS EXPECTED TO MAINTAIN A

WEST TO WEST-NORTHWESTWARD HEADING SOUTH OF A STRONG LOW/MID-

TROPOSPHERIC RIDGE. TRACK GUIDANCE REMAINS TIGHTLY CLUSTERED AND

THE OFFICIAL FORECAST IS CLOSE TO THE MODEL CONSENSUS...BUT IS

SLIGHTLY SLOWER THAN THE PREVIOUS ADVISORY.

FORECAST POSITIONS AND MAX WINDS

INITIAL 04/2100Z 21.4N 72.8W 30 KT

12HR VT 05/0600Z 21.7N 74.5W 30 KT

24HR VT 05/1800Z 22.1N 76.9W 30 KT

36HR VT 06/0600Z 22.6N 79.4W 30 KT...ALONG COAST OF CUBA

48HR VT 06/1800Z 23.2N 82.0W 30 KT...ALONG COAST OF CUBA

72HR VT 07/1800Z 24.2N 87.0W 35 KT

96HR VT 08/1800Z 25.0N 92.5W 40 KT

120HR VT 09/1800Z 25.5N 98.0W 45 KT...INLAND

[crimsone]

Looks like we've taken a jaunt accross the southern tip of Cuba overnight, south of the forecat points.

I'm not even sure I can see it on the latest sattelite image! It'll be intersting to see what NHC says at 0500 AST (0900 GMT?)

Edited August 5, 2006 by crimsone

[Gray-Wolf]

Looks like we've taken a jaunt accross the southern tip of Cuba overnight, south of the forecat points.

I'm not even sure I can see it on the latest sattelite image! It'll be intersting to see what NHC says at 0500 AST (0900 GMT?)

I think you're right! I think the ULL has rolled it flat!! (no circulation). It may come back to the lee of the ULL but if the NOAA has written out the death cert. then we'll be on the next one (storm) won't we?

EDIT: Avila confirms Chris's demise.

Edited August 5, 2006 by Gray-Wolf

[kold weather]

Chris is gone, theres only a slight circulation and it looks like shear has killed Chris off completely and there is only a slight amount of convection present, but its almost certainly a open wave right now. Still needs to be watched if it gets into the gulf and finds itslefin better condtions but for now its goodbye Chris.

[crimsone]

Well, It certainly was a fighter! To be honest, I rather think that the cuban landmass may have caused as much if not more interuption than the shear. I'm no expert on these things though - just an observer in learning. lol

Maybe it'll regenerate, but in all honesty, I'm guessing that it won't. I may well be wrong though! - The death cert is only a provisionary one

Edited August 5, 2006 by crimsone

[Gray-Wolf]

What of the ULL that rolled off Florida? Do they ever 'grow ' downwards (due to the convection) and produce a SLL beneath?

[crimsone]

produce a SLL beneath

Sea Level Low? If a ULL did that, wouldn't that result in the formation of a hybrid?

Edited August 5, 2006 by crimsone

[Gray-Wolf]

Sea Level Low? If a ULL did that, wouldn't that result in the formation of a hybrid?

It's just that all that northern strip of the Gulf had VERY warm waters at the mo' so if convection sets up then that would tend to 'lower' the pressure below and central to it...........maybe I've been watching too many eddy currents whilst cleaning the kiddies paddling pool recently but I did find that you can transfer that upper level motion through quite a depth to produce circulation at the base (even when eddy currents exist at the base!!) Due to constructive/destructive waves these 'eddies' can form a full whirlpool from top to bottom after the Upper Level circulation has 'captured' a lower level circulation.

[Gray-Wolf]

I'll just prattle on for a while while Chris decomposes then. The ULL off Florida has thrown up some very good looking convection to it's N.W. (just flowing of the Gulf coast) so I may well get an answer to my earlier question later today. I am very much a novice in this sat. weather watching but I'm sure the macro picture does relate to that that we replicate in micro in our baths/pools. Sadly fluid dynamics is too tough for my little mind to cognitively manipulate but I find it infinately easier to watch and amass experience in common patterns/events by watching it on the 'micro' scale. I'll be putting a map of the Caribbean/Gulf in the bottom of their pool next and adding ink to the warm water vortices..........

[kold weather]

Okay some intresting looking visables right now on the satelite, looks like convection is re-firing and there may well be the case for the LLC to be re-forming and...dare I say it, if this is the case then we may NOT have seen the last of chris, indeed while it is going to whack into Cuba shortly but convection is re-firing and shear has decreased quite a lot given the size of the new anvils that have gone up. Indeed I mentioned this last night was a possiblty once it got into more favorable condtions it could re-flare.

The key now is just what Cuba may do to the remians of Chris, it may well kill it off for good however given the land isn't that high in the region its covering and its going to cross into the Caribbean/gulf within 24hrs of landfall and since its not very organised to start with land won't hurt it that much which makes it a very intresting system. not saying it will be but it could well re-form into an intrestihng system if it does re-form and get into the gulf as I suggested this morning.

The main worry is that Chris kept at 40-30mph for about 36hrs in strong 30-40kts of shear and dry air...which must mean that heat content in the area is high, which means once it hits better condtions, it could go bang, even if it is just a wave/TD right now!

Good old Chris, keeping us guessing even as a tropical wave!

Just a shame I'll only be on here every now and then over the enxt week, so any updates from myslef will be infrequant annoyingly!

[crimsone]

That's a shame KW

If Chris is Carribean bound, looking at the last sattelites I saw, surely it would be a dramatic shift in direction from the last given forecast track once it gets there?

SAid that, the heat content out there for a tropical cyclone to hold its own in shear of 30-40 knots and dry air must be more than simply high. It must be almost unfathomable! (I just realised, that might be a quite interesting choice of words! lol)

[Paranoid]

Was Chris partially Annular? It seemed to survive much longer than other storms, and was sort of similar to Epsilon in 2005.

Edited August 5, 2006 by Paranoid

[crimsone]

It may not quite be a case of "was" yet Paranoid. The remnant low could yet re-organise - there's about a 50:50 chance, based on the previous unpredicatabilty it's shown. It's certainly trying hard to hold on and keep us all guessing given the recent convection around the remnant low!

As far as I am aware (though my definitions may well be off?), an annular TC is one that has reached it's MPI, usually has a symmetric Eye in the center of a dense CDO, and has been through one eyewall replacement cycle.

Obviously, Chris never obtained a complete eye, but niether did it ever reach it's MPI due to incredibly strong shear, by which it was very seriously affected (given that it broke up).

Chris certainly survived quite some time as a TC in the given climate compared to other storms of this season, but compared to other years it was really not that long at all - just a few days before shearing away.

Edited August 5, 2006 by crimsone

[summer blizzard]

http://www.nrlmry.navy.mil/tc_pages/tc06/A...ull/Latest.html

Could somebody tell me where the centre is located please?