Invest Thread

[Iceberg]

There is certainly rotation in the new precip blob so it looks like the circulation has shifted.

The precip is certainly very impressive and is very large for a non TS.

Should get some quicscat and Dvorak ratings in soon.

[Iceberg]

Minimum pressure was to 1009mb over Bridgetown which should have been somewhere near the centre, so probably a lowest pressure down to 1007-1008 seems realistic. Winds looked to have peaked at around 20-25Kt (in line with quikscat and Dorvrak estimates.)

http://www.srh.noaa.gov/sju/caribm.html

A good site for carib obs.

Final update while I am at lunch.

Recon is due to investigate this afternoon.

The first daylight image is available and things really look to be developing now.

Not much to go on, but purely looking at visuals rapid intensification seems to be underway, this should be heavily caveated but the precip that's there stands a good chance of going on to form a CDO now.

Matt

[SnowBear]

I think this one has quite a potential, just looked through on the loops (funktop, rainbow and water vapour) and for me it looks like this one could go hurricane strength quite quickly and be a threat to possibly Jamaica and later the across the Yucatan. Obviously a long way to go yet, and all depends if it can get organised enough. The last two frames in the loops look good for strengthening though.

[crimsone]

...and no, that little dot in the middle of the bottom half of the blob on the sat image above is not an eye. lol

Sorry... couldn't resist ...I must confess to being curious as to exactly what it is/what caused it though... cosmic dust on the lens of the satellite? :lol:

Edited August 2, 2007 by crimsone

[kold weather]

Certainly in terms of convection its exploding quite rapidly though in terms of organisation I'm still not so sure right now, there may be a weak circulation forming near the new blob but these things tend to take a long time to start from nothing, esp since the wave axis is still to the east of that convection. Given the depth of the convection in that blob a ciruclation will probably try and form there though as well. Its in a very fragile state right now depsite the way it looks because any convective blow off like recent nights will go a long way to killing this system given there is little on the wave itself. It's all dependant on that large convective mass and whether it can keep itself togther long enough for a stronger circulation. IF it can then the wave won't matter too much anymore. The next 6-12hrs wil lbe very interesting and I'll be surprised if recon finds a closed circulation but it may find some decent winds I'd guess. The next 24hrs look okay for this system providing it doesn't increase foward speed anymore, its at 20mph right now which is close to the upper limit for LLCC to develop in this part of the world.

Note by the way that this could go straight to tropical storm if it does develop a circulation so its worth watching.

Long term track just N of west, probably ending up heading across the caribbean and towards the gulf of Honduras, thats what I'd reckon right now. Does have the chance to develop, needs very close watching over the W.Caribbean as heat content is very impressive there, convection could get very deep there and in a decent atmopshere it could strength quite readily if it has a circulation present at the time.

Edited August 2, 2007 by kold weather

[Iceberg]

West to East winds have been recorded again in the south of the precip mass and Recordings of 25-28Kt have been taken in the NW.

It's speed is a prohibiting factor and could be the main reason why circulation close off hasn't been occuring.

The Tropical models have all been sure of one thing, when it does take off, it could only take 2 days or so to go upto huuricane strength.

I think it's a squashed fly :lol:

The dot is purely a very cold cloud top and isnt' shown up by SW IR or water vapour. Centre positioning of these very cold cloud tops is an important indicator though of a circulation forming.

[Somerset Squall]

SHOWERS AND THUNDERSTORMS HAVE INCREASED THIS MORNING IN ASSOCIATION

WITH A TROPICAL WAVE AND AN AREA OF LOW PRESSURE OVER THE EASTERN

CARIBBEAN SEA. ALTHOUGH CONDITIONS ARE BECOMING LESS FAVORABLE FOR

DEVELOPMENT...THIS SYSTEM CONTINUES TO HAVE SOME POTENTIAL TO

BECOME A TROPICAL CYCLONE DURING THE NEXT DAY OR SO AS IT MOVES

WESTWARD NEAR 25 MPH. AN AIR FORCE RESERVE HURRICANE HUNTER

AIRCRAFT IS CURRENTLY ENROUTE TO INVESTIGATE THE SYSTEM.

Although convection is impressive the system is now moving at near 25mph, so an upgrade is unlikely today, or until it slows down.

[Iceberg]

Recon is currently in the system some plus 30Kt winds recorded. A bouy in it's path also recorded +25Kt winds(not in the NW Quadrant)

AF303 02DDA INVEST HDOB 07 20070802

152000 1555N 06517W 4100 07422 0414 -154 -417 088025 027 999 999 03

152030 1555N 06519W 4096 07426 0410 -154 -348 088021 022 044 021 03

152100 1555N 06521W 4096 07420 0406 -155 -294 097025 030 040 026 00

152130 1556N 06524W 4095 07427 0411 -160 -385 090031 031 042 022 00

152200 1557N 06526W 4102 07415 0413 -159 -394 086031 031 026 020 03

152230 1558N 06528W 4097 07428 0417 -155 -376 090029 031 999 999 03

152300 1600N 06528W 4099 07426 0415 -150 -406 098026 027 999 999 03

152330 1601N 06526W 4098 07423 0411 -156 -430 093026 027 999 999 03

152400 1601N 06524W 4100 07420 0413 -160 -386 090028 028 999 999 03

152430 1600N 06522W 4100 07421 0414 -158 -375 090028 028 999 999 03

152500 1559N 06520W 4099 07423 0413 -155 -396 093027 027 999 999 03

152530 1559N 06518W 4100 07421 0411 -155 -401 093025 026 999 999 03

152600 1557N 06517W 4096 07421 0407 -155 -399 094024 024 999 999 03

152630 1555N 06518W 4098 07417 0405 -154 -413 091025 026 999 999 03

152700 1555N 06520W 4101 07506 0419 -157 -327 084021 025 045 018 03

152730 1555N 06523W 4098 07582 0065 -155 -257 068022 025 046 021 00

152800 1555N 06525W 4101 06941 5168 -156 -201 071027 030 048 026 03

152830 1555N 06527W 4098 07264 0241 -158 -230 088023 028 046 028 03

152900 1556N 06530W 4099 07381 0340 -157 -342 091024 026 042 026 00

152930 1557N 06532W 4098 07417 0406 -152 -321 088026 030 044 025 00

[mettalfabrik]

found an on line recon decoder check it out

http://www.tropicalatlantic.com/recon/

[summer blizzard]

35KT is needed to be declared a tropical storm once we have a low level circulation.

[kold weather]

Recon finding 30ts doesn't surprise me however in terms of a clsoed circulation infact this wsystem is much less organised compared to yesterday eveing when recon nearly found a closed low. This time all they've fiound is S/SE/ESE/E/ENE/NE/N winds, in other words no westerly winds have been found which sort of confirms what has been said earilier, that the system is probably moving too fast for a closed low to form and its going to have to slow down somehow before it has a better shot at developing that low level system.

I'm guessing once it does finally slow down probably in central/western Caribbean then we could well see it develop a closed low quite rapidly as it seems to stil lbe convectivly very active indeed with a broad coverage of convection. While its not deep anymore that is to be expected given the peak of daytime heating should be occuring now. Over the next 3-5hrs convection coverage may decrease a little till lapse rates start to increase again as the night kicks in.

Anyway what I said earlier may end up beign the case, a strong open wave with recon fidning high winds but no needed westerly winds and I don't see those developing for another 24hrs and with it moving west so quickly it'll probably be only 2-3 days away from landfall before it has a decent shot at developing a center and so even if it does develop unless it pulls a Wilma it shouldn't be able to get too strong in the end though in the likely landfall zone even an active wave I suppose could cause problems. Also still can't rule out this wave going poof mind you.

(Recon just found 177 degrees wind, so just west of south, better then before but still not close to a closed wave but we'll see what else recon throws up, anything major and I'll add a new post.)

Edited August 2, 2007 by kold weather

[Iceberg]

I was surprised they hadn't found any east to west winds.

The floater IR winds clearly show a circulation, not yet closed though but still very evident.

[kold weather]

There may appear to be a circulation on the IR howeve remember any low would be at the mid-level because IR is seeing the cloud tops rather then the stuff below and so any circulation would be in the upper reaches of the system. not only that but convective bursts can give the apperance of circulation. Best use high resolution Sat.loops to determine low level circulations and at present while there is some cyclonic turning visable its not that strong probably due to the foward speed.

By the way Iceberg I've just spotted an outflow boundary shoot out westward from the main convective mass on your image (see the narrow strip on the LEFT of the system with southerly winds) this is usually a very good (well bad for the system!) sign of a large convective collapse occuring, though the one upside this system has is that its sitting close to a weak upper high which can be seen by the good outflow on its northern, southern and eastern flanks and the system is still developing convection quite readily on the eastern side of the system closer to where any unclosed mid level circulation is present IMO. This is actually a good sign of the system health as it done this two nights ago and couldn't replace its lost convection, at least tonight the atmopshere is condusive for convection to re-develop as fast as it goes. Unlike then it shouldn't lead to a weakening trend for the system hopefully!

Edited August 2, 2007 by kold weather

[crimsone]

just to quote what everybody already knows anyway...

A RECONNAISSANCE PLANE INVESTIGATING THE VIGOROUS TROPICAL WAVE IN

THE EASTERN CARIBBEAN WAS NOT ABLE TO FIND A CLOSED CIRCULATION.

SATELLITE IMAGES INDICATE THAT THIS SYSTEM IS A LITTLE BETTER

ORGANIZED THAN YESTERDAY AND THAT THE AREA OF THUNDERSTORMS HAS

ALSO INCREASED. THE TROPICAL WAVE IS MOVING RAPIDLY WESTWARD AND

HAS THE POTENTIAL TO BECOME A TROPICAL DEPRESSION WHEN THE SYSTEM

REACHES THE WESTERN CARIBBEAN IN A DAY OT TWO. IF NECESSARY...

ANOTHER RECONNAISSANCE PLANE WILL CHECK THE SYSTEM ON FRIDAY. EVEN

IF DEVELOPMENT DOES NOT OCCUR...THIS WAVE WILL LIKELY BRING SQUALLY

WEATHER TO JAMAICA...THE CAYMAN ISLANDS...AND CENTRAL AMERICA IN

THE NEXT COUPLE OF DAYS.

[crimsone]

SATELLITE IMAGES INDICATE THAT THE SHOWER ACTIVITY ASSOCIATED WITH

THE TROPICAL WAVE HAS DECREASED DURING THE PAST FEW HOURS. THIS

SUGGESTS THAT THE SYSTEM IS NOT DEVELOPING AT THIS TIME AND THE

POTENTIAL FOR TROPICAL DEPRESSION FORMATION HAS DIMINISHED. THE

TROPICAL WAVE IS EXPECTED TO MOVE RAPIDLY WESTWARD BRINGING

CLOUDINESS AND SHOWERS TO JAMAICA...THE CAYMAN ISLANDS AND CENTRAL

AMERICA DURING THE NEXT COUPLE OF DAYS.

[Iceberg]

Now that the precip has all virtually gone, the underlying structure looks OK IMO a centre is now visable(if not quite closed still !).

Agree KW those winds where LP related rather than LLCC related.

The speed is still a problem, although TS's have formed at this speed.

The biggest factor coming up is it's very westerly direction, it won't last long enough to do anything unless it can move on a more northward path and I can't see that happening. The Tropical models all forecasted 99l us crash and burn in central america without really making anything and they could well have been right.

[Somerset Squall]

The Tropical models all forecasted 99l us crash and burn in central america without really making anything and they could well have been right.

Indeed, the NHC now think that there will be no development from this system now.

[kold weather]

Latest loops show what seems to be wrong with 99L right now. Indeed as Iceberg noted its circulation doesn't actually look too bad right now though its still not closed. Once again as per previous mornings convection is starting to flare-up again however I'm not so sure that its from the wave and instead I think there is a good case of shear helping to fire up convection and the loops do sort of show the shear quite nicely:

http://www.ssd.noaa.gov/goes/east/carb/loop-wv.html

Note the strip of cloud feeding eastwards to the WSW of system and note the convective burst over the last few frames. Invest 99L is about to get a taster of the shear over the enxt few hours and then it'll be make or break for the system because right now its actually somewhat benefiting from the shear which helping to strengthen it. The key will be for the wave to keep up firing new convection esp if the older stuff is blown somewhat eastwards.

The foward speed is still somewhat of an issue as well though it does appear to have slowed a touch which might help though right now slowing down may not be good with some moderate shear spreading in.

Long term future is more uncertain then its ever been. Firstly its going to have to survive the higher shear and slow down its foward speed. Ahead of it to the WNW there is a more favorable set-up present away from the WSW shear where some new convection from a previous wave started firing up again so looking at the set-up out there it may have shot in about 24hrs for real development but thats only IF itll survive. Of course even if it does start to do something land would be coming up so the system probably wouldn't have even time to become a strong system though heat content is pretty large in the west Caribbean which may help give the system that final push it needs. Track still lookslike taking it close to the Gulf of Honduras and eventually towards Belize, thats my call and i'll stick with it!

[kold weather]

Pretty much what I said yesterday is playing out with 99L. Large convective burst has emerged with this system in response to reduction of shear now that its to the north of the shear. Strong convective burst with some very cold cloud tops due to the very high heat content in the region (slightly higher then 05!) which has allowed some impressivly deep convection to fire. A strong mid level circulation appears to be present near the core of the huge convective burst located further north, visibles will show more later. It does look like given another 12hrs it could develop further given the huge heat content but the system has actually sped up with the model data suggesting its moving at 27kts...a really shocking speed for the deep tropics and means its going to have a might hard time getting a LLCC even if it carries on with this strong convection it has currently unless it slows down a little any development is unlikely.

The main issue now is exactly where that MLC is present and the reason why this is so very important is because land is fast approaching the southern side of the system in the form of Honduras and northern Nicaragua. If any dominant circulation forms over the southern side its about to hit land in the enxt 6hrs and thus end any tropical development when its looking most likely and it has its best shot. IF it forms over the northern side of the convectin then it gets very tough to forecast because it'll skim into the gulf of Honduras and with its current state of development I think you really couldn't rule out development from 99L if thats the case as it'd probably have 18hrs left over the sea and some systems have developed into tropical storms in that time under high heat content like this one and it would landfall in Belize or maybe S.Yucatan but it really does just depend on where the center tries to form.

Still at the very least its going to give quite a lot of rainfall to wherever it ends up given the current strength of the convection and at the very least we've had a good warm-up for the real tropical cyclones.

[kold weather]

System looked close to developing today but alas the systems lower level energy has ended up today over land and while there is some energy associated with the MLC just over the GOH but too close to land for it to really devlop, a shame because it looks very good and probasbly was only 12hrs away from tropical depression however it has been good practice for storms later in the season and to remove the rust left from past seasons.

Worth noting that the energy from this system may well end up in the eastern Pacific where it may have another shot at developing.

Edited August 4, 2007 by kold weather

[Somerset Squall]

System looked close to developing today but alas the systems lower level energy has ended up today over land and while there is some energy associated with the MLC just over the GOH but too close to land for it to really devlop, a shame because it looks very good and probasbly was only 12hrs away from tropical depression however it has been good practice for storms later in the season and to remove the rust left from past seasons.

Worth noting that the energy from this system may well end up in the eastern Pacific where it may have another shot at developing.

Unless I'm mistaken I think 99l has now moved into the east pacific and indeed it looks very impressive on the latest satellite imagery, could well develop there me thinks.

[kold weather]

We have Invest 90L up right now from the African wave. Not that surprising really as we have some still pretty strong convection present with the wave with a nice ball like structure to the convection maybe indicating a circulation is present. Convection is strong tohugh there is some shear present looking at the way the clouds are slightly skewed to the west (If you look at the image at the bottom note the little thinner line extending east from the main blob, thats where the storms are being sparked from it appears)

Also it should be noted there is some dry air coming off from Africa in the wake of the wave probably helped along by the weak low already present near the convection and I dare say ther eis some SAL present hence the slightly shunted look the wave xhas on its eastern side and why the convection is lumped mainly on the western side.

Water Vapor shows both the possible shear and drier air...note the dry air is no where near as intense as recent weeks and it won't stop development, just slow it down a touch:

This is the reason IMO why the ships only go for steady development, indeed the SHIPS forecast just 55kts by 120hrs despite the increasing heat content and I suspect its keying into the shear and weak SAL present.

I'd watch this system very closely though because the system has a very interesting future ahea dof it. Generally track is pretty easy to forecast right now at least for the next few days, straight westerly underneath a strong high pressure belt to the north. What happens around day 7 is a very hard call. The models are currently forecasting a trough to dive down and cause some northerly movement on the wave but depending on how much lattiude it already has gained any northerly movement may be limited, also strength will come into play. Its a very hard thing to cal lright now. Indeed if it stays due weast right now then it may well be a big risk for the Islands tohugh that may be a help to the USA as it would weaken the system. Right now though ther eis to omany variables involved, needless to say it could be a gulf risk way down the road, right now al lof the Caribbean and Florida/Carolinas should be high alert for tropical cyclone in about 7-10 days. The GFS plows the system thorugh several of the Major islands of the caribbean before heading north towards a weakness and then shunted westwards through the keys into the gulf, probably as a weak hurricane with a messy core though it would re-strengthen in the gulf after 12-24hrs. The ECM is far more dangerous with a major hurricane hitting PR before heading northwards into the seas just t othe south of the Bahamaa and through the Cuban straights as a major hurricane with plenty of heat content present and a massive threat.

As for strength, nearly all the global models I've seen take it upto hurricane strength however SHIPS aren't nearly as keen. I suspect some sort of compramise is likely. Given the factors I've previously mentioned I think early development will be slow, maybe a TD late tomorrow as its already wel lon the way then slow development towards a tropical storm. Once it reaches 40-50W I suspect SAL will reduce and SST's rise quite neatly and when that happens the system may well step up its rate of development and become a hurricane pretty quickly. Heat content isn't amazing till about 60W but under condusive set-up no reason why this system can't become a major hurricane given the waters will hardly be mixed at all.

so all in all, we more then likely yhave a a large one to track here and for a long time as well, given the strong high pressure complex to the north its very likely going to hit land somewhere, probably bot hthe Caribbean and the USA at some point and I think its a very good bet for hurricane status as well.

Edited August 11, 2007 by kold weather

[Iceberg]

Morning all,

As you say KW ECM is a very scary model and can't at this time be discounted, leading to a landfall in 10 day time in Southern Florida as a major Hurricane, then re-entering the GOM, possibly in a repeat of a well known hurricane.

The Other GM's are all keen to develop still.

The tropical models GFDL and HWRF both bring it up CAT 2 or CAT 3 now. Ships takes it to a borerline CAT 1 in 5 days.

The path is most certainly westwards and a fish would be very unlikely.(even though it's developed so far east).

A general forecast would be a TD probably tomorrow, A TS Tuesday night or Wednesday and then general, slow strengthening after that.

Moisture doesn't look like a problem.

Edited August 12, 2007 by Iceberg

[tinybill]

Morning all,

As you say KW ECM is a very scary model and can't at this time be discounted, leading to a landfall in 10 day time in Southern Florida as a major Hurricane, then re-entering the GOM, possibly in a repeat of a well known hurricane.

The Other GM's are all keen to develop still.

The tropical models GFDL and HWRF both bring it up CAT 2 or CAT 3 now. Ships takes it to a borer line CAT 1 in 5 days.

The path is most certainly west wards and a fish would be very unlikely.(even though it's developed so far east).

A general forecast would be a TD probably tomorrow, A TS Tuesday night or Wednesday and then general, slow strengthening after that.

Moisture doesn't look like a problem.

thanks for that if it do get in to the gom lets hope it don't go to new Orleans think that the last thing they want there!!

[kold weather]

I haven't the time right now for a deep post about the system so I'll try and keep it fairly short and simple. Still reasonably decent looking with still a nice ball of fairly deep convection and I do believe thereis at least a midlevel circulation present. There still may be some shear on it but this time tomorrow it should be entering a region that is much more condusive for development, good chance of becoming a TD then, if not a low end tropical storm and its close to a TD now.

Models starting to show a little uncertainty. The GFS based models take it into the Caribbean region. Other models such as the UKMO and the ECM taske it further north and to the north of the Caribbean Islands, a track very bad for Florida. SHIP models still only take it upto 54kts by 120hrs but the higher resolution models both take this upto cat-2/3 as Iceberg sats, the HWRF indeed shows a rapidly developing system. ECM also still develops an intense hurricane though a little further north and smaller then before.