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Early August hurricane outlook

By: Dr. Jeff Masters, 2:12 PM GMT on July 29, 2007

A tropical disturbance (98L) a few hundred miles north of the central Bahamas has become only a little better organized since yesterday. Heavy thunderstorm activity has increased, and the beginnings of some upper-level outflow to the northeast is apparent on visible satellite loops. A QuikSCAT satellite pass from 6:38am this morning revealed that 98L is attempting to form a closed circulation at the surface, and had top winds of at least 25 mph.

Water vapor satellite loops show an upper-level low pressure system to 98L's northeast, and this upper low is bringing about 15 knots of wind shear over the disturbance. The GFS and GFDL models predict that the upper low will move north-northeast in tandem with the disturbance, keeping low enough shear over it that a tropical depression could form. The other reliable models do not develop 98L. At present, it appears that Bermuda is the only place that needs to concern itself with 98L. SSTs are warm enough to support tropical storm formation until 98L reaches a point 500 miles or so north of Bermuda. The Air Force Hurricane Hunter aircraft scheduled to investigate 98L this afternoon was canceled, and no new flights are planned.


Figure 1. Preliminary model tracks for 98L.

Early August hurricane outlook
In the first half of August, Atlantic tropical cyclone activity starts to pick up. Since the current active hurricane period began in 1995, eight of 12 years have had one or more named storms form during the first half of August, including the last seven years in row. The fact that we've had a quiet July does not mean we can expect a slower than average hurricane season. To illustrate, consider 2004--the first storm, Alex, did not get named until August 1, yet that season had 15 named storms, 9 hurricanes, and 6 intense hurricanes. Five named storms formed in first half of August of 2004. One item of comfort, though, is the fact that 2007 is definitely not a repeat of 2005--we were already up to "G" in the alphabet at this point in 2005.


Figure 2. Historical Atlantic hurricane and tropical storm activity, 1851-present. Figure modified from NOAA's original.

As seen in Figure 2, hurricane activity does take a bit of an upward jump around August 1, but the real action doesn't start until August 18. It should not surprise us, then if we go a few more weeks without a named storm. I am still expecting an above-average hurricane season with 12-14 named storms (10-12 more, since we've already had two), with at least one major hurricane hitting the U.S. However, the decline in SSTs relative to normal over the past two months means we should have a less active season than originally thought. I'm guessing that the Dr. Bill Gray/Phil Klotzbach August forecast, due to be released Friday August 3, will have two fewer named storms compared to their May 31 forecast.


Figure 3. Tracks of all tropical storms and hurricanes since 1851 that formed August 1-15.

Sea Surface Temperatures
Early August storms can occur anywhere, and strike anywhere (Figure 3), since the oceans have finally heated up to the point where the entire tropical Atlantic can support hurricane formation. Sea Surface Temperature (SSTs) remained near average over the tropical Atlantic between Africa and the Lesser Antilles in July (Figure 4), thanks to plenty of African dust keeping sunlight from heating up the ocean. A stronger than average Bermuda High has also helped cool the ocean more than normal, thanks to the faster trade winds it brought over the ocean in June and July. However, SSTs are 0.5-1.0 C above average over much of the Caribbean and Gulf of Mexico, so there is still good reason to expect an above-average number of tropical storms and intense hurricanes this hurricane season. The total amount of heat energy in the upper layer of the ocean (the Tropical Cyclone Heat Potential, TCHP) remains high in the Western Caribbean--near the record levels observed in 2005. However, TCHP is much lower over the rest of the tropical Atlantic, including the Gulf of Mexico.


Figure 4. Sea Surface Temperature (SST) departure from average for July 26, 2007. Image credit: NOAA.

Wind shear
Wind shear has been near normal, averaged over the tropical Atlantic during July. Wind shear is predicted to be near or below normal for the first half of August.

Dry air and African dust
June and July are the peak months for dust coming off the coast of Africa. By early August, dust activity typically diminishes, but it is not well-understood how to forecast these dust outbreaks. We have seen a decline in the amount of dust over the past week, as one might expect from climatology. Since the long-range GFS forecast does not show any major changes to the weather pattern over Africa the next two weeks, I am expecting African dust activity to remain near normal through mid-August.

Steering currents
The hurricane steering pattern for the next two weeks should be near normal, with no areas at above-average risk for a hurricane strike. I discussed this in detail in Friday's blog. Steering current patterns are not predictable more than about two weeks in advance, and there is no way to tell if this steering current pattern will remain in place past mid-August.

Summary
Recent history suggests a 75% chance of at least one named storm occurring in the first half of August. I'll go with climatology and forecast a 75% chance this year, as well, since SSTs, wind shear, and African dust/dry air should all be near normal. With the steering current patterns expected to be near normal, no areas can be singled out as being at higher risk than average. We'll have to keep a careful eye out late this week, when a cold front is expected to sweep off the East Coast of the U.S. Several of the models are indicating the possibility that a tropical depression could form at the tail end of the cold front by Thursday or Friday. This would most likely happen off the Carolina coast, but could also occur in the Northeastern Gulf of Mexico, near the Florida Panhandle. I think it is still too early to get a tropical storm forming between Africa and the Lesser Antilles Islands this week, but next week we could see something.

Last blog for a week
This will be my final blog until Monday, August 5, as I am taking a week's vacation to do some camping and paddling along Lake Huron's gorgeous Georgian Bay. I've arranged for an able substitute blogger to make daily posts here this week, but I will be able to do some blogging beginning Friday if something nasty pops up.

Jeff Masters

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

What makes you say that, TM07??

There are no systems with immediate potential to develop...

You're probably, though, talking about the CATL wave, and that still has A LOT of things to do before an invest is possible.

Example; it would need a low at the surface, consistent convection and a more favorable environment. Not to mention, it could easily go poof or run into South America.
http://manati.orbit.nesdis.noaa.gov/dataimages21/cur/zooms/WMBds26.png

...sorry, this is the descending pass.
Just back from dinner, how's the blob watching ?
I created a new site that has the current GFS model output and several variables over both hemispheres. In addition to the regular grids, I provide a Sigma analysis, which is roughly how anomalous that given field is away from climatology (using the JRA25 Reanalysis). For example, 98L, which is forecast to be a "bomb" warm seclusion west of Iceland, is the dominant 500 mb Geopotential Height anomaly over Atlantic when expressed in Normalized Anomalies or sigmas. Tropical waves show up very well as well as a host of other features including heat ridges, moisture plumes, and cut-off lows...The method is described at the bottom of the page. Normalized Anomalies. The page will update 4 times daily as soon as NOMADS posts the data.
Not much different. 98L is still forecast to become a cyclone by some models, and the NHC even says it could. I am not a believer though. There is a CATL wave we are watching, but we will see what happens with that.

Afterall, SK, says cane by the third, right?

I honestly don't believe that, mlc. I'm sure you don't either, but if we were to have a hurricane by August 3, something would have to develop either very rapidly, which is not possible in the far eastern or central Atlantic, given the low TCHP there right now (something COULD DEVELOP there, but not rapidly intensify). That, or something would have to have ALREADY developed into an invest or a depression. I think SK is wrong on this one.

I am beginning to think that these things that are classified as invests half the time shouldn't even be classified. 97L was a disorganized area that looked like a cold front, I have no idea why it was classified. 94L sucked too, and wasn't really doing anything. 91L was extratropical, so why was it classified? Showed no signs of becoming warm-core. 95L was overland with its surface low, thus it shouldn't have been classified as an invest until its low got over water.

They get our hopes up for development (I like to track storms, but I wish for recurvature, even though not every storm is going to do that) with invests, but then nothing happens.
A lot of dry African air between it and the islands, so other than providing night time blob watching interest, I doubt it will develop much.
Since we are in a downard motion pulse of MJO, I wouldn't expect development until at least August 15. That may be pushing it a little, but by then the bad part of MJO should lose its grip (bad for cyclones, but good for cyclone supression), and activity should pick up with an upward motion pulse of MJO.
What do you mean by this:

A lot of dry African air between it and the islands, so other than providing night time blob watching interest, I doubt it will develop much.

There is very weak, scattered, and unconcentrated SAL west of the main area of red SAL about 150 miles west of the African coast. I don't see what you're getting at... Yellow SAL is very weak, and that's all I see in that area.
Bad timing I'll be looking to book a flight back from the tropics about then.
that wave has a vary nic spin not sure if its to the sfc yet and it is moveing more N and not runing in to SOUTH AMERICA and it will keep going W in too the CARIBBEAN


wind shear where it is going

un oh

lol

has you can tell from this loop it looks like its trying to get more ORGANIZATION to it has well

Link
Posted By: KoritheMan at 4:17 AM GMT on July 30, 2007.
Not much different. 98L is still forecast to become a cyclone by some models, and the NHC even says it could. I am not a believer though. There is a CATL wave we are watching, but we will see what happens
with that.

Afterall, SK, says cane by the third, right?

I honestly don't believe that, mlc. I'm sure you don't either


...lol, kori....uuuuummm, that'd be correct!
...interesting site, RyanFSU.
any commets from my post?
I was just looking at the band of air that stretches back to the N African desert area, not looking at the color enhanced stuff and mainly just doing it from memory having watched the area from earlier this afternoon and evening. I think the ITCZ will remain low and cross onto SA. Whatever is there at 45 has to climb to reach the islands. It looks like its started doing that, but because of the forward air, I have doubts.
...TAZ, interesting take. I think we're gonna have to wait and see again. Too many times this season already, we've seen these blobs go up and down and around the itcz..then, go pooooof!

...got a chance, but the jury is still out I think. You know the drill. It's gotta get latitude, an llc, convection, low shear and that bit.

...it's definitely still something to watch! Who knows? It might just be our next storm.
ditto
Taz, in my opinion, that area looks connected to the ITCZ. It has a squall line appearance, as opposed to a circular shape. 98L, on the other hand, is beginning to organize again, and get more circular. Not dead yet!

And the ITCZ has been unusually far south this year -- anyone have any idea when it will move to its NORMAL position for August?
The bigger blob from this evening has fizzled and it's pretty much just little bubbly convection all along the ITCZ now. We'll just have to watch the visible loop in the morning to see what we have, if anything.
And the ITCZ has been unusually far south this year -- anyone have any idea when it will move to its NORMAL position for August?


That is true only for the last 10 days, likely because the Bermuda High has been stronger than usual recently, as Dr. Masters mentioned (it forces the ITCZ south):



30 day pressure anomalies:



On the other hand, notice that pressures in the tropical Atlantic, Gulf and Caribbean have been lower than average.
Mean ITCZ

During the period from July 11 - 20, 2007, the African portion of the ITCZ was located near 16.7 degrees north latitude when averaged over the ten day period and from 15W-35E. This compares with a normal position of 17.6N and a position last year of 18.2N. In the west, from 10W-10E, the ITCZ was located near 16.7 degrees north, compared to the long term mean of around 18.7 degrees north, and a position last year of 19.4N. In the east, from 20E-35E, the ITCZ was located near 17.1N, compared with 16.1N for the mean, and 17.2N for last year. The ITCZ continues to move erratically in the west, while in the east it remains above normal.

full ITCZ pdf file
well I'm getting tired, long drive in the morning, time to call it a night.
A late thank you to bappit and the others for trying to answer my question. Looks like that pattern is not that usual... I definitely understand the laminar flow because of my background (aerospace engineering), although I have a hard time imagining the outflow of a storm being laminar... What kind of velocity are we talking about here?
In any case, the symmetry of it makes me think it is a sign of a stable environment. Since these striations are along the spiral and not a disk above the center, I guess it shows the outflow is somewhat uniform no? Also the cirrus clouds being made of ice, I guess it shows the could top is pretty cold no? On the IR viz, you can see the striations in green/blue (-50 degrees C).

So more newbie questions as you can see, I will take my first weather class this fall, in the meantime, I'll watch and learn :)
TROPICAL LOW
11.3S 91.6E -- 30 knots 998 hPa

Gale/Storm/Hurricane Warning
=============================
At 0400am UTC, Tropical Low [998 hPa] was located about 580 km west of Cocos Islands moving southeast at 8 knots.

Outlook Forecast
=================================
12 HRS = 40 knots 994 hPa [CAT 1]
24 HRS = 35 knots 996 hPa [CAT 1]

Gale/Storm/Hurricane Warning for Tropical Cyclone

-----------------------------
Might still get Tropical Cyclone Lee afterall from 01S.
99L tomorrow with disturbance @ 9N, 44W
Have a good night all. Thanks Dr Masters and thanks to all for sharing!

May peace and love and happiness and sustainability grow
ropical weather discussion
NWS TPC/National Hurricane Center Miami FL
205 am EDT Mon Jul 30 2007

...Special feature...
surface trough is along 34n72w 27n73w. System remains poorly
organized but still has some potential for tropical or
subtropical development over the couple of days as it moves
north-northeastward at 10-15 kt. Clusters of scattered moderate
convection are well E of the trough axis within 90-120 nm of
line 32n67w to 28n68w.

...Tropical waves...
tropical wave over the E Atlc along 27w extends from 4n to 19n
and is moving W near 10 kt. Earlier Quikscat pass indicated a
surface low along the wave axis and this will be included on the
0600 UTC analysis.
Scattered moderate isolated strong convection
is confined to the intersection of the wave axis and the ITCZ
between 25w and 35w.


Tropical wave is over the central Atlc along 50w S of 17n moving
W near 12 kt. Wave is of fairly low amplitude covering a narrow
area between 45w-52w.
Scattered moderate isolated strong
convection is confined to the intersection of the wave axis and
the ITCZ between 45w and 53w.
The Normalized anomaly page I plugged a couple hours ago just updated for 00Z. If one is to believe the GFS at 5-7 days, 120 hour GFS 500 mb Anomaly and 144 hours, a monstrous ridge is going to plop itself over the Gulf of Mexico.
Wouldn't that mean no storms for the Gulf of Mexico? 144 hours is quite a long time out though, so I don't trust that outlook.
STL, MLC, thank you both for answering my ITCZ question. :)
Interesting, mlc. That surface low wave, I mean. But can we really expect 99L from this? I'm beginning to doubt when things are classified as invests. Lately the NHC have classified things even though they haven't shown signs of organization.
Good morn to all !!
good morning

very interesting erea of disturbed weather at11N 46W. wind shear is 5 knots and there is no SAL to impede development. this is the same erea that Ivan formed in 2004. this system bears watching as it is in a favourable environment
this is the area 11N 46W

Link
I agree that this is an area that should be watched .More so then the 98L simply cause of it's heading at the momment.
539. IKE
Last blog for a week
This will be my final blog until Monday, August 5, as I am taking a week's vacation to do some camping and paddling along Lake Huron's gorgeous Georgian Bay. I've arranged for an able substitute blogger to make daily posts here this week, but I will be able to do some blogging beginning Friday if something nasty pops up.


Actually, Monday is the 6th of August.LOL
540. IKE
From the San Juan,PR morning discussion...

" We will be watching expanding
area of showers and thunderstorms with next tropical wave
closely...with latest Quikscat pass also showing an apparent weak
low near 9n44.5 west."
541. IKE
Atlantic system appears to be near 9N,46W now.
Morning Ike, How many days to San Juan would you estimate ?
Granted it would have to do a lot of Latitude climbing along the way.
That system near 9N 45W has upper level divergence and lower level convergence, shows up on the 850MB Chart coming out of 20Kt shear into lower shear no real dry air in front of it, steering pattern would take it into the Caribbean, seems like a Charley path looking at the steering maps, hope not.

Also convection off FL keep an eye on that because of proxmity to CONUS.

Ok I pass off the early morning baton off to JP, StormW, Hurricane 23 and the rest of the bloggers! Morning Ike and Taz, ms
Good Morning all...

IKE at 7:08
Last blog for a week
This will be my final blog until Monday, August 5,


yikes, where are the conspiracy theorists.... this MUST have some secret meaning.... LOL

CRS
good morning everyone

The low in the Atl has become better organised overnight and convection has increased. Sat loops show good rotation and quikscat confirms a low near 9.5N 43/44W.
This system is a slow mover as the low was also in this same general position early last night and needs to be watched very carefully.

Here is the morning QS pass

Ike, look for Dr. Masters by Friday "...if something nasty pops up."

It's looking healthy this morning...but there isn't there a lot of SAL to the north?
Straight line to San Juan would be about 22 degrees, estimating 10 kts, means about 5.5 days. I don't expect it to climb that quickly however. Perhaps the southern end of the island chain will see this one. If it goes that far. Pottery's cachement may be the beneficiary.
Interesting tidbit from NWS Melbourne FL early morning forecast discussion:

"EXTENDED...
TOWARD WEEKS END ATLC HIGH PRESSURE RIDGE WL BECOME RE-ESTABLISHED OVER CENTRAL FL FRI/SUN. AIRMASS DRYING TO MORE SEASONAL LEVELS
[..]EASTERLY FLOW OPENING UP UNDER RIDGE DURING THE WEEKEND WITH AXIS OF LARGE T-WAVE APPROACHING THE STATE AROUND MON."
CRS you've got your eye on that stuff poping at the top end of the wave near 63W 21N right ?
Link
Next Invest?
Morning all. I was just looking at that wave at the same time u posted Kman. Agree that we need to keep a close watch on that one throughout the day to see if it maintains or intensifies.
In their update The Weather Channel did not say one word about the Atlantic. All she said was that for those in the islands there is nothing out there to worry about.

Idiots...
Hi Caymanite

I think there are 3 important things to note with this wave
Convection has increased and held together overnight.
The low has pulled to the N by about half a degree since 8 last night ( the descending pass from last night shows the low further S ) so it is gaining latitude and will likely clear the SA coast.
It is a slow mover.

Could be an invest by this afternoon IMO
Most of the convection is well northwest of where Quikscat shows the low center. Later this morning we'll have some nice visible loops to help us out.
From latest JTWC statement on Typhoon (TY) 05w (Usagi)
[...]
"TY 05w will intensify at a climatological rate
through the period due to good radial outflow."
[...]

At least it is not forecast for rapid intensification.
This is from the 8 AM Discussion...
TROPICAL WAVE IS OVER THE CENTRAL ATLC EARLIER ALONG 50W WAS RELOCATED TO THE EAST ALONG 48W/49W BASED ON FORWARD EXTRAPOLATION OF SATELLITE HOVMOELLER ANALYSES. AN EXPANDING AREA OF SCATTERED MODERATE TO STRONG CONVECTION WAS OCCURRING AT THE BASE OF THE WAVE FROM 8N TO 11N BETWEEN 44W AND 50W. RATHER WELL DEFINED LOW TO MID LEVEL TURNING WAS NOTED NEAR 9N45W AROUND WHAT MAY BE A POSSIBLE AREA OF LOW PRESSURE.

Hi Chicklit

The discussion confirms what we have been saying from early last night
Morning all. I'm posting a new blog soon about the CATL low. In my opinion, I need the convection to persist if if wants to become 99L. Also, it needs to stay away from South America.
Kman, it has fared very well over the night. What about the SAL to its north?
From the discussion:

RATHER WELL DEFINED LOW TO MID LEVEL TURNING WAS NOTED NEAR 9N45W AROUND WHAT MAY BE A POSSIBLE AREA OF LOW PRESSURE.

Chicklit
IMO SAL is not a problem as there is hardly any near the system

coffee time for me
Will BB later
Ready to start your engines. The real hurricane season is about to begin. Off to the grind.
570. IKE
Posted By: msphar at 6:29 AM CDT on July 30, 2007.
Morning Ike, How many days to San Juan would you estimate ?


Toward the end of the work week.
Morning Everyone - off to a new job today - out of the kitchen for a change and into their admin dept. Yah!!

Question - if anyone could email me and let me know - I am due to go to Key West next weekend (3 - 5)...anything out there that could screw up my mini-vacation?

Thank you!
Link
The Big Picture
573. IKE
Posted By: clwstmchasr at 6:55 AM CDT on July 30, 2007.
In their update The Weather Channel did not say one word about the Atlantic. All she said was that for those in the islands there is nothing out there to worry about.

Idiots...


Their awful.
The Weather Channel pays no attention to the tropics unless there's a depression. Then they talk about that 24/7. At least spend 5 minutes or so talking about an invest.
Off to work now but will be checking regularly today on cAtl wave. It will probably develop just because I am due to leave on vacation on Thurs. if for no other reason.{ murphys law} LOL.
the weather channel may say that because there is nothing to worry about before the next tropical update
good morning everyone our antilies wave is giving us a show today its also moving further north .if it could make it to 60 west as it looks now it may be the one we are waiting for . stay tuned .


I see kman beat me to it, but it appears we have some rotation here...... not sure if it is at the surface, but something to watch.....
580. IKE
Their(TWC) not the "hurricane authority"...there are too many other sources, including WU, for a lot more information..a lot sooner.

Shear is not bad in the CATL low.
It absolutely IS at the surface Thel and has been since last evening. Nice to see that you still have your diagrams going. Always look forward to them.
Good Morning.
Well, that looks to be holding up nicely !
Makes me wonder whether I could be in for some excitement.
Persistence through the day today is key. Separation from the ITCZ has to continue and it appears to be happening so far in the over night hours. Also it seems to be moving forward quite rapidly today. May be into the islands sooner than expected.
good morning everyone....so if the catl systems develops any idea where it is heading
Morning All!

Looks like the NHC is moving the Satellite over to check out the C-ATL, may have an official invest soon.
will be interesting to watch today, but the rotation appears pretty vigorous......

could this be the "C" we have been waiting for? :)
Based on steering into the Carribean very eerie to Charlie perhaps.
589. IKE
Posted By: emagirl at 7:36 AM CDT on July 30, 2007.
good morning everyone....so if the catl systems develops any idea where it is heading


Right now...appears headed for the islands...then...looks like it continues on W or WNW...high pressure is going to build in over the SE USA...should keep it headed W to WNW.

YES! The NHC finally has a floater on it! Now we can watch it fight the dry air and try to break free from the ITCZ close-up.
ema, may be too early, but in the Carribean, there are some pretty high potential.... were it to head into the gulf via the Carribean, could be "significant" strengthening..... but it is pretty far south......
Ok, darn it, lol. The invest is back up on the C-ATL. Need more coffee.
Models aren't showing anything with this area.
we might know in 12 hours if our possiblie new invest 99l will be a fighter or maybe sooner it is looking strong ! coffee time for me too hehe
does appear to be separating from the ITCZ......
looks like dr m took off for vacation a little too soon her
598. IKE
And it does appear better on each updated visible shot.
so is this system a real possibility?? just wondering...how much of a chance
Figures, Doctor goes on vacation, tropical blob shows up.
601. IKE
99L on the Navy site!!!!!

Link
emagirl, we just have to wait and watch. It is still not very organized. The next 24 hours will be important... does it maintain convection all day, does it fire more organized convection tonight, does it develop a better defined surface circulation, etc.
that seems to always happen this time of year.... Dr. M goes on Vacation, with nothing anticipated, then it happens! LOL
Leading edge is at 50W. Three days to Trinidad at 10Kt. Pottery2 that would be Thursday morning for you but I think it would climb higher Lats by then as well.
Ike that's really great!
The tropics are heating up now!

99LINVEST.20kts-NAmb-98N-457W


99L on the Navy site!!!!!


wow that was fast thanks ike !
what will be next for 99l ?possible td 3? stay tuned
Gooooood Mooooorrrrning guys and gals! Back from vacation and I see we have a few little blobs to watch. The wave near 10N 45W is looking more organized this morning and I see we have a floater over it, good. . . good.

98L still has chance to form and should be a fish storm if it does, nice.

Stuff to watch :)

I'll be lurking, let's have fun today.
good call IKE



Guess we could see 99l coming! LOL
doesnt look like ANY of the models are picking up on this? can an expert please confirm
612. IKE
Posted By: drusierDMD at 7:57 AM CDT on July 30, 2007.
doesnt look like ANY of the models are picking up on this? can an expert please confirm


The GFS does on it's latest run...seems to almost always undershoot the strength of systems...appears headed for the western Caribbean to south Florida area.
99L already? Has the NHC been mentioning this feature? I imagine so, but i've been on vacation. Interesting they wouldn't wait for the convection to persist through the afternoon before posting the invest.

Will be interested to see the Doc's update this morning.
At least the tropics waited for me to come back from vacation......
The GFS does on it's latest run...seems to almost always undershoot the strength of systems...appears headed for the western Caribbean to south Florida area.

Link Please??


very interesting indeed! :)
time to change the charts when will the speghtti models come out for 99l it be interesting to see the new track
anyone want to guess the track before they come out ?
At 20 Kt it would be into the islands at just over 48 hours. Pottery2 maybe Wednesday.
drusier, the models are rarely going to pick up on a weak ITCZ spin like this. Only if this disturbance acquires a well defined and vigorous circulation and breaks away from the ITCZ will the models grab onto it. Sometimes models don't even have a good grasp on well defined tropical storms.
Doc is on Vacation......
Dr. Masters is on Vacay until monday but he did say he has another blogger to fill in for him if something was to develop
models here :

http://www.stormjunkie.com/pages/trophome/trophome.html

then you can click on models and you can find the long range GFS, then you can click on the text to the left and find most other models with more options
Like i mentioned this weekend.....after 98L moves northeast the tropical season will most likely begin. Damn if I didnt happen to call that one....lol 99L looks very impressive. Last night before I went to bed I noticed it on my mobile phone accuweather service satelite imagery. When i woke up this morning i turned on the weather channel and watched the tropical update, but they didnt even make any mention of it, but it was beyond obvious from looking at the satelite that it was something that seemed suspectable to development. This should be interesting to watch folks.
i see we have 99L good morning everyone!
TWC sucks at forecasting the tropics, Dr. Masters and all the people who comment on his blog know so much more.
this could be Deva Ju for St lucians. wednesday will be 27 years that hurricane Allen hit the island. the way things look at the moment it is quite possible that we mightget another visitation.
the area of disturbed weather is getting better organised with every frame and we could have a depression on our hands sooner than we think
629. IKE
Posted By: stormybil at 8:02 AM CDT on July 30, 2007.
time to change the charts when will the speghtti models come out for 99l it be interesting to see the new track
anyone want to guess the track before they come out ?


I imagine it continues WNW.
Morning Drak. 99L looks good this morning and has a 70% chance to become TD 3, according to me.
Posted By: eaglesrock at 1:08 PM GMT on July 30, 2007.

Morning Drak. 99L looks good this morning and has a 70% chance to become TD 3, according to me.


let me look at the models...
not saying that it will but any one from the Caribbean MX and the Gulf of Mexico and W coast of FL needs to watch 99L for the next few days this could be are 1st big storm
just what i expect. I remember that the ECMWF forecast something in this area on monday. the NOGAPS and UKMET had something as well.
well the gfs was developing this wave all week to be at this stage but it droped it when it paseed 60 west due to the dry air we have to wait for the new run to see if it still hold true . and the sal will weaken before it reaches 60 west thats the key to the system for now . as for the sheer its low now so we can see this get stronger if the sal plays out . imo right ike
un oh

yes Taz, remember the TCHP is high in the Caribbean and the Gulf. have to wait and see waht the HWRF/GFDL does. Also the NHC will run their models on the system to get a better read on it.
Like i said the ECMWF is dead on when it comes to cyclogenesis. Definately a relaible model.
Looks like the spaghetti models are already out.
thanks taz for the run
Stoorm - maybe south in the grenadines. Still a long ways to climb to you.
it looks very organized
642. RM706
All winds look favorable for 99L. Hope it steers up and out to sea and becomes a fish storm also. I know I'm a newb to the boards but isn't it rather big and organized for a newborn? Although I don't note any rotation at this time, too early for cyclonic rotation?
643. IKE
Posted By: Tazmanian at 8:12 AM CDT on July 30, 2007.
un oh


Agree!
wind shear where its going un oh

lol
000
WHXX01 KWBC 301254
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1254 UTC MON JUL 30 2007

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

ATLANTIC OBJECTIVE AIDS FOR

DISTURBANCE INVEST (AL992007) 20070730 1200 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
070730 1200 070731 0000 070731 1200 070801 0000

LAT LON LAT LON LAT LON LAT LON
BAMD 9.7N 45.7W 10.5N 48.0W 11.3N 50.4W 11.9N 52.6W
BAMM 9.7N 45.7W 10.5N 48.1W 11.3N 50.7W 12.0N 52.9W

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
070801 1200 070802 1200 070803 1200 070804 1200

LAT LON LAT LON LAT LON LAT LON
BAMD 12.3N 54.9W 12.7N 59.9W 13.1N 65.1W 14.8N 70.2W
BAMM 12.3N 55.4W 12.6N 60.7W 12.8N 66.5W 14.1N 72.4W

...INITIAL CONDITIONS...
LATCUR = 9.7N LONCUR = 45.7W DIRCUR = 280DEG SPDCUR = 10KT
LATM12 = 9.3N LONM12 = 43.7W DIRM12 = 279DEG SPDM12 = 10KT
LATM24 = 8.8N LONM24 = 40.7W
WNDCUR = 20KT RMAXWD = 50NM WNDM12 = 20KT
CENPRS = 1010MB OUTPRS = 1013MB OUTRAD = 160NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM

$$
NNNN
There sure is a lot of dry air out there.

Even if there is no dust per say, that dry air will sure put a damper on convection as the low pulls it into the center.

This invest has a rough future, IMHO. Dry air to the N, and S.A./ITCZ to the S. It'll have to thread the needle to survive.

wv

647. IKE
RM706...it's got rotation.
does anyone else see the other models going further north on the track yet ?
Yes there is a SFC low.Also this system has good lower level convergence and upper level divergence.
seminolesfan it dry air won't matter if it develops in time. It has a SFC, not in SAL so i can fight of the Dry Air better.
Why this will develop:

-low shear
-surface low
-no SAL

Why this won't develop:

-dry air
-S. America to the south
-still partly in the ITCZ
Posted By: nationalcatastrophe at 1:20 PM GMT on July 30, 2007.

anything of interest today



99L.
Some dry air on its path to development



next
Where can I get a link for the Spaghetti models for 99L?

Thanks!
bobw9 lol. It can fight of the dry air easier because it already has a SFC low.
The corilos effect can steer it north like the spagetti models suggest.
oh its on the SSD site now.
her are the mode runs for any one that miss it


658. DDR
trinidad & the southern windard islands could use some rain, its been unusually dry :(
There's no need to go nuts with a possible future track, yet. This thing still has work to do to become a tropical cyclone and there's no guarantee it will make it.
bobw9 lol. It can fight of the dry air easier because it already has a SFC low.

remember 96l?
What are you talkin' about Drak?

Moist upper levels are one of the requirements for cyclogenesis. You can already see the dry air entrainment on the W side of the convection and how its punching a hole in 99L.

I guess time will tell.
My guess: Dry air-1; 99L-0
This will be my final blog until Monday, August 5,

Bad news... Everybody better set their comments to Show 50 Comments (at the bottom of the comments) because I wouldn't be surprised if we hit 10,000 by then (Chris last year got 4,000 in one day) if it develops...
One word: [b]ERNESTO!!!!!![/b]

even if it does develop, that is exactly what i see
yes but 96L was in a lot of dry aire and SAL 99L is not it has moist aire a round it
ya...it has some things going for it...but that dry air looks like a fairly big hurdle to overcome.

Gives us something to obsess over for the time being and the very least.
dr m come back you this took off at a bad time
Posted By: bobw999 at 1:25 PM GMT on July 30, 2007.

bobw9 lol. It can fight of the dry air easier because it already has a SFC low.

remember 96l?


96L formed a SFC low when there was dry air aorund most of the system.

Drak you don't know what your talkin about!!!

How can a surface low help it fight off dry air?

Just the opposite is true. The low pulls the dry air into the system. You understand pressure differentials, right?
seminloesfan do you see evidence of a SFC low pulling dry air in?
Dry air is gonna kill everything. Are you aware that dry air moves?
come to my blog for the truth of 99l
Posted By: WizardApprentice at 1:29 PM GMT on July 30, 2007.

yea but unlike 96L there is weaker shear and much less SAL


exactly.
lets wait to see what the 11:30 two says
99l has a better shot than 98l of developing and just might fight the dry air . its happen many times before
Wow

earlier this morning I called for 99L to be an invest by this afternoon and I come back from my morning coffee to see it up already !
looks like its geting stronger fast

i would say that conditions are marginal-favorable for development.
lol Kman yea...
Taz can you post a the main page for those spaghetti models? so i can get to them in the future. i tried and couldnt find my way there from the main page. thx
Hurricane Katrina had to fight off dry air before hitting Florida. That is why it had most of the nasty stuff to the south of the storm.
Atlantic floater 2 is now on the system between 45 and 50. Labeled as invest.

The visible image appears to support mid and high level circulation. Hard to see if it has low.


Is there a link to a higher resolution loops?
new blog
her you go : drusierDMD

Link
Drak-I already told you my evidence; the hole on the W edge of 99L. You didn't answer my question thou!
Posted By: Tazmanian at 8:32 AM CDT on July 30, 2007.

looks like its geting stronger fast


It is trying to organize, but it will be a slow process.
morning all. I have seen 98l this morning and the two atlantic tropical waves one with a surface low that have thunderstorm activity. I plan on updating my tropical weather dissscusion on my blog later today conerning these areas. However i do not give a crap about 98l. If it develop its a fish storm maybe a bermuda storm. I am far more conerned about the new blob in the carrib near the antillies and the wave with the sfc.
What no storm no depression not anything in atlantic .just waves waves waves.
ah yes and now is see the carrib blob is 99l. Guys the carrib blob will likely become a depression in the next 96 hours. This is what we should be watching because it is in favorable conditions, is organized, and is in a climatolgically favorable area for development.
new blog
the wave at 9 N 46W appears to have circulation with it >It also appears to be traveling at n nw at momment.
weather channel says they are monitoring a wave off the coast of south america.I wonder if it is the same one.yes it is.They are mentioning the air force reserve going into it or making the decision wether they will go into it tommarow. hummm interesting. this one looks like it may have its stuff together.
dew
Looks like the wave at 22 N 63W is firing up.Appears it may have circulations with it as well. still no niticable circulation on what was 98l
Check out the ULL comming oof the coast of africa. looks like it is pulling a tropical wave back onto the coast of africa. lol
anything of interest today

could you read a little of the blog first?
or is it a ULL humm i cant see it all on this map
a few things of intrest as far as im concerned . two waves one at 22N63W and the other around 10 Nand 46W both features have intrest .the weather channelsaid that the air force reserve i thinking about looking into the one at 10N 46W
dewfree the circulation on 98l has transitoned to ther surface u can see it on the rgb sattilite loop.
gfs long range

last frame of long range GFS model of 99L
Hey Drak: have you got a current..err...steering currents map? :-) little bit of austin powers there