Ed Dunham
Former Meteorologist & CFHC Forum Moderator (Ed Passed Away on May 14, 2017)
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Sunday 07/08 11AM (EDST) Update
All quiet on the eastern front. Looking at SST anomalies, the (active Pacific - quiet Atlantic & Indian Oceans), and pressure patterns (surface and aloft), the Atlantic basin seems likely to stay quiet for awhile.
ED
Wednesday 07/04 Noon (EDST) Update
Invest 96L LLCC located near 10.8N 43.7W at 04/15Z continues to move just north of due west at about 15 knots. Minimal convection remains displaced to the south of the circulation center - perhaps under the influence of modest upper level northerly wind shear. Airmass is quite dry immediately north of the system with little change expected over the next few days as the system continues on a west to west northwest track. Overall wind shear is still expected to remain light for the next couple of days, however, an upper level low currently near 14N 60W is forecast to move slowly northward to near 20N 60W by Saturday morning - thus the system will be moving into an increasingly hostile upper air environment by the end of the week.
Still a couple of days for some additional minimal development to occur if the northerly shear relaxes and allows convection to wrap around the north side of the LLCC. But no TD likely unless this happens - with this system you definately need the convection to wrap to the north side and serve as a catalyst for a little intensification before the system encounters the wind shear associated with the upper level low and begins to weaken.
The dry air to the north has kept any deep convection from developing to the north of the circulation thus far, so 96L has not yet met the qualifications for TD status.
ED
Original Post
Since the previous thread is now quite outdated, and since there is some modest interest in a tropical wave located in the mid tropical Atlantic - a new thread seems to be in order.
The weak low along the tropical wave was located near 10N 39W at 03/00Z with movement toward the west at about 15 knots. The system has fair organization and has managed to maintain some convection today in spite of some rather dry air to its north. Wind shear is low and expected to remain low for a few more days as the system continues on its westward journey. SST's are certainly warm enough in the mid Atlantic so there is a small chance that this feature might do something - eventually - but probably not much. The season is still early.
From HanKFranK:
"Yesterday i saw the blip at low latitude out near 35w and said 'nah.' today the thing has gained a tad of latitude and has a slightly better signature (if a tad less convection). I'm still saying 'nah' to myself, but maybe tilting my head at it a bit more. it looks like a reasonably favorable upper pattern will accompany it westward, though the environment is quite dry and its amplitude isn't anything to write home about. just the same, might bear a bit of watching. things rarely happen out there this early, but there is some precedent.
Mess near the north American continent is of the less interesting variety. the weak low near Florida is reduced to a frontal trough closer to Bermuda than anywhere.. still some weak shortwave energy along the sagging frontal boundary that is trying to wash out in the southeast. not much doing just yet."
HF 2249z02july
From Storm Hunter:
"Agree with hank... out near 40w. Some of the Globals take this into the Caribbean in a few days. Its pretty dry out there, and there is some Dust around. Based on the pattern, this wave should keeping moving wnw. I also see that the wants to throw up something of Florida east cost in a few days. VERY WEAK... I would keep my eye on the wave in the Atlantic... if it holds, i would expect an invest from navy on it tomorrow."
Otherwise, nothing else of even minor significance is evident in the basin - but we'll all keep a casual lookout just in case a mid July surprise pops up. Since nothing much is really going on - at least not yet - feel free to comment on the above mentioned wave or any others that might generate a spark of interest in the basin over the next couple of weeks.
ED
Edited by Ed Dunham (Sun Jul 08 2007 11:06 AM)
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Clark
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I'll chime in with some thoughts on that thing in the central Atlantic as well.
I am *kinda* intrigued by the low in the central Atlantic. It's the most interesting thing out there since Barry, to me at least, but I still don't give it much of a shot in the short-term. It's one of those things where if you saw it come August, the alarms would be going off and everyone everywhere would be talking about it, but being the start of July it only merits a passing mention. The environment is just too stable out there right now, largely driven by fairly cool SSTs and ENEly wind surges around the subtropical ridge near the Azores. (This plot shows the end result fairly well.)
However, things improve as it nears the Lesser Antilles -- waters get warmer, the atmosphere becomes more unstable, and there's not a whole lot of shear to speak of right now. If it can hold together another 4-5 days or so, it could get interesting. We are slowly transitioning into that time of year where when things look interesting in the central Atlantic, they can pose problems (re: potential development) further west several days later.
Not really intrigued by the stuff hanging around the southeast coast. If it sat for 5 days and had something to organize around, like a mid-level vortex from some daytime convection dropping into the open waters, it might get intriguing...but if the central Atlantic feature is a 2 out of 10 on the development scale for the next three days, this is a 0.5.
If neither get going -- we could be waiting a couple of weeks into July. Others who know a lot more about intraseasonal and long-range tropical forecasting than I do suggest that things should start to get somewhat favorable basin-wide in about three weeks -- moreso than climatology alone would suggest, at least -- so if nothing develops in the short-term, I say enjoy the respite as things could ramp up fairly quickly on down the line.
-------------------- Current Tropical Model Output Plots
(or view them on the main page for any active Atlantic storms!)
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Storm Hunter
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hmm... Ramsdis Floater Moved... and looks like there is a nice set of storms tonight! Much better than last night.... Little thing is trying to flare up. I don't see that much shear, like clark noted above, maybe some from the NE, but not that strong. Dry air to the north of the system and some to the west. If the current trend holds... i would expect an invest in morning.
Floater
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2012== 23/10/9/5 sys/strms/hurr/majh
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Storm Hunter
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Something of interest i spotted tonight... on the sat page
http://www.nhc.noaa.gov/satellite.shtml
under Atlantic Floater 1 it has:
INVEST
Not sure if it means anything, it may just be something new this year? (Others have Not active and Test Float)
It points to this feature:
http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html
*** this could be a graphical error, or a human error typo, or that this is just an investigated area? I haven't seen any msgs from the Navy, yet!
-------------------- www.Stormhunter7.com ***see my flight into Hurricane Ike ***
Wx Data: KFLPANAM23 / CW8771
2012== 23/10/9/5 sys/strms/hurr/majh
Edited by Storm Hunter (Tue Jul 03 2007 12:27 AM)
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Lamar-Plant City
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I just noticed that about 10 minutes ago too. That's our little darling out in the mid-Atlantic showing up under INVEST on . Maybe they are anticipating the Navy a bit, although I am not exactly clear how that designation stuff works. It certainly has a nice little flare-up of convection on the northeast side tonight, but will need a lot more getting together before it gets really interesting. I always have trouble with scale when they are that far away since there is no land near and few of the satellites give a good view if they HAVE land in them. At least it is something to look at this early in the season. Keep us posted.
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danielw
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EUMETSAT IR Satellite imagery.
Sector 4 EUMETSAT-copyright 2007 EUMETSAT
RAMSDIS shortwave imagery from 0015Z to 0345Z.
SSD "Investigation" Floater 1 from 2345Z to 0315Z.
INVEST
At 0315Z center of convection is located near 9.5N / 37.5W. Lightning has increased quite a bit over the last 3 hours. Diurnal convection-probably.
Strange formation to the main cloud area. While the lower level clouds would suggest the larger 'main' cloud is over the center of circulation. A semicircular notch exists to the NW side of the 'main' cloud. Resembling a 3/4 "Eye". No rotation about this notch is visible.
(Thanks to SSD for the Lat/ Long Grid overlay for this area of the Atlantic)
Current cloud temperatures are in the -64 to -69C range. (colored as black). A short period of higher cloud tops existed around 0215Z. With the indicating cloud tops in the -70 to -75C temperature range. (colored as white).
Current motion appears to be WNW near 15 knots.
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Storm Hunter
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Somebody's working late tonight
96L.INVEST
-------------------- www.Stormhunter7.com ***see my flight into Hurricane Ike ***
Wx Data: KFLPANAM23 / CW8771
2012== 23/10/9/5 sys/strms/hurr/majh
Edited by Storm Hunter (Tue Jul 03 2007 12:52 AM)
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dem05
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Edit to first paragraph: Hi Hunter...Saw you posted while I was typing. We have 96L now, my first paragraph is somewhat "moot" now. Good catch!
FYI...the invest has been up for quite some time now on the mid-Atlantic feature. From best I can tell you, since about 8 pm "ish". I had dinner with the family, so it may have been up longer than that. Since a has come out since the posting of the feature as an invest on the satellite page, I do not expect significant changes in in the invest catgorization (number assignment) and/or 5:30AM unless there is continued progress in organization and/or a status quo in organization. Like other Invests we have seen this year, it apparently has peaked some interests inthe Meteorology community, but it is not enough yet to merit an invest number (i.e. 96L).
The area has undoubtably been battling the stability situation with a level of tennacity and my belief is that it has continued to organize further somewhat. The formation of a Tropical Depression from this while it is out there is not impossible. However, I highly agree with Clark's synopsis also and a system this far out is also a little beyond climo expectations for development. It gets a better shot closer to the leewards in 5 days if it sustains itself, but 5 days is a very long time and a lot can happen (including the idea that this wave could go POOF!). So I'd keep an eye on something possibly happenning with it days +3-+5 (with no guarantees of development). If it does manage to develop before then...track it, but keep in mind that development out there is some what of an anomoly. From a scientific view of anomolies, such events may not be reflective of the rest of the season's activity. Mean time, have fun watching the satellite loops!
Edited by dem05 (Tue Jul 03 2007 01:10 AM)
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danielw
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Update.
Preliminary model run indicates the system could be in an area between 12.3N/ 56.0W and 17.3N/ 61.0W at 120 hours, or July 7 0000Z (8pmEDT on July 6th).
That area would still be East of the Lesser Antilles.
And at 30 knots maximum wind speed. Less than Tropical Storm status
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Storm Hunter
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Yeah i see what your talking about danielw. Although, that movement looks interesting.... Can it hold this far out in atl, and make it to the islands...(warmer water, etc.) or will it fall apart with all the dry air around it to the west and north?
http://www.sfwmd.gov/org/omd/ops/weather/plots/storm_96.gif
-------------------- www.Stormhunter7.com ***see my flight into Hurricane Ike ***
Wx Data: KFLPANAM23 / CW8771
2012== 23/10/9/5 sys/strms/hurr/majh
Edited by Storm Hunter (Tue Jul 03 2007 01:11 AM)
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danielw
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Thanks, I was looking to see if some of the sites had picked up the model run.
That would leave it to crossing the "Hurricane Graveyard" of the Eastern Caribbean. As a 30 knots system I tend to think the Mountains of the Lesser Antilles would/ could 'knock the wind out of it".
Plenty of time to watch and see.
Or "Waiting...But Not Quite There Yet" as ED put it.
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cieldumort
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Whatever can be said about its lack of chances, this is an impressive feature for this far out in the Atlantic this early in a season To put it plainly, this little one looks better to me than 95L and the curiosity I tracked for 12 hours or so a few days ago (the one to the SE of Bermuda) .. combined .. but not by much. Nor were those other two features anything to crow about, to begin with.
Still, now official 96L, currently centered near 9.5N and 38W as I type, is possibly about to enter a region of much-diminished shear (LINK) . This might bring up two possible scenarios as a result:
Scenario A) The low to moderate shear has helped flame the convection in an otherwise dry and stable environment, making some kind of FeS2-based concoction of what is really a benign 96L.. and as a result, the low shear environment merely exposes the Low for what it is: A weak low trying to make its way through a mostly dry, stable environment.
Scenario B) The low to moderate shear may or may not have helped fan the convection of 96L, but the Low itself is a little better-off than Scenario A would suggest. Entering the low shear region ahead leads to a marginally-favorable window for some "real" intensification, even tho this goes against the climo grain.
Given the structure of the surface or near-surface low, and the relatively juicy environ immediately encircling it, my guess is that Scenario A is not the more likely one. However, what I think might be more the impediment for 96L is the dry air just to its north and northwest, not to mention there's still likely to be lots and lots of killer SAL floating around north of 10N by the time it crosses that latitude, to be even more specific. (LINK).
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danielw
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The Navy has posted the 96L INVEST on it's web site.
As of 0600Z or 2 AM EDT. First frame appears to be 0515Z.
96L Invest
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WeatherNLU
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I tell ya, I just got back from work and I am tired but I am interested here. 96L surely looks like it's got it's stuff together to me. I want to see it persist through tomorrow, but looking at it on satellite tonight, I am seriously impressed. We shall see.
-------------------- I survived Hurricane Katrina, but nothing I owned did!
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allan
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Ok, lets not get too ahead of ourselves here We all knew that this blow up would occur last night. Now it needs another boost to gain more power into a Tropical Deppression. Shear is very low on it's path but the reason why it's not already Chantal is 2 things.. SAL and it is still on the ITZS.. which makes a good circulation hard to get because it's all going in one flow, unless i'm wrong. We'll see what happens today, i'll give it a 60% of it becoming TD3. Even though we never ad TDs 1,2.. I think they will go to 3 right? lol
-------------------- Allan Reed - 18,9,5
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Lamar-Plant City
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Are those just upper level features forming to the NE and SW of the 'center' or is it trying to form feeder bands? The thing looks better this am than it did when I hit the sack last night (about 12:45). It also has a little wobble back toward the due west or at least the convection does. No signs of it going 'poof' yet, although I have seen that happen enough before. Is it the 'Little Invest, that COULD"? I see all of the dry air to the north on the water vapor loop, but it seems to be tapping from the to the south. Also a bit of outflow-looking features on that loop on the south side. Will be interesting to keep track of the next couple of days if it holds together.
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weather_wise911
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Looks like the convection just got blown south--displacing it from the low.
Any thoughts??
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allan
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Shear is only 5 knots where it is and headed.. as it enters the Carribean, it will enter around 5 to 10 perhaps 15 knots of windshear.. we'll have to see what happens today..
Unfounded comments removed. If meteorologists don't think that this wave is a TD, perhaps you can benefit by listening and learning from them, Lets not get too carried away with conjecture. Speculation without rationale belongs in the Forecast Lounge.)
Edited by Ed Dunham (Tue Jul 03 2007 11:02 AM)
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cieldumort
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Some notable observations... Brings up the topic of the , or, Intertropical Convergence Zone, some more. While the air tends to be flowing in one direction on its northern side in this hemisphere, "Monsoon Depressions" frequently form within the - but with most never, ever becoming Tropical Depressions, and most never even earning as much as an Invest tag. Besides, 96L is simply not your average depression, however. It's been more like a full-on wave that has transcended the , all along. What is more, the , by very definition, is a vorticity-rich environment. It is one very long trof of low pressure. An elongated nebula of cyclogenesis.
I do believe we are indeed viewing incipient banding features, which have been forming overnight. The internal structure of this Low is really not half-bad. Now if it can actually survive all the dry, stable air it has to contend with...
I suspect that it is not so much the wind that has "blown" the convection to the south, as much as it has been the effect of all that dry air to the humble cyclone's north that has squashed any real attempt to wrap deep convection all the way around. You can see this quite clearly in this morning's QuikSCAT pass, from 827Z, here
and this is still quite evident in the 1037Z TRMM pass
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ftlaudbob
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It is fairly clear at this point what is happening to this system.It is fighting with the dry air to the north,and as of this hour the dry air apperars to be winning.That doesn't mean things can't change down the road,But can it survive until then?I agree that if this were August or even late July there would be alot better chance of this system envolving into a cyclone. http://www.ssd.noaa.gov/goes/east/natl/loop-wv.html
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Survived: 10 hurricanes in Rhode Island,Florida and the Yucatan of Mexico .
Edited by ftlaudbob (Tue Jul 03 2007 11:41 AM)
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