Clark
Meteorologist
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Loc: Great Lakes 45.95N 84.55W
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There's nothing left of the remnants of Lane. The surface circulation never made it more than about 50 miles inland, stopping its progress as it hit the mountains of western Mexico, while the upper level energy associated with the storm was sheared away and has been entrained into the frontal system heading for the eastern seaboard. The rainfall in SW Fla was unrelated to Lane, with those aforementioned upper level remnants currently located somewhere over the S. Central US, and instead was related to a diurnal flareup associated with a moisture gradient from the previous boundary that went through a few days ago.
Helene may be briefly turned further west in the short-term, but there is a significant and deep trough off of the US now that extends to about 24N and another one heading eastward from the central Plains that is projected to clear much of the US in the next 4 days or so. Unless something drastically changes in the next 4-5 days, including Helene nearly stalling in the central Atlantic, I'm not sure that this is a significant threat to anywhere but Bermuda at all. Those in Bermuda still need to watch it, though.
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HanKFranK
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Loc: Graniteville, SC 33.56N 81.82W
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yeah, later model runs haven't shown anything like that 00Z sunday track with the storm near the east coast. the westward track is now still only to near bermuda, with the recurrent troughing snagging the storm late in the week after the ridge fights to push it westward.
the first indications of possible activity in the western caribbean in october have shown up in the in the last day or two. activity down there is usually pattern-induced, and can only come up if the ridging amplifies in the western atlantic and isn't just a zonal ridge across the gulf. no way to say with certainty whether the ingredients will come together.
95L, invest 26 on the season, was declared the other day. it doesn't look like much today, though. there was limited deep convection on the cloud ring during sunday, but it's all shallow stratus/stratocumulus swirled up today. some indications of northwesterly shear.. and it isn't getting a baroclinic surge just yet. might still whip up in a hurry as the front bears down on it and draws it up towards nova scotia, but there doesn't appear to be enough going on right now for it to make a tropical transition.
globals still more or less developing the new wave coming off. that'll probably be isaac by the weekend.
with helene major the hurricane season numbers are starting to look more 'normal', with 8/4/2 now the tally.. and with maybe 40-45% of the typical season left to go.
HF 1715z18september
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Ed in Va
Weather Master
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Posts: 488
Loc: 36.02N 75.67W
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Looks like Helene will be taking the open Atlantic route. Virtually all the 18OZ models recurve it.
http://euler.atmos.colostate.edu/~vigh/guidance/atlantic/early1.png
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Survived Carol and Edna '54 in Maine. Guess this kind of dates me!
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Clark
Meteorologist
Reged: Wed
Posts: 1710
Loc: Great Lakes 45.95N 84.55W
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A few quick thoughts on Gordon and Helene...
Gordon: Heading out to sea quite rapidly, maintaining itself as a minimal hurricane as it does so. discussion earlier hit on the nail: SSTs are cooling, but the upper level environment is cool enough to still support about this intensity of a tropical system. There's not a *lot* of midlatitude forcing impinging upon the storm quite yet, while its acceleration has led to minimal storm-relative shear upon the circulation, leading me to believe that the model depictions of ET are somewhat too quick in coming. Those in the Azores should be prepared for a minimal hurricane impact late tomorrow, and I expect the to hoist a hurricane warning (as they hint at in the 8p Gordon advisory) at 11pm. It should gradually transition into an system -- a quite potent one at that, traversing into this largely zonal flow regime -- over the next two days or so. The end is nearing, just maybe not quite as fast as the models want to bring it about.
Helene -- it's easy to say this now, but the inevitable capture and recurvature of Helene is coming soon. These deep Atlantic storms offer us quite a bit of time to watch the pattern evolve before they become a threat even to Bermuda, and as time has passed the pattern has indeed become clearer. Under the transient early fall-type pattern we are in, it's always been more likely than not that Helene gets turned up before it gets to the US -- just a matter or where it happens. The forecast of before 60W looks pretty good.
The key players are a strong mid-latitude trough currently digging over the central US and a very deep trough over the eastern Atlantic, almost acting like a Rex (high over low) block. There are clear signs in the WV imagery tonight of the large-scale (longwave) trough associated with this block swinging around from the SW (extending into the Florida Straits) toward the east and northeast. As Helene nears this and as the central US trough slides eastward, it should get captured and turned north and northeastward into the midlatitudes through 5 days. Until then, a slow west-northwest motion is likely with the storm largely holding its own intensity-wise. With today's recon data, we'll probably see the peak of 125mph knocked back down toward 115mph in the best track.
Everything else: nothing close in is threatening development...the cut-off associated with 95L is too deeply embedded in a large-scale dry and cold core environment and should begin to move soon enough to preclude any tropical transition. Anything off of the coast of Africa is going to have to tango with an upper trough NW of the Cape Verdes; if it does so favorably, it could be in a diffluent upper environment condusive to development, otherwise it could be sheared for quite some time. Most of the models show some development at some point, though the again suffers (as it did last year) from overdevelopment in the short term I think. Something to watch once Gordon and Helene are out of the way. Usual caveats apply -- if it develops out there, it's likely another fish. Don't think anyone will complain too much.
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danielw
Moderator
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Loc: Hattiesburg,MS (31.3N 89.3W)
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Clark, Hank and others have previously mentioned the troughs moving through the Eastern US.
While viewing the Eastern US WV loops I noticed that there are a few things in common between Helene and the troughs.
They are all nearly at the same latitude. Use the link below and notice the Eye of Helene, Andros Island-Bahamas, and the bottom of the trough in Old Mexico-South of Del Rio,TX.
Hmmm.
http://www.ssd.noaa.gov/goes/east/eaus/wv-l.jpg
http://www.ssd.noaa.gov/goes/east/eaus/loop-wv.html
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HanKFranK
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Loc: Graniteville, SC 33.56N 81.82W
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hmmm... the new wave is energetic, but hasn't come off 'consolidated' like the other quick developers this year. should take a few days, but chances are decent with the upper trough ahead creating a nice upstream environment for it. further west, southeast of helene is another wave that isn't moving quickly and has decent turning on its axis. the upper trough axis is pretty much over it around 38-39w. there is some convection, and the globals 'see' it but aren't showing any development. think it's the same wave that fed a weak low northward near the cv islands the other day... or perhaps it's one that was ahead of it? not sure, but am interested in how far west this one can get. getting any wave energy far enough west to not meet an early recurvature has been a challenge since . with a moderate upper ridge predicted in the western atlantic by the weekend into next week, anything of consequence underneath that would make things a lot more interesting. but, no model support as far as i can tell... aside from something unforseen in the western caribbean/bay of campeche i don't see any chance of a threat for the rest of the month.
95L low off the east coast is well defined but weak and nonconvective. as the environment becomes increasingly baroclinic it may start an organization trend, and will have limited time over support SSTs. but i mean, hey... if it snows in new jersey, maybe it can snow in hell, too. slim chance.
HF 0404z19september
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zacros
Weather Hobbyist
Reged: Thu
Posts: 57
Loc: Johns Island, SC
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Interesting to see how quiet this board gets when there are no storms threatening the US.
Certainly looks like Helene will recurve eventually. However, the storm has taken on a due west motion over the past three hours. Clearly visible on the RGB loop. I don't know if it will be a long term trend, but it may put Bermuda a little more under the gun. Looking at the bigger loops (Eastern US), it would seem something would pick it up and carry her out to sea (weakness caused by 95L or by the trough exiting the east coast).
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Lee-Delray
Weather Master
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Posts: 429
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THe accounted for this westward motion in their 11AM Discussion. Looks like only thing under the gun is some fish (fingers crossed).
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Bloodstar
Moderator
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Posts: 395
Loc: Georgia Tech 33.78N 84.40W
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I wonder if Gordon can hold together to the Portugal Coast? It's possible but unlikely, particularly with the cold SST's....
Helene looks very fish spinning, though it could meander a bit, if the trough doesn't catch it... making it wait a little while before scooting to the east
95L has increased convection a little, but probably only has a day or so to actually acquire tropical characteristics. It'd have to get some concentrated convection before the would upgrade it, but you never know.
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TD/TS/HU/MH
19/18/0905 <- My prediction (2013 Predictions)
00/00/00/00 <- Year Totals
http://blog.bloodstar.org
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typhoon_tip
Meteorologist
Reged: Wed
Posts: 551
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Quote:
... the new wave is energetic, but hasn't come off 'consolidated' like the other quick developers this year.
...aside from something unforseen in the western caribbean/bay of campeche i don't see any chance of a threat for the rest of the month....
...95L low off the east coast is well defined but weak and nonconvective. ....
HF 0404z19september
"Quick developers this year..." ?? Interesting. I was under the impression the opposite was true. These gyres have been tending massive in spatial area and that has apparently contributed to untimely core contractions.. It's been noted throughout the season.. What is interesting about this point is that Helene was forecast to detonate almost the moment she left the African Continent, but...that did still wait 36 hours believe it or not.. She was large, as well... My memory may be different than your on this but the discussion content of virtually every advisory for Flo', Gordo' and Hel', during their development stages, covered this point that largeness of the circulation would limit rate of intensification..
There is currently an impression of cyclonic curl over a large area out there, having an axis of rotation roughly 20/12.
Seems to be a seasonal tendency for large circulations at seedling stages. Large initial circulations will take painfully long to contract cores. This one so far, barring a coincidence in the cloud morphology, appears to be the largest of them all... In fact, it actually may be a vast area with enough room for 3 circulation foci..
No wonder the majority of the guidance is less impressive with the rate of maturation with this new TW than they were with Helene. They do develop it, but there isn't near that same zeal and unanimity that Helene had when her zygote was still far into the African continent. That was amazing! Some 96 hours before TW(Helene) even emerged near Sierra Leone their was large agreement on development and that pretty much verified exquisitely - though as mentioned, the models may have been a day or so too quick.
Anyway, I believe this will take a good bit of time to develop, too. It probably isn't much use to discuss tracks because there is too much uncertain about intensity (if there is even going to be that), let alone the rather ill-behaved nature of the Atlantic Basin westerlies so far this season... Recent model discontinuities conserning the larger mass fields of the Atlantic Basin make even estimating ridge strengths for any would-be system somewhat problematic - for now. We can take a stab at that when the time comes.
It is funny you should mention Gulf... I was just thinking that we ought to be watching the waters just off the SE Coast of the U.S. and drapage out into the Gulf regions with some interest over the next 10 days... We have 2 episodes of unseasonably far S displacements of frontalysis into these regions, and this early in the season that "can" be even more enhanced than the more typical October climatologies for that. The only reason why October has a favored region from the SE Coastal waters and throughout the Gulf really has to do with availability of delivering surface troughs to those latitudes increasing later in the season; thus, there is a climatological intersect where such troughs wind up over top still hot ocean SFCs. The oceanic heat content is larger now than it will be looking forward, such that a stagnated boundary may have more to work with. Short and skinny: If fronts are going to make it down there and stall over 86F water, ...the rest is intuitive. We'll see.
95L I believe is firing off convection very close to the core now, closer than yesterday and if given a chance could take on subtropical in characteristics during the next 24 hours.
...Though we may not be directly threatened close to home... there is an abundance of interesting facets to consider and watch for over the next 2 weeks..
John
Edited by typhoon_tip (Tue Sep 19 2006 03:37 PM)
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cieldumort
Moderator
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Posts: 1023
Loc: Texas 30.40N 97.80W
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Two observations - somewhat related:
95L is looking much-improved this afternoon. Recent CI numbers up on SSD were actually 1.5 Subtropical and 1.0 Tropical. Still, it is nowhere near as impressive as the two best non-named subtropical cyclones of earlier in the season, but at the very least, 95L now rates as a disturbance.
Helene still appears to be on a more due west track than a wnw motion, and the recurve has yet to begin - although it is expected to imminently.
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Clark
Meteorologist
Reged: Wed
Posts: 1710
Loc: Great Lakes 45.95N 84.55W
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Not HF, but by 'quick developers' I think he was referring to CV-type systems rather than close-in developments. We've seen a lot of the former this year (and not many last year) and fewer of the latter (but many last year). The CV storms may have been slow in significant intensification, but generally by 40-50W they had their acts together.
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typhoon_tip
Meteorologist
Reged: Wed
Posts: 551
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Quote:
Not HF, but by 'quick developers' I think he was referring to CV-type systems rather than close-in developments. We've seen a lot of the former this year (and not many last year) and fewer of the latter (but many last year). The CV storms may have been slow in significant intensification, but generally by 40-50W they had their acts together.
Ah, in that context it works.
However, interesting notes about the significance of last year's CV season...
There actually were a fairly large number of them. There were 4, arguably 5.. but they had erratic paths and many actually were moving N when they were first depressions! ...Odd behavior in its self considering that in the depression phase they are shallower systems and tend to be involved in the llv wind field. Maybe they were frontal drapes way out there - interesting question...
Emily was a classy CV wave that went into the Caribbean, ultimately making landfall S of S Tx... I suppose we could argue what qualifies as a CV tropical cyclone; does it have to develop E of 30W for example... But, they were TWs from CV region so not sure of the usefulness of any such distinction...
Well...Helene's still tumbling W.. But, I have no objective reason to give up on the post I made above, regarding some synoptic points and expecations over the next day so we are in wait.
John
Edited by typhoon_tip (Tue Sep 19 2006 07:12 PM)
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IndianRiverFL
Unregistered
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Hope Helene turns north soon, starting to be concerned that this storm could keep west?
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danielw
Moderator
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Posts: 3384
Loc: Hattiesburg,MS (31.3N 89.3W)
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Checking the last two 5 PM postions. Monday vs Tuesday.
Helene has moved 170nm in 24 hours. Track heading of 302degrees True.
Or 32degrees north of due West.
That seems rather odd. Viewing Helene against the Weather Channel's grid overlay she appeared to be moving due west to me also.
Further checking. Previous track. From 5 PM Sunday to 5PM Monday.
190nm/ 24 hours. Track heading of 346degrees True.
Edited by danielw (Tue Sep 19 2006 09:17 PM)
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typhoon_tip
Meteorologist
Reged: Wed
Posts: 551
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There is definitely a discrephancy there from the perspective of what tools the public is allowed to see...
http://www.ssd.noaa.gov/goes/flt/t3/loop-avn.html
-Toggle on the Lat/Lon radio button on the top options... This is a close up grid as well..
This will clearly show the motion has been fluctuating up and down along 24.5 N, straight W...
I think this is pretty correct as a correction against what TPC has set... But, it is really ultimately not that important.. It just cannot get W of 60W given the synopsis of the unanimous model depictions... Barring some obscene permutation that happens once in many Blue Moons, the southern end of the trough is going to exert a deep layer southerly steering field in about 24 hours, along the current track of Helene.
John
Edited by danielw (Tue Sep 19 2006 10:05 PM)
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Tropics Guy
Storm Tracker
Reged: Thu
Posts: 252
Loc: Miami, Florida
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No chance that she will continue moving N of West or WNW much longer. The trough to her NW is fast approaching with SW winds which will start to turn her NW then N starting tomorrow.
Thankfully for Florida's sake this is not a Andrew scenario where a massive high pressure built in to the north & there was no East coast trough present to save the day back in 1992.
TG
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Tropical Cyclones: "Mother nature's heat transfer machines"
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allan
Weather Master
Reged: Thu
Posts: 468
Loc: Palm Coast, Florida 29.55N 81.20W
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Quote:
No chance that she will continue moving N of West or WNW much longer. The trough to her NW is fast approaching with SW winds which will start to turn her NW then N starting tomorrow.
Thankfully for Florida's sake this is not a Andrew scenario where a massive high pressure built in to the north & there was no East coast trough present to save the day back in 1992.
TG
Actually it was supposed to turn NW according to the . Storms do indeed have a mind of there own and sometimes they can actually prove mightier than the trough. Theres a 5% chance that this hurricane may miss the trough. There is a chance but not a good one at all. Just need to watch for that turn. The front to me looks a bit stationary on the bottom where Florida is. Some thing to watch. 
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Allan Reed - 18,9,5
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typhoon_tip
Meteorologist
Reged: Wed
Posts: 551
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Quote:
The front to me looks a bit stationary on the bottom where Florida is. Some thing to watch.
Not uncommon for fronts to slow progress markedly as they near the latitude of Florida... In fact, in September ? That is highly likely... Moreover, a stationary boundary there would not actually indicate a reason to suspect track guidance. Stationary boundaries typically have 2 kinds of winds on their polarward vs equitorial sides. Those are either incident, or along the axis of the boundary.
In this case, the wind in the deep layer is paralleling the boundary on either side... On the E side, SW... There is your drive for gaining latitude...
John
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HanKFranK
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Loc: Graniteville, SC 33.56N 81.82W
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gordon is down to its last few hours. shear is getting to be too much.. you can see the increasing asymmetry with time. it got quite a baroclinic kick, though, on its way up... that was on the substantial side for a storm that high in the atlantic. looks like the right quad of the storm is going mostly south of the azores, which is good. maybe a direct hit on the easternmost islands (sao miguel and santa maria). it's been a good 14 years since an actual hurricane made it up there (that was the 1992 version of ).
helene... will keep us some company this week, at a safe distance from land. there was that one model flip flop that had it driving westward, but now everything has it going straight up and out. will be interesting how it is post analyzed (barring a shot of intensification during the next couple days.. which i don't expect due to it crossing upwelled waters), since the recon found it weaker than analyzed and it may have only been a minimal cat 3 or strong 2. gordon may still hold the seasonal mark after all.
95L has the look of something that just won't have time to consolidate. it should gust its way up to nova scotia and maybe cause some gales, but the respective convective core or spead convection with a broad wind max it needs to become either tropical or subtropical cyclone doesn't seem to be forthcoming. the outlooks indicate they may pull the trigger on it if the convection flashes up and it makes a quick run... but that probably isn't in the cards.
aside from the slow/stewing type of action that may result from the weak low level westerly anomlies pushing out of the eastpac, any future action this week or weekend will likely come from the waves trailing helene. the one near the CV islands has the best definition, but convection isn't close to organized. the one near 43w has some convection and definition, but the convection isn't holding too well (and upper winds are marginal at best with the rear-flank upper trough from helene). modeling likes the one further east better. it also draws that development up into the central atlantic like the last three storms. i'd have to say that anything meaningful for land (aside from bermuda or the azores) would have to develop west of 45w at fairly low latitude and just amble along and not develop quickly. we may be in just a weak/new el nino type situation, but the storm tracks are consistent with such a circulation (early northeast recurvatures, strengthening mostly happening on recurving or northeastward moving storms). if something gets the US this season it will probably be the bay of campeche-northeast or western caribbean-north moving types. we're probably too late in the game for an atlantic-to-east coast storm.
ernesto was the one that could have hurt us. luckily it found ways to stay onshore and not come close to its potential. really if chris would have found the 'sweet spot' right ahead of it it may have been a real problem, too. end result of either, though.. was pretty much a can of corn. not a whole lot after watching the neverending assault of 2005.
HF 0439z20september
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