HanKFranK
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Reged: Mon
Posts: 1841
Loc: Graniteville, SC
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thought the storm was looking better this morning. in the latest discussion they've taken the storm up a notch--because it's obviously stronger. we've seen intensification out of hurricanes over 'below threshold' waters before. under the right conditions they can just ignore the rules. this seems like an appropriate way to end the 2005 hurricane season.. another storm getting stronger than it's supposed to be.
now, if only the season would end...
you hear that zeta? wait til 2006, you can be alberto. not go around sounding like some sorority chick.
HF 2130z03december
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Margie
Senior Storm Chaser
Reged: Fri
Posts: 1191
Loc: Twin Cities
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Epsilon is behaving just like brave, brave Sir Robin, and running away from the westerlies and dry air, but just one step ahead.
Wow, Epsilon looks amazingly good on the sat images! Water vapor image attached. I see they increased the intensity...and continued amazement that the intensity has held, and more, under the conditions.
My met friend was lamenting that there wasn't some way they could find the money in the budget to do at least one recon, since nobody really knows what is going on for hurricanes to flourish under these conditions, and it would be really interesting to have some data.
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Katrina's Surge: http://www.wunderground.com/hurricane/Katrinas_surge_contents.asp
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Ed Dunham
Former Meteorologist & CFHC Forum Moderator (Ed Passed Away on May 14, 2017)
Reged: Sun
Posts: 2565
Loc: Melbourne, FL
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Epsilon is still a minimal Cat I Hurricane at 04/03Z with sustained winds of 65 knots. The storm is actually moving into an area of very light wind shear for about the next 48 hours, so it may hang together as a tropical entity for a couple of days. The projected forecast track moves it into slightly warmer SSTs (24-25C) as it heads south and southwest in a couple of days, however, it will eventually hit the southern jet near 27N 38W and that should reduce it to a low level swirl. Quite a season.
ED
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Tak
Weather Watcher
Reged: Tue
Posts: 41
Loc: Altamonte Springs, FL
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Looks like this thing still has legs. On the IR floater loop ending at 11:15 Z, there is still good convection (although the cloud top temps are a little warmer) with wrap around banding and a well formed eye feature. It cant be the water temps keeping this thing going. Is it because the coriolis effect is greater at that lattitude?
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Random Chaos
Weather Analyst
Reged: Sat
Posts: 1024
Loc: Maryland
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Epsilon just keeps looking better and better. It's got the form of a storm that should be stronger than it is, but the cool SSTs are probably keeping its strength down.
Look at the visible and Microwave - fully wrapped core now, and very good signature:
Visible: http://www.nrlmry.navy.mil/tc-bin/tc_hom...RODUCT=1km_zoom
Microwave: http://www.nrlmry.navy.mil/tc-bin/tc_hom...CT=1degreeticks
Dvorak estimates that just came are at 4.5...that's strong Cat 1...up from the weak cat1 that the 4am discussion talks about.
Also, if you look at it's 5-day track, it's heading toward the Carribean...uh oh. And given it's resiliancy to atmospheric and model attempts to rip it appart or weaken it...
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MapMaster
Weather Guru
Reged: Tue
Posts: 138
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Old Eppy has got at least three things going for him:
1. Strong poleward outflow channel has established itself on the west side....good evacuation going on, hence, lowering pressures, hence enhanced inflow. This is the major factor right now in the intensification.
2. Good 'storm dynamics'--that is to say that Epsilon is making the most of it's environment and is a very efficient heat engine right now...that is basically what hurricanes are, heat engines. Epsilon is squeezing lots of output out of it's input.
3. Increased forward speed= increased translation enhancement of wind speeds...but this is a minor factor.
Also, other factors, as have been mentioned elsewhere....higher latitude= enhanced coriolis effect. Also, the upper tropospheric temps may be a factor.
Some storms just seem to have that 'hang tough' thing more than others. Epsilon sure has that! He is the "junkyard dog" of the hurricane season, for sure (Vince did a pretty good imitation of that too).
Just another oddity of the 2005 season (how much you want to bet that we only see it as an oddity...because we haven't seen enough hurricane seasons (well documented that is) over time....maybe this is NORMAL ?!)
Avila sure is bemused...what a fun discussion this am!
MM
ps....it also seems that Eppy is coming out of, or still in, an ER Cycle....that is interesting...as another poster said, EPPY would be MUCH STRONGER over warmer waters...if that jet doesn't take him apart...hmmmmm?
Edited by MapMaster (Sun Dec 04 2005 10:14 AM)
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Fuzzy
Registered User
Reged: Sun
Posts: 1
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Back up to a hurricane now 75kts and 979mb central pressure. has had those stats since 8am EST which had me wondering why it was downgraded- but per the 11am advisory they're back on track 
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Hugh
Senior Storm Chaser
Reged: Fri
Posts: 1060
Loc: Okaloosa County, Florida
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I just read the 10am discussion. Avila sure has a sense of humor, and I guess all they can do is sit back and laugh after everything that has transpired in the 2005 Atlantic hurricane season. I looked at the visible and IR loops after reading the 4am advisory package and thought "That's not a 70 mph tropical storm, it's a hurricane", but that was a few hours after the advisory, so maybe it did weaken overnight. Satellite estimates are just that, estimates. Also looking at the loop, it appears Epsilon is moving north of due east now, and not making the turn south that is forecast. Maybe it's following the UKMET guidance?
In any case, one thing I am absolutely, 100% certain of. The 2005 Atlantic hurricane season WILL finally come to an end in no more than 27 days. Then we can start preparing to track Alberto.
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Hugh
Eloise (1975) - Elena and several other near misses (1985) - Erin & Opal (1995) - Ivan (2004)
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Margie
Senior Storm Chaser
Reged: Fri
Posts: 1191
Loc: Twin Cities
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The last one, from Avila, had me ROTFLMAO:
THERE ARE NO CLEAR REASONS...AND I AM NOT GOING TO MAKE ONE UP...TO EXPLAIN THE RECENT STRENGTHENING OF EPSILON AND I AM JUST DESCRIBING THE FACTS. HOWEVER...I STILL HAVE TO MAKE AN INTENSITY FORECAST AND THE BEST BET AT THIS TIME IS TO PREDICT WEAKENING
...
AND EPSILON WILL LIKELY BECOME A REMNANT LOW. I HEARD THAT BEFORE ABOUT EPSILON...HAVEN'T YOU?
By way of explanation...in his last two forecasts (Sat am and aft) Avila had stated that Epsilon will likely become a remnant low.
You know we have all hung in there through this long season (which I only joined in mid-July) and we have had our punch-drunk everything-strikes-us-silly moments, but this has got to be some interesting experience for these guys, on the front line forecasting all year. I just hope they have one heck of an end-of-season party (they may have to wait until after New Year to have it).
Just before 8am CST Epsilon really looked beatifully symmetric; attaching another sat image (infared). Dry air seems to be cutting into the center circulation now.
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Katrina's Surge: http://www.wunderground.com/hurricane/Katrinas_surge_contents.asp
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Random Chaos
Weather Analyst
Reged: Sat
Posts: 1024
Loc: Maryland
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Yeah, Epsilon did look excellent then - here's a visible sat of it from about 3-4 hours ago.
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Margie
Senior Storm Chaser
Reged: Fri
Posts: 1191
Loc: Twin Cities
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I was just looking at the MODIS highres from about the same time (it didn't catch all of the storm, but luckily the center), and looking at the detail in the eye. It is remarkably well-formed considering Epsilon is not a very strong hurricane, and has some interesting features. It is another unusual feature of this storm, to see an eye that looks in some respects like the eye of a major hurricane. It sure would be interesting to know what is going in inside that storm.
* * * * * * *
The wind shear has really started to kick in on the 1845Z. It looks like the outflow must have diminished quite a bit (due to the dry air coming in?). How many times can this storm cycle? Should we expect another resurgence in the morning?
I'm thinking probably not, that the strengthening from this morning was due to a pocket of lower shear, as very little shear was noticeable from this morning's vis images. Or...the shear that was there could have been displaced by some very strong outflow. Or...how's this for a crazy theory: somehow it did get some energy from the front to the north, even though it appears to be 100% tropical. Maybe in the colder temp environment there is some as-yet-undefined bizarre baroclinic process that can occur.
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Katrina's Surge: http://www.wunderground.com/hurricane/Katrinas_surge_contents.asp
Edited by Margie (Sun Dec 04 2005 04:18 PM)
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HanKFranK
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Posts: 1841
Loc: Graniteville, SC
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it is interesting to note... because of the inner core symmetry and large eye, if the hurricane were to have deeper convection it probably would get satellite ratings in the cat 3 range. the storm has a ~50nm eye and a nearly complete ring of moderate convection--that's about the closest thing you can get to an annular hurricane in december, i guess.
noticed that jeff masters is speculating that the upper ridging that is forecasting in the caribbean may allow something else to wake up. nothing real convincing on the models in that respect (disturbances on and , but the easterly flow is too strong at low levels when the 'feature' isn't right along the coast of south america). also hints at another cutoff out in the eastern atlantic around mid-month. no consistency on that, thus far.
HF 1948z04december
Edited by HanKFranK (Sun Dec 04 2005 02:49 PM)
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Margie
Senior Storm Chaser
Reged: Fri
Posts: 1191
Loc: Twin Cities
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I've lost track now of how many times Epsilon's convection has waned and improved, but it is sure looking good tonight (again). Convection has wrapped around the center again, looking as good as it has every looked, it still appears to be steady-state, and while not as prominent as today, there is still decent outflow. It's diving south pretty quickly. It certainly doesn't look like it is under 30+ knots of wind shear, but I'm guessing this must have to do with shallow convection? It's a little confusing; I don't know if I'll log in tomorrow to find a Cat 2 hurricane or something that has started being ripped to shreads.
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Katrina's Surge: http://www.wunderground.com/hurricane/Katrinas_surge_contents.asp
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Doombot!
Weather Guru
Reged: Sat
Posts: 160
Loc: Lakeland, Fl.
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Quote:
I've lost track now of how many times Epsilon's convection has waned and improved, but it is sure looking good tonight (again). Convection has wrapped around the center again, looking as good as it has every looked, it still appears to be steady-state, and while not as prominent as today, there is still decent outflow. It's diving south pretty quickly. It certainly doesn't look like it is under 30+ knots of wind shear, but I'm guessing this must have to do with shallow convection? It's a little confusing; I don't know if I'll log in tomorrow to find a Cat 2 hurricane or something that has started being ripped to shreads.
No kidding, this thing is like the zombie of the 2005 season; shoot it and it keeps coming at you...
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UKCloudgazer
Verified CFHC User
Reged: Wed
Posts: 21
Loc: Wallasey
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Went to bed wondering if this was the beginning of the end for TS Epsilon, woke up to find Hurricane Epsilon happy as ever.
Frustrating to have so little information about what is keeping Ep going, but at least we have satellites. I like the models this morning - gets rid of Ep and seems to be starting another in the same place, and have the world's most intense system ever cropping up later in the week - getting a moire pattern off the isobars.
And people wondered what we'd talk about after the end of the Hurricane Season.
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Bloodstar
Moderator
Reged: Mon
Posts: 462
Loc: Tucson, AZ
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I think the storm is going to be around a bit longer. Until The eyewall collapses, I think the storm will create enough of it's own Environment to keep things together. If I had a theory on why the storm has held together so well.
1) The Storm is in steady state, The low water tempratures are death to a system that is disrupted, but for a system that's together, the tempratures don't have to be a magical number.
1a) The storm has also not drifted into REALLY cold water, which most storms usually do once they head off to the norht and east, this storm managed to keep from 'falling off the deep end' so to speak
Tying it all together, A low shear environment, and a storm that has managed to aquire shallow but warmcore characteristics. upper level shear, does almost nothing to this storm. There's no way a storm could *form* like this, but once formed, as we've seen before, storms are tenacious buggers. and without shear or super cold temps. there's no reason for it not to keep going.
of course, I'm also looking at this in hindsight. So maybe in the future in a similar circumstance it won't catch us quite by suprise. I also notice they keep the storm a hurricane for another 24 hours before weakening it. And I suspect the Mets over at the are just ... shruging their shoulders in bemusement. I'd love to see an 'unoffical' blog from a few of them. just to see what their internal thoughts are. particularly in wacky circumstances like this.
-Mark
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M. S. Earth and Atmospheric Sciences, Georgia Tech - May 2020
Brookhaven National Laboratory
U. Arizona PhD Student
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HanKFranK
User
Reged: Mon
Posts: 1841
Loc: Graniteville, SC
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well, i've got a slightly different take on how this thing is functioning.
think epsilon simply isn't a 'true' tropical hurricane. not implying that it isn't really a hurricane, because it obviously is, but to the purists out there who think a hurricane isn't a hurricane unless it functions by barotropic processes over 80F waters, and not cooler waters... this is something else.
i believe that because it's later in the year and the tropospheric heights are generally lower than would be in the summer, that this thing can function with a much shallower warm core and keep the necessary differential 'heat-engine' in a more vertically compact manner. this kind of logic wouldn't hold up with , which managed to intensify in vertical shear conditions somewhat similar (although it was moving a bit quicker and in a stronger baroclinic zone). but in this case, and also with delta somewhat, the hurricane's convective tops are low enough that fast winds above say 300 mb aren't hurting it a whole lot. it'd be really interesting to know what the omega values (sort of like the lift, if i understand correctly) are like near the top of and above the boundary layer. i'd suspect that the outflow levels with this thing is a lot lower than an august or september storm in the deep tropics. it's really too bad a recon can't be managed for this thing, because it defies the rules and could probably expand the understanding scientists have about how hurricanes really function.
anyhow, jeff masters has commented on how weird the storm's ability to function in conditions that usually kill a hurricane in 24-36 hrs for several days is.. and has mentioned that some grad out there ought to be collecting data for a thesis or dissertation. i haven't heard from him, but i'd bet clark is taking notes on this one, or at least some of the oddballs we've had this season... for his phase-analysis work.
a'ite, well, here's to epsilon finally realizing that it's december, and succumbing to shear.
fyi, chaos saying this thing was like a zombie isn't an inept description.
HF 1216z05december
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Margie
Senior Storm Chaser
Reged: Fri
Posts: 1191
Loc: Twin Cities
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Quote:
the hurricane's convective tops are low enough that fast winds above say 300 mb aren't hurting it a whole lot.
This is along the lines of what I've been wondering as well, and I've been looking at the CIMSS upper level winds product the last couple days and comparing that to Epsilon and it is rarely being affected by the shear at the high levels. Last night I noticed again on sat that the shear could be seen just to the north of it at the end of the comma of circulation but not directly over it, and then again just at the southern edge of the circulation. I am not seeing 30 kts of shear affecting Epsilon, and when it was under 20 kts of shear, you could not see that effecting it either. However this morning I am seeing some shear. On the CIMSS upper level winds product, which I am not sure exactly how to read, it appears that the higher winds are over top the TC now, and that strong winds from the 351-500mb range, which maybe could affect it more, if the convection is shallow, are always just to the south of it.
But this info I didn't know:
Quote:
and the tropospheric heights are generally lower than would be in the summer
So maybe that is how it can make sense from an atmospheric point of view, and, if not, then perhaps it really does have some strong outflow that is managing somehow to deflect the shear.
I'm surprised they didn't adjust the floater last night. They've just moved it.
And you know what's funyy...after consistently going south of the forecast points for like six forecasts in a row, now that they've adjusted southward, it's heading due east again.
Edited by Margie (Mon Dec 05 2005 09:27 AM)
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Clark
Meteorologist
Reged: Wed
Posts: 1710
Loc:
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The point about the depth of the storm & the upper-level conditions is largely the big one at play here. I don't have a map handy, but I'm willing to bet that the upper-level temperatures above Epsilon are colder-than-normal, particularly for the given SST. It can't draw a lot out from the ocean, due to the lower temperatures, but what it is getting it is making pretty efficient use of -- this is a part of the heat engine depiction of the tropical system and the so-called maximum potential intensity theory (http://wxmaps.org/pix/hurpot.html). Epsilon's left the most favorable region for maintaining itself as a hurricane and is probably nearing the limits of what it can do until it turns back SW (if the ideal conditions were maintained, which they likely won't be)...we'll see what happens from here.
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Current Tropical Model Output Plots
(or view them on the main page for any active Atlantic storms!)
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Margie
Senior Storm Chaser
Reged: Fri
Posts: 1191
Loc: Twin Cities
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I give up trying to figure this one out. I understand nothing.
Almost like one of those cartoon characters that takes a corner too sharply and the head keeps going the original direction, then rubber-bands back to the body...it turned the corner and the upper level circ almost didn't come along.
Well I can't believe it...Epsilon has reorganized in a big way, after looking like one sick puppy all evening. I had thought this was it, but, no. After the convection seemed to be falling apart, after elongating, after looking like it was decoupling, it managed to rebuild and recover, all in a matter of hours.
Edited by Margie (Tue Dec 06 2005 01:33 AM)
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