LoisCane
Veteran Storm Chaser
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Posts: 1236
Loc: South Florida
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It's a strange shaped storm. I believe it does have dry air from yesterday entrained in it but before it hit Cuba it also had a similar structure.
It was also said several times that it was a "dry" storm... a huge circulation but a very dry storm when you look at the infared imagery. Dry being relative obviously.
Some images of large gulf storms.
http://www.virginmedia.com/microsites/technology/slideshow/vm-tech-gallery/hurricanes/img_11.jpg
Rita.. different but similar spot in Eastern Gulf
http://upload.wikimedia.org/wikipedia/co...05-0115-UTC.jpg
Amazing picture of Gilbert
http://www.nasm.si.edu/exhibitions/lae/images/LE410L11.jpg
Notice in this pic the storm in the Pacific similar to the set up we have now with Ike
Big Gulf storms are always amazing to watch but very dangerous and deadly.
Keep watching imagine Ike will evolve some more before our eyes!
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http://hurricaneharbor.blogspot.com/
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craigm
Storm Tracker
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Posts: 327
Loc: Palm City, Florida
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RC --N42RF just penetrated eye again---942.5mb
Time:
00:29:30Z
Coordinates:
24.7167N 86.3667W
Acft. Static Air Press:
718.5 mb (~ 21.22 inHg)
Acft. Geopotential Hgt:
2,413 meters (~ 7,917 feet)
Extrap. SFC. Press:
942.5 mb (~ 27.83 inHg)
D-value:
-
Flt. Lvl. Wind (30s):
From 167° at 4 knots (From the SSE at ~ 4.6 mph)
Air Temp:
19.8°C (~ 67.6°F)
Dew Pt:
17.0°C (~ 62.6°F)
Peak (10s) Flt. Lvl. Wind:
10 knots (~ 11.5 mph)
SFMR Peak (10s) SFC. Wind:
27 knots (~ 31.0 mph)
SFMR Rain Rate:
0 mm/hr (~ 0 in/hr)
(*) Denotes suspect data
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Why I'm here:
Weather hobbyist
Edited by craigm (Thu Sep 11 2008 12:44 AM)
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lennox
Registered User
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Posts: 2
Loc: Toronto, ON
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Another new low from N42RF:
01:05:00Z
24.733N 86.433W
723.1 mb(~ 21.35 inHg)
2,350 meters(~ 7,710 feet)
941.6 mb(~ 27.81 inHg)
The image loop shows good continued convection over the inner eye wall. Amazing size.
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SeaMule
Weather Hobbyist
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Posts: 64
Loc: Fairhope, Al...on the coast
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I have been watching these things since Frederic of 79....and just missed ...and watched her develop. A few things noteworthy and in need of a met or two to explain if my thought pattern fits what I'm seeing.
Could the reason Ike has a low pressure drop, yet still, wind speeds that haven't caught up to that drop, be because it is so large in diameter? I'm thinking of a skater who the closer she pulls herself in when spinning, the faster she goes...
Here is the thought I'm having. Is the size of this cane, as well as the quick drop in the pressure, and the evident double and perhaps triple eyewall....be an event we just haven't seen before? Is this perhaps the super-type cyclone they talk about? This thing is so large...that when you do the floater loop...it seems like a small picture....it doesn't cover the whole storm...
and now it's reaching the warm eddies...and I heard on the weather....that they can't discount a 5.....
anyhow....given all that...my original feelings that a quickly developing and more dangerous hurricane...might be something the models have NOT considered. Could the size of the storm...and power of it....overcome the high pressure ridges...and in effect...could Ike go wherever it wants...?
I seriously would like a met's thoughts on this.
Edited by Ed Dunham (Thu Sep 11 2008 05:04 AM)
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mikethewreck
Weather Hobbyist
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Posts: 52
Loc: Treasure Coast FL
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We can't be sure what Ike's intensity will be. There are a LOT a variables between now and landfall. Shear and eyewall replacement cycles may be just what the doctor ordered for Ike. Now is not the time to panic or instill panic. Texans, now is the time to put your hurricane plan to use.
Wasn't Ike originally a small storm like Andrew? How did he morph into this Gilbert-like monster?
I think this hurricane season will be the subject for more than one graduate thesis. Lots of very interesting storms...but Cuba, Haiti, and the Dominican Republic must be pretty sick of them by now.
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Earliest memory Hurricane Cleo!
Went under Hurricane Gloria!
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Clark
Meteorologist
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Posts: 1710
Loc:
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Ike is an interesting storm, with a well-defined outer eyewall of about 80-90 nm radius and a reasonably well-defined inner eyewall of about 10 nm radius. The pressure keeps falling, but the wind field is not responding because of this dual eyewall structure. Conventional satellite shows a deep mass of convection atop the center of circulation, but there are also hints of dry air intrusion just outside of this. Due to the thermodynamics behind this and the lack of organization of this tight inner core, the pressure falls are not leading to a significant increase in maximum winds.
Instead, the pressure gradient -- the primary driver of the winds -- is largely uniform from the inner eyewall to about 100 nm radius. As a result, the radii of hurricane-force and tropical storm-force winds continues to expand as the pressure falls. While we don't know enough about dual eyewall structures or hurricanes in general to conclusively attribute this evolution to such a structure, but it seems as though that land interaction and/or dual eyewall structure *plus* less than ideal atmospheric conditions (here, dry air intrusion; with Gustav, upper-level shear) tends to lead to this combination of low surface pressures but not correspondingly maximum winds. Will these conditions change? It's tough to say. We don't know enough about inner core dynamics to determine this, leading there to be a lot of variability right now. Ultimately, a major hurricane is likely at landfall, but how major of one?
In summary, what is important is how the pressure falls change the pressure gradient, not so much just the pressure falls. Something in the storm is keeping the wind field from responding and it almost assuredly is the dual eyewall structure. How that evolves over the next day and a half will determine how the storm's wind field evolves up until landfall. Steady strengthening is possible as is a period of rapid intensification. Which will it be? Truly, it is tough to say.
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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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Allison
Weather Guru
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Posts: 134
Loc: Laredo, Texas
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The latest images on the IR loop show the eye closing over... this couldn't possibly be an eyewall replacement cycle, could it? Is Ike's structure ready for an ?
IR Loop
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Allison
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SeaMule
Weather Hobbyist
Reged:
Posts: 64
Loc: Fairhope, Al...on the coast
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post Clark....one other question....
Could the sheer size and diameter of the 100 mile radius just mean that it a question of size. it just take longer and more heat from the water to get Ike's wind speed going? Assuredly, a smaller buzz saw like Andrew would grab the energy quicker...
at any rate...excellent explanation. This one will teach the mets a lot. All I can do is watch and learn a little....
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Random Chaos
Weather Analyst
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Posts: 1024
Loc: Maryland
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I would personally suggest the JSL loop over the RB loop for looking at the outer eyewall:
http://www.ssd.noaa.gov/goes/east/gmex/loop-jsl.html
And while we are at it, you can see it on Microwave imagery too - it's almost entirely encircled the inner eyewall, with the exception of the very north:
http://www.nrlmry.navy.mil/tcdat/tc08/AT...N-863W.95pc.jpg
This is one strange storm.
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Thunderbird12
Meteorologist
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Posts: 644
Loc: Oklahoma
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When looking at the most recent forecast track, keep in mind that the lines between forecast points do not necessarily represent the expected path of the storm. Drawing a straight line between the 48 and 72 hour forecast points makes it appear the forecast track is closer to Galveston, but the storm (if it takes the path expected by ) is likely to make more of a gradual curve between 48 and 72 hours, bringing it onshore further south and then arcing back into northeast Texas by 72 hours.
That is not to say that a further north landfall is not possible. Ike is a large storm and Galveston is still well within the cone and the Hurricane Watch and everyone in the area should be taking appropriate action at this point.
Drawing straight lines between forecast points occasionally produces misleading results and I wish could correct or note that somehow in their graphic.
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Robert
Weather Analyst
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Posts: 364
Loc: Southeast, FL
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Well Um Ike is in the process of being handed from one ridge to another. He is Headed NW soon to head WNW. Once ike gets under the new ridge and as the ridge axis moves bye to his north and east it should cause hime to tighten up and BAMM the winds will come up.
Edited by Ed Dunham (Thu Sep 11 2008 05:00 AM)
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flahurricane
Weather Hobbyist
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Posts: 55
Loc:
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It appears that strengthening is continuing. A recent increase of convection near the eye - very cold cloud tops. It also looks like there is less dry air penetrating the storm. It will be interesting to see if the storm increases in size now that its cleared some of the dry air from its structure. Also, based on satellite imagery, looks like is slowing and making more of a westward jog. We'll have to see if that trend continues. Night ya'll from Tally.
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BillD
User
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Posts: 398
Loc: Miami
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Agreed. Doing what the said it was going to do. On IR looks like the tight and small center circulation is now merging with the next layer out. Not sure if this is a typical though. Still lots of dry air, and the convection on the west side is lacking. But Ike is huge, and not getting any smaller. As others have noted, this is a storm that will be studied for years to come.
Bill
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Ed Dunham
Former Meteorologist & CFHC Forum Moderator (Ed Passed Away on May 14, 2017)
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Posts: 2565
Loc: Melbourne, FL
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Just a reminder to report your weather observations in the "Ike Conditions in Your Area" thread in the Storm Forum. A few earlier posts were moved there.
Thanks,
ED
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RedingtonBeachGuy
Moderator
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Posts: 342
Loc: St. Cloud, FL
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Since Ike is forecast to hit just west of Galveston Island, I thought these storm surge projections by Will Shaffer at the National Weather Service (produced/published by the Houston Chronicle) would be of interest to folks in the area.
As you can see by the link, they are talking about the potential of a 19' surge with a Cat 3 storm all the way up to the north end of Burnett Bay which is on the East side of Houston.
If you live in that area, be sure to read the comments in the linked blog above as the paper points to a map showing how far inland the surge will carry.
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Random Chaos
Weather Analyst
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Posts: 1024
Loc: Maryland
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It has begun. We have concentric eyewalls:
8nm
42nm
Here's the entire vortex:
URNT12 KNHC 111129
VORTEX DATA MESSAGE AL092008
A. 11/11:02:20Z
B. 25 deg 20 min N
087 deg 52 min W
C. 700 mb 2647 m
D. 59 kt
E. 229 deg 4 nm
F. 312 deg 070 kt
G. 226 deg 036 nm
H. 946 mb
I. 12 C/ 3049 m
J. 17 C/ 3044 m
K. 10 C/ NA
L. OPEN NW
M. CO8-42
N. 12345/7
O. 0.02 / 1 nm
P. AF308 2309A IKE OB 21
MAX FL WIND 92 KT NE QUAD 11:12:40 Z
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Raymond
Weather Guru
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Posts: 112
Loc: Germany
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Things getting really weird with the core dynamics of Ike. In the vortex data message before then one shown above there had been two closed, concentric walls with 4 nm!! and 12 nm diameter. Must be very strange to fly through such a structure! Now we have to concentric walls with 9 and 42 nm diameter. May be the larger one will take over finally.
Otherwise basically nothing new regarding the central pressure, the winds and the overall asymetric structure of Ike.
Edited by Raymond (Thu Sep 11 2008 11:56 AM)
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Random Chaos
Weather Analyst
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Posts: 1024
Loc: Maryland
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I saw that.
I was thinking one might be a typo, but a 4nm eye won't expand to an 8 nm eye unless the storm is doing some really weird dynamics (technically an eye can grow in size, but it requires time and generally a weakening storm; these reccos were too close together to indicate anything like that).
My guess is that the 4nm eye has dissipated and a 3rd, larger eyewall has since formed. I wonder if the first vortex might have better read something like 4nm, 12nm, and 40-some nm as a triple eyewall, since in an hour an eyewall won't just form, but the vortex recons don't allow for a triple eyewall scenario in their messages.
I'm personally thinking that with these multiple eyewalls forming is good for the development of the system (and bad for Texas). As each eyewall develops and contracts, the central pressure will fall and the winds will increase, consolidating this massive storm.
Ike has incredible energy - as evidenced by a huge swath of hurricane force winds - that it is desperately trying to organize. Eyewall cycles will help this.
I was half expecting last night that, based on Microwave, we might get a near 100nm eyewall forming, but the structure never finished closing off in the north. I suspect this same structure is what is now the 42nm eyewall, but without recent microwave data, there is no way to be sure.
Ever seen a category 2 go through eyewall cycles before? This storm is highly unusual.
--RC
Edited by Random Chaos (Thu Sep 11 2008 12:08 PM)
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danielw
Moderator
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Posts: 3525
Loc: Hattiesburg,MS (31.3N 89.3W)
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Quick, and not totally accurate formula for estimating surge height developed at LSU.
Pressure change from 1013mb divided by 4 equals approximate surge height.
1013mb-946mb= 16.75 feet of surge not including waves.
Significant Wave height formula for the average 1/3 of the waves is:
1013mb- 946mb=67 x 0.2= 13.4meters x 3.28 = 43.95 feet !!!
Pressure wind relationship for 946mb would be near 129mph at the surface... should Ike spin up~danielw
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Raymond
Weather Guru
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Posts: 112
Loc: Germany
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On the 11:31 UTC TMI pass you can partly see the two concentric eyewalls, but also the the band to the NE of the outer eyewall, where Recon found recently the highest flight level wind with 100 kt.
Edited by Raymond (Thu Sep 11 2008 01:27 PM)
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