09L: Hurricane Ike

[Chris Lott]

This has to be the largest hurricane I have witnessed. While experiencing some of the rain bands here in Florida yesterday, the Weather Channel was showing that Louisianna was just starting to see rain bands. I can't remember when a hurricane affected such a large area. Is this the largest hurricane or has there been one even larger?

There is some interesting information on damaging hurricanes that you might find what you're looking for. I couldn't tell you if it's the largest or not, but I'm very impressed by it so far. I'm just like everyone else and curious as to what is stopping or slowing it from strengthening.
http://en.wikipedia.org/wiki/List_of_tropical_cyclones

 

[Jeff Richardson]

Anyone know the Tornado count on Hurricane Katrina ?

According to some data from the NHC, Katrina had 43 reported tornadoes. Considering the widespread nature of the damage from straight-line winds, which could have made distinguishing tornado and straight wind damage difficult, and the sometimes erratic behavior of hurricane generated tornadoes, there could have been more.

I'm interested to see when the SPC issues it's first tornado watch for the TX coast and read any MD's issued beforehand.

 

[Sarah Austin]

Thanks for the link Chris. I will definately check it out. And yes, I think there are so many questions. How can one hurricane get to be so large in diameter and another one not so? Perhaps the link will help me on this one.

I'm not sure if the hurricane that hit Galviston, Texas in 1900 was the largest, but it caused a lot of damage. I might have to do some research.

 

[Scott Overpeck]

Scott , My uncle ( 74) is being an as@ , and is going to ride the storm out in Dickinson.
Can Dickinson handle this storm surge that we all fear?

Jason, It all depends on where he is in Dickinson. If he is anywhere close to Dickinson Bayou, he'll have some problems. I live W of I-45 off FM646 close to the office, and think I'll be okay, but nervous about it.

With that, looking at some slosh runs...if he is east of hwy 3, he'll have some issues. If he is between hwy 3 and I-45, may still have some issues but not as bad as farther east. W of I-45 on FM 517, questionable whether surge will get that far. It would have to take some doing to get w of I-45 but the bayou is the wild card.

On a side note - IR imagery showing some vigorous convective bursting at 530z. Hoping this is just a nocturnal increase and not a long term effect. CDO looking much better now on satellite.

 

[Darren Addy]

Missed that one. So a gust barely to hurricane strength, while NHC says sustained winds over that buoy are 80-100mph with gusts to 120mph. Must be a sensor error

Somebody correct me if I'm wrong here, but I think we need to remember that there are estimates and then there is "ground truth". There are rarely anomometers placed right where we need them under hurricanes. The current way of estimating surface winds is a combination of:
1) releasing dropsondes and reduce the data
2) STEPPED-FREQUENCY MICROWAVE RADIOMETER (SFMR) http://www.403wg.afrc.af.mil/library/factsheets/factsheet.asp?id=8314

"Wind retrieval algorithms" are used to calculate the estimated speeds. These algorithms (like the algorithms used in models) is always being refined, hopefully leading to greater accuracy as time goes by.

The SMFR performance (accuracy) relies on two variables: sea surface temperature and salinity. (If those variables are off then the SMFR performance will suffer.)

All of this is an effort to reach "ground truth". However, with an understanding of all the variables, we (perhaps as well as anybody) should understand when it isn't an exact match.

After the event, post-mortems are often done to see what worked and what didn't. This paper is just one example of that (and also the source of the info in this post).

 

[Marc Austin]

Missed that one. So a gust barely to hurricane strength, while NHC says sustained winds over that buoy are 80-100mph with gusts to 120mph. Must be a sensor error

I'm not sure exactly how effective the buoys normally are at measuring the winds, but I would think the wave crests/toughs, if sufficiently large enough might orient the anemometer so that it reads inaccurately? Also, when in a trough, the buoy would be somewhat protected from the strongest winds whereas on a crest, it would be more exposed. Do the buoys take an average of their recordings for the sustained winds? I don't know much about it, but I thought the idea of extreme wave action might create errors in the wind data. Just a thought...

 

[Jason Liedtke]

Hey all, I am not sure if this is the right thread or even forum for this. I just wanted to let you all know I have put a QuadCam page up with the Houston TV station feeds at http://www.weatherserver.net/hurricanefeeds.html Sorry it only seems to work in IE.

Thanks,
Jason
www.weatherserver.net

 

[MClarkson]

on the last GOES-east IR shot before eclipse, you can see the outer eyewall and its cold cloud tops clearly seperated from the inner structure(that just wont die) by an area of sinking air and warmer tops. The impressive part is its about 3 degrees... 180nm... wide.

 

[Chad Cowan]

Is anyone else seeing a hurricane structure in the eye of a larger hurricane? It seems like the CDO (which is finally getting its act together) and its small spiraling bands are encompassed by a huge eye. I haven't followed the tropics closely for more than a few years, but this seems terribly unique.

Edit: Just now read MClarkson's post above.

 

[Jeff Snyder]

Is anyone else seeing a hurricane structure in the eye of a larger hurricane? It seems like the CDO (which is finally getting its act together) and its small spiraling bands are encompassed by a huge eye. I haven't followed the tropics closely for more than a few years, but this seems terribly unique.

I was just thinking that, actually. It looks like some sort of outer ring of convection (an eyewall of sorts, but not sure I can call it an eyewall) surrounds a smaller, but relatively large compared to some of the smaller tropical cyclones of the past several years, core of convection. I wonder if the "inner core" has a large enough area that it's able to sustain itself much like a weak hurricane would, while producing some compensatory subsidence between that inner core and the outer "core". This subsidence acts to increase low-level convergence along the outer ring, thus leading to the persistence of that outer max. All the while, the outer ring is decreasing the pressure gradient and disrupting the inflow to the inner core. Still, though, the inner core has enough ground to "play with" that it doesn't die off completely. In such a case, the inner core convection keeps the outer core at a considerable distance, while the outer core prevents the inner core from becoming particularly intense. That would partially explain why we've seen this quasi-steady state appearance, though I'm not sure that explanation makes any sense (in the way it is worded and/or based on physical principles).

 

[MClarkson]

It does make sense... the outer "eyewall" "windmax"... "very solid rainband", whatever you want to call it, has too much diameter, too far away to provide enough upper level convergence to kill the little inner eyewall completely. So the inner core persists... although disorganized according to the latest VDM... there is plenty of deep convection there.

 

[Ryan Orlando]

According to the 4 AM CDT Hurricane Ike is now up to 105 MPH. The reason he is up this far is because he got rid of the second "eyewall" that he had. It will be interesting if the winds will start to increase dramatically if it keeps this up. Well I better get to bed. I can't wait to see what it looks like at the 10 AM CDT advisory.

 

[Scott Overpeck]

Ike may be up to 105mph, but on satellite it is having a hard time. On a water vapor loop you can see still some dry air to the north of it probably getting entrained. Oh ya, looks like there may be some northerly shear as well as mentioned by NHC. The outflow of this storm is going a long way in maintaining its structure.

 

[Warren Faidley]

Report from Galveston:

5:10 AM. Woke up by large waves crashing into seawall, with water spilling over the highway. Water level still has a way to go, maybe 5-6 feet. Water appears (with night vision) to be going completely over outer regions of piers. Doubt those buildings over the water will survive. Streets empty. Police escorting last evacuees out of town, come going code 3. Unless some of the sat. trucks find high ground, they will be flooded. I don't think some of the media are aware of storm surges. Looks like heavy (and dangerous) northern rain bands will hit in advance of the core by mid-day. A lot of people here were thinking it was going to hit (bad part) at 2-3 AM. This may not be the case as the north eyewall (or bands) may be the most severe portion.

For those who have not been in Galveston, the area near seawall is higher than the main portion of town to the north. I suspect this area could flood quite easily. Local media calling for a 25 foot storm surge now along the Galveston coast. I suspect coastal roads are now flooded, so chasers beware. Word is I-45 leading into Galveston will close when the wind hits 40-45 mph.

Everyone please be safe. Remember the storm surge can rise with amazing speed and trap you in an unprotected area of town. Very likely to see tornadoes embedded in rain bands. BTW: ROTATE and the portable doppler is here. Should be some interesting post-storm data.

Live TV Report just in.... homes being flooded in Surfside. (Evacuated).

W.

 

[B Ozanne]

Check out "buoy" 42361, its actually an oil platform. Sustained winds at 122m are over 90 kts.

http://ndbc.noaa.gov/station_page.php?station=42361

Edit: Up to 99kts right now. I'm sure the NHC will translate that data to a 10m wind speed.