Thursday, September 11, 2008

I want to be like Ike

Ike. Cat 2, insanely large wind field and yet uncharacteristically unorganized. I was almost angry that the wind max at flight level moved from 60 to 80 nmi away from the center. Then I read that the inner eyewall at 8 or 10 nmi still has not been removed.

I am blown away by the absolute lack of outflow on the east side. NHC insists there is no shear, but rather dry air. I need dropsonde proof.

I have noticed recurrent bouts of what appear to spiral bands emanating along the east side which produce brief outflow, but no channel forms aloft because the convection is short lived. But you can see these outflow bursts or waves or something. Fascinating. I recently skimmed Willoughby (2008) on inertia-bouyancy waves so I am thinking these bursts are waves or at least energy radiating away from Ike.

The 0315 satellite IR picture shows Ike transforming. The CDO has expanded eastward and the center still has deep convection (no classic eye). Notice the banded cold cloud tops encircling the center. This is probably the radius of maximum wind. Still the east side has not developed an outflow channel aloft. SIL and LCH at 00 UTC still had 20-30 kt NE winds , while TBW and EYW had 50 knots in the outflow channel. Perhaps they will launch 06 UTC soundings.

Power of Ike: Shown is from a buoy that Ike went by. 48 kt on the east side gusting to 62 kt. 60 kt on the west side gusting to 70. On the east side the wave heights were 30 feet. Notice that tropical storm force winds were experienced at this buoy for 27 hours so far.

Central pressure got as low as 947, but more recently is 956. Based on the sat image I think Ike will be cat 3 by morning. The storm is so large though, it will be hard for the wind maximum to contract enough to drop the pressure in the core for the hurricane to truly spin up 10-15 knots.
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Update 0733: 20 nmi eyewall maybe forming.


Notice the huge cirrus blowoff over the texas coast. The soundings still didnt show an outflow channel to the north nor did the soundings have the cirrus layer though it appeared more towards 00 UTC (confusing since the flow agreed with both the high to the west and the outflow from the storm).

update 9-12: Eye wall at 50 nmi formed, broken to the east now but filling in prior to landfall. flight level winds stillcoming in around 107 kt, with the pressure holding at 953 hPa.

The surface wind field is changing rapidly with winds lessthan 90 kt focusing around the 50 nmi eyewall on the NE side (according to the 0130 HWIND analysis). This is one of the most confusing storms I have seen. Cant wait to see what research papers appear in the next 5 years. especially with all the research flights (2 planes simultanously sampling every 6 hours or so).

I expect surge to approach 20-25 ft east of landfall. unfortunalty a buoy has been unmoored 22 nmi out of Galveston Bay (42035). water levels at Galveston are at about 10 feet, though the pictures on TV indicate closer to 15 feet.

Lets address something controversial. Staying in Galveston. Good Luck. I would say to update your will, however it is likely your material possessions will be non-existent in a few hours. Hopefully the military will pull you out, so your greatest achievement will be to help make heroes even more heroic. Crude? Rude? yup.

Categorical strength misrepresents a hurricanes power. Wind speed, storm surge, rain, forwrad motion, angle to the coastline, and size determine a catostraphe. Andrew was small and a cat 5...I was there... it cleared some Florida areas pretty well. Gustav was bigger, weaker, but hit at the right angle and after the levy's already broke for Katrina (a weakening cat 3).

This is way too long, I will verify my gross speculation tomorrow when the damage reports come in.