Hurricane Dean Recon Discussion

[RL3AO]

919mb extrap

[superfly]

Quadruple wind maxima, never seen that before.

[Normandy]

LOL talk about a flattened windfield....clear work of an ERC

[CrazyC83]

919mb extrap

That suggests the actual pressure is in the low 920s probably unless they go lower in the next set.

[wxwatcher91]

117kts at FL ... perhaps winds catch up to pressure tonight.

[HURAKAN]

[KBBOCA]

Derek wrote about "triple wind maxima" on the recon obs thread. What's that?

[jojo]

Lovely graphic Hurakan - thanks for posting

[CrazyC83]

117kts at FL ... perhaps winds catch up to pressure tonight.

This reminds me of Katrina late on August 27 when it had a pressure of about 937 yet was only 100 kt...

[HURAKAN]

Lovely graphic Hurakan - thanks for posting

No problem. I will post them in other thread so you can have the information and location.

[RL3AO]

Interesting winds. Now wait for the next pass.

[Thunder44]

Lovely graphic Hurakan - thanks for posting

No problem. I will post them in other thread so you can have the information and location.

The automatic recon plane path on Google Earth is actually coming up west of your path.

Here's the latest image:

[CrazyC83]

They were in the SE quad...

[KBBOCA]

Can someone PLEASE explain the meaning / significance of triple or quadruple wind maxima. I tried to find it online, no luck. There was some discussion of triple wind maxima with Katrina on an old weather discussion forum I found. Something to do with the ERC. But still no clear explanation of what "triple wind maxima" ARE.

[Wthrman13]

Can someone PLEASE explain the meaning / significance of triple or quadruple wind maxima. I tried to find it online, no luck. There was some discussion of triple wind maxima with Katrina on an old weather discussion forum I found. Something to do with the ERC. But still no clear explanation of what "triple wind maxima" ARE.

Basically, it means that there are three distinct concentric bands of stronger winds surrounding the center, and usually signals either partial or complete concentric eyewalls. Within each eyewall, the winds become stronger, before weakening somewhat between eyewalls, until you get to the center of the innermost eyewall, where the winds will usually be near calm. Concentric eyewalls usually indicate that the hurricane is undergoing an ERC, with the outer eyewalls contracting, and the inner one slowly getting choked off and finally collapsing.

[Normandy]

KBBOCA,
It in the short term, it means the storm has a very flat wind gradient (Large area of 85kt winds with different areas [wind maxima] of slightly higher values like 100kt, 110kts, and the eyewall 120 kts in the inner eyewall).

What this means in the future for Dean is this:....When Dean intensifies again, not only will it be a Category 5, it will have a VERY LARGE windfield consisting of a large area of major hurricane winds, and a larger area of 85kt winds. Likely very devastating for jamaica....Hours upon hours of Hurricane force winds.

[JTD]

REPEATING THE 800 PM AST POSITION...16.0 N...71.0 W. MOVEMENT
TOWARD...WEST NEAR 17 MPH. MAXIMUM SUSTAINED WINDS...150
MPH. MINIMUM CENTRAL PRESSURE...920 MB.

[cycloneye]

What happened with the VDM?

[superfly]

REPEATING THE 800 PM AST POSITION...16.0 N...71.0 W. MOVEMENT
TOWARD...WEST NEAR 17 MPH. MAXIMUM SUSTAINED WINDS...150
MPH. MINIMUM CENTRAL PRESSURE...920 MB.

I think they kept the winds at 150 MPH just for to continuity until more passes because the first pass gave no indication the max winds are anywhere near 150 MPH right now.

[CrazyC83]

REPEATING THE 800 PM AST POSITION...16.0 N...71.0 W. MOVEMENT
TOWARD...WEST NEAR 17 MPH. MAXIMUM SUSTAINED WINDS...150
MPH. MINIMUM CENTRAL PRESSURE...920 MB.

I think they kept the winds at 150 MPH just for to continuity until more passes because the first pass gave no indication the max winds are anywhere near 150 MPH right now.

Probably that is the case. The pressure of 920 normally justifies such though, but this may be a special case...