Hurricane Dean Recon Discussion

[Thunder44]

They were in the SE quad...

They were in the North or NE Quad they are now in the SW Quad.

[KBBOCA]

Thanks for the helpful replies! Just the type of info I was interested in.

[Wthrman13]

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...

In a storm with several wind maxima, the pressure gradient is spread out over a larger radius, effectively yielding weaker winds for a given central pressure. It's the pressure gradient that matters, not the lowest central pressure itself. That said, I expect that the aircraft did not sample the strongest winds yet.

[vacanechaser]

What happened with the VDM?

410
URNT12 KNHC 190000
VORTEX DATA MESSAGE AL042007
A. 18/23:37:50Z
B. 16 deg 01 min N
070 deg 53 min W
C. 700 mb 2382 m
D. 102 kt
E. 011 deg 005 nm
F. 105 deg 118 kt
G. 013 deg 006 nm
H. EXTRAP 920 mb
I. 15 C/ 3047 m
J. 16 C/ 3024 m
K. 15 C/ NA
L. CLOSED
M. CO
N. 12345/ 7
O. 0.02 / 1 nm
P. AF302 0704A DEAN OB 06
MAX FL WIND 118 KT N QUAD 23:36:00 Z
SLP EXTRAP FROM 700 MB
MET ACCURACY 1NM



Jesse V. Bass III
http://www.vastormphoto.com
Hurricane Intercept Research Team

[x-y-no]

From the VDM:

I. 15 C/ 3047 m
J. 16 C/ 3024 m


That's an incredibly weak temperature profile for a storm like this. What this tells me is that it's not recovered from the ERC yet, and it should start intensifying again soon.

[nolecaster]

Not much differential in the eye temperature. Probably not a huge deal when looking at the big picture at this point.

[superfly]

From the VDM:

I. 15 C/ 3047 m
J. 16 C/ 3024 m


That's an incredibly weak temperature profile for a storm like this. What this tells me is that it's not recovered from the ERC yet, and it should start intensifying again soon.

It's not finished the ERC yet.

[CrazyC83]

In a storm with several wind maxima, the pressure gradient is spread out over a larger radius, effectively yielding weaker winds for a given central pressure. It's the pressure gradient that matters, not the lowest central pressure itself. That said, I expect that the aircraft did not sample the strongest winds yet.

Same here, it has probably not reached the strongest winds, but with several wind maxima, it needs a pressure lower than 920 to reach Cat 5 (probably around or below 910).

Apart from Katrina and Rita, another similar example was Opal in 1995 (pressure 916 but peaked at 130 kt and that was questionable IMO),

[RL3AO]

In a storm with several wind maxima, the pressure gradient is spread out over a larger radius, effectively yielding weaker winds for a given central pressure. It's the pressure gradient that matters, not the lowest central pressure itself. That said, I expect that the aircraft did not sample the strongest winds yet.

Same here, it has probably not reached the strongest winds, but with several wind maxima, it needs a pressure lower than 920 to reach Cat 5 (probably around or below 910).

Apart from Katrina and Rita, another similar example was Opal in 1995 (pressure 916 but peaked at 130 kt and that was questionable IMO),

It will break Wilma's pressure of lowest pressure in a Cat 4.

[tolakram]

Ok, I have google earth, how can I link up with sat pics and hurricane info? Thanks.

[CrazyC83]

In a storm with several wind maxima, the pressure gradient is spread out over a larger radius, effectively yielding weaker winds for a given central pressure. It's the pressure gradient that matters, not the lowest central pressure itself. That said, I expect that the aircraft did not sample the strongest winds yet.

Same here, it has probably not reached the strongest winds, but with several wind maxima, it needs a pressure lower than 920 to reach Cat 5 (probably around or below 910).

Apart from Katrina and Rita, another similar example was Opal in 1995 (pressure 916 but peaked at 130 kt and that was questionable IMO),

It will break Wilma's pressure of lowest pressure in a Cat 4.

Perhaps. I personally think it is a Cat 3 right now (despite the 920 pressure), or at least was at that time but may regain itself for the next advisory.

[WindRunner]

A couple things to note with this first VDM . . . first of all, the NHC got the VDM's estimated pressure a full three or four minutes before we did . . . in time to send the advisory out at 23:59z, whereas we didn't get it until 00:03z (it wasn't even issued until 00:00z!).
Secondly, there is a complete lack of temperature gradient in the stom. Eye temp is 16C, and the warmest FL temp in the entire storm outside the eye and eywall is 15C. A strong gradient is a sign of a strong storm, and a weaker gradient like this is a sign of a storm undergoing some changes . . . but definately not strengthening.

And of course, the pressure is down to its lowest yet . . .



EDIT: Now do you guys really have to put up a page of talking while I'm typing?

[gotoman38]

People asking about GE files to use for tropical overlays etc in the OBS thread...

Here's a good collection - but the GUIWeather HH tracks aren't very helpful
http://www.gearthblog.com/kmfiles/weathertools.kmz

Henk's file is awesome for HH detail
http://wxgr.nl/tmppic/WXRecon.kml
I hope he has it set up to run on every mission!

[miamicanes177]

M. CO

What does this stand for in the VDM?

[senorpepr]

M. CO

What does this stand for in the VDM?

Concentric eyewalls... essentially two (or more) eyewalls surrounding the eye.

[fasterdisaster]

Geez down to 918.

[RL3AO]

Winds might be catching up...129 FL.

[CrazyC83]

129 means it is Cat 4 again. I would put it at 115 kt right now.

[dwsqos2]

021100 1615N 07126W 6957 02492 9276 +133 +133 144109 119 110 000 00

Additonally, higher SFMR winds were measured this pass.

[Thunder44]

People asking about GE files to use for tropical overlays etc in the OBS thread...

Here's a good collection - but the GUIWeather HH tracks aren't very helpful
http://www.gearthblog.com/kmfiles/weathertools.kmz

Henk's file is awesome for HH detail
http://wxgr.nl/tmppic/WXRecon.kml
I hope he has it set up to run on every mission!

Henk's file has hurricane hunter minob plots in real-time. At first it was slow to update, now it updates more frequently.