Hurricane Dean Recon Discussion

[Thunder44]

They just passed the eye. Lowest extrapolated pressure down to about 920mb. I expect to find lower pressure in the new VDM from the last one

[cycloneye]

000
URNT12 KNHC 181212
VORTEX DATA MESSAGE AL042007
A. 18/11:51:20Z
B. 15 deg 23 min N
067 deg 52 min W
C. 700 mb 2437 m
D. 121 kt
E. 5 deg 008 nm
F. 137 deg 145 kt
G. 050 deg 008 nm
H. 926 mb
I. 11 C/ 3049 m
J. 23 C/ 3041 m
K. 11 C/ NA
L. CLOSED
M. C12
N. 12345/ 7
O. 0.02 / 2 nm
P. AF304 0604A DEAN OB 03
MAX FL WIND 145 KT NE QUAD 11:48:40 Z
SMALL HAIL INBOUND NE QUAD
RADAR PRESENTATION EXCELLENT

[WmE]

What does that hail inbound mean??

[tolakram]

What does that hail inbound mean??

My guess is that they ran through some hail on the way in. Hail as in ice, often times associated with severe thunderstorms.

[WmE]

Yep, Frances too has some small hail in its SW eyewall.

[cycloneye]

A. 19/0000Z
B. NOAA9 1004A DEAN
C. 19/1830Z
D. NA
E. NA
F. 41,000 TO 45,000FT


Someone asked,when the gulfstream jet would go out there so here is the plan.Tonight at 8:00 PM EDT it departs.

[Pebbles]

I am willing to bet we will be seeing the signs of an ERC in the next vortex. Everyone keep that in mind when it comes in.

[WindRunner]

Well, we have such indications now. Double eyewall to the north, no eyewall to the south . . . new vortex shortly.

[Windtalker2]

Well, we have such indications now. Double eyewall to the north, no eyewall to the south . . . new vortex shortly.

Quick question....still learning: Could that mean a center relocation more to the north?

[x-y-no]

Well, we have such indications now. Double eyewall to the north, no eyewall to the south . . . new vortex shortly.

Quick question....still learning: Could that mean a center relocation more to the north?

No, the eyewalls are concentric, so this really doesn't affect position.

[WindRunner]

In a storm this strong, it is virtually impossible to have center relocations.

Double eyewalls are typically a sign of an eyewall replacement cycle (ERC), in which the hurricane forms a larger eyewall around its smaller, older one. This new outer eyewall will prevent the hurricanes energy and fuel from reaching the eyewall, however, until this process is complete and the inner eyewall has collapsed, the storm will be somewhat weaker as the energy it has is fueling two eyewalls. After the process is complete, the inner eyewall is completely gone and the outer one will become the main eyewall.

[Windtalker2]

In a storm this strong, it is virtually impossible to have center relocations.

Double eyewalls are typically a sign of an eyewall replacement cycle (ERC), in which the hurricane forms a larger eyewall around its smaller, older one. This new outer eyewall will prevent the hurricanes energy and fuel from reaching the eyewall, however, until this process is complete and the inner eyewall has collapsed, the storm will be somewhat weaker as the energy it has is fueling two eyewalls. After the process is complete, the inner eyewall is completely gone and the outer one will become the main eyewall.

Thank You

[vacanechaser]

Well, we have such indications now. Double eyewall to the north, no eyewall to the south . . . new vortex shortly.

Quick question....still learning: Could that mean a center relocation more to the north?

No, the eyewalls are concentric, so this really doesn't affect position.

in strong hurricanes you get a double eyewall alot of times.. sometimes this can come from an eyewall replacement cycle.. one weakens and moves outward and the other forms in closer.. you get an area of clearness between the two which is called a moat.. in that area you could see a relax in rain and wind for a brief time frame...we did during charley before we got slammed with the winds near 135-140mph when it reached our location..so dean could have started another erc.. that could be the reason why the pressure has risen over the past few hours...

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

[vacanechaser]

In a storm this strong, it is virtually impossible to have center relocations.

Double eyewalls are typically a sign of an eyewall replacement cycle (ERC), in which the hurricane forms a larger eyewall around its smaller, older one. This new outer eyewall will prevent the hurricanes energy and fuel from reaching the eyewall, however, until this process is complete and the inner eyewall has collapsed, the storm will be somewhat weaker as the energy it has is fueling two eyewalls. After the process is complete, the inner eyewall is completely gone and the outer one will become the main eyewall.

i htought it was the other way around... guess i was mistaken .. learn something every day


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

[WindRunner]

VDM in . . . both eyewalls now closed . . .

[vacanechaser]

URNT12 KNHC 181731
VORTEX DATA MESSAGE AL042007
A. 18/17:02:40Z
B. 15 deg 49 min N
069 deg 14 min W
C. 700 mb 2484 m
D. 101 kt
E. 121 deg 007 nm
F. 212 deg 110 kt
G. 121 deg 007 nm
H. 930 mb
I. 11 C/ 3051 m
J. 16 C/ 3052 m
K. 15 C/ NA
L. CLOSED
M. CO 11 22
N. 12345/ 7
O. 0.02 / 2 nm
P. AF304 0604A DEAN OB 27
MAX FL WIND 128 KT N QUAD 16:12:00 Z
MAX FL WIND OUTBOUND 133 KT NE QUAD 17:06:50
CONCENTRIC EYEWALL STRUCTURE


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

[WindRunner]

Yeah, you can figure it works the other way around because of two reasons. One, the ERC always results in a larger eye than before. Secondly, as the storm gets a new, larger eyewall, it weakens. This makes sense because we know a contracting/shrinking eywall is the sign of a stronger storm. Hence, after an ERC and associated weakening, the storm will then begin to shrink its eyewall and strengthen.

[cycloneye]

A. 19/0000, 0600Z
B. AFXXX 0704A DEAN
C. 18/2200Z
D. 16.7N 72.3W
E. 18/2300Z TO 19/0600Z
F. SFC TO 10,000FT


The next mission will depart at 6:00 PM EDT from ST Croix.

[miamicanes177]

how much longer before this thing completes the EWRC so it can strengthen? Word has it Rita is still trying to complete hers.

[WindRunner]

At least another six to twelve hours, though it could very easily be morning before the process is fully completed. From the recon reports, it seems as if the old/inner eyewall isn't going down without a fight . . .