Hurricane Dean Recon Discussion

[tolakram]

145?

possible 150 mph at the surface.

[WindRunner]

Note the SFMR a couple minutes prior recorded 121kts twice . . . means that there is probably winds at least two knots higher than that that aren't being sampled . . . so 125kts sounds very right for the advisory (so far) . . . and VDM shortly.

[WindRunner]

Oh, and we do have AF305 flying in as well now, though it is flying at 1000 feet for some reason . . .

[gotoman38]

Oh, and we do have AF305 flying in as well now, though it is flying at 1000 feet for some reason . . .

AF305 must be the bouy drop mission btwn the Caymans and Cozumel

FLIGHT THREE
A. 19/1200Z
B. AFXXX 0804A DEAN
C. 19/0930Z
D. BOUY DROP MISSION--12 BOUYS CNTR NEAR 20N 84W
E. 19/1200Z TO 19/1800Z
F. SFC TO 10,000 FT

[CrazyC83]

145 kt FL = 131 kt surface...

[fasterdisaster]

Should be putting 150MPH on the next advisory

[CrazyC83]

Should be putting 150MPH on the next advisory

That is what I think as well. It intensified overnight from 110 kt to 130 kt.

[mutley]

145 kt FL = 131 kt surface...

145 kt x 1.1508 = 166.86 mph
166.86 mph x .85 = 141.83 @ surface

Okay, what did I do wrong?

[CrazyC83]

145 kt FL = 131 kt surface...

145 kt x 1.1508 = 166.86 mph
166.86 mph x .85 = 141.83 @ surface

Okay, what did I do wrong?

Isn't it a 90% reduction at that altitude?

[mutley]

145 kt FL = 131 kt surface...

145 kt x 1.1508 = 166.86 mph
166.86 mph x .85 = 141.83 @ surface

Okay, what did I do wrong?

Isn't it a 90% reduction at that altitude?

I'm not sure. That's why I was asking. LOL

[Chris_in_Tampa]

URNT12 KNHC 191443
VORTEX DATA MESSAGE AL042007
A. 19/13:58:00Z
B. 16 deg 49 min N
074 deg 49 min W
C. 700 mb 2448 m
D. 112 kt
E. 220 deg 020 nm
F. 324 deg 111 kt
G. 221 deg 023 nm
H. EXTRAP 926 mb
I. NA C/ 3040 m
J. 18 C/ 3045 m
K. 13 C/ NA
L. CLOSED
M. C16-32
N. 12345/ 7
O. 0.02 / 2 nm
P. AF304 0904A DEAN OB 08
MAX FL WIND 110 KT SE QUAD 12:15:20 Z
MAX FL WIND OUTBOUND FROM CNTR 134KT AT 14:06:50Z
SLP EXTRAP FROM 700 MB

---

For some reason it does not have higher winds noted.

Looking at the HDOBs from that time, air temp/dew point was suspect and pressure readings were unavailable. The winds, of any type, were not noted as suspect though.

[x-y-no]

H. EXTRAP 926 mb

Pressure going up a bit.

Hope that continues.

[WindRunner]

I believe the higher winds were not measured until just after the VDM transmission (which was 1443Z), in which case they are supposed to issue a corrected VDM, but it appears this has not been done.

[gotoman38]

11am advisory keeps winds at 145

MAXIMUM SUSTAINED WINDS ARE NEAR 145 MPH...230 KM/HR...WITH HIGHER
GUSTS. DEAN IS A CATEGORY FOUR HURRICANE ON THE SAFFIR-SIMPSON
SCALE. FLUCTUATIONS IN INTENSITY ARE COMMON IN MAJOR HURRICANES AND
ARE POSSIBLE DURING THE NEXT 24 HOURS.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 60 MILES...95 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 205
MILES...335 KM.

THE LATEST MINIMUM CENTRAL PRESSURE REPORTED BY AN AIR FORCE RESERVE
UNIT RECONNAISSANCE AIRCRAFT WAS 926 MB...27.34 INCHES.

[WindRunner]

Isn't it a 90% reduction at that altitude?

I'm not sure. That's why I was asking. LOL

Yes, the standard reduction from 700mb (10,000 feet) is a factor of .9.

[johngaltfla]

H. EXTRAP 926 mb

Pressure going up a bit.

Hope that continues.

I hope so also and it's not just an ERC underway.....Once it gets closer to the slot and hits that 87+ water, wow....

[Chris_in_Tampa]

I guess we can't go by the peak 10 second wind from HDOBs. Have to use 30 second sustained at least.

[Stephanie]

H. EXTRAP 926 mb

Pressure going up a bit.

Hope that continues.

I hope so also and it's not just an ERC underway.....Once it gets closer to the slot and hits that 87+ water, wow....

Dr. Steve Lyons was just commenting a little while ago that there was an ERC underway.

[pojo]

Oh, and we do have AF305 flying in as well now, though it is flying at 1000 feet for some reason . . .

AF305 must be the bouy drop mission btwn the Caymans and Cozumel

FLIGHT THREE
A. 19/1200Z
B. AFXXX 0804A DEAN
C. 19/0930Z
D. BOUY DROP MISSION--12 BOUYS CNTR NEAR 20N 84W
E. 19/1200Z TO 19/1800Z
F. SFC TO 10,000 FT

5305 IS the buoy drop mission.... NOT DEAN Fix.

[Derek Ortt]

the 90 percent rule is not absolute. Some are incorrectly using it as the absolute reduction

The range of reductions ranges from .6 to 1.2... and for this one, .85 has been consistent throughout its time in the Caribbean