CAT 5 Hurricane Dean - Archived threads

[ekal]

At night a convergent lay or inversion forms. That doe's not allow the winds to mix as good as when the sun can mix this out. So that is why you have stronger winds at day.

A convergent layer inversion? Hmm, I'm thinking that is not the same as a temperature inversion. What is that?

Okay, wait. Are you saying that a temperature inversion occurs at night within the convergence layer? That would mean temperatures increase with height (slightly) in this layer. Parcels would therefore rise less effectively (surrounding atmospheric environment is not as cold), which would inhibit the maintenance of low surface pressures. Surface winds would thereby weaken. Is that correct?

[NCSUwpack]

It looks like Dean is just ramping up for a slam into land. Unbelievable.

[typhoon_tim]

000
URNT15 KNHC 210655
AF306 1504A DEAN HDOB 23 20070821
064500 1825N 08704W 6969 02695 9990 +084 +999 263106 110 098 032 01
064530 1826N 08704W 6956 02661 9990 +087 +999 266116 120 101 044 01
064600 1828N 08705W 6977 02569 9990 +101 +999 271114 121 110 064 01
064630 1829N 08705W 6948 02517 9990 +112 +999 272094 108 120 053 05
064700 1831N 08705W 6999 02375 9159 +145 +145 267076 082 119 009 05
064730 1832N 08705W 6957 02376 9107 +186 +154 270052 062 083 007 03
064800 1834N 08706W 7001 02289 9067 +196 +144 259022 029 037 005 03
064830 1836N 08706W 7002 02278 9053 +204 +139 132008 018 023 003 03
064900 1838N 08707W 6967 02330 9061 +200 +140 100027 032 032 003 00
064930 1838N 08707W 6967 02330 9082 +188 +146 089039 045 049 002 03
065000 1841N 08708W 6972 02362 9107 +188 +142 081060 067 066 000 03
065030 1843N 08708W 6959 02401 9132 +187 +142 078086 096 089 000 00
065100 1844N 08708W 6972 02420 9171 +179 +151 081109 115 109 000 03
065130 1846N 08707W 6960 02486 9252 +138 +138 082143 152 123 000 03
065200 1846N 08707W 6948 02550 9305 +144 +144 084151 154 999 999 03
065230 1848N 08707W 6974 02565 9336 +169 +127 087162 163 123 014 03
065300 1849N 08707W 6958 02637 9408 +150 +126 092159 164 117 013 00
065330 1850N 08707W 6962 02687 9468 +148 +106 087143 147 105 001 00
065400 1851N 08707W 6967 02721 9518 +139 +116 090133 137 098 000 00
065430 1853N 08707W 6966 02755 9567 +129 +120 091125 127 092 000 00
$$


164 FL wind * .9 = 148kt FL ~= 168mph SFC!

[miamicanes177]

065300 1849N 08707W 6958 02637 9408 +150 +126 092159 164 117 013 00

170mph in my book

[Coredesat]

[Scorpion]

Damn...164. And many people said it was weakening

[Scorpion]

164 could possibly round up to 150 kts.. you never know. Supports 145 kt at least

[100feettstormsurge]

I'll guess 85 m.p.h. when Dean comes back over water.

[Normandy]

Its exit of the Yucatan is a GREAT question....

We can't treat this like a normal storm as it is deepening upon its approach, and even as it gets closer the eye continues to warm and convection is not getting anymore ragged.

Case studies for majors passing over the Yucatan (All were weakening):

Gilbert 140 kt: ERC upon striking Cozumel, weakening.
- Exit: 90 kt (?)
- Second Landfall: 105kt Cat3
Emily 115 kt: Sheared upon striking Cozumel, weakening.
- Exit: 65 kt
- Second Landfall: 105kt Cat 3
Wilma 130 kt: Stalled over land, different situation.
- Exit: 65 kt
- Second Landfall: 110kt Cat 3



Case Studies for Majors passing over land (Deepening):
Hurricane Andrew 150 kt: S FL
- Exit: 105 kt
- Second Landfall: 105 kt

Gilbert: Jamaica 105 kt
- Exit: 105 kt

Katrina: Fl 65 kt
- Exit: 60 kt (instant hurricane strength after exit though).



Deepening systems tend to deal with land a bit better....I'd say Dean leaves a Cat 2.

[Sanibel]

Does that mean 164KT FL?

[Matt-hurricanewatcher]

Wilma's flight level winds where only 4 knots stronger.

[Normandy]

Damn...164. And many people said it was weakening

164kt at flight level using the .92 reduction yields 173 mph at the surface.....9 reduction yields 170 mph.

And P.S,
Stop being annoying. Data up until this point suggested the winds had weakened, but now data supports stronger winds.

[JtSmarts]

Pressure 907 per TWC!

[Zardoz]

I am guessing this storm will exit the Yucatan with 100 mph winds. Any other guesses?

Sounds right. Now the question is how much harm he'll do to the rigs in the big Cantarell field in the Bay of Campeche. We'll see how quickly he powers up once he gets over those waters. He could do a lot of damage out there.

[Scorpion]

Damn...164. And many people said it was weakening

164kt at flight level using the .92 reduction yields 173 mph at the surface.....9 reduction yields 170 mph.

And P.S,
Stop being annoying. Data up until this point suggested the winds had weakened, but now data supports stronger winds.

I wasn't referring to you.. mainly to people in another forum who were going crazy saying it was down to Cat 4

[Chris_in_Tampa]

It was 117 knots at the surface though. Wind did not translate.

Using the 71.3% reduction factor at that moment, it would be:

113.4 knots (~ 130.4 mph)
Category Three Hurricane

Very close to SFMR estimate.

[Normandy]

It was 117 knots at the surface though. Wind did not translate.

Using the 71.3% reduction factor at that moment, it would be:

113.4 knots (~ 130.4 mph)
Category Three Hurricane

Very close to SFMR estimate.

Nah, convection is way to intense for this to have a 71.3% reduction factor. SFMR likely was wrong in that instance imo.

[typhoon_tim]

000
URNT15 KNHC 210704
AF306 1504A DEAN HDOB 24 20070821
065500 1854N 08707W 6964 02785 9598 +127 +122 089120 122 086 000 00
065530 1856N 08707W 6965 02805 9633 +116 +116 091115 116 084 000 00
065600 1857N 08707W 6959 02834 9654 +115 +115 093110 111 078 000 00
065630 1859N 08707W 6949 02860 9675 +097 +097 096107 109 079 003 01
065700 1901N 08707W 6978 02847 9691 +112 +112 099111 113 074 003 00
065730 1902N 08707W 6960 02885 9697 +129 +108 099110 112 076 000 00
065800 1904N 08707W 6967 02890 9715 +129 +095 099105 106 079 000 00
065830 1906N 08707W 6960 02912 9736 +126 +094 098104 105 087 000 00
065900 1908N 08707W 6969 02917 9748 +124 +111 097100 101 087 000 00
065930 1909N 08707W 6966 02932 9759 +122 +122 094094 095 086 000 00
070000 1911N 08707W 6965 02936 9778 +114 +114 096095 098 082 005 00
070030 1913N 08707W 6967 02951 9812 +092 +092 102105 108 080 044 05
070100 1914N 08707W 6975 02947 9830 +090 +090 100114 115 075 017 00
070130 1916N 08707W 6959 02980 9835 +097 +097 096109 114 074 017 03
070200 1918N 08707W 6966 02981 9855 +089 +089 095103 108 071 014 03
070230 1919N 08707W 6961 02992 9844 +111 +111 094109 113 071 006 00
070300 1921N 08706W 6964 03001 9840 +118 +118 096111 113 070 007 00
070330 1923N 08706W 6964 03012 9853 +116 +113 098107 109 068 004 00
070400 1924N 08706W 6967 03010 9852 +124 +101 098102 102 065 003 00
070430 1926N 08706W 6968 03016 9863 +123 +094 099102 104 063 004 00
$$

[Normandy]

Damn...164. And many people said it was weakening

164kt at flight level using the .92 reduction yields 173 mph at the surface.....9 reduction yields 170 mph.

And P.S,
Stop being annoying. Data up until this point suggested the winds had weakened, but now data supports stronger winds.

I wasn't referring to you.. mainly to people in another forum who were going crazy saying it was down to Cat 4

Understood. my apologies.

I assume you mean easternuswx?

[Coredesat]

URNT12 KNHC 210702
VORTEX DATA MESSAGE AL042007
A. 21/06:48:30Z
B. 18 deg 36 min N
087 deg 06 min W
C. 700 mb 2285 m
D. 120 kt
E. 171 deg 7 nm
F. 268 deg 123 kt
G. 171 deg 009 nm
H. 907 mb
I. 9 C/ 3049 m
J. 21 C/ 3009 m
K. 14 C/ NA
L. CLOSED WALL
M. C15
N. 12345/7
O. 0.02 / 2 nm
P. AF306 1504A DEAN OB 13
MAX FL WIND 156 KT N QUAD 05:48:20 Z
EXCELLENT RADAR PRESENTATION