ATL: IGOR - Ex Hurricane - Discussion

[HURAKAN]

vortices inside Igor's eye

[JonathanBelles]

hmm....Usually vorticies are seen in intensifying systems and in Cat 5's.

[cwachal]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 14 SEP 2010 Time : 171500 UTC
Lat : 18:34:33 N Lon : 52:22:42 W


CI# /Pressure/ Vmax
6.1 / 947.1mb/117.4kt


Final T# Adj T# Raw T#
6.1 6.5 6.5

Latitude bias adjustment to MSLP : +1.7mb

Estimated radius of max. wind based on IR : 32 km

Center Temp : +12.9C Cloud Region Temp : -69.9C

Scene Type : EYE

Positioning Method : RING/SPIRAL COMBINATION

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

****************************************************

[Gorky]

Igor is certainly ramping up again. Solid ring of cold tops around the eye again and ADT numbers shooting up.



CI# /Pressure/ Vmax
6.1 / 947.1mb/117.4kt


Final T# Adj T# Raw T#
6.1 6.5 6.5

[leaf blower]

Lookin very healthy,Can he make it to cat 5?

[HURAKAN]

solid ring again

[cwachal]

I think that it is undergoing a rapid strengthening trend again that will up it from 115 knts to 140-150 knts (cat 5)

[Scorpion]

Euro is 200 miles WSW of its previous run.

[Buck]

Yeah, he is starting to look angry again!

[HURAKAN]

14/1745 UTC 18.6N 52.7W T6.5/6.5 IGOR -- Atlantic

125 knots

[cwachal]

14/1745 UTC 18.6N 52.7W T6.5/6.5 IGOR -- Atlantic

125 knots

isnt 6.7 Cat 5??? if it is then only .2 from cat 5 hurricane

[HURAKAN]

14/1745 UTC 18.6N 52.7W T6.5/6.5 IGOR -- Atlantic

125 knots

isnt 6.7 Cat 5??? if it is then only .2 from cat 5 hurricane

7.0 is 140 knots.

[brunota2003]

14/1745 UTC 18.6N 52.7W T6.5/6.5 IGOR -- Atlantic

125 knots

isnt 6.7 Cat 5??? if it is then only .2 from cat 5 hurricane

I know 7.0 is 161 mph, and 6.5 is 146...so probably not too far off...but the T #s only go by .5s (those do).

Here is a link to the Dvorak Current Intensity Chart:
http://www.ssd.noaa.gov/PS/TROP/CI-chart.html

[TheBurn]

[HURAKAN]

Loop

[CrazyC83]

14/1745 UTC 18.6N 52.7W T6.5/6.5 IGOR -- Atlantic

125 knots

isnt 6.7 Cat 5??? if it is then only .2 from cat 5 hurricane

No, 6.7 equates to about 130 kt.

[cwachal]

14/1745 UTC 18.6N 52.7W T6.5/6.5 IGOR -- Atlantic

125 knots

isnt 6.7 Cat 5??? if it is then only .2 from cat 5 hurricane

No, 6.7 equates to about 130 kt.

so 6.8-6.9 then right?

[Wthrman13]

hmm....Usually vorticies are seen in intensifying systems and in Cat 5's.

Not necessarily, at least not that I've heard. Sure, you usually see them in more intense hurricanes, but I'm not aware of any dynamical dependence on strengthening or on reaching Cat 5 status for them to appear; they have more to do with the internal dynamics of vortices (the ratio of inflow wind to rotational wind -- something known as the swirl ratio) than on the strength of the vortex. It just so happens with hurricanes that they tend to be most obvious in strong hurricanes, but I wouldn't be surprised if they showed up to some extent in lesser storms as well.

[CrazyC83]

so 6.8-6.9 then right?

Need 7.0 for a Cat 5. Those would equate to 135 kt.

[cwachal]

so 6.8-6.9 then right?

Need 7.0 for a Cat 5. Those would equate to 135 kt.

no 7.0 is 140 knts

CI MWS MWS MSLP MSLP Saffir-Simpson
Number (Knots) (MPH) (Atlantic) (NW Pacific) Category
1 25 KTS 29 MPH (Approximate)
1.5 25 KTS 29 MPH
2 30 KTS 35 MPH 1009 mb 1000 mb
2.5 35 KTS 40 MPH 1005 mb 997 mb
3 45 KTS 52 MPH 1000 mb 991 mb
3.5 55 KTS 63 MPH 994 mb 984 mb
4 65 KTS 75 MPH 987 mb 976 mb 1 (64-83 KTS)
4.5 77 KTS 89 MPH 979 mb 966 mb 1 (64-83 KTS); 2 (84-96 KTS)
5 90 KTS 104 MPH 970 mb 954 mb 2 (84-96 KTS); 3 (97-113 KTS)
5.5 102 KTS 117 MPH 960 mb 941 mb 3 (97-113 KTS)
6 115 KTS 132 MPH 948 mb 927 mb 4 (114-135 KTS)
6.5 127 KTS 146 MPH 935 mb 914 mb 4 (114-135 KTS)
7 140 KTS 161 MPH 921 mb 898 mb 5 (136+ KTS)
7.5 155 KTS 178 MPH 906 mb 879 mb 5 (136+ KTS)
8 170 KTS 196 MPH 890 mb 858 mb 5 (136+ KTS)