ATL: KATIA - Post Tropical - Discussion

[cycloneye]

18z Best Track is below hurricane strengh.

AL, 12, 2011090318, , BEST, 0, 196N, 564W, 60, 993, TS, 50

[Aric Dunn]

Also the fact that lee has stalled could be a signal that the shortwave wont pick him up to the NE which mean that earlier and present solutions of a westerly turn of katia is quite possible. still to early to tell if the east coast is clear.

[Aric Dunn]

18z Best Track is below hurricane strengh.

AL, 12, 2011090318, , BEST, 0, 196N, 564W, 60, 993, TS, 50

what was the previous best track position.

[Maritimer71]

Halifax gets it pretty bad in the 12Z Euro, and possibly hurricane force wind gusts on Cape Cod.

Bottom line from the 12Z model runs: Way to early for the east coast, especially NC northward, to stop watching this storm.

It's still early so I'm hoping that changes...

[Hurricaneman]

Halifax gets it pretty bad in the 12Z Euro, and possibly hurricane force wind gusts on Cape Cod.

Bottom line from the 12Z model runs: Way to early for the east coast, especially NC northward, to stop watching this storm.

Hopefully not an Irene copycat, because this most likely would be stronger windwise

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products

[clfenwi]

(snip)
... any recon going out ?

As cycloneye posted, nothing within the schedule time-frame,but I would expect to see recon start on Tuesday, with a G-IV flight on Tuesday afternoon as well.

[supercane]

what was the previous best track position.

Last 4 best track positions:
AL, 12, 2011090300, , BEST, 0, 184N, 539W, 65, 988, HU
AL, 12, 2011090306, , BEST, 0, 188N, 546W, 65, 988, HU (delta 0.4 N 0.7 W)
AL, 12, 2011090312, , BEST, 0, 192N, 555W, 65, 988, HU (delta 0.4 N 0.9 W)
AL, 12, 2011090318, , BEST, 0, 196N, 564W, 60, 993, TS (delta 0.4 N 0.9 W)

[clfenwi]

18z Best Track is below hurricane strengh.

AL, 12, 2011090318, , BEST, 0, 196N, 564W, 60, 993, TS, 50

what was the previous best track position.

AL, 12, 2011090312, , BEST, 0, 192N, 555W, 65, 988, HU
AL, 12, 2011090306, , BEST, 0, 188N, 546W, 65, 988, HU

calculated 6 hr motion 9 knots heading 295
calculated 12 hr motion 10 knots heading 295

Above post caused sanity check for the 12 hr heading.

[WeatherGuesser]

Last 4 best track positions:
AL, 12, 2011090300, , BEST, 0, 184N, 539W, 65, 988, HU
AL, 12, 2011090306, , BEST, 0, 188N, 546W, 65, 988, HU (delta 0.4 N 0.7 W)
AL, 12, 2011090312, , BEST, 0, 192N, 555W, 65, 988, HU (delta 0.4 N 0.9 W)
AL, 12, 2011090318, , BEST, 0, 196N, 564W, 60, 993, TS (delta 0.4 N 0.9 W)

Looks more west than north to me.

[cpdaman]

18z Best Track is below hurricane strengh.

AL, 12, 2011090318, , BEST, 0, 196N, 564W, 60, 993, TS, 50

what was the previous best track position.

AL, 12, 2011090312, , BEST, 0, 192N, 555W, 65, 988, HU
AL, 12, 2011090306, , BEST, 0, 188N, 546W, 65, 988, HU

calculated 6 hr motion 9 knots heading 295
calculated 12 hr motion 10 knots heading 295

Above post caused sanity check for the 12 hr heading.

i would think a .4 N .9w movement would be 290-292 headingish

[supercane]

i would think a .4 N .9w movement would be 290-292 headingish

You can calculate the heading from the given information as:
sin-1 (4/9)=26.3 degrees (-1 should be superscripted, but cannot enter this)
275+26=301 degrees

[BigA]

Here's a good site that gives headings for various movements.

http://www.movable-type.co.uk/scripts/latlong.html

It calculated movement in the last 18 hours as at a 297 degree heading, movement in the last 12 and 6 hours as at 295 degrees. \

True NW is 315 and true WNW is 300 I believe, though I am not certain.

[clfenwi]

i would think a .4 N .9w movement would be 290-292 headingish

Comes out to 293.96. And that increases ever so slightly when you adjust for the shorter distance represented by a degree of longitude.

[supercane]

i would think a .4 N .9w movement would be 290-292 headingish

You can calculate the heading from the given information as:
sin-1 (4/9)=26.3 degrees (-1 should be superscripted, but cannot enter this)
275+26=301 degrees

Sorry, made a mistake above, actually have to use arctangent for this:
tan-1 (4/9)=23.96 degrees (-1 should be superscripted, but cannot enter this)
275+24=299 degrees

The calculation above presumes Euclidean (plane) geometry. The site listed above corrects for a spherical earth and gives a number quite close to this of 295 degrees.

[floridasun78]

so will nhc see this change again models move cone back to left or wait for later runs to change it

[floridasun78]

i would think a .4 N .9w movement would be 290-292 headingish

You can calculate the heading from the given information as:
sin-1 (4/9)=26.3 degrees (-1 should be superscripted, but cannot enter this)
275+26=301 degrees

Sorry, made a mistake above, actually have to use arctangent for this:
tan-1 (4/9)=23.96 degrees (-1 should be superscripted, but cannot enter this)
275+24=299 degrees

The calculation above presumes Euclidean (plane) geometry. The site listed above corrects for a spherical earth and gives a number quite close to this of 295 degrees.

so moving more to west to wnw or still nw?

[storm4u]

I think it will move to the left but not by much

so will nhc see this change again models move cone back to left or wait for later runs to change it

[cpdaman]

GFS ens. are ummm intersting esp. frame 5 (very very close to NW bahamas) at 144

GFS ENS don't really look much like the operational run

http://www.meteo.psu.edu/~gadomski/ENSPRS_12z/f156.html

[fci]

just got back... why is everyone so quiet.. ?

Welcome back. We were protecting your honor while you were gone.
Quiet due to recurve and all the attention from the GOM'ers and Texans is on Lee.

[clfenwi]

Solid west-northwest heading.