Unregistered User
(Unregistered)
Fri Sep 02 2005 10:31 AM
terminology

can someone please explain to me the use of the terms "invest", and the assignment of the numericals "92", "97", etc.?

Clark
(Meteorologist)
Fri Sep 02 2005 05:03 PM
Re: terminology

Invest means they are investigating it for possible development. The numbers 90-99 (recycled after 99 back to 90) are assigned so as not to conflict with any actual system that may be out there while still keeping them in the two-digit realm (good for model runs and such). The letter after the number designates which basin the invest is in -- L is for Atlantic, E is for the East Pacific, W is for the West Pacific, and S is for the Southern Pacific. There's one for the Indian Ocean too, but I don't think it is I.

Unregistered User
(Unregistered)
Fri Sep 02 2005 06:31 PM
Re: terminology

mr clark, i appreciate your response. the recycling of the numbers was most confusing.

SkeetoBiteAdministrator
(Master of Maps)
Fri Sep 02 2005 06:40 PM
Re: terminology

Quote:

mr clark, i appreciate your response. the recycling of the numbers was most confusing.




Indeed they are. Try programming around them!

mr. clark, you're my hero! heheh. -HF


Random Chaos
(Weather Analyst)
Tue Sep 06 2005 07:03 PM
Re: terminology

Indian Ocean is B on NRL
Indian Ocean is S on SSD



There are also Central Pacific, Bay of Bengal, and Arabian Sea storms, but I'm not sure even if they have letters. I'll have to wait until we get a system listed to see how it's numbered.

---------

Also, I'm not positive 90 is the break point. I think I've seen an 89L before...and this last time they skipped 90L and 91L.


Clark
(Meteorologist)
Tue Sep 06 2005 11:04 PM
Re: terminology

Ah, that's how it goes -- thanks Random Chaos! The B is for the Northern Hemisphere storms, while the S is for those in the Southern Hemisphere to avoid confusion. I believe the S includes all storms in both the Southern Indian & Pacific Oceans as there is generally less activity in that hemisphere and only the two related basins where you really see tropical activity down there.

There has been an 89L, but that was a test product and not an actual storm or invest. They didn't skip 90L or 91L this time around -- they just weren't out there for very long. Trying to keep up with the overall terminology for the current cycle: 95L became Irene (I believe), 96L dissipated in the central Atlantic, 97L also dissipated in the central Atlantic, 98L became Jose, 99L became Katrina, 90L dissipated in the central Atlantic, 91L became Maria, 92L dissipated (yes, in the central Atlantic...notice a theme? ), 93L became Nate, and 94L became TD 16/Ophelia. Whew.


Unregistered User
(Unregistered)
Wed Sep 07 2005 10:35 AM
Re: terminology

thanks again clark, i feel slightly less unintelligent. and i'm somewhat comforted that skeetobite is slightly confused as well! (thanks for your maps)
is the "they" who first determine an "invest" rating, and who later assign a numerical, the nws? but that would not cover all global would it?
i believe it was the nws who decided to give a new number to what eventually became katrina, is that correct? the explanation given at that time seemed rational, at least to a relatively superficial observer such as myself.


Random Chaos
(Weather Analyst)
Wed Sep 07 2005 12:11 PM
Re: terminology

Quote:

The B is for the Northern Hemisphere storms, while the S is for those in the Southern Hemisphere to avoid confusion.




Ah!

Hmm. NRL and SSD were reporting different systems. Makes sense now - 93B in "Indian Ocean" at NRL, and 95S in "South Indian Ocean" at SSD.


Clark
(Meteorologist)
Wed Sep 07 2005 06:59 PM
Re: terminology

The various centers coordinate on setting up the invests; I'm not sure it's any one group that assigns them, but it's the Navy's website that shows them most prominently. The NHC has the final say on actually classifying a tropical cyclone in the Atlantic and E. Pacific. In the NW Pacific, it's the JTWC. The JTWC does their own advisories for the other basins that way (incl. the Indian Ocean) as well, though there are other agencies (e.g. Australia's Bureau of Meteorology) that issue their own advisories as well.

Just a note to add that the CPHC (Honolulu) has these same responsibilities for the Central Pacific basin.



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