Ex Invest 99L in Western Atlantic

[wxman57]

I thought a classified tropical cyclone anywhere in the Basin meant more work for you. It is Friday, go out for dinner, catch a movie. Little warm for bike riding.

Yes, a classified system means quite a bit more work. But we don't mind that if there's a serious threat to our clients - that's why we're here. Notice I also said that perhaps the NHC should use the same discrimination when there's a weak low in the northern Gulf. Will it weaken? Maybe don't call it a TD.

Speaking of 98L, I see it's back to an Invest now. Model data just came out as 99L. Of course, the one big storm over the center is now gone.

[Ed Mahmoud]

I thought they conserved the numbers for the same system.


Interesting.

[HURAKAN]

[KWT]

Why is it now 99L, surely its the exact same system as it was when it was 98L!

[DESTRUCTION5]

Why is it now 99L, surely its the exact same system as it was when it was 98L!

That would be a good question...

[cycloneye]

The pro mets may have the answer.

[KWT]

Well its certainly an interesting question but anyway 98/99L has got a good circulation to it, we really just need convection with it, I think once it reaches the warmer waters then convection may finally get going.

Also worth noting its gone slight south of west in the last 6hrs.

[gatorcane]

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

I'm not making many changes to my forecast reasoning. I'll provide a North Atlantic Water Vapor Loop link for this discussion:

http://www.ssd.noaa.gov/goes/east/natl/loop-wv.html

The north Atlantic subtropical ridge is continuing to build westward across the Atlantic and there is a narrow axis extending as far west as the Eastern GOM (although its western periphery is weak and Bermuda High is fairly weak also). This should allow 99L to continue moving 270 or just south of 270 for at least the next 3-5 days mostly with the low-level easterly flow. A series of TUTTs are present North and West of 99L. The one of particular interest is spinning at 27N, 50W, that may produce some unfavorable conditions for 99L in the 4-5 day timeframe or it may allow 99L to "breathe." Either way I continue to forecast gradual development of 99L (because SSTs are rising gradually) into a depression or tropical storm over the next 3-5 days with a west movement putting it just NE of the Leewards (50-100 miles) in 5 days. I will need to reevaluate synoptics over the next couple of day to determine when/if 99L can reach hurricane status but appears unlikely until possibly days 4 or 5.

Climatology does suggest 99L is an ultimate recurve candidate. No hurricane has made it to the CONUS where 99L is currently tracking.

[HURAKAN]

I sent an e-mail to the NHC asking why 98L has been reclassified as 99L. It always good to get the answers directly.

[AJC3]

:uarrow: The pro mets may have the answer.

Can't see any other logical explanation other than it's misnumbered.

[HURAKAN]

Hello 98-99L:

BEGIN
NHC
invest_al992008.invest
FSTDA
R
U
040
010
0000
200808011421
NONE
NOTIFY=ATRP
END
INVEST, AL, L, , , , , 99, 2008, DB, O, 2008080112, 9999999999, , , , , , METWATCH, , AL992008
AL, 99, 2008072918, , BEST, 0, 137N, 172W, 20, 1008, DB, 0, , 0, 0, 0, 0,
AL, 99, 2008073000, , BEST, 0, 144N, 179W, 20, 1008, DB, 0, , 0, 0, 0, 0,
AL, 99, 2008073006, , BEST, 0, 146N, 189W, 20, 1007, DB, 0, , 0, 0, 0, 0,
AL, 99, 2008073012, , BEST, 0, 154N, 198W, 25, 1008, DB, 0, , 0, 0, 0, 0,
AL, 99, 2008073018, , BEST, 0, 165N, 215W, 25, 1008, DB, 0, , 0, 0, 0, 0,
AL, 99, 2008073100, , BEST, 0, 169N, 232W, 25, 1007, DB, 0, , 0, 0, 0, 0,
AL, 99, 2008073106, , BEST, 0, 176N, 250W, 25, 1007, DB, 0, , 0, 0, 0, 0,
AL, 99, 2008073112, , BEST, 0, 178N, 269W, 25, 1008, DB, 0, , 0, 0, 0, 0,
AL, 99, 2008073118, , BEST, 0, 180N, 290W, 25, 1008, DB, 0, , 0, 0, 0, 0,
AL, 99, 2008080100, , BEST, 0, 184N, 314W, 25, 1008, DB, 0, , 0, 0, 0, 0,
AL, 99, 2008080106, , BEST, 0, 185N, 334W, 25, 1008, DB, 0, , 0, 0, 0, 0,
AL, 99, 2008080112, , BEST, 0, 184N, 354W, 25, 1008, DB, 0, , 0, 0, 0, 0, 1010, 150, 45, 0, 0, L, 0, , 0, 0, INVEST, S,

Can we call it, 98.5L!!!!

[Derek Ortt]

I have no clue why this is 99L, unless they changed invest numbering policy this year.

That said, I personally would not have made this an invest again

[Ed Mahmoud]

I have no clue why this is 99L, unless they changed invest numbering policy this year.

That said, I personally would not have made this an invest again

WxMan57 said it is close to being a depression.


I love it when pro-mets bring differing view points to a subject.

[KWT]

Hmm I'm not sure Derek, 6hrs ago and it was easily good enough to be an invest but since then convection hass once again really decreased. I believe once we get into higher temperature waters we will see the convection re-develop.

[gatorcane]

It's definitely invest worthy. The 99L sat pic on the NRL page is pretty impressive for an invest:

http://www.nrlmry.navy.mil/tc_pages/tc_home.html

Another nice view of 99L and its relation to the Leeward Islands:

[wxman57]

I have no clue why this is 99L, unless they changed invest numbering policy this year.

That said, I personally would not have made this an invest again

WxMan57 said it is close to being a depression.


I love it when pro-mets bring differing view points to a subject.

Actually, I said if this same system was in the northern Gulf the NHC would be all over it, calling it a depression rather than waiting 12-24 hours to see if it does weaken. I realize that being in the middle of nowhere that the NHC has the luxury of being able to wait.

[gatorcane]

Hey Wxman - can you explain the recurve possibility predicted by the initial model runs (BAMS) which recurve 99L around 60W? I'm not sure I buy those initial runs. Maybe a recurve a bit further west but not at 60W. I see a solid ridge all the way across to about Florida with a ridge axis between 30N and 25N....between 80W and the longitude where 99L is at. Water vapor imagery shows this ridge.

Furthermore TWC last night (Jim Cantore) during the Tropical Update showed an animation of a model (not sure which one) that was forecasting the north atlantic subtropical ridge located in the central North Atlantic to expand and build westward flattening E-W through the next 3-5 days.....all the way to about Florida.

Assuming 99L develops and this ridge is building the way I think it is, how is it going to recurve at 60W? Am I missing something?

[KWT]

I think your right gatorcane this does look ok but it obviously needs some more convection over that center.

[wxman57]

Hey Wxman - can you explain the recurve possibility predicted by the initial model runs (BAMS) which recurve 99L around 60W? I'm not sure I buy those initial runs. Maybe a recurve a bit further west but not at 60W. I see a solid ridge all the way across to about Florida with a ridge axis between 30N and 25N....between 80W and the longitude where 99L is at. Water vapor imagery shows this ridge.

Furthermore TWC last night (Jim Cantore) during the Tropical Update showed an animation of a model (not sure which one) that was forecasting the north atlantic subtropical ridge located in the central North Atlantic to expand and build westward flattening E-W through the next 3-5 days.....all the way to about Florida.

Assuming 99L develops and this ridge is building the way I think it is, how is it going to recurve at 60W? Am I missing something?

I don't see as strong of a ridge there. The models sure see the western edge of the ridge between 55-60W. That should allow for WNW and eventually NW-N movement. Looks like a track similar to Bertha.

[gatorcane]

Hey Wxman - can you explain the recurve possibility predicted by the initial model runs (BAMS) which recurve 99L around 60W? I'm not sure I buy those initial runs. Maybe a recurve a bit further west but not at 60W. I see a solid ridge all the way across to about Florida with a ridge axis between 30N and 25N....between 80W and the longitude where 99L is at. Water vapor imagery shows this ridge.

Furthermore TWC last night (Jim Cantore) during the Tropical Update showed an animation of a model (not sure which one) that was forecasting the north atlantic subtropical ridge located in the central North Atlantic to expand and build westward flattening E-W through the next 3-5 days.....all the way to about Florida.

Assuming 99L develops and this ridge is building the way I think it is, how is it going to recurve at 60W? Am I missing something?

I don't see as strong of a ridge there. The models sure see the western edge of the ridge between 55-60W. That should allow for WNW and eventually NW-N movement. Looks like a track similar to Bertha.

Great thanks, lets see what happens, not sure I buy it yet though. I guess considering climatology also, it would be wise to bet on the scenario you describe: recurve at 55-60W