ATL: INVEST 92L - Discussion

[ronjon]

Ok what development percentage will the NHC state at the 8 Pm TWO? I say 50% within 48 hrs, 60% within 5 days.

[northjaxpro]

I would hedge a guess and say 40-50% in 48 hours and 60% in the next 5 days in the next TWO.

[cycloneye]

A TROPICAL WAVE OVER THE WESTERN CARIBBEAN SEA IS PRODUCING A LARGE
AREA OF CLOUDINESS...SHOWERS...AND A FEW THUNDERSTORMS EXTENDING
FROM CENTRAL AMERICA NORTHEASTWARD TO JAMAICA AND EASTERN CUBA.
UPPER-LEVEL WINDS HAVE BECOME MORE FAVORABLE...AND SOME DEVELOPMENT
OF THIS DISTURBANCE IS POSSIBLE OVER THE NEXT COUPLE OF DAYS AS IT
MOVES NORTHWESTWARD AT 10 TO 15 MPH TOWARD THE YUCATAN PENINSULA
AND SOUTHERN GULF OF MEXICO. ENVIRONMENTAL CONDITIONS COULD BE A
LITTLE MORE MARGINAL FOR DEVELOPMENT WHILE THE SYSTEM IS OVER THE
GULF OF MEXICO LATER THIS WEEK. THIS SYSTEM HAS A MEDIUM CHANCE...
30 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48
HOURS...AND A MEDIUM CHANCE...40 PERCENT...OF BECOMING A TROPICAL
CYCLONE DURING THE NEXT 5 DAYS.

[ronjon]

Really NHC?? 30% next 2 days and 40% next 5 days. Wow, can you say super conservative or what? Heck its mid-August with a large covective mass in the western caribbean with model support - I don't get it.

[northjaxpro]

NHC staying persistent with gradually increasing the percentages. They will keep doing that with the percentages with each TWO with the current trends.

[Dean4Storms]

I could see a 50/50 in 5 days but 40/60? Please!

[ozonepete]

Agree on the MLC in that area. Strong rotation, though. I suspect NHC will up the development chances this evening. At least 50%. Should have been there or higher 2 days ago.

I agree, but then they may get to 50% at 2AM anyway. I would also agree with northjaxpro that this is just the way the NHC rolls. They usually wind up looking really good in hindsight.

[MGC]

It don't matter what percentage the NHC assignes to 92L, nature will take its course. I'm going with the cloud mass up near Jamacia as the most likely to spin, southern end of wave axis will be over CA soon. Should be an interesting week for us NGOM folks.......MGC

[Alyono]

Really NHC?? 30% next 2 days and 40% next 5 days. Wow, can you say super conservative or what? Heck its mid-August with a large covective mass in the western caribbean with model support - I don't get it.

why are they still saying no development?

These numbers defy all logic. Almost as if they are scared of a false alarm

[Hammy]

Presumably its like the wind graphs, where the further you go out, even if you have a 100mph storm over 85 degree waters, that at the end of the graph you still only have a 20-30% chance of TS winds.

[tolakram]

But if they expect a TS to form sometime in the next 5 days then the 5 day chance should be 100%. To say 40% means they expect a 60% chance that no storm will form in the next 5 days. That seems odd, but props to them if it works out.

[ozonepete]

But if they expect a TS to form sometime in the next 5 days then the 5 day chance should be 100%. To say 40% means they expect a 60% chance that no storm will form in the next 5 days. That seems odd, but props to them if it works out.

Can't argue with that, Mark.

[ozonepete]

I think the 12Z GFS this morning gave them the jitters, since it basically said this would strengthen til the Yucatan and then sputter out. And even though the 18Z runs are much better now, most mets, tropical or not, still don't give them the heft they give to the 12Z and 00Z runs. I think they want to see what the 00Z runs say and then they can bump it to red.

[Tyler Penland]

Anybody know when we might have a floater up on 92L?
Got one for 93L already but of course they don't have one up for the one that's actually a threat.

[Dean4Storms]

I'm scratching my head, this looks like it is organizing fairly quickly when you think of what things looked like just this morning.

[HurricaneBelle]

Never can understand why everyone gets so worked up over the NHC's percentages on invests. It's either going to develop or not develop regardless of what % it gets at a given time.

[tolakram]

Anybody know when we might have a floater up on 92L?
Got one for 93L already but of course they don't have one up for the one that's actually a threat.

Not sure. Here's the actual floater site and so far no directory for 92L. Hopefully soon.

Until then, here's a live IR loop: http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... umframes=5

Sometimes these stop updating at night, not sure why.

[tropicwatch]

The upper level winds are definitely looking better.



Now if the winds in the upper levels come down a bit, I think we will see some more convection firing over night.

Oopps posted the wrong image, sorry

[cycloneye]

00z Best Track.

AL, 92, 2013081400, , BEST, 0, 162N, 814W, 20, 1009, DB

[ozonepete]

The upper level winds are definitely looking better.



Now if the winds in the upper levels come down a bit, I think we will see some more convection firing over night.

Those aren't upper level winds, ok? that's wind shear on that chart. Wind shear is calculated as the difference in wind speed from the lower layer (925 mb to 700 mb) and the upper layer (300 mb to 150 mb). But your idea is correct - wind shear to the west and northwest of this system has to come down or it won't be able to develop.