ATL : HARVEY - Tropical Depression - Discussion

[ozonepete]

Very nice analysis, as usual, GCANE. Pretty good convection already with some banding now. I think we could see a TS by 5PM.

Thanks Phil.

What's your take on its track?

It's clearly gaining some latitude. I don't have time to post the steering winds charts from CIMSS right now, but they show a weakness ahead of 93L, with very strong easterlies just south of it and a recurving southeast flow over western Cuba that is just north of it. If you watch the flow of the mid-level clouds ahead of 93L, you can actually see the flow of clouds going west-northwest ahead of it now, so I think it should remain on its current track of about 280-285 (I'm estimating) or maybe go even a little more north of that - depends on how strong it gets.
If you assume it will stay on this heading, you could just extrapolate it's direction for the next 24 hours. Since it went from 14.9 yesterday morning to 15.8 this morning, that's .09 of a degree northward in 24 hours. So it should be around 16.7N tomorrow morning. Since it's slowing down due to lighter steering winds I would say it should be around 84 or 85W at the most tomorrow morning. So 16.7N, 84W for tomorrow at 12Z is my best guess. I have to check more before I'd commit to the longer term, but I'm guessing landfall in north Belize or southern Yucatan Sat. morning.

Is that what you're seeing?

[KWT]

ozonepete, yeah there is acvtually a slight weakness for the system to explit, may well bend back just a touch furrther west before landfall as it gets closer to the upper high to its NW over the states.

I'd be amazed if this wasn't a TD...

[MGC]

Will recon find the elusive west wind? Looks very close to becoming a TC. Convection is now located near the MCL which should help the surface low to form.....MGC

[CrazyC83]

I'm thinking Recon might find a TS-strength system. But an LLC?

[KWT]

Hmmm it'll be close crazy, but the fact its held deep convection for a while now may have been enough to drag a weak surface down...maybe like Don and Emily, not strong but enough to get the upgrade nod.

[KWT]

models just slightly further north then they were yesterday but that does make the difference.

[clfenwi]

Mission #2 is now airborne.

URNT15 KNHC 181409
AF300 02FFA INVEST HDOB 02 20110818
135930 1742N 06448W 0146 ///// 0141 +356 +303 360000 000 /// /// 23
140000 1742N 06448W 0145 ///// 0140 +349 +294 360000 000 /// /// 23
140030 1742N 06448W 0145 ///// 0139 +349 +307 360000 000 /// /// 23
140100 1742N 06448W 0144 ///// 0143 +342 +304 360000 000 /// /// 23
140130 1742N 06448W 0146 ///// 0142 +341 +289 360000 000 /// /// 23
140200 1742N 06448W 0146 ///// 0141 +340 +293 360000 000 /// /// 23
140230 1742N 06448W 0146 ///// 0138 +336 +273 360000 000 /// /// 23
140300 1742N 06448W 0144 ///// 0138 +330 +284 360000 000 /// /// 23
140330 1742N 06448W 0146 ///// 0138 +327 +290 360000 000 /// /// 23
140400 1742N 06448W 0145 ///// 0137 +318 //// 360000 000 /// /// 25
140430 1742N 06448W 0145 ///// 0137 +298 //// 360000 000 /// /// 25
140500 1742N 06448W 0145 ///// //// +300 //// 360000 000 /// /// 25
140530 1742N 06448W 0145 ///// 0139 +296 //// 360000 000 /// /// 25
140600 1742N 06448W 0143 ///// 0138 +290 //// 360000 000 /// /// 25
140630 1742N 06448W 0141 ///// 0138 +288 //// 360000 000 /// /// 25
140700 1742N 06448W 0138 00001 0139 +285 +275 360000 000 /// /// 03
140730 1742N 06449W 0134 00003 0139 +285 +269 360000 000 /// /// 03
140800 1742N 06449W 0130 00007 0139 +284 +275 360000 000 /// /// 03
140830 1742N 06449W 0126 00008 0138 +293 //// 360000 000 /// /// 05
140900 1742N 06449W 0129 00009 0139 +290 +275 360000 000 /// /// 03
$$
;

[SouthDadeFish]

I do not see 93L running into Honduras. Already seems to be gaining latitude.

[SouthDadeFish]

The vorticity graphics from CIMSS do not show a very well organized system. Apparently 93L is no longer stacked:

http://www.canefever.com/#!at-a-glance/vstc1=vorticity

[KWT]

Yeah the models have shifted a touch northwards.

ECM has done a stunning job with this system, track has been nearly perfect!

[KWT]

Thats actually a little bit surprising, recon will tell the story thats for sure soon!

[SouthDadeFish]

Yeah the models have shifted a touch northwards.

ECM has done a stunning job with this system, track has been nearly perfect!

Euro did a good job? Surprise, surprise.

[SouthDadeFish]

Center estimate as of 1345Z:

[wxman57]

models just slightly further north then they were yesterday but that does make the difference.

That would be do to the repositioning of the center north of 15N.

[SouthDadeFish]

For a little fun, evolution of 93L over the last three days:

8/16 1815Z:


8/17 1315Z:


8/18 1415Z:


I see consolidation and organization.

[clfenwi]

At crusing altititude; on track to make it to the invest as scheduled; should descend around 1:15-1:30 EDT.

URNT15 KNHC 181439
AF300 02FFA INVEST HDOB 05 20110818
142930 1717N 06603W 4399 06856 0351 -134 //// 039004 005 /// /// 05
143000 1717N 06605W 4346 06948 0356 -140 //// 048005 006 /// /// 05
143030 1716N 06608W 4302 07025 0360 -143 //// 055005 006 /// /// 05
143100 1715N 06610W 4242 07133 0367 -150 //// 071005 006 /// /// 05
143130 1715N 06612W 4180 07245 0374 -157 //// 101007 007 /// /// 05
143200 1714N 06615W 4131 07337 0380 -165 //// 092007 008 /// /// 05
143230 1714N 06617W 4088 07415 0386 -168 //// 093006 006 /// /// 05
143300 1713N 06619W 4047 07491 0390 -174 //// 094006 006 /// /// 05
143330 1712N 06621W 4005 07570 0395 -176 //// 080004 004 /// /// 05
143400 1712N 06624W 3966 07643 0399 -181 //// 086004 004 /// /// 05
143430 1711N 06626W 3938 07698 0402 -185 //// 083004 005 /// /// 05
143500 1711N 06628W 3925 07720 0403 -185 //// 067004 004 /// /// 05
143530 1710N 06630W 3925 07721 0402 -186 //// 046005 006 /// /// 05
143600 1709N 06633W 3925 07718 0400 -186 //// 038006 006 /// /// 05
143630 1709N 06635W 3925 07736 0416 -190 //// 041005 006 /// /// 05
143700 1708N 06638W 3926 07734 0416 -190 //// 044006 006 /// /// 05
143730 1707N 06640W 3925 07733 0416 -190 //// 037007 008 /// /// 05
143800 1707N 06643W 3926 07732 0414 -190 //// 043008 008 /// /// 05
143830 1706N 06646W 3925 07732 0414 -190 //// 042008 008 /// /// 05
143900 1705N 06648W 3926 07728 0413 -190 //// 044008 009 /// /// 05
$$

[KWT]

Yeah the models have shifted a touch northwards.

ECM has done a stunning job with this system, track has been nearly perfect!

Euro did a good job? Surprise, surprise.

Yeah, I remember commenting on a run a few days ago and that run has come out nearly spot on both in terms of strength and location.

[ozonepete]

The vorticity graphics from CIMSS do not show a very well organized system. Apparently 93L is no longer stacked:

http://www.canefever.com/#!at-a-glance/vstc1=vorticity

You have to take a lot of those CIMSS diagrams with a grain of salt. I was taught that their accuracy is only to maybe 50 miles or even worse, in which case it can't do well for a small circulation like this. The vis satellite certainly shows much better stacking.

BTW, for those who don't know, we don't look for positive vorticity at 200-300 mb - we expect anticyclonic flow or negative vorticity at those levels.

[FireRat]

Exactly when is this system supposed to hit CA?

Most models have Friday afternoon, roughly. If it goes a little north of west and heads for Yucatan, it's 72 hours or Saturday afternoon.

Thanks for the info, in that case it's possible that the storm will get named before hitting CA late tomorrow or the Yucatan on Sat. I notice many of the members can't stand seeing 8/0/0, what's so bad about that? I know it's something that hasn't been seen before but is this going to bust the season forecast?? Just curious.

[ozonepete]

You can pretty much bet this will be named by 5PM or 11PM later today, IMHO.

As far as 8/0/0, a lot of us here are very intense storm watchers and really love to see big hurricanes so we can analyze them and learn more, 8/0/0 is disappointing on that level. But please remember none of us ever want to see them hit populated areas and hurt people. That's why we like "fish" storms that stay out in the open waters. That's a win for everybody.

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