Hurricane Lorenzo - any thoughts?

[Stuart Robinson]

On paper this actually looks quite good - warm pocket of water to cross with low upper air shear and about 4 days over water - negative is that the storm will be churning up water ahead of it therfore mixing out the warm water layer.

I agree nothing really to look at now - in fact it looks quite poor but I would love to chase at least one tropical system this year (after missing out in 2006) and this may be my best shot.

What are your thoughts??

 

[Jim Leonard]

You don't have to be concerned about upwelling with a weak system. Usually upwelling would be a factor if it were to be a hurricane moving less than 5mph for more than 24 hours.
This system has to consolidate more and have at least 30kts at the surface to be called a TD. The models are in good agrement that this system is in no-way a threat to the U.S. A slow westward or SW drift seems most likely, while gradually becoming a tropical storm.

 

[Stuart Robinson]

Thanks Jim for your thoughts

Since miday here in the Uk I have been looking at the MM5 model run for this storm / TD whatever.

After looking at the run you can see where my interest comes from.

http://moe.met.fsu.edu/mm5/slp.d1b.html (time sensitive link)

However the forthcoming 00z runs will have the benift of the recon flight Obs from today's mission - these will tell a better story.

 

[Stuart Robinson]

Wow RECON have just found SFMR surface winds of 77 MPH / 999mb - we are certainly looking at Lorenzo now - but will this be upgraded to HURRICANE Lorenzo?? - it is VERY possible.

 

[Josh Morgerman]

I'm thinking of chasing it-- haven't decided. If it's a 'cane with the 4 pm CDT advisory and looks to be continuing the deepening trend, I might. I can catch a latenight flight from L.A. to Mexico City and drive to the coast from there.

If this thing were to strengthen to, say, 85 kt, it would be premium chase material, in my opinion. These small, rapidly deepening cyclones have really sweet core structures-- nice eyewalls, etc.

The big problem for me is that this thing is so darn close to the coast already-- makes the whole venture feel risky. If I decide to chase it and then it scoots onshore a little early, that's some serious time and money down the drain.

Anyway, I'm going to make a decision with the next advisory-- due out in ~40 mins.

 

[Stuart Robinson]

Josh - I am on stanby in the UK to chase this - my problem is the time it will take me to get there but I agree Mex City is the ideal target air port.

 

[Josh Morgerman]

Hey Stuart-- the 4 pm CDT advisory just came out, and my feeling is that this one's a no go for me:

Reasons?

* It's made relatively fast progress toward the MX coast during the last six hours-- with the current advisory now indicating landfall within ~12 hours. I just can't get into position that fast. (And I'm in L.A., which is not actually that far. I can't imagine you flying from the UK in time!)

* It's looking to be yet another nighttime landfall-- meaning much less opportunities for good footage.

I'm perversely relieved-- was almost dreading having to leave for the airport for this. This will be another one to enjoy from the comfort of home.

What we need is another intense, multi-day long tracker, moving briskly in a straight line-- a la Felix or Dean. Despite its extreme intensity-- which created some unique challenges, as I had to take all kinds of extra precautions-- Dean was a very well-behaved chase subject compared with this erratic little Lorenzo!

 

[Josh Morgerman]

Current intensity is 993 mb/65 kt. I notice that they say "some additional strengthening is likely" up to landall. Given the satellite presentation and the trend, I would not be surprised to see this get up to 80 or 85 kt. It has several more hours and it's on a roll. The satellite presentation has improved spectacularly, and there's a hint of an eye forming within a ring of very deep convection.

<sigh> I felt like this could have been a good chase subject-- but it's a classic example of how difficult it is to chase these small storms that suddenly bomb out right near the coast. To have been able to chase this, I would've had to have left L.A. early this morning-- but, early this morning, this was just a measly depression!

 

[Josh Morgerman]

Latest Mexican radar shows a contracting eyewall. I believe it's continuing to deepen. This thing is looking spectacular for a recently upgraded Cat 1:

 

[Josh Morgerman]

Well, now I'm relieved I didn't bother to go after this one. After some fast deepening last night, it seemed to fizzle in the end. The radar presentation really deteriorated in the final hours-- the eyewall opened up and got all messy-- and the estimated landfall intensity was only ~990 mb/65 kt. Plus, it was another nighttime landfall. Definitely not worth it, in my book.