07/10/05 TALK: Major Hurricane Emily

[Thomas Loades]

You can certainly see where a center — probably not a real eyewall yet, but eventually — is forming now; it looks as though its southern fringes will go through Venezuela as it passes. Looks like another contender for "southernmost tropical system," like that one last year, whichever it was.

 

[Owen Shieh]

I am beginning to see a possible problem....Emily will be entering the "tropical cyclone graveyard" soon, as most systems that are not well organized (especially those that are not hurricane strength yet) tend to weaken or dissipate in this region. Dennis was a huge exception in that it developed in the eastern Caribbean, but climatology dictates that *something* is causing stuff to die out in that region unless it is well-established (like Ivan). It's still a mystery, and it would take a lot of research to go beyond just theoretical speculation. I would not be surprised if Emily doesn't make it.....or perhaps degenerates into an open wave until it reaches the western Caribbean. This is a low confidence statement since all I'm going on here is climatology (and assuming it doesn't make landfall in Venezuela!).

 

[Jeff Snyder]

Owen,

I'm more worried about some dry air ahead of Emily, but more of the low latitude of the system and any possible interactions with South America... Coriolis force doesn't work too well at those low latitudes...

edit: I have serious doubts that Emily will develop much more, much less reach major hurricane status. It may be a make-or-break type of deal, as conditions appear good for development/strengthening if it can make it north, but I can't see it persisting much longer if it keeps on it's current path. Then again, "it" may be difficult to define, as there is very little symmetry and increasing disorganization seen on IR imagery. There's a blob of convection / colder cloud tops moving norhtwestward from the center, but there's more convection near/southeast of the "center" that's moving westward. The latter area of convection is developing/cooling nicely, but it's current motion would take it across far northern Venezuala... This actually is looking a lot like T.S. Earl in terms of a relative lack of organization, fast forward motion, and close proximity to Venezuala.

 

[David Wolfson]

It looks like Emily got a steroid shot the last few hours. There're radial (gravity?) waves in the cirrus outflow which has often caught my eye as a sign of rapid deepening.

 

[Owen Shieh]

Right, I was actually neglecting the Coriolis variable on purpose because it is only crucial for open waves or weak circulations trying to develop. For low pressure systems that already exist, the present vorticity should be enough for it to be perhaps 1-2 degrees closer to the equator. As long as there is already vorticity, it would take a slightly less amount of Coriolis to maintain the circulation.

The question over the eastern Caribbean is not so much land interaction, because the many cases where disturbances degenerate within that area occur well away from land - far enough where South America doesn't play a direct part. However, in my opinion, there are 2 possible inhibiting factors (present most of the time) in this area. First, the downsloping of air from the mountainous Tepuis of northern Venezuela into the southern semicircle inflow of tropical cyclones. Second, the surface divergence/diffluence values that are higher between 61 degrees W and 68 degrees W longitude. This is evident in recent QuikScat passes, where there is speed divergence just south of Puerto Rico. Both of these things would slow or inhibit development (most of the time). My theory is that perhaps these two factors contribute to the lack of cyclogenesis in the eastern Caribbean, but I'm sure there are other factors that still need a lot more study.

 

[Warren Eckels]

Climatology out window, Mexican oilfields

Originally posted by Owen Shieh
Yeah...let's just throw common sense and why not climatology as well (as NHC put it) out the window this year. The Atlantic is just going to break loose. There's no stopping it!!

Well, I guess if Emily hits the Yucatan and then emerge into the Bay of Campeche, which it could very well do, the oil rigs in the Gulf would have a higher chance of being spared.

Climatology is not particularly helpful now, even by 2005's low standard. The historical map from the Weather Underground shows Augusta ME, Wilmington NC, Pensacola FL, Houston TX, Belize City and Hondura's Gulf coast taking hits. Only three storms of eight died. (Anna in 1961 counted for two hits, raking Honduras and hitting Belize).

As for oil and gas, Mexico's largest offshore oilfield is located at Cantarell, in the southeastern Bay of Campeche. The Yucatan Peninsula stands between it and most hurricanes. Inland natural gas fields in the lower Rio Grande Valley close to the Gulf (Reynosa, Matamoros) and inland oilfields from Ciudad Madero south to Tuxpan are more exposed to hurricanes. (Of course, oil markets can raise prices without a hurricane's help...)

Petrochemical map of Mexico, red for natural gas, green for oil

 

[Brandon Clement]

I am beginning to see a possible problem....Emily will be entering the \"tropical cyclone graveyard\" soon, as most systems that are not well organized (especially those that are not hurricane strength yet) tend to weaken or dissipate in this region.

Under normal comditions this would be true, but for some reason the strong upper level winds that are normally in this area until mid August are just not to be found so far this year. That is what allowed Dennis to become a major hurricane so early. If this shear does not show up it will be a hotspot for tropical development with the high water temps and is going to eventually lead to the most active tropical season on record.

I was reading somewhere that the East Pacific is cooler than normal and nature's way of compensating is for the Atlantic to be warmer. If anyone has any information on this I would love to read up on this theory. Emily looks as though she is trying to get her act together. The last few frames on Visible loop look quite impressive. It is hard to really see a classic rotation unless you look at the Dvorak loop and then you can see it spinning on the last two frames. As long as she can make her way up to 15N before passing Dominican Rep. she will have a much better shot of exploding and making it into the gulf. If she is south of 15N then it is going to take some sort of steering mechanism to form to get her in the gulf.

 

[Owen Shieh]

The eastern Caribbean thing is more of a cyclogenesis issue than just pure survival of storms. Yes, Emily has a very good chance of surviving, as well as all the other storms cited on Wunderground passing close to Emily's current location. This is because they already have a circulation. What I wanted to emphasize was cyclogenesis - actual origination. Take a look at this:

http://stormcarib.com/climatology/origin1944.htm

Scroll through, and you will notice that there is a complete absence (except for Dennis) of origination points in the eastern Caribbean in any month....not just July.

Emily has definitely gotten stronger before entering the eastern Caribbean, so as long as it doesn't interact with South America, it should survive and even intensify without a problem.

 

[Owen Shieh]

Emily is now a hurricane, announced in a special advisory by NHC based on recon.

 

[Brandon Clement]

She is looking really good on the Water loop. It also looks like she took a considerable jog north.

 

[Brett Adair]

Originally posted by Brandon Clement
She is looking really good on the Water loop. It also looks like she took a considerable jog north.

Models are shifting ever so slowly towards the north...not good for the Gulf Coastal region.

 

[Darren Addy]

It is a looooong way out, but if I was managing a lumberyard in Galveston I'd make sure I was stocked up on plywood by next weekend.

Darren Addy
Kearney, NE

 

[Brandon Clement]

Emily is now up to 90mph and looking very health. The path gets moved a little north every update. It is really starting to look a lot like Emily wants to visit Tx. I'm not seeing a whole lot that is going to slow her down. I would expect that we will be looking at a major hurricane by this evening or tom. morning. If her current pace continues then the Bay of Campeche is not going to inflict any damage that the gulf can't make up for. I'm going to go ahead and start preparing for a Tx chase.

 

[Thomas Loades]

Well, Emily's now up to a cat. 2 with pressure of 976 mb and winds nearing 100 mph. Certainly she appears more intense, too, with better-defined outflow and the eye starting to appear through the cirrus shield. The NHC is now calling for her maximim winds to be 121 mph and gusts to 149 rather than 110 and 132. She also looks to have turned more to the north than before, which will probably keep her going a while longer.

 

[Owen Shieh]

The reformation of the center to the north last night really saved Emily. Now that it has nothing going against it, we should have a major hurricane on our hands soon. And if the trend continues, it will only cross the tip of the Yucatan - or perhaps into the Yucatan Channel - and in that case, there would be no land interaction all the way through the Gulf. Of course, Jamaica is mountainous, but if it moves quickly, that wouldn't be too big of a problem. With the higher oceanic heat content out ahead of it, the originally unfavorable thermodynamic properties (instability and such) will now become better.

The earlier discussion about the eastern Caribbean being hostile for development is now irrelevant. Emily has a strong enough circulation that any possible small inhibiting factors will be overcome.