Frances Advisories

[LowMug]

"TRENDING A LITTLE MORE WESTWARD"...

damn...I hope this is not Georges all over again except no Haiti/DR mountains to disrupt the circulation

[Geoff Stormcloud]

Then the gulf ...

[Vortex]

Obviously the ridge is stronger thus the model actually brings it very near the north coast of Cuba....I've watched this model for days and its performance so far has been right on track and consistent...This is the first run with such a westward component.....I still think this is going to cross south florida and even possibly the Keys and reemerge in GOM then turn nw towards the e/central gulf before recuring out ahead of the trough..

http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_078l.gif

[dhweather]

Things that make you go "hmmmmmmmm"

[dhweather]

Ah, our old buddy ZORCH......

[B-Bear]

"The evidence to be presented suggests that
annular hurricane formation is preceded by a
dramatic asymmetric mixing event where mesovortices
mix eyewall air into the eye and visa
versa (See Schubert et al. 1999, Kossin and
Eastin 2001), culminating in the formation of the
axisymmetric storms with large eyes (i.e. annular
hurricanes). The thermodynamic structures (as
determined from aircraft data) of these storms
suggest that a dramatic horizontal mixing event
has recently occurred, which is characterized by
more uniformly distributed values of e in the
eye. At the same time the wind field suggests
that some eye-to-eyewall mixing is still occurring,
as shown by step-like features in the tangential
wind that are associated with local vorticity and
angular velocity peaks.

Once annular hurricanes have formed, they
can maintain their annular shape for days if the
environmental conditions remain favorable.
Annular hurricanes are also very intense,
averaging 108 knots in intensity at roughly 85%
of their MPI with respect to SST. As a result,
annular hurricanes pose an interesting challenge
when forecasting intensity change. Unlike typical
hurricanes, annular hurricanes tend to
experience a long period of nearly steady
intensities with a relatively slowly decreasing
intensity following their maximum intensity, Fig. 2.
As a result of this intensity change characteristic,
intensity forecast errors are larger for these
storms than for the 1995-2000 mean, with large
negative biases, suggesting that the forecasts
overestimate the future rate of filling.

Composite analysis will be presented that
reveals that typical annular hurricanes exist in a
very favorable hurricane environment generally
characterized by the combination of 1) weak
easterly or southeasterly vertical wind shear, 2)
easterly flow and relatively cold temperatures at
200 hPa, 3) a narrow range (25.4 to 28.5 oC) of
SSTs that are nearly constant, and 4) a lack of
200-hPa trough interaction. These individual
characteristics are quite commonly observed, but
the combination of these factors is quite rare
occurring 0.8% and 3.0% of the time in the
Atlantic, and Eastern Pacific tropical cyclone
basins, respectively."

http://ams.confex.com/ams/pdfpapers/36712.pdf

[bahamaswx]

Eh... don't think it will verify.

[btsgmdad]

Derek, what does the 40nm eye mean? I think I know but I have grown to respect your opinion in the short time I've been on this board. Have you made the call you said you'd have to make for the university?

[Vortex]

In fact the 00z at H-84 is furthur s and west as Stewart alluded to this potential..


http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_084l.gif

[B-Bear]

So what this means is that conditions are nearly PERFECT for hurricane development, and that happens in the Atlantic less than 1% of the time.

IF this is an annular eye developing, that is.

[LaBreeze]

Let's hope that it's not things that go bump in the night! (or day)

[TLHR]

Hurricanes are so fickle. That's what makes them so unpredictable.

While I can't speak for others, I tend to predict a storm's path a bit to the right of the NHC path because storms have done so in the past. Fran was supposed to hit Charleston dead on, then hooked to the right. The same with Floyd. First Edisto Beach, but wound up in Wilmington. Recently, the Weather Channel had someone stationed in Tampa but Charley came ashore more towards Ft. Meyers.

If the NHC is saying Melbourne, then I liable to say Jacksonville or the FL/GA border.

We'll know more into Wednesday.

[Air Force Met]

Ive noticed something...... The forecasters are doing a good job, but has anyone noticed{Or has discussed} that the carolina guys forecast landfall north of the Florida folks???


Just wondering.
Paul

I've noticed something too. Given a few more forecasts...ncwxwiz may actually forecast the storm where its really going! He started good...but got that NC wishcast going Now it's catchup time.

[Air Force Met]

Hurricanes are so fickle. That's what makes them so unpredictable.

While I can't speak for others, I tend to predict a storm's path a bit to the right of the NHC path because storms have done so in the past. Fran was supposed to hit Charleston dead on, then hooked to the right. The same with Floyd. First Edisto Beach, but wound up in Wilmington. Recently, the Weather Channel had someone stationed in Tampa but Charley came ashore more towards Ft. Meyers.

If the NHC is saying Melbourne, then I liable to say Jacksonville or the FL/GA border.

We'll know more into Wednesday.

Gilbert hooked to the left all the way to Mexico...

[B-Bear]

If he tells you that it might be developing and annular eye, I posted information about what this is here:

http://www.storm2k.org/phpbb2/viewtopic.php?t=39959

I don't know if that's what is happening or not, but I've heard it speculated by others--so I did a little digging and posted the information I found. It's an interesting read, regardless.

[Derek Ortt]

the call has not been made yet as we at rsmas aren't certain at all. what we said in a conference call is that the actual track may be south of NHC, but I wnt say anything definitive for a while (you'll know things are happening when I suddenly go a day or longer without posting)

[Dean4Storms]

This verifies what the NHC Discussion alluded to and what I've been saying. With the only viable trough way back in the central Conus the ridge can do nothing but build back westward thus sending Frances further westward. Although I'd like to see her stay on more of a due west track to take hope in this ETA track, it looks as if she is stair stepping on a general heading just north of due west or 280. This alone would bring her closer to the Keys then the northern coast of Cuba.

[Air Force Met]

The ETA? You know...way back in the day I actually paid attention to what the ETA said...that was of course before much better tropical and global models made an appearance.

[Matthew5]

If this develops a annular eye this will likely hit as a cat5. What are the chances for this to be the first stages of a annular eye derek?

[btsgmdad]

Thanks for the info.