ATL HANNA: Extratropical - Discussion

[bahamaswx]

Somehow the center seems to have been sucked to the east toward the convetion, at least per the Colorado State infrared.

Yep. Looks like she spat out the LLC ahead only to have it do a little cyclonic loop back under the heavy convection.

Or at least almost under, anyway.

[BigA]

http://hadar.cira.colostate.edu/ramsdis ... at1_0.html

[eastcoastFL]

still looking decent

[bahamaswx]

Not sure I've ever seen a TC drive head-first into an ULL like Hanna is and come out on top.

[cpdaman]

Not sure I've ever seen a TC drive head-first into an ULL like Hanna is and come out on top.

me neither...lol in fairness it looks like she ran up took a sniff......went bonkers...and decided to stay the heck away and drift erratically now (appears traumatized)

150 edt bouy update.....tells me she is still stalled at 21/65 or a hair NW

http://www.ndbc.noaa.gov/station_page.php?station=41043

[thetruesms]

Not sure I've ever seen a TC drive head-first into an ULL like Hanna is and come out on top.

I don't necessarily know if I'd call it coming out on top (yet!), but it is very impressive to watch them trade shots - it's quite an entertaining battle to watch. I mostly just keep a tab dedicated to this water vapor loop to keep up to date.

[eastcoastFL]

her drifting should have an effect on the current forecast track.

[eastcoastFL]

hanna is a big girl

[cpdaman]

her drifting should have an effect on the current forecast track.

track will be shifting Southward and slower in the short term at 5 am

consider these forecast positions as of 11 pm

30/0300Z 22.1N 65.3W 45 KT
12HR VT 30/1200Z 22.9N 67.0W 50 KT

now consider we she is NOW 21.1 65.3 (or so) well south of her 11pm 'ish position and not going to make anywhere near her 12z position of 22.9

[eastcoastFL]

what makes me a bit nervous is if she takes to long and misses the shear that the NHC in anticipating towards the end of the current track

[fci]

what makes me a bit nervous is if she takes to long and misses the shear that the NHC in anticipating towards the end of the current track

However, the longer she takes the more chance that a trough will pick her up and take her out to sea

[bahamaswx]

Still can't believe the completely exposed LLC drove almost a full degree latitude southward. Bizarre.

[wxmann_91]

This storm reminds me a bit of Philippe in 2005. Rita's outflow entrained into a giant ULL that basically shredded Philippe to bits. I don't know how models can be so adamant on a large hurricane a week out with such a horrific upper level environment in store for Hanna.

[SouthFLTropics]

Let's hope that the forecast for the high shear continues because Hanna is firing some VERY deep convection tonight...If she had ideal conditions I would think that she would ramp up pretty quick...

SFT

[wxmann_91]

Let's hope that the forecast for the high shear continues because Hanna is firing some VERY deep convection tonight...If she had ideal conditions I would think that she would ramp up pretty quick...

SFT

Yeah, she's under the entrance region of an upper jet, which enhances upward motion. Without this she'd be dead or dying right now, most likely.

[physicx07]

Not sure I've ever seen a TC drive head-first into an ULL like Hanna is and come out on top.

me neither...lol in fairness it looks like she ran up took a sniff......went bonkers...and decided to stay the heck away and drift erratically now (appears traumatized)

150 edt bouy update.....tells me she is still stalled at 21/65 or a hair NW

http://www.ndbc.noaa.gov/station_page.php?station=41043

LOL! I had a prof once who would personify FORTRAN code like that. "Your code is like your baby. You crash code, you kill baby!"

[SouthFLTropics]

Man that ULL is very strong...Thankfully. Based on my amatuer observations I think that the ULL may not have moved to the SW like it was forecast to because of Gustav being there. Right now it is sandwiched between Gustav and Hanna and it appears that Gustav's outflow may be enhancing the ULL. Despite the very intense, deep convection I think Hanna has a tough road to hoe over the next few days...

SFT

[KWT]

It does remind me so much of Phillippe in terms of the situation its in. Yet for some reason the models continue to show strengthening for this system?

[SouthFLTropics]

It does remind me so much of Phillippe in terms of the situation its in. Yet for some reason the models continue to show strengthening for this system?

Heck even Avila can't seem to figure it out...The following is from the 5:00AM NHC discussion:

THE SHEAR IS FORECAST TO INCREASE AND THIS IS
REFLECTED IN THE OFFICIAL FORECAST BY SHOWING SOME SLIGHT
WEAKENING. MOST OF THE MODELS CONTINUE TO INTENSIFY HANNA...SOME OF
THEM QUITE SIGNIFICANTLY...DESPITE THE SHEAR. I DO NOT HAVE AN
EXPLANATION FOR IT.

SFT

[SouthFLTropics]

Another interesting tidbit from Avila at the 5:00AM NHC Disco:

I TRIED
VERY HARD NOT TO FORECAST THE WEST-SOUTHWEST TURN SINCE THIS IS NOT
A VERY COMMON TROPICAL CYCLONE TRACK BUT RELIABLE DYNAMICAL
GUIDANCE HAS FORCED ME TO DO SO. THE OFFICIAL FORECAST IS
PRACTICALLY ON TOP OF THE MODEL CONSENSUS. I ALWAYS WONDERED HOW
TODAY'S SOPHISTICATED DYNAMICAL MODELS WOULD HAVE FORECAST
HURRICANE BETSY BACK IN 1965. THIS HURRICANE MOVED SOUTHWESTWARD
OVER THE BAHAMAS.

SFT