ATL: KATIA - Post Tropical - Discussion

[BigA]

Forecasts for storms weakening due to shear often seem too cautious (not predicting as much weakening as actually occurs). I would not be surprised if this gets severely disrupted during the next day. I don't think the shear will kill it, but storm after storm has shown that neither the global models nor the HWRF or GFDL have good skill at predicting shear's effect on tropical cyclones.

Could shear and ULL's kill this thing?

My educated guess is yes they could, but they probably wont, based on the fact that no models kill it or even weaken it a great deal, when dealing with past storms in that area where that has happened (Karen in 2007 comes to mind), I think the models did see it weakening. Also, the NHC seems pretty confident that this shear will last only 24 to 36 more hours.

So possible, but not likely. I do see this likely weakening to a middling (50-60 mph) tropical storm. I believe it will rebuild, though afterward.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[summersquall]

Funktop IR shows some intensification and a jog to the NW as per NHC track.

[CrazyC83]

Forecasts for storms weakening due to shear often seem too cautious (not predicting as much weakening as actually occurs). I would not be surprised if this gets severely disrupted during the next day. I don't think the shear will kill it, but storm after storm has shown that neither the global models nor the HWRF or GFDL have good skill at predicting shear's effect on tropical cyclones.

Could shear and ULL's kill this thing?

My educated guess is yes they could, but they probably wont, based on the fact that no models kill it or even weaken it a great deal, when dealing with past storms in that area where that has happened (Karen in 2007 comes to mind), I think the models did see it weakening. Also, the NHC seems pretty confident that this shear will last only 24 to 36 more hours.

So possible, but not likely. I do see this likely weakening to a middling (50-60 mph) tropical storm. I believe it will rebuild, though afterward.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

That is my thinking too, but this opens up a new realm of possibilities (weaker = more west). Conditions have not been that great out in the deep tropics all season. This might be the only Cape Verde storm.

[Aric Dunn]

new steering... ridging seems to be building in even stronger and building farther west. no turn until that changes.. ridging could be getting beefed up a little by the outflow from 94L and that low off NC. seems there is something thats helping stay farther south and not turn yet. if you remember the turn was already supposed to have started.. but instead in turned west.. lol

wv http://www.ssd.noaa.gov/goes/east/tatl/loop-wv.html
500mb

[KWT]

SS, center is to the SW of the deep convection, center is 100% south of 16N, I think thats pretty clear to see judging by the microwave imagery...

Reminding me ALOT of Earl now, it also got a blast from shear and dry air and became a little exposed at one point, which allowed it to get a good deal further west then the models were expecting to begin with.

Pattern still loooks troughy and any energy from 93L will likely help to still pull enough of a weakness down but not quite the slam dunk it appeared a few days ago.

[BigA]

Lower latitude puts her farther from the ULL though?

A bit. The big factor in determining when the shear lessens will be when the ULL starts to scoot off to the northeast, which the hurricane center says will happen tomorrow evening and tomorrow night.

[Jevo]

18z GFS is rocking and rolling initialized @ 1001mb (24hr intervals)

[meriland23]

gfs 18z run initiated, will post per 24 h period

24h

[cpdaman]

They put the center at 16.1 N. Agree?

no I do not.. microwave that just came out has it 15.8 or so

pretty clear it cant be above 16N

[img]http://www.nrlmry.navy.mil/tcdat/tc11/ATL/12L.KATIA/tc_ssmis/91h/2degreeticks/20110901.2038.f17.x.91h.12LKATIA.65kts-987mb-158N-486W.78pc.jpg[/ig]

ehh not that clear b/c the microwave imagery that just comes out is always lilke over 4 hours old

[Aric Dunn]

hmmm maybe the GFS is finally going to kick that low of NC out like the rest of the models in 36 to 48 hours.. already at 36 its weakening couple hundred miles north of the 12z

[KWT]

If i saw more of a WNw/NW motion right now, or see it kick in during the next 12-24hrs then i'd feel more confident about the model solution out to sea, my fear is though it keeps on tracking near west, exactly like Earl did and that system had a close call to the east coast...

[SootyTern]

actually most of the problem is what is occurring with the low of NC. the models that turn westward kick that out in about 36 to 48 hours ( which its slowly on the move already) the rest keep it there way way to long and thus leave a weakness there till the trough comes to pick it up. future lee has little to do with it right now.

But doesn't the future Lee (or Maria if they decide to name 94L for its very short life); have a big say in where Katia "might" go.
If Lee is in the GOM, then how could Katia take a west route towards the GOM?
It would seem to take that possibility off the board (selfish Florida resident's question)

well most of the models that take a west turn either drop future lee/nate or whatever either SW or stall over land when katia is north of Hispaniola thats 5 days or more out. both which would be a weak system and would have little influence.

http://raleighwx.americanwx.com/models/ ... _loop.html
Euro +192 shows a FL sandwhich? or am I gonna get Noob slapped?

if you look at it closely the Euro move LEE/nate inland weakens it then drops it s again as the ridging build in strong. that weak system is not going to have any real affect on a large hurricane like that.

I'm confused. Is this today's 12z EURO showing that west track along 25N until she takes a sharp turn northwards? Didn't it show the same thing yesterday and then the 0z showed a recurve well off the US coast?

[Aric Dunn]

pretty clear it cant be above 16N

[img]http://www.nrlmry.navy.mil/tcdat/tc11/ATL/12L.KATIA/tc_ssmis/91h/2degreeticks/20110901.2038.f17.x.91h.12LKATIA.65kts-987mb-158N-486W.78pc.jpg[/ig]

ehh not that clear b/c the microwave imagery that just comes out is always lilke over 4 hours old

not this one.. its from 20Z and when I posted that it was barely an hour old..

[cycloneye]

ehh not that clear b/c the microwave imagery that just comes out is always lilke over 4 hours old

That one is only old by one and a half hour.

[cpdaman]

anything the euro shows past 4.5 days is generally not reliable. just sayin.

the euro scores the best inside 4.5 days . outside of that time frame...it's not to be taken with alot of grains of salt . i think that isn't often comprehended because the euro is king in the short/medium term in alot of forecasts and people get abit excited when the D7 euro keeps bouncing around..but it is something to watch ...esp when having other model support

[meriland23]

48h

[KWT]

I'd trust the ECM over any other models, its scored more *hits* so to speak then any other model when it comes to outside 6-7 day period from my memory, and IMO only the GFS is close when it comes to longer term model guidence.

[Aric Dunn]

anything the euro shows past 4.5 days is generally not reliable. just sayin.

the euro scores the best inside 4.5 days . outside of that time frame...it's not to be taken with alot of grains of salt . i think that isn't often comprehended because the euro is king in the short/medium term in alot of forecasts and people get abit excited when the D7 euro keeps bouncing around..but it is something to watch ...esp when having other model support

you do realize that the bend back to left in the 12z euro happens in side your 4.5 days

[Jevo]

18z GFS +48

[DESTRUCTION5]

Anyone wanna tell Jevo hes posting in wrong thread? lol