ATL: Tropical Depression Fay

[Derek Ortt]

>>When the western edge of the ridge erodes it will turn more NW its just a matter of when and where and just because he misses the early track positions doesn't mean it won't over correct and be N of one further down stream.

NHC's 5pm discussion has it at 19.9/77.0 as of 5am tomorrow (currently at like 19.17/75.38). I agree with you but it doesn't always work that way FWIW.

Steve

the forecast point is for 2 a.m. tomorrow

[Dean4Storms]

Until we see the models make a significant shift west...fay is still within the cone of the NHC forecast track and behaving pretty much in line with expectations of the NHC...as evidenced by the fact that the forecast track has essentially been unchanged for 24 hours.

Fay has about 10 hours before she clears Cabo Cruz Cuba at here current heading assuming she does not start her northward turn. Fay will be transiting across some very warm waters and if she should remain offshore Fay could become a hurricane prior to crossing the Cuba coast tomorrow. Fay will be taking a path simular to Dennis in 2005. Dennis intensified rapidly traveling the same path Fay is expected to travel, reaching 130KTS at landfall in Cuba. I do not expect Fay to reach that intensity. I am a bit troubled by Fay's heading of almost due west as the NHC forecast a more WNW track ATT. I can not count the times the models insist on moving a TC poleward when in fact they continue to track westward. Hurricane Ivan as I recall went way futher west than the models wanted it to go......MGC


This is not an official forecast just MGC's opinion for what it is worth...

I'm getting concerned here MGC. I can think of the same thing with Katrina, the models kept moving west as they overestimated the ridge. Fay could very well be a Panhandle problem if this more westward track is still ongoing come tomorrow morning.

The NHC track, not the cone is pretty much a split down the middle of the model consensus and the NHC usually puts more emphasis on the GFS. Many of the models do come west toward the Panhandle including most all the BAMM models, UKMET, NOGAPS and even some of the others. So yes, if Fay continues more westward than what the NHC track indicates it would be foolish to not give weight to those models in this situation.

[cheezyWXguy]

Usually when you see a storm slow, a direction change is soon to follow.

Steering currents do not suggest a turn to the north to begin for about another 12-24 hours. It maybe slowing, but the northward turn shouldnt commence immediately

[Hurricanewatcher2007]

is this flight trying to see what the High is doing? If so I don't call 1053mb a weakness!

000
URNT15 KBIX 170007
AF302 1006A FAY HDOB 43 20080817
235600 2353N 07837W 2994 09711 0539 -310 -330 161015 016 026 002 00
235630 2354N 07840W 2994 09716 0540 -310 -330 168014 015 020 003 00
235700 2355N 07843W 2994 09710 0537 -312 -330 166016 017 019 002 00
235730 2355N 07846W 2993 09707 0533 -315 -330 154018 020 026 008 00
235800 2356N 07849W 2993 09708 0533 -314 -330 155018 020 032 011 00
235830 2357N 07852W 2992 09711 0534 -316 -330 159018 020 031 011 00
235900 2358N 07854W 2994 09704 0533 -315 -330 169022 023 037 008 00
235930 2359N 07857W 2988 09716 0531 -312 -330 158024 031 040 013 00
000000 2400N 07900W 2992 09707 0529 -307 -330 160030 032 039 009 00
000030 2401N 07903W 2993 09707 0531 -311 -330 115018 024 032 004 00
000100 2402N 07906W 2994 09704 0529 -310 -330 103022 023 022 004 00
000130 2403N 07909W 2992 09711 0530 -305 -330 134018 021 017 002 00
000200 2404N 07912W 2995 09701 0529 -302 -330 150026 027 012 002 00
000230 2405N 07915W 2994 09701 0529 -305 -330 159028 029 009 002 00
000300 2406N 07918W 2994 09701 0529 -308 -330 158033 035 008 002 00
000330 2407N 07921W 2994 09704 0529 -305 -330 155034 035 006 002 00
000400 2408N 07923W 2993 09704 0530 -306 -330 154030 036 001 003 00
000430 2409N 07926W 2994 09703 0530 -308 -330 132020 022 006 002 00
000500 2410N 07929W 2993 09707 0531 -313 -330 141017 018 005 002 00
000530 2411N 07932W 2994 09704 0531 -317 -330 154023 027 004 001 00
$$
;

[KWT]

EJ is totally right, what could happen in the end is that it track more west at first hits the warmer waters, deepens rapidly and taps into deeper steering currents where the weakness is expressed better and turns harder then some of the models show.

Thats only one option and I think the general synoptic idea is correct but at the moment Fay is moving pretty much due west over the last few hours anyway, the only issue is the center could wobble about a bit as its still trying to stack up.

[physicx07]

I believe there wouldn't be a drastic correction because the weakness in the ridge is pretty subtle. It's not like a deep trough is coming down and practically scraping along the latitude that the system is at. If that were the case, it could possibly recorrect, speeding up as it does to get back on track. There's just nothing that drastic grabbing onto the system. In fact, if it stays far enough south, the way the weakness/trough looks, it could possibly end up missing the recurve entirely IMO. I'm not saying I think it's likely but really the driving force for the recurve doesn't look very strong.

This won't be a situation where a correction on the course can occur downstream, there is nothing turning it but a weakness to develop in the ridge.

Why couldn't there be a correction? If it feels a weakness in the ridge its going to go for it period. If this weakness sets up somewhere further east of where the NHC track is then it will turn up east of the later plots. If it sets up west of there then it keeps going west. To say it will not correct or that it CAN'T correct itself is entirely untrue.

[jinftl]

One unknown in all of this is the possibility that the westward motion will afford more time over water leading to a more developed system than is forecast....and i am reading alot of posts saying that a more developed system would actually be more influenced by the conditions that could lead to a north or even northeast turn in time....

so nothing is etched in stone....the NHC is urging all Floridians to remain vigiliant....they have not issued any all clears for any part of the state...in fact, they keep stressing quite the opposite.

[wxman57]

I wouldn't worry too much about the track of a poorly-defined center being a little north or south of the projected track for the next 24 hours. And don't look for any 90 degree turn tomorrow. Expect only a slow gain in latitude the next 24 hours followed by a gradual turn NW tomorrow night and Monday morning. It really makes little difference if Fay is a half degree either side of the forecast track, the turn will come. The only difference it might make is whether the center tracks inland along the western peninsula of FL or just offshore Tue/Wed.

[KWT]

Also yep its slowing down a little but still moving at a decent clip around 14mph.

Dean4Storms, yeah also it should be noted the GFS has been known to have a slight right bias though its not that noteable really at this range to be fair.

[caneman]

Usually when you see a storm slow, a direction change is soon to follow.

Steering currents do not suggest a turn to the north to begin for about another 12-24 hours. It maybe slowing, but the northward turn shouldnt commence immediately

yep, I'm aware of that 12-24 is sounds about right. Didn't say immediately.

[physicx07]

Sometimes storms begin to slow down in response to a trough to the north, and in some cases the trough passes on by and it keeps its direction and speeds back up as the ridge builds back in. Just because its slowing doesn't mean it has to turn at all.

Usually when you see a storm slow, a direction change is soon to follow.

Steering currents do not suggest a turn to the north to begin for about another 12-24 hours. It maybe slowing, but the northward turn shouldnt commence immediately

[Bgator]

When do you think watches will go up for the keys, and florida peninsula? and do you think the SE coast will get watches too? School starts here on Monday in Miami.

[jinftl]

is there any model update suggesting a landfall west of florida....that would indeed be telling.

I believe there wouldn't be a drastic correction because the weakness in the ridge is pretty subtle. It's not like a deep trough is coming down and practically scraping along the latitude that the system is at. If that were the case, it could possibly recorrect, speeding up as it does to get back on track. There's just nothing that drastic grabbing onto the system. In fact, if it stays far enough south, the way the weakness/trough looks, it could possibly end up missing the recurve entirely IMO. I'm not saying I think it's likely but really the driving force for the recurve doesn't look very strong.

This won't be a situation where a correction on the course can occur downstream, there is nothing turning it but a weakness to develop in the ridge.

Why couldn't there be a correction? If it feels a weakness in the ridge its going to go for it period. If this weakness sets up somewhere further east of where the NHC track is then it will turn up east of the later plots. If it sets up west of there then it keeps going west. To say it will not correct or that it CAN'T correct itself is entirely untrue.

[Dean4Storms]

I believe there wouldn't be a drastic correction because the weakness in the ridge is pretty subtle. It's not like a deep trough is coming down and practically scraping along the latitude that the system is at. If that were the case, it could possibly recorrect, speeding up as it does to get back on track. There's just nothing that drastic grabbing onto the system. In fact, if it stays far enough south, the way the weakness/trough looks, it could possibly end up missing the recurve entirely IMO. I'm not saying I think it's likely but really the driving force for the recurve doesn't look very strong.

This won't be a situation where a correction on the course can occur downstream, there is nothing turning it but a weakness to develop in the ridge.

Why couldn't there be a correction? If it feels a weakness in the ridge its going to go for it period. If this weakness sets up somewhere further east of where the NHC track is then it will turn up east of the later plots. If it sets up west of there then it keeps going west. To say it will not correct or that it CAN'T correct itself is entirely untrue.

I missed his response, Thanks for giving the input that I was trying to convey.

[shaggy]

I believe there wouldn't be a drastic correction because the weakness in the ridge is pretty subtle. It's not like a deep trough is coming down and practically scraping along the latitude that the system is at. If that were the case, it could possibly recorrect, speeding up as it does to get back on track. There's just nothing that drastic grabbing onto the system. In fact, if it stays far enough south, the way the weakness/trough looks, it could possibly end up missing the recurve entirely IMO. I'm not saying I think it's likely but really the driving force for the recurve doesn't look very strong.

This won't be a situation where a correction on the course can occur downstream, there is nothing turning it but a weakness to develop in the ridge.

Why couldn't there be a correction? If it feels a weakness in the ridge its going to go for it period. If this weakness sets up somewhere further east of where the NHC track is then it will turn up east of the later plots. If it sets up west of there then it keeps going west. To say it will not correct or that it CAN'T correct itself is entirely untrue.

I agree that there is no strong trough to turn this storm to the NE and whisk it away at 30mph. A weakness in the ridge is still a weakness and the storm will take the path of least resistance in this steering flow. Where this weakness occurs will determine when the turn to the N occurs and that can be anywhere along the forecasted cone. If she gets stronger now because of her west t movement and longer time over water she will feel that weakness and turn.

IF that scenario played out and she turned up east of the official track after having gone west now in the short term wouldn't that be a "correction"?

[KWT]

It really makes little difference if Fay is a half degree either side of the forecast track

I'm not sure i would agree with that statement, clearly half a degree difference may make the difference between W.Florida being in an eastern eyewall or not...

However yeah as you say the same synoptic set-up is going to occur and that has not changed, the only difference is the further west it goes now slightly further west the systems goes.

[RL3AO]

When do you think watches will go up for the keys, and florida peninsula? and do you think the SE coast will get watches too? School starts here on Monday in Miami.

5am tomorrow would be my guess.

[Blown Away]

The 11am advisory had Fay at 11pm tonight at 19.3N 75.4W, so based on that Fay is a little N and W of her 12 hour predicted position from 11am this morning.

[Steve]

>>the forecast point is for 2 a.m. tomorrow

My bad. Next point out.

[Dean4Storms]

Also yep its slowing down a little but still moving at a decent clip around 14mph.

Dean4Storms, yeah also it should be noted the GFS has been known to have a slight right bias though its not that noteable really at this range to be fair.

Yep, the GFS has had a long history of underestimating ridges in this situation, I've seen it for years and this year so far does not seem to be different. It was just two days ago that the GFS and company had Fay deepening just north of Eastern Cuba and abruptly turning north into the weakness up over the Bahamas and up the East coast and I was questioning that then. I'm hoping that Fay makes the turn now but I'm also a realist when it comes to the GFS estimating ridges.