ATL: Tropical Depression Fay

[HURAKAN]

In my house we're always ready. The gas generator did its normal testing of the motor yesterday and it powers the entire house. Shutters are ready, if needed. Enough food is always available for a few days. In case it becomes more serious, enough water will be bought.

[MGC]

EEK, I'm in the 5 day cone. Fay had better stay away. Fay looks pretty good for being over land so this has me concerned as it looks like the circulation has not been disrupted to any great extent. I also don't like the model trend....westward. Fay has the potential to be a pretty significant hurricane out over the GOM......MGC

[MiamiensisWx]

The following post is NOT an official prognosis.

Let's take a look at the system from a synoptic perspective. WV imagery indicates an upper low and associated TUTT to the NE of Fay is moving SW in tandem with the TC's (N of due W) movement. It is clearly providing a favorable outflow channel on the eastern semicircle of Fay. At the same time, a weak TUTT to the west of Fay is continuing to retrograde WNW. This is often a strong signal for a building mid/upper level ridge to the north. You can detect the well established 300 mb anticyclone over and north of Fay as it is moving west. Over the intermountain West, the heralded cutoff low at H5 is developing and deepening, while the the shortwave over the eastern Great Lakes is moving east with a relatively sharp temperature gradient at 500 mb. The evolving set-up is evident on upper air charts at 500 mb. Let's compare it to the latest (18Z) operational GFS. Firstly, note that the GFS is clearly not as deep with the cutoff low over intermountain West, when compared to the current reality. The GFS' initialization indicates the lowest heights are near ~580 dm, while current data indicates heights are as low as ~578 dm over Wyoming and South Dakota. Keep in mind that the current pattern is very progressive (with an intense Pacific disturbance progged to enter the region off the Pacific Northwest), and with the lower heights/deeper cutoff evolving over the intermountain west, some models such as the operational GFS may be underestimating the downstream height rise. Note that current data also indicates the 500 mb ridge axis over the Florida peninsula is currently slightly stronger than initialized as well. By 36 hours, as the Northeastern CONUS shortwave deepens slightly farther east, heights will already be rising over the Florida peninsula and Southeast as the cutoff low deepens along the Front Range. With the strong Pacific disturbance and intense Pacific jet (coupled with trends), I strongly suspect the ridging (at its weakest when the NE shortwave briefly creates the weakness) will be stronger than progged, and it will rebuild quicker than progged. At that time, Fay will be moving west of Hispaniola. If the 500 mb ridging and amplification of the pattern is stronger than progged, the 300 mb anticyclone over the Florida peninsula and Gulf of Mexico will be stronger as well. Overall, the latest trends in the models; their variations; and ensembles (all with a track farther west in the Gulf of Mexico) are likely picking up on these trends.

Initially, Fay's organization over the next 30-36 hours will be critical. If it maintains a more vigorous low level circulation, the chances of greater intensification west of Hispaniola and south of the Cuban coast will be greater. Based on trends and Fay's current movement, it is likely that Fay will make landfall on Cuba farther west than the original model CONU (consensus) and the NHC's CONU-based track, which suggests that the TC will affect the flatter, less mountainous regions of western Cuba. If any inner core is present at the time of landfall (and I suspect a formative one may be present), Fay will not weaken as significantly when compared to a region with higher elevations and greater land coverage like Haiti/Dominican Republic. The western half of Cuba is much flatter and narrower than Hispaniola, and based on Fay's persistent speed (slightly faster than guidance), it would likely spend even less time over Cuba. This may be very dangerous for the United States down the road. Specifically, I'm referring to northwestern Florida from Pensacola to Panama City Beach.

As mentioned above, Fay will have an EXCELLENT outflow pattern when it enters the Gulf of Mexico; if an inner core is present, the potential for rapid intensification is quite high. In addition, a consequence of a track farther west would be a track would be the fact that the TC would traverse the highest tropical cyclone heat potential region of the Loop Current, as seen here. This area will be completely undisturbed when Fay enters the region, with peak August SSTs and very high oceanic heat content (and a deep 26 C isotherm). Another concern is the fact that the pattern will be completely different than the one that affected Ivan and Katrina; those TCs were not entering the Gulf as a strong cutoff low evolved over the intermountain West. I suspect that mid level moisture will be greater around the time of landfall in Fay's case, so the weakening trends exhibited by Dennis, Katrina, Ivan, et al may not occur (or may not evolve to a significant extent), unlike the preceding cases. We won't have a strong continental shortwave coming down; we WILL have a BUILDING ridge and a TC recurving around the periphery WITHOUT a significant trough (with mid level dry air) this time. A analog in regards to Fay's intensity trends prior to landfall and around landfall may be Frederic 1979 or Eloise 1979. Interestingly, Fay will likely approach landfall around August 18, which is the anniversary of Hurricane Camille's infamous Category 5 landfall on the Mississippi coast. Camille, Frederic, and Eloise (as well as Carla 1961 and Celia 1970) are vivid reminders that all Gulf TCs do NOT weaken significantly prior to landfall; in fact, as illustrated by Eloise, Federic, Carla, and Celia, some may even INTENSIFY from a lower (Cat 1/2) category to major hurricane status shortly prior to landfall.

Based on all available data, my early guess for a landfall is the Pensacola-Panama City Beach region. All data suggests that Fay has a very high probability to become a major hurricane; my guess is a peak intensity in the Gulf of Mexico of at least Category 3 intensity, and Category 4 strength is possible.

Bump for others

[MiamiensisWx]

Center is avoiding the highest mountains of Hispaniola... this is not good...

Winds have shifted to SSE at Santo Domingo... center is immediately west and moving WEST, missing highest mountains...

http://www.wunderground.com/global/stations/78486.html

[Dean4Storms]

We should narrow down the synoptic tomorrow night Dean.


If it stays 75 miles west of me it will be a good one to ride out. I'll need water since I'll be camping out again without electricity. If it heads right here I have to get busy because the odds of two no surge storms is low. Other direct hits have washed right over Sanibel with surge in the past.

Agree Sanibel. You need to prepare for the worst tomorrow for sure.

I'm getting bothered by what I'm seeing on IR, it looks to me that this center maybe turning WSW or relocating with that deep convection now over the water just south of the island. If that verifies it could track more toward my direction if all the other synoptics remained the same.

http://www.ssd.noaa.gov/goes/flt/t1/loop-avn.html

[El Nino]

Very bad news this evening. Has to be confirmed, but it won't be the first time to see this. Last time was ... Katrina.

[gatorcane]

MiamiWx excellent analysis of the situation as always. I'm sure members appreciate these comments in situations like this. Thanks again

[TheShrimper]

I would ask Frank2 about east coast implications. You may have to pull his head out of the sand...if you can find him. " I wouldn't worry about it" (Fay threat) per Frank2.

[OuterBanker]

There is one hurricane that hasn't been used as a comparable. I guess no one wants to use it. And I see the jog up the east coast is finally out completely. But earlier it was possible. Of course I'm referring to the ultimate scenario.

Donna

[MiamiensisWx]

This is a Gulf threat with a VERY HIGH POTENTIAL of rapid intensification, in my view...

[ronjon]

Jeez , Miami, thanks for cheering me up with that analysis.

[JtSmarts]

Excellent analysis Miami, and not good news for the Gulf coast. I've learned a lot from reading your very informative posts, keep up the great work. Like many of you I've also noticed that persistent area of convection south of the coast, it seems Fay would definitely have a good place to reform her center, if the mountains severely disrupted the current one.

[gatorcane]

Jeez , Miami, thanks for cheering me up with that analysis.

I'm afraid I may have to agree with him on this one...

[fci]

What is the chance of a direct/indirect threat in SFL at this point?

Personal Forecast Disclaimer:
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.[/quote]


OK, I am answering based on what I have recalled in the past.

I think that this storm will get further West than expected and due to this Fay will pass about 100 miles West of Key West.
The landfall will be in the Panhandle area (Destin or Panama City) and I would not be shocked to see it further west even as far as Alabama/Missisippi.

The effect on Southeast Florida, where you and I live; will be minimal with a little bit of a gusty wind.

We caught a big break when Fay waited so long to develop and ended up going so far west
Had she developed north of Puerto Rico or just barely skimmed the coast of DR; we would be very worried right now with all the warm water ahead of the storm

If Fay were to turn earlier and go across the mountainous part of Cuba, she would be greatly weakened and woudl limp towards us.

We caught a break here.......again.

Just my opinion based on years of following storms.

[El Nino]

This is a Gulf threat with a VERY HIGH POTENTIAL of rapid intensification, in my view...

I agree. Some long nights ahead I think.

[Vortex]

00Z NAM-east of florida and excellent initialization. GFS should prove interesting to determine any trends


http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml

[MiamiensisWx]

OK, I am answering based on what I have recalled in the past.

I think that this storm will get further West than expected and due to this Fay will pass about 100 miles West of Key West.
The landfall will be in the Panhandle area (Destin or Panama City) and I would not be shocked to see it further west even as far as Alabama/Missisippi.

The effect on Southeast Florida, where you and I live; will be minimal with a little bit of a gusty wind.

We caught a big break when Fay waited so long to develop and ended up going so far west
Had she developed north of Puerto Rico or just barely skimmed the coast of DR; we would be very worried right now with all the warm water ahead of the storm

If Fay were to turn earlier and go across the mountainous part of Cuba, she would be greatly weakened and woudl limp towards us.

We caught a break here.......again.

Just my opinion based on years of following storms.

I think southeast Florida is mostly safe from this one, FCI... agreed.

[Dean4Storms]

The following post is NOT an official prognosis.

Let's take a look at the system from a synoptic perspective. WV imagery indicates an upper low and associated TUTT to the NE of Fay is moving SW in tandem with the TC's (N of due W) movement. It is clearly providing a favorable outflow channel on the eastern semicircle of Fay. At the same time, a weak TUTT to the west of Fay is continuing to retrograde WNW. This is often a strong signal for a building mid/upper level ridge to the north. You can detect the well established 300 mb anticyclone over and north of Fay as it is moving west. Over the intermountain West, the heralded cutoff low at H5 is developing and deepening, while the the shortwave over the eastern Great Lakes is moving east with a relatively sharp temperature gradient at 500 mb. The evolving set-up is evident on upper air charts at 500 mb. Let's compare it to the latest (18Z) operational GFS. Firstly, note that the GFS is clearly not as deep with the cutoff low over intermountain West, when compared to the current reality. The GFS' initialization indicates the lowest heights are near ~580 dm, while current data indicates heights are as low as ~578 dm over Wyoming and South Dakota. Keep in mind that the current pattern is very progressive (with an intense Pacific disturbance progged to enter the region off the Pacific Northwest), and with the lower heights/deeper cutoff evolving over the intermountain west, some models such as the operational GFS may be underestimating the downstream height rise. Note that current data also indicates the 500 mb ridge axis over the Florida peninsula is currently slightly stronger than initialized as well. By 36 hours, as the Northeastern CONUS shortwave deepens slightly farther east, heights will already be rising over the Florida peninsula and Southeast as the cutoff low deepens along the Front Range. With the strong Pacific disturbance and intense Pacific jet (coupled with trends), I strongly suspect the ridging (at its weakest when the NE shortwave briefly creates the weakness) will be stronger than progged, and it will rebuild quicker than progged. At that time, Fay will be moving west of Hispaniola. If the 500 mb ridging and amplification of the pattern is stronger than progged, the 300 mb anticyclone over the Florida peninsula and Gulf of Mexico will be stronger as well. Overall, the latest trends in the models; their variations; and ensembles (all with a track farther west in the Gulf of Mexico) are likely picking up on these trends.

Initially, Fay's organization over the next 30-36 hours will be critical. If it maintains a more vigorous low level circulation, the chances of greater intensification west of Hispaniola and south of the Cuban coast will be greater. Based on trends and Fay's current movement, it is likely that Fay will make landfall on Cuba farther west than the original model CONU (consensus) and the NHC's CONU-based track, which suggests that the TC will affect the flatter, less mountainous regions of western Cuba. If any inner core is present at the time of landfall (and I suspect a formative one may be present), Fay will not weaken as significantly when compared to a region with higher elevations and greater land coverage like Haiti/Dominican Republic. The western half of Cuba is much flatter and narrower than Hispaniola, and based on Fay's persistent speed (slightly faster than guidance), it would likely spend even less time over Cuba. This may be very dangerous for the United States down the road. Specifically, I'm referring to northwestern Florida from Pensacola to Panama City Beach.

As mentioned above, Fay will have an EXCELLENT outflow pattern when it enters the Gulf of Mexico; if an inner core is present, the potential for rapid intensification is quite high. In addition, a consequence of a track farther west would be a track would be the fact that the TC would traverse the highest tropical cyclone heat potential region of the Loop Current, as seen here. This area will be completely undisturbed when Fay enters the region, with peak August SSTs and very high oceanic heat content (and a deep 26 C isotherm). Another concern is the fact that the pattern will be completely different than the one that affected Ivan and Katrina; those TCs were not entering the Gulf as a strong cutoff low evolved over the intermountain West. I suspect that mid level moisture will be greater around the time of landfall in Fay's case, so the weakening trends exhibited by Dennis, Katrina, Ivan, et al may not occur (or may not evolve to a significant extent), unlike the preceding cases. We won't have a strong continental shortwave coming down; we WILL have a BUILDING ridge and a TC recurving around the periphery WITHOUT a significant trough (with mid level dry air) this time. A analog in regards to Fay's intensity trends prior to landfall and around landfall may be Frederic 1979 or Eloise 1979. Interestingly, Fay will likely approach landfall around August 18, which is the anniversary of Hurricane Camille's infamous Category 5 landfall on the Mississippi coast. Camille, Frederic, and Eloise (as well as Carla 1961 and Celia 1970) are vivid reminders that all Gulf TCs do NOT weaken significantly prior to landfall; in fact, as illustrated by Eloise, Federic, Carla, and Celia, some may even INTENSIFY from a lower (Cat 1/2) category to major hurricane status shortly prior to landfall.

Based on all available data, my early guess for a landfall is the Pensacola-Panama City Beach region. All data suggests that Fay has a very high probability to become a major hurricane; my guess is a peak intensity in the Gulf of Mexico of at least Category 3 intensity, and Category 4 strength is possible.

Bump for others

I hope you are wrong as I lie directly between P'Cola and PCB just west of Destin. But that is a great job and I cannot find any argument toward your reasoning at this point. All I can hope for is that the weakness doesn't verify and Fay heads off further west, sorry LA.

[Jason_B]

As far as the Gulf is concerned, we'll know a lot more by Monday when this thing gets past Cuba. But folks in the Keys and SFL better start preparing this weekend.

[fci]

oh boy the NHC hardly move the track west. I thought they would by more than that based on the board consensus. The nudge was as I expected (maybe 50 miles or so west):

http://www.nhc.noaa.gov/archive/2008/gr ... p_5W.shtml

They are waiting for more model consensus to take it further west. Too radical to make the whole change now so they are on the East side of the consensus, for now.