ATL: Tropical Depression Fay

[Evil Jeremy]

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

[Dean4Storms]

Guess I'll be hitting the store tomorrow to stock up on some water, gas and batteries. Those are the only items I wait to stock up on so as to have them fresh.

[Jason_B]

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

If the latest NHC track verifies there would be a very significant impact on SFL which would be in the right side of the storm.

[Dean4Storms]

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

Still fairly good.

[vaffie]

Anyone think there is any chance of landfall in the western gulf?

When my family asked me, I told them that I thought there was less than a 5% chance. But things change. The last couple days, the consensus was going to the north of Puerto Rico, then it being a fish, then a hit on North Carolina, then east Florida, then west Florida, with each hour the models are shifting westward it seems. It already looks like it is reforming to the south. If this keeps on going like this, the weakness in the ridge might cause it to stall and then start heading westward under a building ridge. I think this is unlikely however, as the weakness seems like it will be quite strong. Nevertheless, I would seriously be preparing for landfall if I lived as far west as central Louisiana. It is worth pointing out the latest GFS ensemble forecasts. They are further west than anything else so far. http://moe.met.fsu.edu/~acevans/models/al062008_ens.png

[cpdaman]

depends on how large windfield is

is this forecast to be small in size

[Sanibel]

Serious look for me tomorrow morning. Gas, house preparation etc. - since they have an intensifying cyclone headed right over us.

NHC track is right over Key West as an intensifying cyclone.

[Dean4Storms]

If Fay stays over the Gulf to a landfall on the upper Gulf Coast she could grow to substantial size.

[Sanibel]

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.

[SouthFLTropics]

Serious look for me tomorrow morning. Gas, house preparation etc. - since they have an intensifying cyclone headed right over us.

NHC track is right over Key West as an intensifying cyclone.

Considering that the track is right over Key West one has to wonder when the evacs of the Keys will begin. It is crucial that this happens in a timely manner as we all know because it takes a good amount of time to get everyone out.

SFT

[lbvbl]

what does you guys think about a SE FL landfall? still a possibility? why or why not?

[gatorcane]

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

[ronjon]

Serious look for me tomorrow morning. Gas, house preparation etc. - since they have an intensifying cyclone headed right over us.

NHC track is right over Key West as an intensifying cyclone.

Sanibel, I'm making contigency plans. I live right on the GOM on a canal 40 miles north of Clearwater. Need to think about planing for evacuation. I hate this. Just like Charley four years ago.

[SouthFLTropics]

what does you guys think about a SE FL landfall? still a possibility? why or why not?

Definitely still a possibility...It's all about timing of the trough...It could bring it up right over us...Timing is everything in this situation.

SFT

[Sanibel]

Maybe erring on the safe side to keep people alert. Sort of opposite what they did with Charley.

We live 3-400 yards from the beach right in the bite of a south approaching cyclone of intensity.

[gatorcane]

look folks if you are in or even around the cone then yes, you could be impacted directly

[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.

[cycloneye]

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

And look what AVILA said about that.


MOST OF THE GUIDANCE HAS SHIFTED WESTWARD AND THE
OFFICIAL FORECAST IS ON THE EASTERN EDGE OF THE ENVELOPE. BEFORE I
AM COMMITTED TO SHIFT THE TRACK FARTHER WEST...I WOULD RATHER WAIT
TO SEE IF GUIDANCE BECOMES MORE STABLE FROM ONE RUN TO THE NEXT.

[CYCLONE MIKE]

wxman, how substantial do you think the weakness forecast to develop will be. Is there anyway to determine how strong the weakness will be before it happens. You mentioned the steering currents will become weak come tues. and therefore would that not slow fay down allowing the the ridge to rebuild to turn her more west?

[gatorcane]

Indeed so they are looking for a trend and that is definitely smart because these models have been flip-flopping back and forth between West and East Coast of FL over the past 24 hrs. I'm curious how much climatology plays a role as it would suggest East Coast of Florida not west coast (possibly panhandle though).

and the new news is NHC thinks it could be a hurricane. By the way did they look at Derek Ortt's 5pm EST update? Seems to be indentical to it. Good job Derek as always.