10/15/05 FCST: Hurricane Wilma

[MClarkson]

Seas are warm and shear is light. The GFDL has been forecasting some really massive deepening the last few runs, the 12Z says 898mb... a little early to put too much trust in that but I dont see anything to impede development in the near future.

Steering currents are light and erratic. Some models are calling for slow westward movement. The feature of interest is a trough digging down late in the forecast period. Its too early to even start guessing where/if the trough will catch the storm, but if it does, florida could have chase potential in about a week. If the trough misses the storm then the region of central america allready flooded by the remnants of stan could get a slow moving major storm.

...assuming this depression continues to organize, wilma is the last name on the list.

 

[John Gnuechtel]

TD 24 still looks pretty ragged this morning. From the satellite images, it seems to me that there isn't even really a good, solid center yet. However, model concensus is far better than it was yesterday, with most runs putting the storm in a position to take aim at Florida's Gulf coast by the end of the week. The last few GFS runs have consistently brought it over Tampa around Saturday afternoon as a ~980mb low. The forecast trough slowly curving the storm to the NNE late in the period is a pretty classic track scenario for this part of the season, so I don't have much reason to doubt it. We'll probably have a good bead on the landfall location by Wednesday night.

 

[Scott Olson]

While TD24 still doesn't look that great. There is a good consensus that this system will not only become Wilma but a major Hurricane.

http://euler.atmos.colostate.edu/~vigh/gui.../intensity1.png

While the GFDL is no longer forecasting the super-intense Hurricane it was previously it does now have a bigger Hurricane. Even the FSU-MM5 forecasts has a 950mb Hurricane. If this tropical depression can begin to take on some better features and a more defined center then I think we will have ourselves Hurricane Wilma by Tuesday. Track guidance is now starting to look like an enventual Florida/Gulf Coast landfall though I still think there is enough uncertainity on whether the storm would first go through Cuba or even the Yucatan Pennisula.

 

[MClarkson]

the 12z navy and gfs have jumped north towards south florida late in the forecast period. They are both on the rightside of guidance at the moment. The WRF hurricane and Euro from last night take the storm towards the northern tip of the yucatan. Overall i'd say that the models are starting to agree better on a track somwhere in the vicinity of west cuba-cancun and then recurving NE. Once into the gulf SSTs start to drop off, but the southern gulf is till warm enough to support a major.

 

[Sam Sagnella]

...what a difference a day can make...

Wilma is looking excellent this afternoon. Persistant, deep convection has been present for much of the day along the cyclone's southern semicircle -- and, more recently, directly over the center of circulation. As the inner core continues to become better established, I expect rapid intensification to commence later today or tonight. I'm thinking Wilma is about 50kt now, and should be close to hurricane status within 12hr, though will wait to see what the recon flight finds when it reaches the system in an hour or so. Regardless of the current intensity, I believe 24L has the potential to attain major hurricane status by about 60hr and that it poses a grave threat to the northeastern Yucatan Peninsula -- specifically the Cozumel-Cancun region.

All indications are that this will be yet another massive storm, with a large radius of intense winds. As far as the threat the United States is concerned, the key lies in whether or not the center crosses any significant land masses before entering the Gulf. As it stands now, I believe that a landfall along the Yucatan is the most likely scenario, though with such significant inconsistancies within the model guidance it's impossible to say for sure.

EDIT: The latest VORTEX at 2024z has a central pressure of 989mb! Highest FL winds so far are 50kt southeast of the center of circulation -- 21z update will probably bump the winds up another 5kt to 45kt or ~50mph. Temperature inside the 'eye' is +2C compared to in the 'eyewall.'

 

[Scott Olson]

Wilma has slowly organized into a nice looking tropical storm with the center surronded by convection, good banding and a much more defined center than previously. Latest Dvorak numbers are nothing to get excited about basically not moving throughout the day (cold cloud tops associated with convection likely one reason.) But 1912 Quickscat indicates a good area of 40kt winds and likely on the increase. Pretty decent spread in model consensus on just how fast Wilma will turn to the north. And as Sam pointed out this could have a big impact on Wilma if she can avoid to much land interactions as she swings back to the N/NW. I actually thought the GFDL looked a little hillarious cause it aims at the tip of NE Yucatan only to push away at the last minute and maintain a CAT 3 intensity as it nears FL. (I guess the GFDL has a sense of humor). Despite this I think Wilma will impact the NE Yucatan and albiet briefly.

I think its pretty safe to say that with decreasing vertical shear (5kts!) and warm SST's with 80-100cm depth to 26c. That Wilma will probably undergo a rapid intensification that we have seen time and time again this year.

989mb, with winds at least at Quickscat levels of 40kts surface. Likely even more graident pressure forces lagging behind. At least the AODT Dvorak is way off.

 

[Mark Farnik]

Wilma's satellite presentation, increasingly symmetrical banding and outflow plus central low pressure (980 millibars) say she is already a Cat 1 hurricane. But reconaissance aircraft have only found sustained winds no higher than 60 knots. So for now she is still a TS, but I imagine she will be upgraded to a hurricane in the 11 a.m. advisory. I have a bad feeling that Wilma could be just as ferocious as her sisters Katrina/Rita that preceded her, given the very warm SST's in the NW Carribean/Yucatan Channel/southern GoM and very light shear over her entire forecast path through 120 hours. An interesting note in the 5 A.M. discussion:
WILMA
IS EXPECTED TO BECOME AN INTENSE HURRICANE IN THE NORTHWESTERN
CARIBEAN SEA...TYPICAL OF THOSE HURRICANES WHICH COMMONLY OCCURRED
IN OCTOBER DURING THE 30'S 40'S AND 50'S. THIS IS NOTHING NEW.

Some of those October storms (I.e. Hazel) were extremely nasty, powerful storms. I think Wilma will be an October cane that will do her parents (Hazel and Mitch) proud. I know that seems like a silly analogy, but it fits. I say that there is at least a 50% chance Wilma will at one point or another reach Cat 4 or Cat 5 status. The conditions (aside from steering currents) are eerily similar to those present when Supercane Mitch formed in October of 1998. It's very possible Wilma could get that strong. :shock:
Models are now showing Wilma rounding the western tip of Cuba rather than glancing off the northeastern tip of the Yucatan and have her pass just north of Key West late on Saturday and slam into Miami from the west around midnight Saturday night. I'm willing to bet Wilma will still be at least a Cat 3 at landfall, possibly a Cat 4. Another major landfalling hurricane strike on the Gulf Coast; one begins to wonder how long it will be before it falls into the Gulf because of all the intense hurricanes that are slamming it!

 

[Sam Sagnella]

I say that there is at least a 50% chance Wilma will at one point or another reach Cat 4 or Cat 5 status.

I'm willing to bet Wilma will still be at least a Cat 3 at landfall, possibly a Cat 4.

Well I think the chances of it attaining category 4 status are significantly higher than 50%, though if it's going to do the Katrina/Rita cat 5 thing, it's going to need to do it in the Caribbean. With increasing shear by the time it makes it to the Gulf, I don't think it will be able to maintain cat4 until landfall. I think that it will peak out at around 120kt as it nears the Yucatan channel and begin to weaken thereafter. However, I do think that it will be at least a moderate category 3 at landfall and by then it could be moving at >20kt, thereby translating intense winds quite far across the FL peninsula. I created a landfall intensity map and posted it on another forum, and I'll update this at some point later today...but one should note that in all likelihood, this is going to be another monstrous storm area-wise.

 

[cdcollura]

Good day,

Watching this one like a hawk too as it may be close to the end of the week / weekend and I will be chasing this one since it is down in my home state.

If the track does go too far to the right, then it can affect the FL Keys, or even skirt south of them, depending on how deep the trough digs in and the timing of the cyclone versus the arrival of that trough.

The SST's and heat content in the extreme SE Gulf are still rather warm. A farther north movement, say to Tampa, may weaken the storm due to the cooler water and possible shear from the trough.

A southern track, say near Fort Meyers, will have less shear and warmer waters to work with. Many models show a 115 MPH storm, or higher, if this is the case (Category 3).

Never in my wildest dreams would I imagine chasing the "W" storm and the LAST storm name on the Atlantic hurricane season.

Chris C - KG4PJN

 

[Scott Olson]

Wilma is looking pretty good with Vortex, QuickScat and Microwave all showing a continued strengthning trend. Based on Microwave Vmax rate of strengthning and current and ADJ T numbers I think 75kts is pretty reasonable.

A couple interesting notes for today:

1. Model Consensus seems to indicate that Wilma could successfully avoid any serious land-interactions prior to landfall.

2. Intensity guidance from the SHIPS model has come aboard the GFDL band wagon and the GFDI and such seem to have a consensus of a near 110kt peak of surface winds.

3. While longer range intensity forecasts can be a joke, I think it's interesting to see the SHIPS, AVN and GFDL's response to Wilma crossing Florida as nearly no-weakening. While the GFDL reintensifies the Hurricane on the other side of Florida (very very doubtful but interesting).

 

[MClarkson]

Looks like the eye is starting to clear out. 970mb. There is a load of dry air in her path but that isnt holding back the GFDL and SHIPS. GFDL takes her down to 922 before land interaction with the yucatan. As she approaches florida she should really be moving, making the difference between left and right sides more pronounced, and also perhaps the reason why the GFDL shows no weakening, as it has the storm across the peninsula in ~5 hours.

 

[Alex Lamers]

TRACK FORECAST

This will be important in determining final intensity and I will explain why below. For my forecast I leaned GFDL and NHC with a landfall around Charlotte Harbor, FL and Port Charlotte, FL. I think the advancing Central CONUS trough will be a little slower than the GFS/UKMET would indicate and as a result a more gradual recurvature. Plus I think that with Wilma exploding in the next 24-30 hrs that it will take more to recurve it than what the weaker intensity forecasts of the GFS/UKMET would indicate.

INTENSITY FORECAST

The intensity forecast still has a lot of spread, but it appears likely that Wilma will make a landfall as a hurricane along the current official NHC forecast track. Right before landfall time, most models off the 18z runs were cloistered with an intensity AOA 84 knots (96.6 mph or a low end Cat 2). The vast majority pegged an intensity between 94 and 102 knots (108-117 mph or borderline Cat 2/3). I have long preferred the GFDL as the model of choice for hurricane intensity forecasts as it does the best in simulating the actual dynamics. It shows 102 knots at landfall which is a low end cat 3 storm but also takes it to cat 5 intensity several times during Wilma's life cycle, which seems unlikely but is possible.

http://argo.colorado.edu/~realtime/gifs_tm...sh/gmt.5270.gif

The Gulf Loop Current is an important factor (seen in image link above) that cannot be discounted and oceanic heat content will be quite high, acting like high octane fuel for Wilma. Based on my track, it should encounter that high octane fuel up until about 12-18 hrs before landfall. UNLIKE Rita and Katrina, which moved out of warm eddies farther away from land, and were slower moving, this storm will be moving into a cooler eddy very close to land and accelerating which should mitigate some of the subsiding of the intensity. Thus a substantial decrease from its intensity in the base of the Loop Current off NW Cuba seems somewhat improbable. As was proved with Rita and Katrina so far this year, that Loop Current can lead to RAPID intensification far ahead of the curve of most model's intensity forecasts.

However, it must also be noted that shear will likely be decreasing in the strait between Cuba and the Yucatan as Wilma arrives, providing an arresting probability of rapid intensification with little to no mitigating factors. This would be 30-42 hours out from landfall. Then I would expect to see a levelling off as shear gradually increases to the northeast with deintensification in the 12-18 hrs prior to landfall with the combination of increasing wind shear and a shallow cool eddy in the nearshore environment. The jet streak providing the shear will be exiting the Gulf around the time Wilma arrives, so despite the likelihood of some increasing shear, it may not be as substantial as some predict.

Latest GOES-12 derived mid-upper level water vapor winds show a trifecta of well defined outflow channels dominating all quadrants. Wilma is over some very warm water and thus it would seem plausible that we could see a rapid increase in intensity over the next 24 hours...and I am thinking we could have another major hurricane on our hands by tomorrow evening.

Thus I'm looking at possibly a Cat 4 when it passes by the tips of the Yucatan and Cuba with inner core dynamics and structure maintaining a major hurricane intensity at least until the day of the landfall with a likely landfall as a Category 2 or a Category 3. I'm thinking something in the triple digits for wind speed. 100-120 mph for now. Extrapolating NHC trends on their intensity forecast, mine is centered slightly higher at the moment...based on the fact that I think intensification may be underplayed by the majority of the models up for consideration.

IMPACTS

Category 2/3 type storms normally catch people off guard and after Rita failed to live up to the fabled level of Katrina (although I think everyone was happy about that)...some people may think we got our disaster out of the way for the year. A surprisingly strong storm could have bad consequences for an area still recovering from Charley!

EDIT

REPORTS FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE THAT MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 100 MPH...160 KM/HR...WITH HIGHER GUSTS. THIS MAKES WILMA A CATEGORY TWO HURRICANE ON THE SAFFIR-SIMPSON SCALE. THE AIRCRAFT REPORTS THAT THE CENTRAL PRESSURE IS FALLING RAPIDLY... AND WILMA IS EXPECTED TO BECOME A MAJOR HURRICANE LATER TONIGHT OR ON WEDNESDAY.

FORECASTER BEVEN

Looks like my pegged rapid bombout was right on. Look for it to continue. I may need to adjust up if this continues but we'll see what the 11 pm advisory says.

...Alex Lamers...

 

[Sam Sagnella]

Well it is quite obvious that Wilma is undergoing rapid intensification this evening. I see no reason why this should abate anytime soon, and, unfortunately, we're likely to see another jaw-dropping category 5 hurricane out of 24L. I think that it should peak out at around 145kt in a couple days before weakening back down to a category 4 over the Yucatan Channel. Earlier today I had considered shifting my forecast track slightly to the right, but, given that I'm expecting a stronger Wilma, it will take more energy -and therefore time- (as AlexL noted) to make the turn toward the northeast. For this reason, I've actually shifted my track slightly to the left (mainly while the center is still over the Caribbean). As we're already beginning (and should continue to) see, Wilma is expanding in size and, as I have been saying all along, *could* rival Katrina as far as overall area of hurricane-force winds go.

As the hurricane begins to accelerate, and as it approaches the Gulf coast of FL, winds on the right side of the storm will be markedly stronger than those on the left, though still quite intense. Intensity at landfall should be somewhere on the order of 100-110kt, with the strongest of these winds occurring south and east of wherever the eye comes ashore. The center of circulation should make the trip across the Florida Peninsula in less than six hours, and the hurricane will therefore experience relatively minimal frictional weakening. The bottom line is that the SW FL peninsula is looking like the 'target zone,' though with such a great deal of time on our hands before any potential landfall, things could easily change.

NOTE: BASED ON CURRENT TRENDS (SINCE I DREW OUT THE FCST MAP), STRENGTHENING TO CATEGORY 4 AND 5 STATUS WILL OCCUR MUCH EARLIER THAN INDICATED.

 

[Alex Lamers]

TRACK DISCUSSION

Per latest satellite loops of Wilma, it appears as though a left adjustment of the previous track is in order with Wilma continuing to slowly wobble off to the west or west-northwest. It is definately headed left of the 21Z NHC track which has me thinking that my idea of a more gradual recurvature is still on tap. I am still expecting the trough to deepen a little more which should slow down its longitudinal progression...enough to cause Wilma to gain a bit more latitude on the official forecast. Still looks like a Port Charlotte, FL region landfall is on tap based on what I am thinking. 18Z GFDL is in and it looks pretty close to what I'm thinking.

INTENSITY DISCUSSION

Obviously my intensity forecast will probably need to be increased based on latest trends. The initial intensity pegged by the NHC is 110 mph which seems reasonable based on new Dvorak estimate of 102 knots (117 mph) which doesn't account for the wind field lag from a pressure drop. The wind field is still rather small but latest satellite imagery shows a very cold symmetric core of convection around the eye now and the eye beginning to expand. We could see an intensity fluctuation in the near future as a larger eye tries to become established and the GFDL actually picks up on this between now and 12Z Wednesday.

Otherwise it will remain in a low shear environment coupled with high oceanic heat content and SST's which point to very favorable conditions for continued deepening. Three distinct outflow channels have evolved and all are relatively balanced which could also be contributing to the bombogenesis we're seeing. Bottom line is that Wilma should be a major hurricane in the next couple advisories if she isn't already.

I will maintain my initial thoughts about the Loop Current and the shear over Florida...two factors that will play a pivotal role in Wilma's intensity. A track shifted left would keep Wilma out over the high oceanic heat longer but it could be mitigated by a more extended interaction with higher shear.

SHIPS and GFDL seem like the most reliable models as of right now so I have based my updated forecast off of them. They have been behind the curve thus far and it seems plausible to compensate for this by a higher intensity forecast. I'd say sometime in the next 36 hours Wilma will hit just about as high as she's gonna get and then intensity fluctuations (up or down) will be controlled by inner core structure changes until the 12-18 hours before landfall when less oceanic heat and more shear will begin to take their toll. Given the fast forward speed by then, these should not be enough to weaken Wilma sufficiently to not pose a major hurricane threat to the SW FL Coast.

FORECAST

Track up through 20 N:
Rapid increase in intensity. Will likely peak at 150 MPH, forecast peak range 140-160 MPH...as a strong Category Four or weak Category Five hurricane. Potential for even stronger winds but did not get overzealous for now.

20-25 N:
Levelling off in intensity. Fluctuations in intensity due to eyewall replacement cycles likely. Will probably remain at similar intensity to its peak intensity as it crosses the loop current. If vertical wind shear is coincidentally low enough, potential for another cycle of rapid deepening over about 12 hrs in the strait between Cuba and the Yucatan.

25N - Landfall:
Gradual decrease in intensity. Landfall estimate is 130 MPH with a forecast range of 120-140 MPH. This is in agreement with the SHIPS and GFDL in general. Basically borderline Cat 3/4 is what I have it at right now. Lets pray I'm wrong!

...Alex Lamers...

 

[Alex Lamers]

Forget my forecast lol this is crazy...Wilma is defying all odds. 175 MPH sustained winds and 901 mb extrapolated sfc pressure.

...Alex Lamers...