Frances Advisories

[Anonymous]

Actually it got sheared, which is why it weakened.

[Anonymous]

I think a Cat 4 at landfall is likely, remember it only needs to break 130 to become a cat 4, only 10 mph off.

[jlauderdal]

In the 5:00 discussion the TPC says the intensity of Frances is problematic. I should say so! They have the hardest time figuring that out on these storms. So far they've blown it on Frances, saying she will be stronger than she may end up. In fact it seems that she is much weaker now than they are even telling us! They say she has 120 sustained winds on the Public advisory, but in the discussion they even doubt she's close to that! Charley was the opposite. They thought he wouldn't be any stronger than a cat 2 before landfall and look what happened. We here in Orlando got 105 mph winds nearly 120 miles inland! Now Frances could be much worse based on her overall size, speed and direction from which she is approaching us (much less land to traverse) but I'm beginining to think other than a tremendous amount of rain (due to the slow motion) we won't see much in the way of wind, at least not here in Orlando. They really need to get a handle at some point on these intensity forecasts. They don't have any real explanations for her current state of prolonged deteriation. And they are making a wild guess that she will strengthen before landfall, contradictory to the models. If they don't watch it this could be another case of crying wolf, if she makes landfall as a cat 1 all the while calling it something else.

The consistently admit that intensity forecasting is still a mystery and they do their best. Now we have a slow mover weaker can which is even more difficult to predict as mesoscale features can pop up unexpectadly. Give them a break...this is very difficult and you can be assured they have all hands on deck and literally hundreds of years of experience between the forecasters. I am getting more concerned about this become a rain event more than a wind event as long as it doesnt compeltely fall apart.

[das8929]

Ok what gives. I would be expecting at least some kick up in the winds this morning and some of the hurricanes outer bands coming ashore. Nothing.Nada. This thing is almost stalled. And how is it weakening? Lets hope it doesnt strengthen again.

[Tip]

From this CMISS map it seems that a compact upper level high formed south of Cuba that is the culprit for the shear. This was not forecast or at least I saw no information on it.

http://cimss.ssec.wisc.edu/tropic/real- ... g8shr.html

[otowntiger]

Actually it got sheared, which is why it weakened.

That may be, but they had no idea that was going to happen, and as it was happening they didn't seem to know what was going on, maybe still don't. Just now they mentioned shear in the forecast, but they didn't offer that as an explanationg to what has happened so far.

[rainstorm]

could it just die out due to upwelling? how could it stall for so long?

[caneman]

could it just die out due to upwelling? how could it stall for so long?

Shear and dry air. Local weather guy showed how it was expanding in size rather than pulling together. Unless it starts pulling itself together it will more than like just be a heavy rain maker for Florida wilth lots of flood potential. Its got tp get together and soon.

[das8929]

I don't understand. Where is this dry air coming from? Isnt the area a very humid area, and they said that it would strengthen in this area?

[otowntiger]

In the 5:00 discussion the TPC says the intensity of Frances is problematic. I should say so! They have the hardest time figuring that out on these storms. So far they've blown it on Frances, saying she will be stronger than she may end up. In fact it seems that she is much weaker now than they are even telling us! They say she has 120 sustained winds on the Public advisory, but in the discussion they even doubt she's close to that! Charley was the opposite. They thought he wouldn't be any stronger than a cat 2 before landfall and look what happened. We here in Orlando got 105 mph winds nearly 120 miles inland! Now Frances could be much worse based on her overall size, speed and direction from which she is approaching us (much less land to traverse) but I'm beginining to think other than a tremendous amount of rain (due to the slow motion) we won't see much in the way of wind, at least not here in Orlando. They really need to get a handle at some point on these intensity forecasts. They don't have any real explanations for her current state of prolonged deteriation. And they are making a wild guess that she will strengthen before landfall, contradictory to the models. If they don't watch it this could be another case of crying wolf, if she makes landfall as a cat 1 all the while calling it something else.

The consistently admit that intensity forecasting is still a mystery and they do their best. Now we have a slow mover weaker can which is even more difficult to predict as mesoscale features can pop up unexpectadly. Give them a break...this is very difficult and you can be assured they have all hands on deck and literally hundreds of years of experience between the forecasters. I am getting more concerned about this become a rain event more than a wind event as long as it doesnt compeltely fall apart.

I know they have always admitted it and did so in this morning's discussion, again. What I'm saying is they may need to be more honest in that this storm is no longe a major hurricane and may not be that way at the time of landfall. Regardless, as I know they admit, they need to get a better handle on the intensity forecasts.

[otowntiger]

This is one that will need to be analyzed after the event. A remarkable collapse of a borderline CAT 5 at one time to a 105mph storm with no discernible eye. Water temps were fine, no heavy duty shear, no dry air entrainment, no mountains. Whatever happened I will be interested to fin out.

I agree completely.

[charleston_hugo_veteran]

Today's Discussion
POSTED: September 3, 2004 5:01 a.m.


Category 3 Hurricane Frances, as of 5 A.M. EDT, is centered at 24.9 north and 76.0 west. That's 95 miles east of Nassau, in the Bahamas and 285 miles east southeast of the lower Florida east coast. Frances is moving toward the west-northwest at 9 mph. Maximum sustained winds have dropped to 120 mph. This makes Frances a strong category 3 hurricane. San salvador in the Bahamas reported a wind gust of 120 mph late Thursday afternoon. The central pressure within the hurricane is 954 millibars (28.17 inches). A hurricane warning remains in effect for the central and northwestern Bahamas. A hurricane warning also remains in effect for the Florida east coast, from Florida City northward to Flagler Beach, including Lake Okeechobee. A tropical storm warning and a hurricane watch are in effect for the middle and upper Florida Keys, from south of Florida City, to the Seven Mile Bridge, including Florida Bay.

Frances is moving west-northwest at about 9 mph. The forward speed has slowed since earlier Thursday. This slower speed will delay the onset of tropical storm force winds and heavier rain along the southeast coast of Florida during Friday. Tropical storm force winds probably won't reach the southeast coast of Florida until Friday afternoon and Hurricane force winds might not show up along the southeast Florida coast until early Saturday morning. This will give residents along the Florida coast time to prepare. The hurricane is still being affected by eye wall replacement. Strong hurricanes will have two eyewalls. During the process the inner eye wall dies falls apart and the pressure rises. Then the outer eye wall contracts causing the pressure to fall which then causes the wind to increase. This process takes 6 to 10 hours. So, the rise and fall in the pressure and wind speed is to be expected. An upper-level ridge of high pressure to the north of Frances will control movement. This will keep Frances on a course that will take it into Florida this weekend. Recent model runs and other data and observations we have looked at during Thursday evening suggests this course is still the most likely scenario. However, a weakening in the high pressure area to the north could still allow Frances to take more of a northwesterly turn meaning a hit further up the Florida coast. As for the timing of landfall, keeping the storm's current forward speed and movement, Frances will make landfall between Melbourne and West Palm Beach later Saturday. A slowdown, and subsequent turn to the northwest means a much later arrival, much farther up the east coast of Florida. One big concern about a slower movement is rainfall. Torrential rainfall could occur over parts of Florida Saturday through Sunday night. Given typical rainfall rates in hurricanes some places could pick up as much as 10 to 20 inches of rain causing major flooding.

The strong tropical wave in the eastern Atlantic near the Cape Verde islands has become Tropical Storm Ivan. As of 5 am AST Tropical Storm Ivan was located near 10.0 north and 30.7 west or about 610 miles southwest of the Cape Verde Islands. Maximum sustained winds are near 40 mph and the depression is moving west near 16 mph. Current forecast tracks by model output show this system tracking nearly due west for the next several days then turning northwest. Some longer range model output is suggesting this system will move into Hispaniola late next week then into the Bahamas next weekend. Until this system develops further this is mostly speculation. But it is possible another tropical cyclone could threaten the southeast U.S. in about 10 days.

[Tip]

Just shows how important the ENTIRE environment affects intensity. The models may not be refined enough for predicting the development of an almost mesoscale upperlevel high pressure.

[charleston_hugo_veteran]

A slowdown, and subsequent turn to the northwest means a much later arrival, much farther up the east coast of Florida.

Oh....that answered my question!

[rainstorm]

upwelling may kill it. it appears to have totally stalled

[Trader Ron]

When it passes over the gulf stream there will be NO upwelling.

[Wacahootaman]

I think the storm just ran into a dead end street with blocking high pressure to the north and west.


If it finds a new direction starts mooving out of this trap it will pick up strength.

Although it will probably keep going on the track predicted, it would not surprise me if it did stall completely and reverse course like Betsy in 65 or Elena in 85.

Both those storms were moving NE, did a complete stall and almost fell apart before reversing themselves and moving west or SW and getting much stronger.

Of course this also could also be a last minute collapse like the one that threatened Louisana a while back or Isabel up north.

[Cyclone Runner]

The waters in the Central Bahamas are too shallow for significant upwelling of sufficiently cool water, so it should not be a defining issue.

[quickychick]

Of course this also could also be a last minute collapse like the one that threatened Louisana a while back

Lili. And thank goodness she did what she did.

Frances is rather the undecided gal.

[rainstorm]

if it passes over the gulf stream