ATL: TROPICAL LOW ex-FRED (ex-07L)

[brunota2003]

The center is still around 20N, so that puts the heavier convection about 125-150 miles to the NE of the center. The center is still just to the east (almost under) an upper-level low. That's why the convection is off to the NE of the center. Probably a temporary flare-up, but something to keep an eye on.

Well I hope those people on this bored that you said there was NO WAY this is heading for the U.S. did not listen to you then and are now keeping an eye on it

he's talking about the convection flare up is something to keep an eye on, not it's track or anything else.

[bahamaswx]

On a historical note, has a major hurricane ever dissipated only for the remnants to later regain hurricane status?

Ivan comes to mind, but I believe he only regained TD status in the GOM.

[brunota2003]

On a historical note, has a major hurricane ever dissipated only for the remnants to later regain hurricane status?

Ivan comes to mind, but I believe he only regained TD status in the GOM.

Ivan made it back to being a weak TS prior to landfall.

[wxman57]

I do think that whatever's left of Fred will be near the Bahamas by Sunday. Probably as a remnant low, but no guarantee of that. Lots of shear in its path for the next few days as it fights with that upper low, despite what SHIPS may be suggesting for the next 24-48 hrs.

[ozonepete]

I do think that whatever's left of Fred will be near the Bahamas by Sunday. Probably as a remnant low, but no guarantee of that. Lots of shear in its path for the next few days as it fights with that upper low, despite what SHIPS may be suggesting for the next 24-48 hrs.

Does the SHIPS model completely ignore shear?

[hurricanetrack]

Excellent. I am rooting for Fred big time. Something about it. So many people were saying it would die off days ago. I guess I am concerned that the global models do not see it, and wonder why. But hey, they failed to see cat-5 Felix in 2007 so there you have it. This is very interesting, may never amount to much on par with the entire season as whole but who cares? Fred has my vote. Just hope it does not turn out to be the season's big spoiler in terms of rolling some place up. Don't like that so much...but you can't pick and choose. The hurricanes will come or not no matter what I or anyone else says, thinks or posts on the Internets.

[jinftl]

Maybe he is looking for his wife, wilma?

He's gone from Fred Flintstone to Drop Dead Fred to now, Freddy Krueger - back from the dead and starting to look scary.

[wxman57]

I do think that whatever's left of Fred will be near the Bahamas by Sunday. Probably as a remnant low, but no guarantee of that. Lots of shear in its path for the next few days as it fights with that upper low, despite what SHIPS may be suggesting for the next 24-48 hrs.

Does the SHIPS model completely ignore shear?

No, it doesn't ignore shear, but the way it calculates shear over a very large area can lead to over or underestimation of shear. For example, since the model looks so far to the north of a disturbance, it may see shear a few hundred miles away and assume it's impacting the disturbance. In such a case, it will not forecast much development (and often be wrong). But in other cases, there may be favorable winds in the outer parts of the area where it's calculating shear but much less favorable conditions near the the disturbance center and it may erroneously assume shear is low near the disturbance. These problems are amplified with smaller storms/disturbances.

There was talk of a dynamically-adjusted shear box for SHIPS at one conference I attended in 2008. It was just an idea, though.

[Aric Dunn]

I do think that whatever's left of Fred will be near the Bahamas by Sunday. Probably as a remnant low, but no guarantee of that. Lots of shear in its path for the next few days as it fights with that upper low, despite what SHIPS may be suggesting for the next 24-48 hrs.

Does the SHIPS model completely ignore shear?

actually the opposite .. ships is decent with shear..

[sponger]

Maybe good for the Dolphins Monday night. I got my tickets for my first game in 3 years. I had better bring a parka!

[cycloneye]

I do think that whatever's left of Fred will be near the Bahamas by Sunday. Probably as a remnant low, but no guarantee of that. Lots of shear in its path for the next few days as it fights with that upper low, despite what SHIPS may be suggesting for the next 24-48 hrs.

Does the SHIPS model completely ignore shear?

actually the opposite .. ships is decent with shear..

00 UTC SHIP Shear Forecast

Moderate shear thru the period.

Code: Select all

*   ATLANTIC SHIPS INTENSITY FORECAST       *
                    *      GOES DATA AVAILABLE                  *
                    *      OHC  DATA AVAILABLE                  *
                    *  FRED        AL072009  09/16/09  00 UTC   *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120

SHEAR (KT)        17    16    13    11    12    21    14    22    10    17    13    21    21

SHEAR DIR        251   287   327     8   346    13    43    36    21     2   330   319   314


[jinftl]

Hmmm....nonsense model runs or something to at least consider?

Track:


Intensity:

[AdamFirst]

Maybe good for the Dolphins Monday night. I got my tickets for my first game in 3 years. I had better bring a parka!

I'll be there too...parkas are for sissies!

[gatorcane]

Thing is though, the global models are not really bullish on redeveloping Fred. Usually if no model is bullish, that is usually the outcome. It was interesting to note the last run of the GFDL model several days ago showed pretty much this exact path for Fred, albeit the GFDL thought it would be stronger by this point.

Let's see if models start to come on board.

[ozonepete]

I do think that whatever's left of Fred will be near the Bahamas by Sunday. Probably as a remnant low, but no guarantee of that. Lots of shear in its path for the next few days as it fights with that upper low, despite what SHIPS may be suggesting for the next 24-48 hrs.

Does the SHIPS model completely ignore shear?

No, it doesn't ignore shear, but the way it calculates shear over a very large area can lead to over or underestimation of shear. For example, since the model looks so far to the north of a disturbance, it may see shear a few hundred miles away and assume it's impacting the disturbance. In such a case, it will not forecast much development (and often be wrong). But in other cases, there may be favorable winds in the outer parts of the area where it's calculating shear but much less favorable conditions near the the disturbance center and it may erroneously assume shear is low near the disturbance. These problems are amplified with smaller storms/disturbances.

There was talk of a dynamically-adjusted shear box for SHIPS at one conference I attended in 2008. It was just an idea, though.

Sounds like an overdue and necessary adjustment, though.

OK, I'll stop here. I know we're going off topic, but thanks, wxman57.

[Aric Dunn]

red circle is the upper level low (yellow is fred) which over the last 6 to 12 hours has been steadily heading wsw which is good news for the environment, because if the ull continues to drop wsw it will end up putting fred in a improved upper environment. this motion that the ull is doing right now does not seem to be in any of the 12z model runs, all them take the ull west keeping pace with fred. I would bet if the ull continues its present motion long enough that the models will bring up the intensity and lower the shear forecast some what.
http://www.ssd.noaa.gov/goes/east/tatl/loop-wv.html

[ozonepete]

red circle is the upper level low (yellow is fred) which over the last 6 to 12 hours has been steadily heading wsw which is good news for the environment, because if the ull continues to drop wsw it will end up putting fred in a improved upper environment. this motion that the ull is doing right now does not seem to be in any of the 12z model runs, all them take the ull west keeping pace with fred. I would bet if the ull continues its present motion long enough that the models will bring up the intensity and lower the shear forecast some what.
http://www.ssd.noaa.gov/goes/east/tatl/loop-wv.html

and that would also cause a steering of Fred to the west-northwest or northwest, right?

[Aric Dunn]

red circle is the upper level low (yellow is fred) which over the last 6 to 12 hours has been steadily heading wsw which is good news for the environment, because if the ull continues to drop wsw it will end up putting fred in a improved upper environment. this motion that the ull is doing right now does not seem to be in any of the 12z model runs, all them take the ull west keeping pace with fred. I would bet if the ull continues its present motion long enough that the models will bring up the intensity and lower the shear forecast some what.
http://www.ssd.noaa.gov/goes/east/tatl/loop-wv.html

[img][/img]

and that would also cause a steering of Fred to the west-northwest or northwest, right?

probably not.. that upper low is at the 200mb layer and is cut off, the low to mid level steering is straight west and so is the upper levels. we know this since the ull is for the most part heading westerly except for this present motion as of late. Fred will like head west for the next 2 to 3 days regardless of strength and after that is the global models are correct on that strong ridge building then west on days 4 and 5 is a good possibility again regardless of the strength.

[jinftl]

could this actually be a developing system east of the bahamas a few days out? Is it me or is this looking like less of a comet and more like something to keep an eye from the latest satellite?

[ozonepete]

red circle is the upper level low (yellow is fred) which over the last 6 to 12 hours has been steadily heading wsw which is good news for the environment, because if the ull continues to drop wsw it will end up putting fred in a improved upper environment. this motion that the ull is doing right now does not seem to be in any of the 12z model runs, all them take the ull west keeping pace with fred. I would bet if the ull continues its present motion long enough that the models will bring up the intensity and lower the shear forecast some what.
http://www.ssd.noaa.gov/goes/east/tatl/loop-wv.html

[img][/img]

and that would also cause a steering of Fred to the west-northwest or northwest, right?

probably not.. that upper low is at the 200mb layer and is cut off, the low to mid level steering is straight west and so is the upper levels. we know this since the ull is for the most part heading westerly except for this present motion as of late. Fred will like head west for the next 2 to 3 days regardless of strength and after that is the global models are correct on that strong ridge building then west on days 4 and 5 is a good possibility again regardless of the strength.

makes sense to me...