ATL Tropical Depression GUSTAV - Model Runs

[gatorcane]

I don't know. I'm trying hard to believe some good ridging is building over the GOM and across FL into the Bahamas. I'm sorry I just don't see it yet.

If you look at the vis loop you can see Florida is still seeing East Coast Pops as flow is SW to NE....and in the Bahamas the low-level flow is from SSE to NNW..

how much ridging is really there? Maybe its all at the mid and upper-levels or *should* build in nicely over the next 24 hours. I think Fay is still influencing the large-scale synoptics over the SE US, GOM, and Florida.

http://metofis.rsmas.miami.edu/~dortt/s ... 1_loop.gif

[terrapintransit]

Look where the GFDL takes it here...............

[Meso]

Still new at this...not really sure what I am looking at? What is the approx. wind speed on the 12Z ECMWF coming into the Fl Panhandle?

Actually not that strong, on that exact image the wind speeds are around 25-30 ms (meters per second)

30*60 = 1800 meters a minute = 1.8km per minute

1800 m/m (1.8km)*60 = 108km/h

108km/h = 72mph

So below hurricane strength

[IvanSurvivor]

Still new at this...not really sure what I am looking at? What is the approx. wind speed on the 12Z ECMWF coming into the Fl Panhandle?

Actually not that strong, on that exact image the wind speeds are around 25-30 ms (meters per second)

30*60 = 1800 meters a minute = 1.8km per minute

1800 m/m (1.8km)*60 = 108km/h

108km/h = 72mph

So below hurricane strength

Thank You!

[canegrl04]

Look where the GFDL takes it here...............

Pretty much the HWRF,too.If this comes to pass,bad news coming in the GOM

[Ed Mahmoud]

No need to do math with meters per second. Doubling it gives a pretty close approximation in knots. 30 m/s is ballpark 60 knots, or about 70 mph.


Of course, Euro, as a global model, doesn't have super fine resolution, and the versions available to the public for free have even worse graphical resolution, so while it isn't officially showing a hurricane, it is showing a hurricane.


Oh, only out to 12 hours, but 18Z GFS knows Gustav is there now...

[Derek Ortt]

I was told that the full EURO is 13-14km resolution

[mutley]

What's with the NOGAPS this year? Wasn't that a reasonable model the last several years; at least to be considered?

[gatorcane]

18Z GFS farther north (right) so far on this run.

But only 36 hours is in so far...

It even looks like it may lose Gustav somewhere between Cuba and the SW tip of Haiti in the Windward passage.

[x-y-no]

Looks like 18z GFS will be a lot slower with it - it's building in the 500mb ridge tilted NE-SW ahead of it ...

[gatorcane]

Looks like 18z GFS will be a lot slower with it - it's building in the 500mb ridge tilted NE-SW ahead of it ...

Yes the 48 hour shows a weak Gustav or something moving WSW.....towards or just south of Jamaica.

Note it really ramps up 95L though:

[Ed Mahmoud]

I was told that the full EURO is 13-14km resolution

I think the free version displays less than that.


per NHC web page

European Center for Medium-range Weather Forecasting (ECMWF) Model

Developed and maintained by an international organization supported by 28 European member states, the ECMWF model is the most sophisticated and computationally expensive of all the global models currently used by NHC. Due to model complexity/resolution, data assimilation, and operational requirements of the member states, the ECMWF model run is among the latest arriving of all available dynamical model guidance. The ECMWF model is a hydrostatic spectral model where the linear terms are triangularly truncated to 799 waves (the nonlinear terms are calculated at a coarser resolution) with 91 vertical levels (TL799L91). This corresponds to a horizontal grid spacing of about 25 km. The ECMWF model employs a hybrid vertical coordinate system which is terrain following in the boundary layer (sigma) and becomes purely isobaric (pressure) near the tropopause. The ECMWF was the first modeling center to use four-dimensional (4-D VAR) data initialization which allows better assimilation of off-time (non-synoptic) observations, particularly from satellite data. The ECMWF system provides forecasts out to 240 hours (10 days) twice daily. Beyond the good medium-range tropical cyclone track prediction skill of the ECMWF model, its high spatial resolution has shown potential for useful intensity forecasting.

[x-y-no]

18z GFS at 48 hours:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _048.shtml

What's left of Gustav is still south of the eastern tip of Cuba, ridge stronger ahead of it.

[Wx_Warrior]

That's why some of us get tired of hearing OMG ITS RI Cat 3

Chill and let nature take it's course....who knows?

[x-y-no]

54 hours, low centered over Jamaica, ridge a bit weaker still centered over SFL tilted NE-SW

[Ed Mahmoud]

Through 48 hours, following 850 mb loop, GFS weakens it, but still has it, between Cuba and Jamaica.

[gatorcane]

66 hour ridge over South Florida and EGOM starting to weaken even more and retreat East. Thin ridge layer out to about 75 miles west of the West Coast of Florida

Gustav or Gustav's low now just WSW of Jamaica....

[x-y-no]

18z GFS 66 hours

Low a bit west of Jamaica, ridge weaker, centered in Gulf north of Yucatan.


http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_066l.gif

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_066l.gif

[Ed Mahmoud]

That's why some of us get tired of hearing OMG ITS RI Cat 3

Chill and let nature take it's course....who knows?

You didn't like the amateur forecast of a 160 knot Cat 5 in 5 days crossing Cuba headed for somewhere in the Gulf about 10 pages back in the main thread?

[Wx_Warrior]

gfs weak on it