ATL: Ex COLIN - Models

[Vortex]

12Z GFS brings system right through the northern leeward islands...


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

[Vortex]

Big change from earlier runs...Has Low over turks and caicos now


http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_102l.gif

[CYCLONE MIKE]

Also still showing the highway wide open for it to curve to the north. System does not look very strong at all and could still get caught in the low level flow.

[KWT]

Shear really powers up over TD4 this run...probably back to a wave at 96hrs.

ps, for whatever reason this run develops two Vort regions as well...not sure this run is to have too much faith put into it given it does that.

[CYCLONE MIKE]

Still showing the strong trough digging down past North Carolina as well. Just does not want to let up on this feature. Looking like as time goes by this could be shaping up to be just like Bonnie. A sheared mess not bothering anyone expect for a few squalls that can be expected with any typical summertime t-storms.

[KWT]

Gone at 144hrs:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... v_144m.gif

Looks like the idea to really weaken it in the shear zone is looking increasingly a good one.

[MWatkins]

One thing to note through the key day 6/7 period, the GFS is flatter with the ridge/trough pattern compared to the 12Z at 500MB (assuming TD4 is deep enough to be steered there):

0Z GFS: http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_144m.gif

12Z GFS(same V-time): http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_132m.gif

Could be more of a slowdown as opposed to a full turn (see HPC discussion, they sniffed this out this morning).

MW

[HurrMark]

Forward speed can kill this before the shear does. There have been multiple depressions/weak TS's in recent years that simply move too quickly in the easterlies and lose their west wind component since the translational speed is greater than the rotational speed. I remember one case back in July 1997, when one of the most vigorous waves you can imagine was racing through the Caribbean at 30-35 mph. It had very strong winds with it...gusts of 60+ mph, but it was never classified as anything because it never had a clear-cut rotation due it moving so fast.

[ronjon]

One thing to note through the key day 6/7 period, the GFS is flatter with the ridge/trough pattern compared to the 12Z at 500MB (assuming TD4 is deep enough to be steered there):

0Z GFS: http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_144m.gif

12Z GFS(same V-time): http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_132m.gif

Could be more of a slowdown as opposed to a full turn (see HPC discussion, they sniffed this out this morning).

MW

Good point, MW - and the western Atlantic Ridge (594 dm) is more expansive and further to the west.

[hurricanefloyd5]

which means what this could bring the storm closer to florida up the east coast????

[KWT]

Yeah the upper ridge is stronger on the 12z run by 144hrs but the system is totally dead by that point anyway.

GFS sending a strong signal that the shear could well be pretty strong, thats both the ECM/GFS that do the system in with the shear.

[MWatkins]

Yeah the upper ridge is stronger on the 12z run by 144hrs but the system is totally dead by that point anyway.

GFS sending a strong signal that the shear could well be pretty strong, thats both the ECM/GFS that do the system in with the shear.

Looking at 850V as a proxy for the strength of the cyclone, it looks like it doesn't ramp up in the model until 36+ hours, then ramps back down again to not even reflecting at 500MB by day 5.

Have to consider the real possibility that TD4 won't strengthen much at all. Banding looks a little better than yesterday, but waiting to see a deep burst of convection near the center before I am sold that it will surive another 48-60 hours.

It looks more like July out there, environmentally, than August...

MW

[StormClouds63]

It looks more like July out there, environmentally, than August...

That's the point I was asking about previously ... perhaps the peak of the 2010 season will be much later (2-3 weeks) than the traditional September 10 mid-point. Either that, or forecasts for favorable environmental conditions for 2010 were greatly overestimated.

[KWT]

MW, yeah true, though I think it has no real troubles other then some dry air for the next 3 days, its the period afterwards that the shear could become an issue, esp if the models do forecast it to remain in place.

[lester]

Remember to add 20 knots to TD4 for the new gfs

[Vortex]

Anyone have the 12Z canadian yet?

[Bocadude85]

One thing to note through the key day 6/7 period, the GFS is flatter with the ridge/trough pattern compared to the 12Z at 500MB (assuming TD4 is deep enough to be steered there):

0Z GFS: http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_144m.gif

12Z GFS(same V-time): http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_132m.gif

Could be more of a slowdown as opposed to a full turn (see HPC discussion, they sniffed this out this morning).

MW

This is starting to remind me of Hurricane Frances... steering currents went slack as it approached Florida and she just creeped towards the coast.

[KWT]

Yeah thats true apart from the big difference with Frances is there will likely be an upper trough rather then an upper high in place...

[rockyman]

12z Canadian at 144 hours:



loop:
http://www.weatheroffice.gc.ca/model_fo ... 12_....jpg

[Vortex]

12Z canadian..sends weak system through NE carribean than greater antilles. System then strengthens in western bahamas and nears landfall along the SE FL coast in 6 days..

12Z from GFS and Canadian would surely have an impact on track with next advisory with a shift SW longer term appears a good bet.

** If Euro/Ukmet indicate a further W/SW posiiton than I thinks its a given track is changed longer term.