Global model runs discussion

[ninel conde]

Not necessarily. The gfs has shown waves of storms lined up a couple times already this season with no developments. Same with 92l. Might have some waves coming off but until conditions out in the Atlantic change don't expect much action out there unless you like watching storms like the last three.

06zGFS showing zilch thru 180 hours.

[WPBWeather]

Not necessarily. The gfs has shown waves of storms lined up a couple times already this season with no developments. Same with 92l. Might have some waves coming off but until conditions out in the Atlantic change don't expect much action out there unless you like watching storms like the last three.

06zGFS showing zilch thru 180 hours.

Perhaps it better to see model trends, not one off runs that may contain errors, to better determine what may be happening over time.

[cycloneye]

This is how the August 17th 12z GFS run ends.

[WPBWeather]

This is how the August 17th 12z GFS run ends.

http://oi40.tinypic.com/kb6ddj.jpg

And this seems to be a trend.

['CaneFreak]

Yep. One key thing to note is the Azores high retreating to the far North Atlantic which will allow for 1) pressures to lower throughout the basin and 2) a return of moisture to the tropics. Looking more and more like a hyperactive September into October.

This is how the August 17th 12z GFS run ends.

http://oi40.tinypic.com/kb6ddj.jpg

[ninel conde]

Yep. One key thing to note is the Azores high retreating to the far North Atlantic which will allow for 1) pressures to lower throughout the basin and 2) a return of moisture to the tropics. Looking more and more like a hyperactive September into October.

This is how the August 17th 12z GFS run ends.

http://oi40.tinypic.com/kb6ddj.jpg

last season there was no atlantic ridging at all and the tropics were quite dry. i hope you are right though and it would be nice to see something in sept if the 384 map verifies.

[BigA]

last season there was no atlantic ridging at all and the tropics were quite dry. i hope you are right though and it would be nice to see something in sept if the 384 map verifies.

This is not entirely correct. According to this document (the relevant map can be found on page 27), sea-level pressure was above normal in the subtropical Atlantic north of the MDR during September, 2012.

http://www.cpc.ncep.noaa.gov/products/C ... _color.pdf

Regardless, this part of the season is often the anxious time--when will things finally get active?. Activity, in some way or another, always picks up unless there is an El Nino, which there isn't this season.

[BigA]

Important to note if any storms were to develop



Uploaded with ImageShack.us

Note the solid ECMWF and GFS agreement on solid ridging over the NE US and Canada. This would tend to make it more difficult for TCs to recurve, though storms could still find weaknesses farther east.

[gatorcane]

Here is how the 12Z GFS ends at 384 hours:



We see several Cape Verde systems it is showing (AKA the "African Wave Train") in the long-range and they are all heading W to WNW from Africa to the NE leewards.

Granted this is way out there in la la land, but the past several runs of the GFS are showing something similar, and it's the overall pattern it is showing that is a little concerning not necessarily the exact location of where these systems are at or how strong they really will be.

Here is the full 384 hour loop to see what I am talking about:
http://www.tropicaltidbits.com/analysis ... n_atl.html

[BigA]

It should be noted that not only does the 12Z GFS operational run show the Main Development Region Springing to life, but this is consistent among its ensemble members. Of the 20 members, 19 show some sort of significant tropical cyclone either in or from the MDR at the end of the run.

See for yourself if you'd like

http://tc.met.psu.edu/

(Full disclosure: This is the site I run)

[Alyono]

The only trend I see in the GFS is to keep delaying the timing of development in each successive run

Would not surprise me at all if we see no further storms until September

[Blown Away]

It seems the GFS/Euro generally missed seeing the initial development of this season's 5 TS's so far, but in defense they all were mostly very weak and shallow systems and each had small pockets of opportunity to pull together before being consumed by the overwhelming negative conditions...So do we trust that the GFS/Euro are not seeing significant development until at least Sept 3rd b/c they have been spot on not predicting significant development so far...

[caneman]

The only trend I see in the GFS is to keep delaying the timing of development in each successive run

Would not surprise me at all if we see no further storms until September

Me either. The trend is your friend. People have been upset with the models, however, it appears they have been mostly right. Not much to track.

[beoumont]

Current GFS run for 500 mb. for Labor Day Weekend.

[RainbowAppleJackDash]

Frankly speaking I'm bord of no/weak storms... Come on tropics.

[NDG]

At the rate we are going we'll be lucky if we get to track a weak tropical storm in the middle of the Atlantic on September 10th
I am sure activity is going to pick up, but I am beginning to be very doubtful on the forecasted higher than normal activity until I see the evidence of the stable air gone in the basin, IMO.

[RainbowAppleJackDash]

We will get fernand on the 22nd. That's my opinion

[ozonepete]

I miss the CMC making every developing TC a cat-5 in 2 or 3 days.

[ninel conde]

Current GFS run for 500 mb. for Labor Day Weekend.

big east coast trof should protect the states if anything were to develop.

[Scorpion]

I never take the forecast numbers seriously, there's just too many variables we don't even know about. The numbers are mostly meaningless anyway. 2010-12 had very high numbers but seemed insignificant since there were no major threats or landfalls. There is no way that something significant won't develop this year it's just a matter of when.