[NCwxman]

Heres a look at why the tropics are calm right now and outlook on when is look to pick up. Frist i would like to start with some upper air images here as to why not much is happening right now in the tropics, frist lets look at the 700mb image, can you notice the big hindering cause to storms...... dry air.
http://img411.imageshack.us/img411/6056/f144700mb.gif

As you can see here is the wind shear and the shear has been on the increase here.
http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8sht.GIF

Next thing i want to look at is upper level divergence and infact i have too areas of interest circled here. 1, and 2.
http://img180.imageshack.us/img180/8251/wg8dvg.gif
Notice i have in yellow dry air and therefore No1 i am not so worried about but two could be a player later on as some models have that developing.


and got to watch this low in white here this is 144hr out.
http://img833.imageshack.us/img833/355/f144low.gif


and last but not least the CMC with some kind of tropical system
http://img37.imageshack.us/img37/3182/f144cmc.gif

Also i have a lot more things to say and post but not the time to do it all but as you can see we will have to watch close to the tropics next week and thank you for reading
Nic.

[rainstorm]

thanks. im wondering if some others will also explain why things are so slow. great work.

[Jack]

The MJO also wasn't in the most favorable phase, but will be moving in better phases soon. The CMC is suspect with tropical systems, but the more reliable euro ensembles have been pointing to the first week of august or so for a while now. Last night more members jumped on board, and a few developed a stronger system or systems.

[NCwxman]

Thank you too all the readers, and yeah Jack i forgot all about the MJO my mistake but good idea adding that in and yeah the CMC always likes to go overborad with tropical systems.

[ThatWxGuy16]

and last but not least the CMC with some kind of tropical system
http://img37.imageshack.us/img37/3182/f144cmc.gif

FWIW...
The Canadian model is somewhat known for a high false alarm rate. The CMC is apparently aware of this and have been testing internally a "parallel" version (thing to do lately) that includes some changes to the thresholds for convective initiation in the tropics and it shows some promise in reducing the false alarm rate with tropical events.

 FARs_CMC_GLB (2).gif (22.71K)
Number of downloads: 11

One of the comparison maps to the parallel version and the operational version was posted yesterday to show the difference between the two. Both show the system mentioned in the original post to this threat, but the "X" version (on the right) is less aggressive with the development.

 CMC_Comp.png (202.04K)
Number of downloads: 9

[Jack]

Well it's good to know CMC is addressing the issue because it has been doing this for far too long. Part of the GFS upgrade yesterday was hurricane relocation, and it is also supposed to reduce some errors. Modeling is now starting to pick up on the system in the eastern Atlantic, probably the one the euro ensembles have shown developing in various spots over the last few days.

[NCwxman]

ThatWxGuy16, on 29 July 2010 - 09:17 AM, said:

and last but not least the CMC with some kind of tropical system
http://img37.imageshack.us/img37/3182/f144cmc.gif

FWIW...
The Canadian model is somewhat known for a high false alarm rate. The CMC is apparently aware of this and have been testing internally a "parallel" version (thing to do lately) that includes some changes to the thresholds for convective initiation in the tropics and it shows some promise in reducing the false alarm rate with tropical events.

FARs_CMC_GLB (2).gif

One of the comparison maps to the parallel version and the operational version was posted yesterday to show the difference between the two. Both show the system mentioned in the original post to this threat, but the "X" version (on the right) is less aggressive with the development.

CMC_Comp.png

Hey that comparison map is really helpful where did you find that at?.

[Rainshadow]

Jack, on 29 July 2010 - 01:31 PM, said:

Well it's good to know CMC is addressing the issue because it has been doing this for far too long. Part of the GFS upgrade yesterday was hurricane relocation, and it is also supposed to reduce some errors. Modeling is now starting to pick up on the system in the eastern Atlantic, probably the one the euro ensembles have shown developing in various spots over the last few days.

Ironically the CMC last season had the best fcst positional errors at 96 & 120hrs. The problem as noted are the false alarms. Once you know the system is for real, it does ok. FWIW (not much) I think the favorable MJO phase is still a couple of weeks away (not that its the be all and end all), this would coincide well(?) with the climatological ramp up. Of course this reads like predicting a cold wave for the second half of January.