Wednesday, July 14, 2010

Tropical Storm Conson's Path...

For more information on the Asian trough/ridge pattern (teleconnection), click here!

Conson is forecasted to remain a tropical storm (could get to a typhoon) as it heads towards China/Vietnam... This western motion correlates to a strong ridge across southeastern Asia... A few days ago the forecast track was more toward Hong Kong, so this trend south and west really shows the strength of this ridge across southeastern Asia! I suspect this trend south and west will be a common theme in the Atlantic basin, especially with the US models (GFS will almost always be too far right 48 hours + out), once we start getting tropical cyclones approaching the US coastline! Refer again to the post above for more information on the Asian trough/ridge pattern (teleconnection), but remember this strong southeastern Asian ridge should correlate to a strong ridge across the southeastern US in about 7 days... I have been following this Asian trough/ridge pattern fairly regularly for the last six weeks or so, and a week ago there was a strong ridge over southeastern Asia, hence the strong ridge over the southeastern US right now... Don't expect that to change much either for at least the next 10 days, and probably much longer (14 days +)!

I posted 4 500mb charts (12z ECMWF) below showing how the ridge across southeastern Asia should stay strong for at least the next several days to come... You only see quick moving short wave troughs along the northern periphery of the strong ridge... This particular pattern has been fairly persistent in eastern Asia, and also the eastern US most of the summer!

So when I look at the 0z GFS 500mb charts 7 to 10 days out, and see a strong ridge over much of the southeastern US, I agree 100% with the long range GFS forecast! "IF" there is any tropical development, it should have a fairly straight shot towards the southeastern Atlantic/Gulf of Mexico... Again, this teleconnection DOES NOT predict tropical development in the Atlantic basin, but it does help you get an idea where tropical cyclones in the Atlantic basin should track "if" development were to occur!


  1. P.J. here...Always fascinating! Conson is something we've been all over here on CNN International...if that correlation comes to fruition (alog with tropical development)it'll be one busy week for all of us!

  2. With the MJO pulse moving deep into octave 2 in the next 4-5 days, and with this strong ridge across the SE US, there is an alley lined up towards the SE US/Gulf of Mexico if any tropical cyclones form!

  3. Great info, Greg! Looking forward to seeing how this sets up. My question is... based on this... how long could this set up persist? looks good for a southeast US/Gulf landfall but what about a turn up the east coast? you know someone is hoping for that to pan out at some point!

  4. It's hard to say Devin, but I don't see this pattern changing much until mid-late September... The ridge should hold strong, but that doesn't mean there won't be some weaknesses here and there!