2017 WPAC Season

[1900hurricane]

Speaking of the Mei-yu, there are some signs that it may be on its way out (at least for now) as the large scale regime begins to change. Guidance begins replacing the persistent troughing near Japan with some higher heights in the 5-10 day period. Higher than average heights across the Tropical Western Pacific aren't particularly favorable tropical cyclogenesis since it is often a sign of subsidence, but the removal of constant convective focus in the subtropics and mid-latitudes is a step in the right direction.

[mrbagyo]

Latest Euro @ 240 hrs


gfs is also showing " something" in the last days of june to early July.

[euro6208]

The GEFS tool indicates that an area east of Philippines may become more favorable for tropical cyclone development by Week-2.

[mrbagyo]

Oh, We have a nice looking random tropical wave out in the Marshall Island. Such an uncommon occurence for the past couple of weeks.
Certainly, environment is now becoming more conducive for tropical activity

[1900hurricane]

Oh, We have a nice looking random tropical wave out in the Marshall Island. Such an uncommon occurence for the past couple of weeks.
Certainly, environment is now becoming more conducive for tropical activity

Tracing back the vorticity, this appears to be the incipient disturbance that some guidance is developing. It's on an Intertropical Convergence Zone instead of a Monsoon Trough, so it doesn't have a ton of convergence to aid it in development, but it does look fairly healthy at the moment. We'll see how it does developing. The WPac doesn't look overly hostile at the moment, but it's not a cakewalk either. It looks like dry air may be the biggest hurdle at first. Satellite derived PWs are less than 2.00" to the north of it all the way past the Marianas. Beyond that, it may still have to deal with some northeasterly shear from leftover Mei-yu convective exhaust funneling into the Tropical Easterly Jet. Guidance as a whole is only lukewarm with it, but I think there is a medium chance that it will end up becoming a classifiable system down the road.

[1900hurricane]

In fact, you can see some of the direr air already hooking around in front of the disturbance. This can be seen in today's 12Z Truuk (PTKK) sounding.



(The text file for this one was long and a pain in the butt to put in SHARPpy format)

[1900hurricane]

[1900hurricane]

In fact, the disturbance is now tagged as Invest 97W as of 18Z! I shamelessly copied and pasted my most recent posts here to make the new invest's thread.

[1900hurricane]

Looks like the Mei-yu is officially on its way out.

 https://twitter.com/robertspeta/status/877713636898226176

[dexterlabio]

Looks like the Mei-yu is officially on its way out.

 https://twitter.com/robertspeta/status/877713636898226176

I did a recap of the previous WPAC seasons and I noticed that even those years with above average (or El Nino-induced) activity had suppressed conditions in June. In June 2015, only a short-lived TS managed to form in SCS.

We don't know for sure if this year will have the same story with an uptick of activity by July. Although looking at the SST maps, far western Pacific is already boiling hot. Atmosphere only needs to get rid of dry air plus the shear needs to relax a bit.

[euro6208]

This quietness has scorched the waters to 31 to 32C. Someone somewhere is going to get hit really hard.

[euro6208]

The GFS models for the past few runs has Nanmadol intensifying as it nears Taiwan. Latest run has it stalling.

[euro6208]

Very noisy in the WPAC. A few of the models try to spin up something but EURO and now GFS (Past runs had something striking Taiwan), keeps the basin quiet.

[mrbagyo]

Another Tropical wave is forming in the Marshall Islands south of Kwajalein Atoll.
Marshall Island Loop

[euro6208]

Another Tropical wave is forming in the Marshall Islands south of Kwajalein Atoll.
Marshall Island Loop

Low shear, high sst, good vorticity. and strong convection. The models aren't too enthusiastic about it though.

[euro6208]

Activity coming soon?

[euro6208]

Another Tropical wave is forming in the Marshall Islands south of Kwajalein Atoll.
Marshall Island Loop

Low shear, high sst, good vorticity. and strong convection. The models aren't too enthusiastic about it though.

Seems like the the models especially the GFS are becoming more aggressive with this.



Makes it a typhoon before a landfall over Taiwan.

[euro6208]

GFS with Talas recurving after bringing the Marianas more rain.

[euro6208]

CMC shows both features. Has Nanmadol a typhoon and Talas visiting the Okinawa region.

[euro6208]

EURO takes it through the Batanes Islands and into China.