WesternPacificWeather.com

At least six people have been killed an a University student has gone missing due to the floods this week in Western Japan.

The rain seen over the last several days in Kyushu in many areas is equal to the entire months worth of rainfall.

Reports topped 600mm in the hardest hit areas.

Wide spread evacuation advisories have been issued in wide swaths of Kyushu. Including in the Kumamoto area where 49 died in Aprils earthquakes.　The earthquakes have also left the ground unstable leaving it prone to landslide in the event of additional aftershocks or heavy rainfall.

In Hiroshima a train became derailed forcing operations to suspend. About 120 passengers were on board when it went off the tracks.

In Ehime Prefecture Thursday morning 35 people have been ordered to evacuate after a collapse on a levee wall for a pond. A total of 15 homes were reported to be threatened in this specific instance.

72hr rainfall Outlook VIA ECMWF

Good news is the forecast calls for a short break in the rain Thursday before conditions start to worsen again heading in to the weekend.  Storms are expected to kick back up in Kumamoto on Friday , the city is already fairly prone for landslides so the additional rainfall will put the area at even higher risk. The image below is the landslide threat map as of Thursday Morning.

Landslide Threat Map

Tokyo will also see passing showers Thursday morning before clearing up until Friday as well. Thunderstorms and wide spread showers are possible Friday night and Saturday as the next wave of energy rolls across Japan along the rainy season front.

Rainy Season Front Dynamics

Finally there is good news as far as the “Baiu” front itself, it is lifting north and is breaking a part, this means the rainy season should start to come to an end in the near future, hopefully before the start of July across Japan and then soon after in China.

China has been devastated by the same front this past week. Read the latest report on whats been going on there. 

The question for some is what is the rainy season?

In the episode above of Westpacwx 101 we discuss the rainy season.

There are a few tips to remember if you are in any of the places that get this annual drencher. Every day ideas that you should keep in mind before heading out and about.

Tips for the Rainy Season

Lastly I do want to note the rainy season is all apart of a bigger process with the North East and South West Monsoons. The video below breaks down what both of them are and how they impact the seasons across East Asia and the Western Pacific.

Its not all gloom though in the rainy season, of of the symbols of the time is the Hydrangea, a flower that blooms in June and July during the peak of the wet season in Japan.

This years tropical season has been insanely slow, especially when you compare it to last year this time when we already had .. named storms and several super typhoons.

Numerical Guidance from specifically the American GFS model early this week seemed to indicate the chance of a typhoon developing but since then even that has backed off showing a low pressure area forming up in the South China Sea later this week.  You may have heard about this through a popular facebook page out of Okinawa that posted the model on Tuesday.

2015 vs 2016

A few things are working against the development of this storm though, for starters there is really no defined center of circulation.  The broad area of convection seen on the imagery below is actually the combination of two previous invest areas 94W and 95W that have now merged together.  Often when we get to much convection over a broad area the energy can not consolidate and thus it takes longer for a storm to develop.

Second wind shear, easily visible on water vapor imagery there is a upper level low to the north east of the convection over the Philippines. This is going to keep it relatively weak and sheared off.

Third, it is currently over the Philippines and disorganized.  Fortunately for farmers in the area who need the rain but unfortunate for local areas that may be seeing flooding from this “blob” of convection.

The heaviest of the rainfall over the next 3 days will be in South West Luzon, Palawan and Western Visayas. Most of the Philippines will see some sort of rainfall though.

With all of that said there is a chance this could track north west and get some organization together over the South China Sea. If this does happen due to the broad circulation and its attachment with the monsoon there is a good chance we would get a “monsoonal gyre” type of storm.  A broad circulation of convection that looks more like a tire on satellite imagery instead of a consolidated warm core low.

Time will tell though, the honest truth is this is a disorganized tropical area of convection over a series of islands with little model support to indicate its development.  At this time I would not expect a typhoon, nor a named storm for that matter this week.

LONG RANGE??

Eh, nothing really out there.. to much shear and dry air at this time. We are going to have to wait to at least the 1^st or 2^nd week of July for the chance of something developing. Stay safe guys!