Archive | May, 2017

Deadly floods in Sri Lanka and Cyclone Mora nearing Bangladesh

Heavy early season rains have killed at least 151 people and left 111 missing across Sri Lanka this past week in some of the worst floods in 15 years.  The rains are coming right on time as far as the south west monsoon is concerned, so to see precipitation this time of year is not uncommon. The problem is the amount of rainfall that has fallen. In Rathnapura 591mm was reported in the past week, to put that in perspective the average for the month of May is 456mm.


The above average totals have a lot to do with Cyclone Mora to the north east which enhanced these rainfalls over the island during its development. Now that Mora is moving away the rains should taper off slightly but given we have just entered the south west monsoon the relaxation of the precipitation will not be all that much.


The monsoon season or Sri Lankas “wet season” runs from May to September”.


Cyclone Mora is tracking north as well and will be a major threat for the low lying country of Bangladesh. According to JTWC (the US Military) Mora should make landfall Tuesday evening with winds possibly gusting over 65kts (typhoon strength). This could result in coastal flooding as well as damage to thatched homes and non-sturdy buildings. The big issue though will be rainfall, up to 300mm is possible with more than that in isolated coastal areas as the storm heads inland. This will surely result in river flooding along the Padma and Meghna rivers.


In Bangledesh Cyclones have a historical track record of causing serious damage and deaths. In fact the deadliest tropical cyclone and tornado on record both occurred in this region. Good news in recent years warning advancement and preparations have led to fewer deaths in these storms but they are still very dangerous.


PAGASA announces the start of the Southwest Monsoon

As we head more and more in to May and June the south west monsoon as scheduled is starting to get a hold on across southeast Asia. His includes the Philippines where on Wednesday May 24th PAGASA announced the official start of the “Hagabat” or the southwest monsoon.

This does not mean the “rainy season” has begun in the country though, it just stresses that persistant south westerly winds instead of north easterly are going to dominate. Although soon after the wind switch the rains follow close behind. According to PAGASA Meteorologist Robert Sawi stated that typically the full force of the rainy season moves in by late May to Early June.


One difference between this year and last year is the fact that the rainy season may bring more typhoons to the Philippines. Last year a strong El Nino kept most storms away from the country but with that being much weaker now the risk of potential cyclones hitting the country are higher.

Weather outlook

2017 Typhoon Predications




As we approach typhoon season it looks more and more like we will see a above average season across the western pacific. This will be due to the above average sea surface temperatures already building in across the Westpac. That combined with the common trend over the past few years of above average seasons with the exception of 2016 one can come to the conclusion that given the factors in place this season should be no different.

 Weather outlook

The average number of tropical storms (named storms via JMA) is 26 per year with 16 typhoons and 9 super typhoons.


Also thanks to the warm waters off the Philippine east coast stronger than average storms are possible in this region, in years past this has become to be known as the “Philippine sea effect”. Right now though this forecast is what I would like to call a “educated guess” , it is not completely a shot in the dark but do realize that it is a long term outlook. One should continue to check the daily and weekly outlooks to see if any threats are looming on the horizon.


big and useful update on the JMA (Japan meteorological agency) website was put in place on Wednesday the 17th of May 2017, now more details are being released on warnings/ advisories. In English!


This is a big jump from the warning information provided before which in short was released simply “there is a thunderstorm advisory in place” with little more information beyond that.  Now upon clicking ones local ward/ city you can find out how long the advisory is in place and what the details associated with it are.

For example with thunderstorms you may see in the remark section they have hail associated with them, or with dry air the exact minimum relative humidity in the forecast.

In short for any one in Japan looking for decent weather information (in english) this is a big step in the right direction. Check it out at this link.