This attached thread from this morn looks at Typhoon #INFA ("In-fa" TS09W) which is poised to be extraordinarily disruptive to the 2021 Olympics in Japan.

It has since come clearer what we can expect from a dangerous and unusual weather system developing over the West Pacific. Image
This is the story of three storms rather than one, but IN-FA will play the starring role.

1. TD10W currently menacing Hong Kong
2. "IN-FA" which is technically still TS09W (fmrl. #invest98w)

& a 3rd storm which models forecast TD10W & IN-FA will bring about in 5 days time. Image
Here's the latest satellite imagery of TD10W (left) and #INFA (right) ImageImage
Here is In-fa's current warning graphic from the Joint Typhoon warning center.

But what this does not mention is the unusual way in which In-fa is expected to respond when it gets near to TD10W. Image
This first animation from the latest GFS model shows the next 120 hours.

The thing to watch here is how the buzz saw anticlockwise spin on #INFA carves into the outflow moisture from #TD10W and flings it back out into the Pacific.
And that takes us to July 23rd, the day of the Olympics Opening Ceremony.

Here is another view of this same data looking at the anomaly. Because this is a super wet part of the world this time of year you can't even see #TD10W.
You can see #TD10W actually but barely. What is more obvious is the signature of the the depression's outflow moisture flowing back out into the Pacific.
Here, courtesy of @zoom_earth we can se the two storms together with their tracks as of now, in the early hours local time. Both storms are associated with huge areas of convection due to the moisture both low pressure systems are creating.
And this moisture is the fuel which the models suggest will create the storm that might disrupt the Olympics.

This animation shows the next 72 hours. In this forecast the storm is probably a Tropical Depression but may not strengthen enough to become a cyclone.
This storm, if it does come about as forecast, arrives in Tokyo in the afternoon on the 25th, and parts of it remain over the Japanese Archipelego until the end of the forecast on August 3rd.
Now there are a lot of ifs and buts about this, especially about the timing and the intensity of processes that we can see in these simulations.

That said the first five days can be expected to be similar to what we see in the forecast.
These are the accumulated GFS model rainfall forecasts for Hong Kong, Taiwan, Shanghai and China for the coming week, till Saturday. (And you can see half of Japan in there also) ImageImageImageImage
As for Japan while there is a lot of uncertainty it is clear that it is under significant threat. This series of forecasts are for:

1. 5-Days (Olympics Opening - storm is beginning to form)
2. 7-Days (Outer rain bands approaching Tokyo)

1/2 ImageImage
Accumulated rainfall forecasts for Japan at:

3. 10 days (July 28)
4. 12 Days (July 31st)
5. 14 Days (August 2nd)
6. 16 Days (Agust 4th)

2/2 ImageImageImageImage
Whilst preparing to hold the Olympics, Japan is going to put in place civil defence plans to prepare for this potential deluge.

Also, this is not the worst case scenario.

It is entirely possible that this, for now hypothetical, super rain storm could become a Typhoon.
... Or this hypothetical super rain storm could miss Japan altogether and head north east into the Pacific.

To be prepared is to be fore-armed.

This is clearly the last thing Japan need's. But this is also what's so. And if anyone can manage this Japan can.


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More from @althecat

20 Jul
Two typhoons getting closer and closer to each other. #INFA on the right is sucking the much smaller #Cempaka into its orbit. Sucking up all its outflow and chucking it out east.

The pair of typhoons current winds are fixed by JTWC at 70 and 65 knots at 06Z.
Here are the current warning graphics from the JTWC. ImageImage
#Cempaka is a midget Typhoon (1). Spinning like a top south west of Hong Kong.

Disregarding its size, #Cempaka is directing rain from Hanoi to Taiwan (2). The forecast (3 & previous tweet) shows Cempaka moving west in a loop, but this hasn't started yet. ImageImageImage
Read 31 tweets
19 Jul
Absolute scenes in South China Sea.Track forecast for Typhoon #Cempaka shows how weird set up of 2 typhoons in the same space is expected to resolve itself. Once #FabianPH / #INFA gets close it will going to drag Cempaka back out, with #Taiwan caught in between. Image
Latest JTWC satellite images of typhoons #Cempaka and #Fabian / #INFA ImageImage
And the corresponding two JTWC Warning Graphic / Track Forecasts ImageImage
Read 4 tweets
19 Jul
Congratulations to Ethiopia and Ethiopians everywhere on today's completion of the 2nd filling of the #GERD. It has been a great honour to follow along during this moment.

Today's rainfall forecasts for #NorthAfrica, #HornOfAfrica and #MiddleEast follow.
In honour of the #GERD we will change up the order of today's bulletin and get right to the most important issue, rain over the #Abbay basin, which due to its great quantity and consistency made this possible over such a short time period.
But first a brief explanation, as when it comes to the GERD not all rainfall counts. The first image here shows the path of the #BlueNile / #Abbay from Lake Tana to Khartoum where it meets the White Nile and becomes "The Nile".
Read 40 tweets
19 Jul
Today's #FabianPH #INFA, #Olympics, #Olympics2021 disruption update thread.

See yesterday's thread below.

TL/DR: There is a significant typhoon/extreme rainfall threat to Japan in the opening days of the Olympics.
Here's a view of the two storms, #FabianPH / #INFA whose interaction is forecast to produce a 3rd storm in 4 days time which was forecast yesterday to arrive in Tokyo two days after the Olympics opening.

#Olympics, #Olympics2021
In the latest GFS 1hourly simulation model the solution remains the same as of today. A large typhoon like low (in terms of water content) will make landfall in Japan and stay over the country for some time bringing torrential rains during #Olympics2021

#Fabian #FabianPH #INFA
Read 14 tweets
18 Jul
This killer #EuropeBigWet storm is still packing a punch. Here you see it yesterday over Italy and the Balkans.
And here it is today. It still has a clearly defined circulation over the Adriatic Sea.
This shows the jet stream forecast for today which pretty perfectly matches what we are seeing here from the satellite imagery.

But while the circulation is gone the jet remains. This jet looks like it is going to move into the business of delivering moisture to the Middle East.
Read 5 tweets
18 Jul
The presentation of the #ArabianMonsoonBurst has changed dramatically today with the consolidation of activity over the Arabian Peninsula into a single huge storm which is currently moving into the Red Sea over Makkah and Jeddah.

Today's rainfall forecasts follow.
The scale of the storm over Islam's holiest city is huge, larger than France. Two more huge storms loom over the greater region tonight. One on the Iranian Gulf coast and another supercell thunderstorm complex over New Delhi/Rajastan, India, the size of the United Kingdom.
The last six hours in three animations, first India which is experiencing a massive monsoon day today in the north.

[Here the initial frames show a blank SEA as their was a satellite data outage.]
Read 30 tweets

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