Thread by @althecat

#ExtremeWeather TS #Emnati Update:

After a night of explosive convection and organisation What was #96s #Invest96s or #TD5 is now #TSEmnati - and forecast to become - like #Batsirai an Intense Tropical Cyclone on Sunday packing Cat3 Hurricane intensity winds of 185kmh.

And the good news is that JTWC - [metoc.navy.mil/jtwc/jtwc.html… website seems to be back online. They were missed. Here is the latest official track forecast issued by JTWC Pearl Harbour this morning at 3:00Z (UTC). This storm can now be considered to be a major threat to Madagascar.

The forecast track is almost identical to that of #Batsirai, which has left over 120 Malagasy dead, destroyed and damaged 10s of thousands of homes and buildings. Flooded areas have not even drained yet.

Information on the current state of UN/NGO/Relief damage assessment following #Batsirai can be found here >> reliefweb.int/country/mdg
1. Number of damaged and destroyed classrooms in the districts as of Feb 14, 2022
2. Summary map issued Feb 15th 2022.

It hasn't really stopped raining since Batsirai, and is not expected to do so in the lead up to the forecast arrival of #Emnati generated more intense rains on Sunday/Monday most likely. Core cyclone strength rains are forecast to begin on Tuesday 22nd.

Like #Batsirai #Emnati is forecast to head West South West and cross Madagascar in approximately 48 hours. With hurricane force winds and storm surge arriving late Monday.

The track and heaviest rains are expected in exactly the same areas hit by #Batsirai.

Here's the 10m Wind forecast for the landfall period.

And from the ECMWF model a maximum wind gust forecast during the period of landfall.

On its final approach to Madagascar #Batsirai went through a eyewall replacement cycle - and weakened and slowed down a little before resuming strengthening.

But #Batsirai was a much more long duration cyclone. en.wikipedia.org/wiki/Cyclone_B…

And so far #Emnati is not behaving as predicted. It is moving West North West rather then due west as expected in the track forecast. And as we can see here this is taking it into more shear which is slowing it down a little.

As you can see here its moving towards the area where #Dumako formed, and it is possible that this apparent variation in heading could result in a more northerly landfall in roughly 6 days time.

Here's another animation, zoomed out, without shear lines which shows the track variation more clearly.

This storm has proven very unpredictable so far and could continue to be unpredictable.

Cyclone forecast accuracy is considered good up to three days so it is unlikely that there will be a significant deviation from what is currently expected - beyond the landfall location site.

In the meantime the people of Madagascar have roughly five days to prepare for the arrival of a second Intense Cyclone #Emnati in the space of just over two weeks - the fourth landfalling Tropical Storm to strike the island in less than a month (#StormAna arrived Jan 24).