There are two weather features globally today which stand out – an usual high pressure zone between NZ and Antarctica and a rare tropical cyclone that has made landfall in Oman.
HIGH PRESSURE SOUTH OF NZ
In spring New Zealand can be impacted by a number of highs and lows in a 7 day period, but it’s not so normal to see high pressure parked over the Southern Ocean in October – especially when it connects to another high further north and links up to pull down sub-tropical air into Antarctica.
That is the set up today though – New Zealand is in the middle of it with both Fijian/Tongan and Queensland airflows moving down our way. It basically sets up a number of days with milder than usual weather for NZ (frost free too) – then this mild airflow makes it way southwards into coastal Antarctica on the NZ/Australia side. This area will see temperatures jump well above normal for parts of coastal Antarctica. This set up falls apart by Wednesday as the high heads back northwards towards the Chatham Islands.
OMAN – CYCLONE SHAHEEN
Tropical Cyclone Shaheen has made landfall in Oman today, just west of the capital Muscat. Incredibly SHAHEEN is forecast to dump up to five times the annual rainfall for the region, with 500mm forecast in 24 hours in northern coastal areas to the west. Annual rainfall is this desert nation is normally around 80 to 100mm.
Oman is naturally tree-free and mostly grass-free, so any heavy rain event causes mudslides, flash flooding and erosion.
It’s been 14 years since Oman was last hit by a serious tropical cyclone. Reuters has reported 3 deaths at the time of this update.