Search

You may also like

0 Views
2015 Atlantic Hurricane Season Arrives Early
Articles Local News Snow Thunderstorm

2015 Atlantic Hurricane Season Arrives Early

Despite the recently declared El Nino, known for inhibiting tropical

Articles Local News Snow Thunderstorm

Another Cape Town Mammatus Cloud Event

Above are some images taken from my cellphone this morning,

Articles Local News Snow Thunderstorm

Western Cape Fires

This summer has seen very little fire activity compared to

secretkiss

Cutoff-low and heavy snow 24-26 Jul 2016

Numerous model runs have indicated the likely formation of a cutoff-low (COL) over the south-eastern parts of the country between Sun 24th and Tues 26th. All indications are that this system will produce heavy rainfall (> 100mm) in places, and extremely heavy snow (more than a meter) over the Drakensberg and surrounding peaks.

Edit: The first indications that this event will develop into a COL (and not just a normal cold-front) will be the arrival of (mid-winter) thundershowers over Gauteng tomorrow afternoon (Sun 24th), as shown by the SAWS thunderstorm probability chart.

tsprob[20160724_24Z]

The first image shows the expected rainfall for the 5 day period from 00Z on Thurs 21st to 00Z on Tues 26th. Peak falls are likely over the central Free State, Lesotho, Drakensberg, KZN and parts of the Eastern Cape coast.

By 00Z on Sun 24th the freezing-level will be down to 1500m over the majority of the southern half of SA, though moisture in circulation will be limited.

850mb_tmp_072[20160724_0000_crop]

During Sun 24th the cutoff-low will begin to develop, with moist tropical air drawn under the cold-upper air. This will produce instability, and by Mon 24th very heavy showers will form.

24h_totp_d5_safrica[20160726_0000_crop]

As the cutoff-low develops the freezing-level will rise slightly (due to the mixing of air-masses), but extremely heavy snow will fall above 2000m on the highest peaks in the Drakensberg.

Edit: Recent model runs show the COL drifting westwards along the S-Cape coast, and reaching the SW-Cape by Tues 26th. This chart shows possible heavy showers (and snow) over the SW-Cape mountains (during the 6 hours from 06Z to 12Z on Tues 26th).

mslp_6h_totp_084[20160726_1200_crop]

Comments

comments

Next post Previous post

You may also like

0 Views
Model Inconsistencies Leave Snow Potential Up In The Air
Articles

Model Inconsistencies Leave Snow Potential Up In The Air

Firstly, I’d like to state the discussion of this upcoming

0 Views
Articles

2009 – The Year of Mammatus

For the past week, memebers of Storm Chasing SA have

0 Views
Local News

Cape Town Storm – 26 October

You may have read media reports about a hurricane which

0 Comments

No Comments Yet!

You can be first to comment this post!

Only registered users can comment.

Skip to toolbar