The Tornadoes, Cyclones, Hurricanes & Typhoons Thread.

THE SYSTEM IS LARGE WITH EXTENSIVE DEEP MOISTURE AND
SHOULD BRING HEAVY RAINFALL AS IT TRACKS INLAND AFTER TAU 18.

The point is the longer it stays over water, the more it will intensify, the higher the moisture content that needs to be dumped before it will dissipate, Given the size/ diameter of the system and the speed with which it is rotating makes it difficult make hard and fast claims about the broader extent of the storm's effects.
 
Made landfall in the early hours of the morning.
A well formed eye developed. Rated as an Intense Tropical Cyclone. Talk of 200 km/h winds. 400 mm of rain.
Storm will now dissipate but move into north of SA.
Influence of the storm will be felt in DBN, Swaziland most of the north eastern provinces and GP will also get some rain.
Rain predicted in north eastern Botswana.
 
The final track. Eloise is now considered over and fully dissipated.

Looking where it ended up, its pretty clear that without that dogleg over Madagacar, Eloise would have ended up in Guateng! We were all lucky!

1611595836629.png
 
Just managed to access the Reunion weather site where a very interesting and highly unusual tracking of a TC .
Eloise is now over SA, and is expected to track through Botswana, curling back and maybe re enter SA!
I personally have never come across an event like this. It demonstrated clearly how we are generally very dependent on weather activity over the Indian ocean.
trajectoire.png
 
TD 09 entered an area of high wind shear accompanied by very dry conditions Difficult to comprehend how a dry area can exist over the ocean.
The TD has moved out of that area now and once again showing signs of consolidation. The track has moved slightly northwards.
MU weather is still monitoring but not issuing any warnings.
 
Geoff.D said:
Difficult to comprehend how a dry area can exist over the ocean.
Click to expand...

As I posted in the thread about the Neckartal dam, it takes 7-10 days for the ocean and atmosphere to come into equilibrium (evaporation and mixing). During that time, dry air can blow in from desert landmassses, etc.

Another factor is depth of the atmosphere. There is no point in having a kilometer thick layer of moisture, with dry air above. That will not produce precipitation, but fog, as found along the coast of Namibia.

A tropical storm requires the combination of several factors simultaneously, and if any one is missing, nothing will develop.
 
Followup: The best single chart to understand the total amount of moisture in the atmosphere (from the surface to the stratosphere) is called PWat (precipitatable water), and is equivalent to millimeters of rainfall. Typical values range from < 5 over the deserts, to > 50 over the tropics. You can see very nice 6-hourly animations, as bands of moisture circulate and disperse: https://www.cpc.ncep.noaa.gov/products/international/cpci/data/00/gfs_pwat_africa.html
On the same scale you can follow precipitation, which track moisture bands, but are not directly correlated: https://www.cpc.ncep.noaa.gov/products/international/cpci/data/00/gfs_mslp_precip_africa.html
The most critical factor is convergence, where surface isobars and winds force moisture to be uplifted and produce precipitation. By contrast high pressure areas show divergence, where dry air descends from above (the South Atlantic is the most prominent example).
 
Taken near Middleburg
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