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Old 3rd Dec 2018, 19:26
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FullWings
 
Join Date: Dec 2003
Location: Tring, UK
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Can any body provide a reference doc or explanation why CBs in Equatorial regions have a higher cloud base and are generally less severe in relation to wind gusts than those experienced in mid latitudes over land.
For example SIN vs SYD.
I’m not sure that is the case. You’re more likely to get higher relative humidity near the equator, which leads to lower cloud bases. All other things being equal, mid-latitude thunderstorms over land have higher bases (I was under one at 14,000’ a few days ago in South Africa).

As far as wind gusts go, one reason I can think of is that there is generally not much in the way of wind in low latitudes in the low to mid layers as the pressure gradients are fairly slack most of the time. Precipitation can bring winds aloft down to the surface, so that can be additional to the normal outflow, which makes mid-latitude storms potentially more gusty.

If you take SIN and SYD, in SIN you could have 30/26 with CB which is a cloud base of c.1,600’AGL. In SYD, it’s possible but with a westerly wind that dew point would be quite unusual; more likely 30/15 which is 6,000’.
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