 
 <prompt> How systems dey affect weather? Based on di last question, write one context wey contain di answer. E fit be 1 - 20 sentences. Context: <response>: Di effects of local surface low pressure dey very limited because upper-level subsidence still dey block any form of air ascent. Also, to dey protected against rain-bearing weather systems by di atmospheric circulation itself, di desert dey even drier because of im geographical configuration and location. Indeed, di extreme aridity of di Sahara no fit only explain by di subtropical high pressure. Di Atlas Mountains, wey dey Algeria, Morocco and Tunisia also dey help to enhance di aridity of di northern part of di desert. These major mountain ranges dey act as barrier wey dey cause strong rain shadow effect for di leeward side by dropping plenty of di humidity wey atmospheric disturbances along di polar front bring, wey dey affect di surrounding Mediterranean climates. 