▁only ▁two ▁to ▁three ▁light ▁rain ▁show ers . ▁However , ▁the ▁timing ▁and ▁volume ▁of ▁ra ins ▁in ▁the ▁winter ▁is ▁far ▁from ▁predict able . ▁After ▁a ▁significant ▁rain , ▁the ▁region ' s ▁air ▁is ▁cleared ▁of ▁the ▁usual ▁atmos pher ic ▁ha ze ▁as ▁well ▁as ▁man - made ▁sm og , ▁giving ▁exception ally ▁clear ▁views ▁across ▁the ▁giant ▁metropol is . ▁ ▁Most ▁cold ▁front s ▁and ▁de press ions ▁sp un ▁off ▁by ▁the ▁polar ▁low , ▁the ▁strong ▁winter ▁season al ▁low - press ure ▁area ▁in ▁the ▁G ulf ▁of ▁Al aska , ▁fail ▁to ▁carry ▁significant ▁precip itable ▁mo ist ure ▁as ▁far ▁south ▁as ▁Los ▁Angeles , ▁resulting ▁in ▁the ▁region ' s ▁relatively ▁low ▁average ▁ra inf all ▁amount ▁of ▁ ▁even ▁in ▁normal ▁years . ▁However , ▁a ▁" normal " ▁year ▁rarely ▁occurs , ▁since ▁ra inf all ▁in ▁Los ▁Angeles ▁is ▁subject ▁to ▁the ▁position ▁and ▁strength ▁of ▁the ▁jet ▁stream , ▁and ▁the ▁strength ▁of ▁the ▁G ulf ▁of ▁Al aska ▁low . ▁Some ▁years , ▁a ▁well - develop ed ▁series ▁of ▁cold ▁front s ▁moves ▁into ▁the ▁area ▁with ▁relatively ▁short ▁separation ▁between ▁each , ▁bringing ▁inter mitt ently ▁ra iny ▁periods ▁to ▁Los ▁Angeles ▁for ▁several ▁weeks ▁at ▁a ▁time . ▁If ▁this ▁pattern ▁pers ists ▁in ▁a ▁ra iny ▁season , ▁significantly ▁above - aver age ▁precip itation ▁will ▁be ▁received . ▁Other ▁years , ▁especially ▁in ▁the ▁dr ought ▁years ▁of ▁