Why Does More Snow Seem to Come from the N-W

Discussion in 'Alpine & Southern' started by Ulmerhutte, Jun 5, 2011.

  1. Ulmerhutte

    Ulmerhutte First Runs

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    I know this has been discussed before, but I could not find the right search terms to locate the thread.

    In short, why does more snow seem to come from north-westerly winds than from s-w winds? I think it had something to do with n-w winds being the prevailing winds with the arrival of a low pressure system and s-w on departure, but is it that simple? Is that even right?
     
  2. Snow Blowey

    Snow Blowey Old n' Crusty Ski Pass: Gold

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    Oragraphic effects plus moisture content.

    Most of the moisture is in the frontal cloud band and this generally comes in on a NW or W wind. By the time the low moves east of the mountains and the wind turns SW we are left with colder drier air.

    Oragraphic - Moisture hits mountains, rises, cools, falls close to where it rises. Leaves a rain shadow on the leeward side of the mountains.

    In NSW there are no high mountains to the north west or west of the main range so the main range sucks the moisture out of the air. Thredbo and Perisher are on the eastern side of the main range but close enough to get the dregs. Mountains to the east (Such as tinderry range east of Michelago - 1600m high) get virtually nothing from the W.

    When wind come from the south west the mountains east of Melbourne get first dibs at the moisture and places like Buller and Baw Baw go really well. More moisture gets striped from the air as it passed Hotham, Bogong etc. so by the time it reaches NSW there isn't as much moisture left.

    When it comes from the SE or E mountains on the eastern sid of the main range do well and we end up with decent snow on the Monaro, tinderries and the coastal ranges.
     
  3. Ulmerhutte

    Ulmerhutte First Runs

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    Thanks, SB. Makes sense.