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Changes are coming

Discussion in 'Weather' started by FISHERBOY, Jan 9, 2013.

  1. FISHERBOY

    FISHERBOY Senior Member
    Messages: 542

    THE SECOND PATTERN CHANGE WILL BEGIN TO SHOW ITS CARDS BY THE MIDDLE
    OF THE MONTH. A MAJOR SUDDEN STRATOSPHERIC WARMING EVENT IS UNDERWAY
    AND NEARING COMPLETION. SUDDEN STRATOSPHERIC WARMING EVENTS ARE
    FAVORED TO OCCUR DURING AN EASTERLY PHASE OF THE QUASI-BIENNIAL
    OSCILLATION /QBO/...WHICH IS THE PHASE THE STRATOSPHERE IS IN THIS
    WINTER. THE SUDDEN STRATOSPHERIC WARMING CAUSES A DRAMATIC
    WEAKENING...AND SOMETIMES ENTIRE BREAKDOWN OF THE STRATOSPHERIC
    POLAR VORTEX...AND A GREAT WEAKENING OR EVEN REVERSAL OF THE
    STRATOSPHERIC POLAR NIGHT JET. THE GFS FORECASTS THIS TO OCCUR OVER
    THE NEXT WEEK AT THE 2MB LEVEL.

    THE RESULT OF ALL OF THIS IS THE GENERATION OF STRONG HIGH LATITUDE
    BLOCKING AS THE DRAMATIC CHANGES IN THE STRATOSPHERE FEED DOWN INTO
    THE TROPOSPHERE. HIGH LATITUDE BLOCKING FORCES THE COLDEST AIR SOUTH
    OUT OF THE HIGH ARCTIC AND TOWARDS THE MID LATITUDES...AND ALSO
    FAVORS LASTING STRONGLY NEGATIVE EPISODES OF ARCTIC OSCILLATION /AO/
    AND NORTH ATLANTIC OSCILLATION /NAO/. THIS TYPICALLY BEGINS TO TAKE
    PLACE 10-15 DAYS AFTER THE SUDDEN STRATOSPHERIC WARMING EVENT. HOW
    LONG IT LASTS CAN VARY...BUT TYPICALLY THE COLD PATTERN LASTS FOR AT
    LEAST A FEW WEEKS...AND OCCASIONALLY CAN PERSIST THROUGH THE REST OF
    WINTER.

    AS ALL OF THIS IS OCCURRING...THE MJO IS FORECAST BY THE GEFS
    ENSEMBLES TO WEAKEN AND FADE AWAY IN ABOUT 10 DAYS. THE PACIFIC
    NORTH AMERICAN PATTERN /PNA/ IS FORECAST TO REMAIN NEGATIVE OVER THE
    NEXT 10 DAYS...WHICH WILL DIRECT THE FIRST BATCHES OF COLD INTO THE
    WESTERN AND EVENTUALLY CENTRAL UNITED STATES. GEFS ENSEMBLE MEMBERS
    SUPPORT A TREND TOWARDS A NEUTRAL OR POSITIVE PNA BY THE MIDDLE OF
    THE MONTH...WHICH SHOULD ALLOW THE GROWING COLD TO SPREAD EASTWARD.

    WHAT ALL OF THIS TECHNICAL JARGON MEANS IS THAT THERE IS MODERATE TO
    HIGH CONFIDENCE IN A PATTERN CHANGE TOWARDS MUCH COLDER WEATHER FOR
    THE CENTRAL AND EASTERN UNITED STATES STARTING AROUND THE MIDDLE OF
    JANUARY...WITH COLD LIKELY PEAKING IN LATE JANUARY INTO EARLY
    FEBRUARY. THERE IS THE POTENTIAL FOR THE COLDEST AIR WE HAVE SEEN IN
    AT LEAST SEVERAL YEARS DURING THIS PERIOD. WHAT SNOW POTENTIAL THIS
    WILL BRING IS MUCH MORE UNCERTAIN DUE TO UNKNOWN DETAILS WITH
    SYNOPTIC STORM TRACK AND LAKE EFFECT POTENTIAL.Thumbs Up payup
     
  2. Charles

    Charles Moderator Staff Member
    Messages: 256

    I would think the Lake effect would be high since they aren't frozen
     
  3. unit28

    unit28 PlowSite Fanatic
    Messages: 6,533

    just curious to see how this really pans out

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