Thursday, March 7, 2013

WX UNIT DISCUSSION 03/07/2013 2200Z

FOR OFFICIAL NWS WX DATA SEE WWW.WEATHER.GOV

BRIEF DISCUSSION FOR WI AND SURROUNDING REGION:

SPRING AND WINTER BOTH IN THE AIR

UPSTREAM UPPER AIR ANALYSIS AND MODEL CONSENSUS PUTS WISCONSIN ON THE BORDER OF RAIN AND SNOW FOR THE NEXT COUPLE OF WEEKS.  COLD AIR IS TRYING TO STAY AROUND AND THE SUBSTANTIAL SNOW COVER CAN AID THIS IF STRONG WAA HOLDS BACK.  

A LARGE POLAR VORTEX/GYRE IS LOCKED IN NORTH OF HUDSON BAY THAT COVERS MUCH OF CANADA.  A VERY COLD CORE REMAINS WITH THIS BUT IT DOES RETROGRADE WEST IN ABOUT A WEEK FROM NOW PERHAPS ALLOWING FOR MORE SOUTHERLY VECTORS TO TAKE OVER.  

A LARGE RIDGE ACROSS THE CONUS RIGHT NOW WILL GIVE WAY TO A LARGE AMPLIFIED TROUGH MOVING INTO THE GREAT PLAINS FOR SUNDAY AND EWWD ON MONDAY.  LOOKS LIKE THE RAIN/SNOW LINE IS RIGHT ON TOP OF WI FOR THIS.  

PRECIP WILL START ALREADY ON FRI WITH WAA AHEAD OF IT WITH A BAROCLINC ZONE AND OVERRUNNING PCPN PROBABLY FREEZING RAIN OR A LIGHT MIX.  

HAVE TO WATCH THE WARM AIR CLOSE WHICH COULD CAUSE RAPID SNOW MELT AND AREA LAKES ARE ALREADY EXPERIENCING THIS TODAY SOON TO BECOME UNSAFE FOR RECREATIONAL ACTIVITY.  

IT'S GOING TO BE ANOTHER WEEK OR TWO WHERE WINTER DOES TRY TO STICK AROUND AND EVEN THE NCEP MODELS PREDICTING BELOW NORM TEMPS BUT THE WARM AIR TO THE WEST AND SOUTHWEST NEEDS TO BE MONITORED CLOSELY SHOULD IT NUDGE INTO HERE WITH CLEAR SKIES.

WE COULD EASILY SEE A SITUATION WHERE IL IS IN THE 60'S AND WITH LACK OF CLOUD COVER A RAPID SNOW MELT PICKS UP.  WATCHING A POSSIBLE RAIN EVENT FOR SUNDAY WHICH COULD CAUSE PROBLEMS WITH THAT. 

KEEP UP WITH THE FORECAST.

WX UNIT