395  
FOCN45 CWWG 161930  
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM  
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 2:00 PM CST MONDAY  
DECEMBER 16 2024.  
 
ALERTS IN EFFECT...WINTER STORM WATCH FOR CLYDE RIVER. FOG ADVISORY  
FOR SOUTHERN ALBERTA.  
 
SYNOPTIC OVERVIEW...THE 12Z UPPER ANALYSES REVEALED LOWS OVER THE  
EASTERN ARCTIC, THE EASTERN PACIFIC, AND THE SOUTHEAST PRAIRIES.  
A HIGH SAT OVER THE ARCTIC OCEAN.  
 
THE SURFACE ANALYSIS SHOWS LOWS OVER DAVIS STRAIT AND NORTHWESTERN  
ONTARIO. HIGH PRESSURE STRETCHES FROM THE BEAUFORT SEA TO THE FOUR  
CORNERS OF THE UNITED STATES.  
 
DISCUSSION...  
 
AB...IN SOUTHERN ALBERTA, DENSE FOG DEVELOPED LAST NIGHT AND WILL  
LIKELY PERSIST IN WEAK EASTERLY FLOW THROUGH THE DAY. MODERATE  
IMPROVEMENT IN VISIBILITY IS POSSIBLE THIS AFTERNOON, BUT FOG IS  
EXPECTED IN THE AREA UNTIL LATER TONIGHT WHEN SOME SNOWFALL MOVING  
THROUGH THE REGION WILL SCATTER OUT THE FOG.  
 
OVERNIGHT LOWS UNDER THE SURFACE RIDGE AXIS MAY DROP INTO THE -30S  
EARLY THIS WEEK FOR PARTS OF ALBERTA, WITH WIND CHILL VALUES  
APPROACHING THE -40 MARK. EXTREME COLD WARNINGS MAY BE REQUIRED, BUT  
THIS WILL BE DEPENDENT OF THE STRATUS CLOUD DRIFTING AROUND UNDER THE  
RIDGE, WHICH IS KEEPING TEMPERATURES WARM IN SOME AREAS.  
 
SK/MB...AFTER THE MODEST WEEKEND SNOWFALL IN SOUTHERN MANITOBA, AN  
ARCTIC RIDGE WILL BUILD IN OVER THE PRAIRIES, CLEARING SKIES AND  
DROPPING TEMPERATURES. AS THE RIDGE BUILDS IN, A TIGHT NORTHERLY  
GRADIENT WILL DEVELOP RESULTING IN INCREASING NORTHWESTERLY WINDS.  
THESE WINDS, FALLING TEMPERATURES, AND FRESH SNOW WILL LIKELY RESULT  
IN REDUCED VISIBILITIES IN BLOWING SNOW, NOTABLY THROUGH THE SOUTHERN  
RRV AND MB LAKES TODAY. AT THIS TIME IT DOESN'T APPEAR VISIBILITY  
WILL BE AFFECTED ENOUGH FOR AN ADVISORY, BUT WE WILL CONTINUE TO  
MONITOR. MENTION OF BLSN HAS BEEN ADDED TO THE PUBLIC FORECASTS.  
 
OUTLOOK: LOOKING AHEAD TO WEDNESDAY, ANOTHER SYSTEM WILL DEVELOP IN  
THE LEE OF THE ALBERTA ROCKIES AND MAKE ITS WAY ACROSS THE SOUTHERN  
PRAIRIES, BRINGING WARNING LEVEL SNOWFALL TO PARTS OF SASKATCHEWAN  
WEDNESDAY AND WEDNESDAY NIGHT. THIS SYSTEM WILL CONTINUE INTO  
SOUTHWESTERN MANITOBA EARLY THURSDAY MORNING BRINGING POTENTIALLY  
WARNING LEVEL SNOWFALL TO THE REGION. THERE IS ALSO THE RISK OF  
FREEZING RAIN/FREEZING DRIZZLE OVER SOUTHEASTERN AB AND SOUTHWESTERN  
SASKATCHEWAN WITH THIS SYSTEM AS WELL AS SNOW/BLOWING SNOW OVER  
SOUTHEASTERN SASKATCHEWAN WEDNESDAY. ALERTS WILL BE ISSUED AS TIME  
APPROACHES AND THE SYSTEM'S TRACK BECOMES CLEARER.  
 
ARCTIC...A POLAR LOW LOOKS TO DEVELOP OVER CENTRAL DAVIS STRAIT COME  
TUESDAY. GUIDANCE HAS BEEN CONSISTENT RUN-TO-RUN, WITH THE SYSTEM  
STILL PROGGED TO RETROGRESS TOWARDS CLYDE RIVER DURING THE DAY,  
SPREADING LIGHT SNOW THROUGH THE COMMUNITY. OF GREATER CONCERN IS THE  
TIGHT BACK SIDE GRADIENT. NORTHWESTERLY WIND GUSTS IN EXCESS OF  
80 KM/H ARE LIKELY IN THIS GRADIENT WHICH, CONCURRENT WITH THE  
FALLING SNOW, IS LIKELY TO LEAD TO BLIZZARD CONDITIONS TUESDAY.  
A BLIZZARD WARNING WILL BE ISSUED THIS AFTERNOON. WINDS WILL ABATE  
WEDNESDAY MORNING AS THE LOW DISSIPATES OVER THE STRAIT.  
 
NWT...SNOW TODAY FOR REGIONS NEAR GREAT SLAVE LAKE. ACCUMULATIONS OF  
2-5 CM ARE EXPECTED BEFORE THE SYSTEM MOVES SOUTHEAST INTO  
SASKATCHEWAN. SKIES SHOULD CLEAR GRADUALLY FROM THE NORTH, BRINGING  
COOLER TEMPERATURES GOING FORWARD.  
 
THE METEOROLOGICAL SERVICE OF CANADA IS INVESTIGATING THE  
DISCONTINUATION OF THIS SIGNIFICANT WEATHER DISCUSSION. IF YOU USE  
THIS BULLETIN AND HAVE ANY COMMENTS OR CONCERNS, PLEASE CONTACT US AT  
FOCN45@EC.GC.CA WITH THE SUBJECT: "SIGNIFICANT WEATHER DISCUSSION  
FEEDBACK". INCLUDE YOUR ORGANIZATION AND HOW YOU USE THIS PRODUCT.  
 
END/CARLSEN/STAUNTON  
 
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