480  
FOCN45 CWWG 242000  
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM  
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 2:00 PM CST SATURDAY  
FEBRUARY 24 2024.  
 
ALERTS IN EFFECT...BLIZZARD WARNING FOR CLYDE RIVER, BAKER LAKE,  
RANKIN INLET, WHALE COVE AND ARVIAT. SPECIAL WEATHER STATEMENTS FOR  
SOUTHERN SASKATCHEWAN AND SOUTHERN MANITOBA.  
 
SYNOPTIC OVERVIEW...ALOFT, A NORTHWESTERLY FLOW OVER BC BECOMES  
DECIDEDLY ZONAL OVER THE PRAIRIES. UPPER RIDGING OVER ONTARIO SNEAKS  
UP INTO THE NORTHERN KIVALLIQ. OVER THE ARCTIC, A LOW CENTRE OVER  
SOUTHERN VICTORIA ISLAND HAS A DISTINCT SHORTWAVE TROUGH THAT ARCS  
THROUGH MAINLAND NUNAVUT, DOWN INTO THE SOUTHERN KIVALLIQ, AND BACK  
INTO CENTRAL SASKATCHEWAN. A SECOND, POTENT LOW CENTRE LIES OVER  
BROUGHTON ISLAND.  
 
AT THE SURFACE, LOW PRESSURE OVER THE GULF OF ALASKA. RIDGE FROM THE  
BEAUFORT SEA ARCS SOUTHWARDS, DOWN THE MACKENZIE RIVER VALLEY. THE  
REMAINDER OF WESTERN CANADA IS DOMINATED BY A 980 MB LOW CENTRE WITH  
BULLSEYE JUST EAST OF ARVIAT. THE SOUTHERN HALF OF THE PRAIRIES ARE  
IN THE WARM SECTOR OF THIS LOW. INVERTED TROUGH FROM ARVIAT LOW  
HEADS UP TOWARDS THE GJOA HAVEN REGION. COMPACT BUT INTENSE 978 MB  
LOW IS MOVING NORTH IN DAVIS STRAIT.  
 
DISCUSSION...  
 
PRAIRIES AND NWT...ACROSS MUCH OF THE NWT, CLEAR AND COLD CONDITIONS  
HAVE SETTLED IN FOR THE REST OF THE WEEKEND. WINDCHILL VALUES MAY  
APPROACH MINUS 50 BY SUNDAY MORNING FOR PORTIONS OF CENTRAL AND  
SOUTHERN NWT. EXTREME COLD WARNINGS MAY NEED TO BE ISSUED LATER  
TODAY.  
 
THE COLD FRONT FROM THE ARVIAT LOW WILL MOVE ACROSS ALBERTA AND  
NORTHERN SK TODAY, BRINGING SCATTERED FLURRIES, BLUSTERY NORTHWEST  
WINDS AND COOLER TEMPERATURES TO MOST REGIONS. IN ADDITION, WESTERLY  
FLOW ALOFT IS PRODUCING SOME SNOW FOR THE MOUNTAIN PARKS, WHERE UP  
TO 10 CM IS POSSIBLE ALONG HIGHWAY 93 OVER THE NEXT 24 HOURS.  
 
A LARGE IMPULSE AND DECAYING WAVE NOW IN THE EASTERN PACIFIC WILL BE  
THE IMPETUS FOR THE NEXT MAJOR CLIPPER SYSTEM ON THE PRAIRIES. A NEW  
LOW WILL DEVELOP NEAR THE ALBERTA ELBOW ON SUNDAY MORNING AND TRACK  
SOUTHEAST THROUGH SOUTHERN SK AND MB THROUGH MONDAY. WHILE THERE  
WILL BE SOME INEVITABLE SHIFT WITH THE CLIPPER POSITION, SIGNIFICANT  
SNOW, WIND, FREEZING PRECIPITATION, AND WILD TEMPERATURE SWINGS ARE  
ON TAP IN THE AREA.  
 
FOR AB, THE HEAVIEST SNOW WILL FALL IN THE CENTRAL REGIONS AND THE  
MOUNTAIN PARKS FROM SUNDAY THROUGH MONDAY MORNING. IN GENERAL,  
10 TO 25 CM APPEARS LIKELY AT THE PRESENT TIME. STRONG EASTERLY  
WINDS OVER EAST-CENTRAL AB WILL LEAD TO LOCALIZED BLOWING SNOW. IN  
ADDITION, AS THE LOW DEEPENS OVER AB ON SUNDAY, PORTIONS OF  
SOUTHERN AB MAY EXPERIENCE STRONG WIND GUSTS, POSSIBLY UP TO 100  
KM/H, FROM SUNDAY AFTERNOON THROUGH EARLY MONDAY MORNING. THE  
BLUSTERY SOUTHWESTERLIES WILL EXTEND INTO SOUTHWESTERN SK AS WELL,  
THOUGH CLOSER TO THE GUSTING 70 KM/H MARK.  
 
CENTRAL SK AND MB ARE STILL BROADLY LOOKING AT 10 TO 20 CM OF SNOW  
SUNDAY THROUGH MONDAY NIGHT ALONG WITH GUSTY EASTERLY WINDS. MODELS  
TRACKS BOBBLE SLIGHTLY NORTH OR SOUTH BUT GENERALLY CONTINUE TO BE  
CENTERED ROUGHLY ALONG THE YELLOWHEAD AND NORTH FOR THE MAJOR  
ACCUMULATIONS. SOME AREAS MAY NEED COMBINATIONS OF SNOWFALL WARNINGS  
AND BLOWING SNOWADVISORIES WITH A DECIDEDLY NON-ZERO CHANCE OF  
SUSTAINED BLIZZARD IN POCKETS. INCREASINGLY, THE BATTLEFORDS AREA IS  
LOOKING AT VERY POOR CONDITIONS - GUSTING 80 KM/H AND SNOWFALL  
RATES OF 1 CM/HOUR OR MORE - LATE SUNDAY NIGHT THAT WOULD WARRANT A  
BLIZZARD WARNING. BUT, THE SWATHS OF HEAVIEST SNOW AND STRONGEST  
WINDS ARE RATHER NARROW SO CONFIDENCE IS NOT THERE YET; A LAST DAY  
SHIFT IN TRACK IS TYPICAL AS MORE ONSHORE REAL DATA COMES INTO THE  
FORECAST MODELS.  
 
FURTHER SOUTH, PRECIPITATION IS LIGHTER, BUT ODDS STEADILY INCREASE  
FOR BOUTS OF FREEZING RAIN FROM SOUTHEASTERN SK ACROSS SOUTHERN  
MANITOBA SOUTH OF THE LAKES LATE SUNDAY OR EARLY MONDAY. SNOW  
NUMBERS ARE ALSO BORADLY LESS CONFIDENT FOR SOUTHEASTERN MB - QPF  
TRACKS HERE REMAIN VERY UNCERTAIN, WITH SOME MODELS NOW BRINGING  
WINNIPEG INTO HEAVY SNOW WHILE OTHERS KEEP THE WORST OF THE SNOW  
WELL OFF IN THE NORTHERN INTERLAKE. IN THE SOUTH, MOISTURE  
DISTRIBUTION THROUGH THE COLUMN AND MILD TEMPERATURES WILL ALSO PLAY  
HAVOC WITH TYPING AND POTENTIAL QPF VALUES REGARDLESS. WILL NEED TO  
WAIT AND SEE A BIT LONGER TO FIRM UP FORECAST NUMBERS.  
 
WITH THE LOW PASSAGE, WARM SECTOR HIGHS COULD THEN BRUSH THE  
POSITIVE DOUBLE DIGITS NEAR THE INTERNATIONAL BORDER ON MONDAY  
ITSELF, BUT THE COLD FRONT WILL BE SWIFT AND INTENSE - GUSTING 70  
KM/H OR MORE WITH A DROP TO -20C OR COLDER BY TUESDAY MORNING. MUCH  
OF THE SOUTHERN PRAIRIES IS EFFECTIVELY BARE OF SNOW, BUT SHOULD THE  
PRECIP SHIELD SHIFT MORE SOUTHWARD AND/OR LIGHT SNOW CONTINUE POST  
COLD FRONT, BLOWING SNOW AND POOR VISIBILITIES WILL BE A CONCERN AS  
WELL ACROSS THE REMAINDER OF THE SOUTH.  
 
THE SYSTEM DEPARTS SWIFTLY AND CONDITIONS WILL BE COLD AND  
RELATIVELY CALM BY MIDDAY TUESDAY. A SPECIAL WX STATEMENT WAS ISSUED  
ON FRIDAY DETAILING THIS SYSTEM FOR EARLY NEXT WEEK. THE LEADING  
EDGE OF THE COLD MAY DIP INTO THE NORTHERN REACHES OF THE PRAIRIE  
PROVINCES AS EARLY AS TONIGHT, AND THE FIRST OF THE EXTREME COLD  
WARNINGS COULD FOLLOW AS EARLY AS THIS AFTERNOON.  
 
NU...THE POTENT DAVIS STRAIT LOW WILL BRING ANOTHER CLASSIC BARRIER  
JET TO CLYDE RIVER TODAY. WIND GUSTS WILL REACH UP TO 80 TO 90 KM/H  
TODAY AND WITH FALLING SNOW A WHITEOUT BLIZZARD IS IN PROGESS. THE  
SEVERE WINDS AND BLIZZARD WILL LAST UNTIL THE LOW PUSHES NORTH  
PAST CLYDE MIDDAY SUNDAY.  
 
OVER IN THE KIVALLIQ, NORTHWESTERLIES ARE RAMPING UP SWIFTLY AS  
THE MAIN LOW NOW DRIFTS INTO HUDSON BAY. ARVIAT PROMPTLY DESCENDED  
TO 1/8SM THIS MORNING WITH 50 KM/H WINDS. ALL THIS IS ACCOMPANIED BY  
5 TO 10 CM OF SNOW AND PLUMMETING TEMPERATURES NEAR TO THE -30 MARK  
THROUGH TODAY AND TONIGHT. RANKIN INLET AND WHALE COVE ARE ALSO IN  
THE HEART OF ALL OF IT AND SHOULD FOLLOW BY EVENING. ODDS OF  
BLIZZARD HAVE DIMISHED SLIGHTLY AT BAKER - BUT STILL ALREADY 5/8 SM  
AT 45 KM/H SUSTAINED. ONGOING ICE CRYSTALS, A LITTLE MORE WIND, AND  
THE FALLING TEMPERATURES ARE STILL ON TAP SO THE BALANCE IS TIPPED  
TOWARD CONTINUING THE WARNING THERE. ODDS REMAIN SLIGHTLY LESS  
PROBABLE STILL IN CHURCHILL BUT NEAR BLIZZARD CONDITIONS HERE REMAIN  
QUITE LIKELY. CONDITIONS TO IMPROVE SUNDAY MORNING BUT COULD LAST  
INTO THE DAY ON SUNDAY IN THE RANKIN INLET/WHALE COVE REGION.  
 
THE GJOA HAVEN LOW IS FORECAST TO MOVE VERY SLOWLY OVER THE NEXT 36  
HOURS. THE MOST LIKELY AREA FOR BLOWING SNOW WILL BE IN THE NW WINDS  
BEHIND IT, OVER VICTORIA ISLAND, TODAY, TONIGHT AND SUNDAY.  
 
END/KNIGHT/STAUNTON  
 
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