037  
FOCN45 CWWG 192000  
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM  
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 2:00 PM CST THURSDAY  
JANUARY 19 2017.  
 
ALERTS IN EFFECT...BLIZZARD WARNINGS FOR COMMUNITIES ALONG THE ARCTIC  
COAST. FREEZING RAIN WARNINGS FOR WEST-CENTRAL ALBERTA. SPECIAL  
WEATHER STATEMENT FOR NORTH-CENTRAL AND EASTERN ALBERTA.  
 
SYNOPTIC OVERVIEW...SOUTHWEST FLOW ALOFT CONTINUES TO ALLOW MILD  
PACIFIC AIR TO SPREAD ACROSS THE PRAIRIES. LARGE UPPER TROUGH OVER  
THE WEST NOAM COAST IS SHIFTING SLOWLY TO THE EAST. AN UPPER LOW IS  
SPINNING OVER ALASKA AND ANOTHER UPPER LOW IS SPINNING OVER NORTHERN  
DAVIS STRAIT.  
 
AT THE SURFACE, THERE IS A 990 MB LOW PRESSURE SYSTEM LOCATED NEAR  
KASBA LAKE THAT CONTINUES TO MOVE NORTHEAST. THE ASSOCIATED COLD  
FRONT CUTS BACK THROUGH NORTHERN SK AND NORTHERN AB BEFORE LINKING UP  
TO A 977 MB LOW ON THE ALASKAN PANHANDLE. AN ARCTIC RIDGE OF HIGH  
PRESSURE STRETCHES FROM ALASKA EASTWARD TOWARDS NORTH BAFFIN ISLAND.  
 
DISCUSSION...  
 
WESTERN PRAIRIES...LOW PRESSURE SYSTEM DEVELOPING OFF THE NORTHERN  
FOOTHILLS TODAY WILL BRING AN AREA OF MIXED PRECIPITATION TO MOST OF  
CENTRAL AND NORTHERN ALBERTA OVER THE NEXT 24-36 HOURS. PRECIPITATION  
TYPING WILL BE DIFFICULT WITH THIS QUICK, NORTHWARD MOVING SYSTEM.  
THE PREDOMINANT PRECIPITATION TYPE IS FREEZING RAIN, AS SURFACE TEMPS  
ARE BELOW ZERO AND 850 MB TEMPS REMAIN NEAR +3C. AS COOLER AIR WRAPS  
AROUND THE LOW, PRECIPITATION WILL CHANGE TO SNOW THIS EVENING AND  
OVERNIGHT. THE LAST FEW MODEL RUNS HAVE BEEN VERY INCONSISTENT WITH  
THE PLACEMENT OF PRECIPITATION TRANSITION ZONES AND REALLY, THE  
PRECIPITATION PLACEMENT IN GENERAL. FREEZING RAIN IS FALLING IN  
GRANDE PRAIRIE AND PEACE RIVER REGIONS, CAUSING ROADS TO BE  
HAZARDOUS, AND IS EXPECTED TO MOVE INTO THE WABASCA REGION LATER THIS  
AFTERNOON. A SPECIAL WEATHER STATEMENT HAS BEEN ISSUED TO HIGHLIGHT  
THE FREEZING RAIN RISK FOR NORTHERN ALBERTA HIGHWAYS, AS WELL AS THE  
UNCERTAINTY IN THE TRACK OF THIS STORM. THE AREA OF FREEZING RAIN IS  
LIKELY TO PUSH INTO NORTHERN SASKATCHEWAN OVERNIGHT TONIGHT AS WELL  
BEFORE SWITCHING TO SNOW FRIDAY MORNING.  
 
EASTERN PRAIRIES...FREEZING RAIN HAS ENDED IN NORTHERN MANITOBA,  
LEAVING PATCHY FOG AND A RISK OF FREEZING DRIZZLE IN ITS WAKE FOR THE  
NEXT COUPLE DAYS. FURTHER SOUTH, VERY MILD CONDITIONS CONTINUE WITH  
PACIFIC FLOW FIRMLY ESTABLISHED ACROSS THE PRAIRIES. 925 MB TEMPS IN  
THE +2 TO +8C RANGE WILL LIKELY LEAD TO RECORD HIGHS FOR THE THIRD  
DAY IN A ROW. SNOW FREE AREAS OVER SOUTHWEST SASKATCHEWAN WILL LIKELY  
SEE TEMPERATURES CLIMB INTO THE LOW DOUBLE DIGITS. SOUTHWEST WINDS  
OVER THE MB ESCARPMENT AND RIDING MOUNTAIN WILL CONTINUE TO ALLOW FOR  
COMPRESSIONAL HEATING SO EXPECT TEMPERATURES JUST ON THE DOWNSLOPE  
SIDES TO REACH UP TO 5C TODAY. WITHIN THE RED RIVER VALLEY,  
TEMPERATURES AROUND THE FREEZING MARK ARE EXPECTED AS IT WILL TAKE A  
BIT OF TIME TO FLUSH OUT THE COOLER AIR THAT FLOODED BACK IN DURING  
THE OVERNIGHT HOURS. SOUTHERLY WINDS AROUND 20 KM/H CHANNELING ALONG  
THE SNOW COVERED VALLEY AREN'T QUITE FAVORABLE FOR AMPLE WARMING  
EITHER.  
 
ELSEWHERE, STRATUS AND PATCHY FOG HAS DEVELOPED OVER NORTHERN  
MINNESOTA AND NORTH DAKOTA AND LOOKS TO ADVECT ACROSS MOST OF THE RRV  
AND SE THIS EVENING AS WELL, SO FRIDAY LOOKS LIKE A CLOUDY DAY THOUGH  
THE TEMPERATURES WILL REMAIN VERY MILD. A FEW MORE IMPULSES ALSO RIDE  
NORTHWARD OUT OF THE SOUTH STARTING LATE FRIDAY, BRINGING A FEW MM OF  
PRECIPITATION ACROSS SOUTHERN MANITOBA THROUGH THE WEEKEND.  
WITH SURFACE TEMPERATURES HOVERING AROUND ZERO STILL, AND A DECENT  
LAYER OF SATURATED AND AROUND-ZERO AIR JUST ALOFT, THERE'LL LIKELY BE  
A MIX OF PRECIPITATION TYPES INCLUDING SNOW, RAIN, AND POCKETS OF  
FREEZING DRIZZLE/RAIN. THE IMPULSES ARE RATHER SMALL, SO INTENSITY  
AND CLEARER TRACKING/PHASING IS STILL TOO DIFFICULT TO TELL THIS  
EARLY WITH ANY PRECISION. IN ANY CASE, CONDITIONS ARE ALREADY  
SLIPPERY OUTSIDE WITH ONGOING NEAR FREEZING TEMPERATURES, SO THAT  
WILL CERTAINLY CONTINUE INTO THE WEEKEND. BY THE TIME THE  
PRECIPITATION REACHES NORTHERN MANITOBA, AND BACK WESTWARD INTO  
SASKATCHEWAN, LIGHT SNOW LOOKS TO BE THE DOMINANT TYPE.  
 
WESTERN AND CENTRAL ARCTIC...AFOREMENTIONED SYSTEM MOVING THROUGH  
ALBERTA TODAY WILL SPREAD A MIX OF FREEZING RAIN, ICE PELLETS AND  
SNOW INTO FORT SMITH AND FORT RESOLUTION OVERNIGHT TONIGHT. CANADIAN  
MODELS CONTINUE TO HINT AT WARNING LEVEL SNOWFALL FOR AREAS SOUTH OF  
GREAT SLAVE LAKE ON FRIDAY, BUT AS MENTIONED EARLIER, WE'VE SETTLED  
ON A SLIGHTLY WEAKER SOLUTION AND HAVE THEREFORE BROUGHT SNOWFALL  
AMOUNTS DOWN TO 5-10 CM.  
 
CONDITIONS ARE BEGINNING TO DETERIORATE AT SACHS HARBOUR. WINDS AT  
SACHS HARBOUR AND ULUKHAKTOK WILL STEADILY INCREADE THROUGHOUT THE  
DAY TODAY. COMBINED WITH FALLING SNOW, BLIZZARD CONDITIONS ARE  
EXPECTED TO BEGIN THIS AFTERNOON AND PERSIST UNTIL FRIDAY.  
OF PARTICULAR NOTE IS ULUKHAKTOK, WHERE NEW GUIDANCE SUGGESTS WINDS  
MAY PEAK AT 70 GUSTING 90 KM/H, AND THE DURATION LOOKS TO BE ON THE  
ORDER OF 18 TO 24 HOURS.  
 
EASTERN ARCTIC...LOW PRESSURE SYSTEM MOVING ALONG THE 60TH PARALLEL  
WILL SPREAD SNOW INTO SOUTHERN KIVALLIQ TODAY. PROGGED SLR OF 12:1  
SHOULD ALLOW FOR UP TO 10 CM OF SNOW IN ARVIAT AND RANKIN INLET BY  
THE END OF THE DAY. SOME REDUCED VISIBILITIES IN BLOWING SNOW WILL  
ALSO BE POSSIBLE LATER THIS EVENING OVER RANKIN AND CHESTERFIELD AS  
WINDS STRENGTHEN FROM THE NORTHEAST TO 50 GUSTING 70 KM/H. WILL KEEP  
AN EYE ON THIS, SHOULD THE SNOWFALL AND HIGHEST WINDS OVERLAP A BIT  
LONGER TONIGHT CONDITIONS COULD CLOSE IN ON BLIZZARD.  
 
END/KNIGHT/CARLSEN/VALLEE  
 
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