758
FOCN45 CWWG 171930
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 2:00 PM CST SUNDAY
NOVEMBER 17 2024.
ALERTS IN EFFECT...WINTER STORM WATCH FOR PARTS OF EASTERN SK/WESTERN
MB WILL LIKELY BE ISSUED LATE THIS AFTERNOON.
SYNOPTIC OVERVIEW...ALOFT, AN UPPER LOW IS OVER THE BEAUFORT SEA WITH
A TROUGH SOUTHWARD ALONG THE NORTHERN COAST OF BC. SEVERAL SHORTWAVES
ARE ROTATING AROUND THE LOW: ONE OVER ALASKA, ONE OVER THE NORTHERN
COAST OF BC, ANOTHER NEAR GREAT SLAVE LAKE AND ANOTHER OVER SOUTHERN
KIVALLIQ. AN UPPER LOW IS OVER SOUTHERN MANITOBA. AN UPPER RIDGE IS
OVER BAFFIN ISLAND.
AT THE SURFACE, A 983 MB LOW IS NEAR PEACE RIVER, AB WITH A TROUGH
SOUTHWARD ACROSS ALBERTA. ANOTHER TROUGH EXTENDS NORTHWARD FROM THE
LOW, THROUGH TO VICTORIA ISLAND. A 994 MB LOW IS MOVING INTO
NORTHWESTERN ONTARIO. A RIDGE OF HIGH PRESSURE IS OVER EASTERN BAFFIN
ISLAND.
DISCUSSION...
ALBERTA/NRN SK...STRONG WEST-SOUTHWESTERLY WINDS ACROSS THE SOUTH
WILL EASE AS THE FLOW WEAKENS ALOFT BY THIS EVENING. THE LOW OVER
NORTHERN ALBERTA WILL MOVE TOWARDS THE NE THROUGH THE PERIOD WITH
5-10 CM OF SNOW POSSIBLE FOR SOME AREAS ALONG ITS TRACK. ALONG THE
COLD FRONT, CONVECTION IS EXPECTED THIS AFTERNOON IN THE FOOTHILLS,
WITH THE POSSIBILITY OF A FEW LIGHTNING STRIKES. A NEW LOW IS
FORECAST TO DEVELOP OVER SE AB BY EARLY MONDAY MORNING WITH LOCAL
SNOWFALL AMOUNTS OF 4-8 CM POSSIBLE. WITH THE INSTABILITY, EXACTLY
WHERE AND HOW MUCH SNOW WILL FALL, IS TOUGH TO PIN DOWN.
SOUTHERN SASKATCHEWAN/MANITOBA...WIDESPREAD STRATOCUMULUS IN THE WAKE
OF THE SYSTEM WHICH AFFECTED EASTERN SK/SOUTHERN MB YESTERDAY/
OVERNIGHT. OTHERWISE NIL SIG WX TODAY.
THE NEXT SYSTEM POISED TO HIT THE EASTERN PRAIRIES WILL MOVE INTO
SOUTHERN MANITOBA ON TUESDAY, TRACKING IN FROM THE US. AHEAD OF THE
SYSTEM, AN INVERTED TROUGH WILL BRING RAIN, SNOW, AND A RISK OF
FREEZING RAIN TO EASTERN SASKATCHEWAN MONDAY AFTERNOON AND THROUGH
THE OVERNIGHT. THERE IS CURRENTLY LITTLE MODEL AGREEMENT ON LOCATION
OR AMOUNT OF SNOW ALONG THE INVERTED TROUGH, LEADING TO LOW
CONFIDENCE ON SNOWFALL AMOUNTS FOR MONDAY NIGHT. THIS WILL BE
MONITORED AS THE LOW BEGINS TO DEVELOP AND WARNINGS WILL LIKELY BE
REQUIRED. WHAT BECOMES MORE CERTAIN IS INCLEMENT WEATHER FOR MUCH OF
EASTERN SASKATCHEWAN AND MANITOBA TUESDAY AND THROUGH WEDNESDAY AS
THE LOW APPROACHES. MODELS COME INTO AGREEMENT WITH HEAVY SNOW
BLOSSOMING ALONG THE INVERTED TROUGH IN SASKATCHEWAN EARLY TUESDAY
MORNING AND PERSISTING THROUGH THE DAY. FOR MANITOBA, AS THE LOW
TRACKS NORTHWARD, IT WILL PULL A DECENT AMOUNT OF WARM AIR WITH IT.
WITH THE WARM AIR ADVECTING NORTHWARD, PRECIPITATION WILL LIKELY
BEGIN AS RAIN, OR FREEZING RAIN OVER AREAS WITH SNOW ON THE GROUND.
COLD AIR WILL QUICKLY WRAP INTO THE LOW, AS AN ARCTIC HIGH SLIDES
SOUTHWARD ON TUESDAY, AND TRANSITION THE RAIN TO HEAVY SNOW.
ALONG WITH THE SNOW, GUSTY NORTHWEST WINDS WILL DEVELOP ON TUESDAY,
RESULTING IN REDUCED VISIBILITIES IN BLOWING SNOW. GIVEN THE
MAGNITUDE OF THIS APPROACHING SYSTEM, AND THE HIGH PROBABILITY OF
WARNINGS BEING ISSUED AS THE EVENT DRAWS NEARER, WILL LIKELY ISSUE A
WINTER STORM WARNING LATE THIS AFTERNOON HIGHLIGHTING HEAVY SNOW,
FREEZING RAIN AND STRONG WINDS.
NWT, KITIKMEOT AND HIGH ARCTIC...A TIGHT GRADIENT IS CAUSING STRONG
WINDS WITH NEAR BLIZZARD CONDITIONS THAT WILL IMPROVE THROUGH THE
DAY.
MODERATE NORTHWESTERLY WINDS AND FALLING TEMPERATURES ARE EXPECTED
FOR SOME COMMUNITIES IN THE NWT BEHIND THE TROUGH MOVING ACROSS THE
TERRITORY.
KIVALLIQ...FOG, LIGHT SNOW, AND FREEZING DRIZZLE WILL IMPACT KIVALLIQ
AND THE MELVILLE PENINSULA TODAY. THE SYSTEM OVER NORTHERN BC WILL
TRACK EASTWARD OVER THE NEXT 24 HOURS, PUSHING SNOW THROUGH THE
REGION ON MONDAY. GENERAL AMOUNTS OF 4 TO 8 CM ARE FORECAST BY THE
TIME THE SYSTEM DEPARTS.
NIL SIG WX FOR BAFFIN ISLAND.
END/FULTON/GREENHOUGH
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