002
FOCN45 CWWG 041200
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 7:00 AM CDT SATURDAY
OCTOBER 4 2025.
ALERTS IN EFFECT...RAINFALL WARNING FOR SOUTHERN MANITOBA.
SYNOPTIC OVERVIEW...ALOFT, A BROAD RIDGE IS OVER THE EASTERN PACIFIC,
WITH A BROAD TROUGH CENTERED OVER ALBERTA AND THE NORTHWEST
TERRITORIES. DEEPER TROUGHING IS FOUND FURTHER SOUTH OVER THE WESTERN
UNITED STATES. SHORTWAVES ARE LOCATED OVER NORTHEASTERN ALBERTA AND
NEAR THE YT/BC BORDER WITHIN THIS TROUGH. AN UPPER LOW IS CENTRED
OVER BAFFIN BAY, AND AN UPPER TROUGH IS LOCATED WEST OF BANKS ISLAND,
EXTENDING WESTWARDS INTO THE BEAUFORT SEA.
AT THE SURFACE, A 990 MB LOW IS CENTRED OVER THE MIDDLE OF KITIKMEOT,
WITH A WARM FRONT EXTENDING TO THE EAST AND A COLD FRONT EXTENDING
SOUTHWEST. A 1000 MB LOW IS OVER SOUTHEASTERN MANITOBA, WITH A COLD
FRONT EXTENDING SOUTHWARDS AND A WARM FRONT NORTHEASTWARDS. A LOW IS
ESTIMATED BY GUIDANCE TO BE 984 MB JUST NORTH OF ELLESMERE ISLAND.
HIGH PRESSURE IS LOCATED OVER THE PACIFIC NEAR 140 DEGREE LONGITUDE.
DISCUSSION...
AB...A COLD FRONT CONTINUES TO SWEEP SOUTHWARDS ACROSS THE PROVINCE
TODAY AND TONIGHT. A COOLER, MORE UNSTABLE AIR MASS, WILL RESULT IN
GUSTY WINDS AND RAIN SHOWERS FOR MUCH OF ALBERTA TODAY.
THE INTERACTION OF THIS COLD FRONT WITH THE FOOTHILLS DURING THE
AFTERNOON IN CONJUNCTION WITH SOME MODEST INSTABILITY WILL LIKELY
LEAD TO A FEW LIGHTNING STRIKES. AS TEMPERATURES DROP SHARPLY BEHIND
THIS FRONT, SOME SNOW IS LIKELY IN HIGHER ELEVATIONS DURING THE
EVENING AND OVERNIGHT HOURS. AREAS SUCH AS THE ICEFIELDS PARKWAY,
HIGHWOOD PASS, CROWSNEST PASS AND WATERTON PARK ARE MOST VULNERABLE;
BUT WET SNOW COULD REACH EASTWARDS CLOSE TO THE CITY LIMITS OF
CALGARY AND LETHBRIDGE. FORECASTING SNOWFALL ACCUMULATION IS COMPLEX,
BUT IN HEAVIER FLURRIES UP TO 5 CENTIMETRES ARE POSSIBLE IN THE MOST
VULNERABLE AREAS, AND EVEN A LITTLE MORE THAN THAT ISN'T OUT OF THE
QUESTION IN WATERTON PARK.
SK/MB...ANOTHER COLOARDO LOW IS EXPECTED TO DEVELOP STATESIDE AND
MOVE NORTHEASTWARDS INTO SOUTHERN MANITOBA SUNDAY. COLORADO LOW TAKES
SHAPE STATESIDE. A SLIGHT THREAT OF SEVERE CONVECTIVE WEATHER REMAINS
TODAY AND TONIGHT ALONG THE MB/ON BORDER, BUT A GREATER CONCERN IS
STEADY AND INTENSIFYING RAIN ALONG AND NORTHWEST OF THE WARM FRONT
WHICH WILL STALL OUT NEAR SPRAGUE. MODEL MEAN QPF TOTALS REMAIN IN
THE 50 MM RANGE FOR PORTIONS OF THE RED RIVER VALLEY AND SE MB FOR
LATE SATURDAY THROUGH END OF SUNDAY. RAINFALL WARNINGS HAVE THUS BEEN
ISSUED FOR SOUTHEASTERN MANITOBA, THOUGH THE TIMING HAS BEEN PUSHED
BACK A LITTLE.
NT...ONSHORE FLURRIES ARE EXPECTED OVER THE NEXT 24 HOURS GENERALLY
FOR THE ARCTIC COAST. A WEAK LOW PRESSURE SYSTEM WILL GIVE SOME LIGHT
RAIN OR WET SNOW TO A NUMBER OF COMMUNITIES OVER THE SOUTHERN NT
TONIGHT AND SUNDAY. AN ONSHORE FLOW COULD HELP ENHANCE RAINFALL IN
THE FORT RESOLUTION REGION TODAY.
NU...A STRENGTHENING LOW PRESSURE SYSTEM OVER THE KITIKMEOT LOOKS TO
BRING RAIN, FOLLOWED BY STRONG WINDS (GUSTING TO 60 OR 70 KM/H) AND
SNOW OVER THE EASTERN KITIKMEOT REGION. FORECASTING SNOWFALL AMOUNTS
IS A LITTLE TRICKY GIVEN TEMPERATURES NEAR ZERO AND THE TIGHT QPF
GRADIENT, BUT GENERALLY THESE COMMUNITIES COULD EXPECT TO SEE 2-4
CENTIMETRES OF SNOW TONIGHT OR SUNDAY. FURTHER SIGNIFICANT SNOWFALL
AND STRONG WINDS ARE POSSIBLE OVER KUGAARUK TONIGHT. THIS SYSTEM WILL
ALSO BRING MODEST RAIN OR SNOWFALL AMOUNTS TO THE KIVALLIQ REGION
WITH WINDS GUSTING TO 70 KM/H ON SUNDAY.
END/BATE
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