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FOCN45 CWWG 081200
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 7:00 AM CDT SATURDAY
AUGUST 8 2026.
ALERTS IN EFFECT...AIR QUALITY WARNINGS IN FORT SIMPSON AND PARTS OF
WESTERN ALBERTA.
OVERVIEW...ALOFT THIS MORNING, THE FLOW IS DOMINATED BY A LARGE UPPER
LOW COMPLEX OVER WESTERN HUDSON BAY WITH SEVERAL SHORTWAVES ROTATING
AROUND IT. WEAK UPPER RIDGING LIES OVER SOUTHERN BC AND SOUTHERN AB,
WHILE AN UPPER LOW SITS OVER THE GULF OF ALASKA. ANOTHER UPPER LOW
LIES OVER ALASKA AND UPPER RIDGING LIES OVER THE HIGH ARCTIC AND
STRETCHES SOUTHEASTERN ACROSS BAFFIN ISLAND.
AT THE SURFACE, A 997 MB LOW SITS OVER CENTRAL HUDSON BAY WITH AN
OCCLUDED FRONTAL WAVE ITS EAST NEAR THE QUEBEC COAST; A COLD FRONT
SWEEPS SOUTHWEST THROUGH NW ONTARIO INTO THE UNITED STATES WHILE A
WARM FRONT IS DRAPED EAST INTO QUEBEC. A TROUGH OF LOW PRESSURE
EXTENDS WEST FROM THIS LOW ACROSS THE NORTHERN PRAIRIES. WEST OF
THIS, A 1019 MB HIGH SITS OVER THE MIDWESTERN US WITH RIDGING THAT
EXTENDS NORTHWEST ACROSS SASKATCHEWAN INTO NORTHERN ALBERTA. IN THE
NORTH, A BROAD AREA OF HIGH PRESSURE IS DRAPED ACROSS THE CANADIAN
ARCTIC ARCHIPELAGO WITH RIDING SOUTH INTO THE NORTHWEST TERRITORIES
AND EAST TO A 1032 MB HIGH OVER GREENLAND. A 1009 MB LOW IS OVER THE
WESTERN ARTIC NORTH OF THE BEAUFORT SEA WITH TROUGHING EXTENDING
SOUTHWARD THROUGH THE NWT. A WEAK LOW LIES OVER CENTRAL MONTANA.
DISCUSSION...
WESTERN PRAIRIES...AIR QUALITY WILL CONTINUE TO BE AN ISSUE FOR
PORTIONS OF WESTERN ALBERTA, INCLUDING THE MOUNTAIN PARKS AS SMOKE
WILL CONTINUE TO STREAM IN FROM BC WITH THE WESTERLY FLOW ALOFT. THE
QUESTION THAT REMAINS HOWEVER, IS HOW FAR TO THE EAST THE SMOKE WILL
TRACK. WITH THE SURFACE FLOW EXPECTED TO REMAIN EASTERLY TODAY, THE
EXPECTATION IS THAT THE SMOKE WILL REMAIN TIED TO THE WESTERN MOST
REGIONS, HOWEVER, THERE IS A CHANCE THAT WE MAY SEE SOME OF THE
HEAVIER SMOKE DRIFT SLIGHTLY FURTHER EAST IN THE LATE AFTERNOON TO
OVERNIGHT HOURS. ALERTS WILL BE UPDATED AS NECESSARY IS AIR QUALITY
BECOMES A SIGNIFICANT RISK.
A SHORTWAVE CURRENTLY OFF THE BC COAST, WILL MOVE INTO CENTRAL
ALBERTA LATE THIS AFTERNOON AND INTO THE EARLY EVENING HOURS. IN
ADDITION, A SURFACE TROUGH ALONG THE ALBERTA FOOTHILLS WILL TRIGGER A
FEW THUNDERSTORMS LATE THIS AFTERNOON. AS THE STORMS MOVE OFF THE
FOOTHILLS, THE UPPER TROUGH MOVING IN THIS EVENING WILL ALLOW STORMS
TO CONTINUE THOUGH CENTRAL ALBERTA LATE THIS EVENING AND OVERNIGHT AS
THE UPPER SUPPORT IS ABLE TO CARRY THE STORMS FURTHER THE EAST. A FEW
OF THESE STORMS ARE ANTICIPATED TO BECOME SEVERE WITH HAIL AND RAIN
BEING THE PRIMARY THREATS HOWEVER SOME STRONG WIND GUSTS ARE ALSO
POSSIBLE. OVER SOUTHERN ALBERTA, A WARM THERMAL RIDGE AND SMOKE MAY
WORK IN TANDEM TO KEEP CONDITIONS CAPPED TO THUNDERSTORMS TODAY. MOST
STORM ACTIVITY SHOULD BE AROUND/TO THE NORTH OF CALGARY AND EXTEND
NORTHWARD INTO THE PEACE RIVER REGION.
EASTERN PRAIRIES...SCATTERED THUNDERSHOWERS WILL DEVELOP OVER
PORTIONS OF NORTHERN AND CENTRAL MANITOBA THIS AFTERNOON AS DAYTIME
HEATING PRODUCES A COUPLE OF HUNDRED J/KG OF SBCAPE. BULK SHEAR IS 20
KNOTS OR LESS. NO SEVERE WEATHER IS EXPECTED.
LITTLE CHANGE OVER THE COMING DAYS AS A NORTHWEST FLOW CONTINUES OVER
NORTHERN MANITOBA.
AN INCREASING AMOUNT OF SMOKE ALOFT WILL SPREAD ACROSS SOUTHERN
SASKATCHEWAN INTO SOUTHWEST MANITOBA OVER THE COMING DAYS, BUT THE
NEAR-SURFACE IMPACT IS EXPECTED TO BE MINIMAL. SOME DETERIORATION IN
AIR QUALITY WILL BE POSSIBLE IN THE COMING DAYS OVER FAR SOUTHWESTERN
SASKATCHEWAN, OTHERWISE HAZY SKIES WILL BE THE PRIMARY IMPACT FOR THE
REST OF THE REGIONS IN THE PATH OF THE SMOKE PLUME.
ON SATURDAY NIGHT INTO SUNDAY, A SHORTWAVE WILL SUPPORT AN AREA OF
SHOWERS AND NON-SEVERE THUNDERSTORMS OVER SOUTHWESTERN SASKATCHEWAN
THAT WILL MOVE EASTWARD ACROSS SOUTHERN SASKATCHEWAN ON SUNDAY AND
ACROSS MANITOBA ON SUNDAY NIGHT.
NT....SOME WEAK THUNDERSTORMS ARE POSSIBLE PRIMARILY ALONG THE
TERRAIN AND INTO NORMAN WELLS AND GOOD HOPE REGIONS THIS AFTERNOON.
AIR QUALITY WILL ALSO BE AN ISSUE IN THE NT, PRIMARILY AROUND AND IN
THE FORT SIMPSON AREA WHERE THE AIR QUALITY HAS BEEN POOR AT TIMES
DUE TO FOREST FIRES NEAR THE COMMUNITY. SMOKE WILL LIKELY IMPACT
NEIGHBOURING COMMUNITIES AS THE WINDS SHIFT, MOVING THE SMOKE AROUND
WITH THE WIND SHIFTS.
NU...RAIN SHOWERS WILL CONTINUE TO ROTATE AROUND THE HUDSON BAY UPPER
LOW OVER THE COMING DAYS. SOME AREAS ALONG THE HUDSON BAY COAST COULD
SEE AS MUCH AS 10 TO 15 MM OF RAIN BY SATURDAY EVENING, BUT BROADLY
ACCUMULATIONS WILL BE LESS THAN THAT.
ON SATURDAY, MODERATE WINDS WILL DEVELOP OUT OF HUDSON STRAIT AND
ACROSS SOUTHAMPTON ISLAND AND TO THE KIVALLIQ COAST. WIND GUSTS OF 50
TO 70 KM/H WILL BE POSSIBLE LATER SATURDAY AND INTO SUNDAY BEFORE THE
WINDS DIMINISH. MODERATE WINDS WILL PERSIST A BIT LONGER OVER HUDSON
STRAIT AND INTO KINNGAIT (CYTE), NOT EASING UNTIL MONDAY.
IN ADDITION TO THE RAIN SHOWERS, RELATIVELY MILD AIR BEING PUMPED
OVER THE COOLER WATERS OF HUDSON BAY HAS RESULTED IN BROAD AREAS OF
FOG ACROSS THE REGION STUCK BELOW THE MARINE INVERSION. FOG PATCHES
WILL BE COMMONPLACE ACROSS HUDSON BAY AND THE ADJACENT COASTAL
COMMUNITIES INTO THE WEEKEND.
END/STAMMERS/GREENHOUGH
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