054
FOCN45 CWWG 091900
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 2:00 PM CDT SUNDAY AUGUST
9 2026.
ALERTS IN EFFECT...AIR QUALITY WARNINGS FOR PARTS OF WESTERN ALBERTA
AND FORT SIMPSON NWT.
OVERVIEW...ALOFT TODAY, THE DOMINANT WEATHER FEATURE CONTINUES TO BE
THE LARGE VORTEX OVER HUDSON BAY THAT HAS SEVERAL SHORTWAVES ROTATING
AROUND IT. WEST OF THIS, ANOTHER UPPER LOW SPINS OVER NORTH-CENTRAL
BC. IN THE NORTH, AN UPPER LOW SITS ALONG THE COAST OF THE ARCTIC
OCEAN NEAR THE ALASKA/YUKON BORDER WHILE EAST OF THIS A BROAD UPPER
HIGH SITS BETWEEN THE CANADIAN ARCTIC ARCHIPELAGO AND GREENLAND.
AT THE SURFACE, THE SURFACE REFLECTION OF THE HUDSON BAY UPPER LOW
CONTINUES TO SPIN OVER HUDSON BAY. A FLAT PATTERN EXISTS OVER MUCH OF
THE REST OF THE AREA OF RESPONSIBILITY.
DISCUSSION...
WESTERN PRAIRIES...AIR QUALITY WILL CONTINUE TO BE AN ISSUE FOR
PORTIONS OF WESTERN ALBERTA, INCLUDING THE MOUNTAIN PARKS AS SMOKE
WILL STREAM IN FROM BC WITH THE WESTERLY FLOW ALOFT. THE QUESTION
THAT REMAINS, HOWEVER, IS HOW MUCH SMOKE WILL MIX DOWN TO THE
SURFACE. 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 FARTHER EAST IN THE LATE AFTERNOON TO
OVERNIGHT HOURS, AS PRECIPITATION FROM AFTERNOON THUNDERSTORMS MIXES
DOWN THE SMOKE FROM ALOFT. ALERTS WILL BE UPDATED AS NECESSARY IF AIR
QUALITY BECOMES A SIGNIFICANT RISK.
A NORTHWESTERLY FLOW WITH SEVERAL SHORTWAVES TRAVERSING THE PROVINCE
WILL CONTINUE TO TRIGGER A FEW THUNDERSTORMS THIS MORNING THROUGH
CENTRAL AND SOUTHEASTERN PARTS OF THE PROVINCE, WHERE CLOUD TOP
COOLING HAS LEAD TO INCREASED INSTABILITY. IN ADDITION, ACROSS
WESTERN PARTS OF THE PROVINCE, WHERE SOME CLEARING HAS DEVELOPED, FOG
PATCHES HAVE DEVELOPED. AS DAYTIME HEATING STARTS TO KICK IN, THE
THUNDERSTORMS SHOULD WEAKEN AND DISSIPATE AND THE FOG WILL DISPERSE.
A COUPLE OF SHORTWAVES APPROACHING ALBERTA WILL MOVE INTO CENTRAL
REGIONS 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 WILL ALLOW STORMS TO CONTINUE
THOUGH CENTRAL ALBERTA LATE THIS EVENING AND OVERNIGHT AS THE UPPER
SUPPORT IS ABLE TO CARRY THE STORMS FARTHER TO 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.
HOWEVER, THERE IS A SLIGHT RISK THAT A FEW STORMS MAY TRIGGER OFF THE
SOUTHERN FOOTHILLS AS WELL. MOST STORM ACTIVITY SHOULD BE AROUND
CALGARY AND EXTEND NORTHWARD INTO THE PEACE RIVER REGION. THE BEST
AREA FOR SEVERE STORMS WILL BE FROM HINTON TO CALGARY WHERE THE SHEAR
PROFILE WILL BE MORE CONDUCIVE TO SUPPORTING SEVERE THUNDERSTORMS.
EASTERN PRAIRIES...A SHORTWAVE TRACKING OUT OF SOUTHERN ALBERTA
CONTINUES TO SUPPORT AN AREA OF SHOWERS AND THUNDERSTORMS OVER
SOUTHWESTESTERN SASKATCHEWAN EARLY THIS AFTERNOON.
LATER THIS AFTERNOON, THUNDERSTORMS WILL BE POSSIBLE OVER SOUTHERN
SASKATCHEWAN ALONG A WEAK INVERTED TROUGH IN ASSOCIATION WITH THE
AFOREMENTIONED SHORT WAVE TROUGH. SBCAPE VALUES WILL CLIMB INTO THE
500 TO 1,000 J/KG RANGE WITH 50 KNOTS OF DEEP SHEAR THAT COULD
PRODUCE ISOLATED MARGINALLY SEVERE THUNDERSTORMS WITH PRIMARY HAZARDS
OF STRONG WIND GUSTS AND/OR DAMAGING HAIL. THIS ACTIVITY WILL TAPER
OFF OVERNIGHT.
SCATTERED SHOWERS AND PERHAPS THE ODD LIGHTNING STRIKE OR TWO WILL
ALSO ONCE AGAIN DEVELOP ACROSS MUCH OF NORTHERN AND CENTRAL MANITOBA
THIS AFTERNOON. WITH ONLY 200 J/KG OF SBCAPE AND 20 KNOTS OF BULK
SHEAR, LIGHTNING STRIKES ARE EXPECTED TO BE FEW AND FAR BETWEEN WITH
NO SEVERE WEATHER THREAT.
ANOTHER SHORTWAVE PUSHING INTO WESTERN SASKATCHEWAN BY MONDAY MORNING
WILL SUPPORT ANOTHER AREA OF SHOWERS AND THUNDERSTORMS ACROSS
SOUTHERN PORTIONS OF THE PROVINCE. NO SEVERE WEATHER IS EXPECTED.
OTHERWISE, HAZY SKIES WILL CONTINUE ACROSS MUCH OF THE SOUTHERN
PRAIRIES AS THE UPPER-LEVEL FLOW SPREADS WILDFIRE SMOKE THROUGH THE
UPPER ATMOSPHERE. AIR QUALITY SHOULD BE LARGELY UNAFFECTED, ALTHOUGH
POOR AIR QUALITY IN WILDFIRE SMOKE IS LIKELY TO DEVELOP OVER PARTS OF
SOUTHWESTERN SASKATCHEWAN EITHER LATER TODAY OR MONDAY AS WILDFIRE
SMOKE FROM BRITISH COLUMBIA BEGINS TO SURFACE IN THE AREA.
NT....A FEW SHOWERS IN THE DELTA AND IN THE NORTHERN RIVER REGIONS,
ASSOCIATED WITH A LOW PRESSURE SYSTEM FROM THE BEAUFORT. A VERY
SLIGHT RISK OF A THUNDERSTORM OR TWO ALONG THE LEADING EDGE OF THE
SYSTEM, IN THE WRIGLEY REGION.
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 BECOME MORE
OF AN ISSUE THIS AFTERNOON AND OVERNIGHT AS THE WIND BECOMES MORE
NORTHERLY AND PUSHES SMOKE FROM THE NEARBY FIRES BACK INTO THE AREA.
NU...WAVES OF PRECIPITATION CONTINUE TO WRAP AROUND THE HUDSON BAY
LOW, THE LATEST OF WHICH HAS NOW PUSHED TOWARD SOUTHAMPTON ISLAND.
THIS RAIN IS EXPECTED TO WRAP BACK INTO THE KIVALLIQ TONIGHT.
THIS WILL BRING 5 TO 10 MM OF RAIN TO CORAL HARBOUR BY THIS EVENING,
FOLLOWED BY SIMILAR AMOUNTS IN THE KIVALLIQ OVERNIGHT TONIGHT AND
MONDAY.
GUSTY WINDS ACROSS THE KIVALLIQ WILL CONTINUE AROUND SOUTHAMPTON
ISLAND, HUDSON STRAIT AND INTO THE KINNGAIT REGION. THE WINDS HERE
WILL RE-STRENGTHEN WITH THE NEXT WAVE OF RAIN MOVING IN AND BRING
MORE GUSTY WINDS PERHAPS AS HIGH AS 80 KM/H UNTIL LATER TODAY.
IN ADDITION TO THE RAIN, RELATIVELY MILD AIR BEING PUMPED OVER THE
COOLER WATERS OF HUDSON BAY HAS RESULTED IN BROAD AREAS OF FOG ACROSS
THE REGION. FOG PATCHES WILL BE COMMONPLACE ACROSS HUDSON BAY AND THE
ADJACENT COASTAL COMMUNITIES INTO THE WEEKEND.
END/CARLSEN/STAMMERS/GREENHOUGH/VAN LOCHEM
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