614
FOCN45 CWWG 261900
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 2:00 PM CDT SUNDAY JULY
26 2026.
ALERTS IN EFFECT...AIR QUALITY WARNINGS FOR PARTS OF THE ALBERTA
FOOTHILLS AND PARKS, SOUTHWESTERN SASKATCHEWAN, AND SOUTHERN NT.
HEAT WARNINGS FOR PARTS OF THE SOUTHERN PRAIRIES.
OVERVIEW...ALOFT, AN UPPER LOW IS OVER THE ARCTIC OCEAN. A TROUGH
EXTENDS SOUTHWARD FROM THE LOW, THROUGH YUKON AND WESTERN NWT, TO
ANOTHER LOW THAT SITS IN THE BASE OF THE TROUGH, NEAR HAIDA GWAII.
SEVERAL POTENT VORTICITY CENTRES ARE EMBEDDED IN THE TROUGH. AN UPPER
RIDGE IS BUILDING OVER THE PRAIRIES AND EXTENDS INTO WESTERN NUNAVUT.
AN UPPER LOW IS OVER HUDSON BAY WITH A TROUGH THROUGH ONTARIO AND
QUEBEC.
AT THE SURFACE, 12Z ANALYSIS SHOWS A 1004 MB LOW EAST OF KINDERSLEY
WITH A WARM FRONT SOUTHEAST AND COLD FRONT SOUTH. A RIDGE OF HIGH
PRESSURE IS OVER NUNAVUT AND EXTENDS INTO NORTHERN MANITOBA.
LOW PRESSURE IS OVER EASTERN HUDSON STRAIT. ANOTHER LOW IS OVER
CENTRAL HUDSON BAY.
DISCUSSION...
AB/NORTHERN SK...ALTHOUGH TODAY IS EXPECTED TO BE A QUIETER DAY,
THERE REMAINS A THUNDERSTORM RISK ACROSS CENTRAL AND NOTHERN REGIONS
OF THE PROVINCE. UPPER TROUGHING TO THE WEST AND A MOIST AIRMASS
REMAINS IN PLACE, BUT OVERALL IT APPEARS THERE WILL BE LESS SHEAR AND
INSTABILITY TO WORK WITH THAN YESTERDAY. GENERALLY WE'RE EXPECTING
WEAKER TO BORDERLINE SEVERE SINGLE AND MULTICELLS. SHEAR MAY BE
HIGHER AS WE REACH THE FRINGE OF OUR UNSTABLE AIRMASS NEAR THE
LATITUDE OF RED DEER, SO PERHAPS THERE'S SOME RISK OF SEVERE STORMS
THERE. GUIDANCE VARIES A BIT IN THIS CORNER OF ALBERTA.
SMOKE CONTINUES TO BE A COMPLICATING FACTOR THOUGH OBVIOUSLY IT
DIDN'T HINDER STORMS YESTERDAY.
AIR QUALITY HAS GENERALLY BEEN MODERATE OVER MOST OF SOUTHERN
ALBERTA, AND WITH NO GUIDANCE SHOWING A SERIOUS INVASION OF SMOKE
WE'VE PARED BACK THE AIR QUALITY WARNING TO THE FOOTHILLS, WHERE RAP
SMOKE GUIDANCE INDICATES SOME RISK OF AN INVASION OF SMOKE AGAIN
TODAY, ALONG WITH IN CENTRAL ALBERTA.
HEAT WARNINGS HAVE BEEN PARED BACK FROM CROWSNEST AND COULD BE PARED
BACK SOME MORE TONIGHT IF LOW TEMPERATURES ARE STILL EXPECTED TO BE
AS LOW AS FORECAST. HOWEVER, TEMPERATURES IN THE 30 TO 36 DEGREE
RANGE ARE INDICATED FOR THE SOUTHEAST CORNER OF THE PROVINCE TO THE
END OF THE EXTENDED FORECAST - SATURDAY.
SOUTHERN SK/MB...AIR QUALITY CONTINUES TO BE A FORECAST CHALLENGE
WITH ACTIVE WILDFIRES IN PARTS OF NORTHERN SK AND MB. AIR QUALITY
WARNINGS HAVE ENDED FOR PARTS OF NORTHERN MB WITH AN EASTERLY FLOW
SETTLING IN BUT WILL BE WATCHED CLOSELY FOR FURTHER DEVELOPMENT.
FURHTER SOUTH, SMOKE MOVED INTO SOUTHWESTERN SASKATCHEWAN FROM OREGON
(USA!) AND AIR QUALITY WARNINGS REMAIN OUT FOR THESE AREAS.
A PERIOD OF SEASONABLY HOT AND HUMID WEATHER CONTINUES FOR SOUTHERN
SASKATCHEWAN AND MANITOBA. HEAT WARNINGS ARE PROVING TO BE TRICKY AS
TEMPERATURES AND HUMIDEX VALUES WILL BE JUST SHY OF HEAT WARNING
CRITERIA FOR MOST REGIONS, BUT THE NEAR HEAT WARNING CRITERIA IS
EXPECTED TO HANG ON UNTIL AT LEAST NEXT WEEKEND. SO, A PROLONGED, BUT
RELATIVELY MARGINAL HEAT EVENT. HEAT WARNINGS ARE OUT FOR PARTS OF
SOUTHERN SASKATCHEWAN AND SOUTHERN MANITOBA WHERE TEMPERATURE AND/OR
HUMIDEX VALUES ARE EXPECTED TO MEET CRITERIA. EXPECT REGIONS TO BE
ADDED AND SUBTRACTED THROUGH THE COMING WEEK.
THERE IS THE POTENTIAL FOR SEVERE THUNDERSTORMS TODAY OVER
EAST-CENTRAL SASKATCHEWAN AND MUCH OF SOUTHERN MANITOBA, PARTICULARLY
OVER WESTERN MANITOBA. THE LOW NEAR KINDERSLEY WILL CONTINUE TO TREK
EASTWARD TODAY AND WILL BECOME THE FOCUS FOR THUNDERSTORM DEVELOPMENT
LATE THIS AFTERNOON AND EVENING. THE SURFACE LOW IS PROGGED TO BE
OVER EAST-CENTRAL SK BY 21Z WITH A WARM FRONT DRAPING SOUTHEASTWARD
AND A COLD FRONT WESTWARD. THUNDERSTORMS THAT ARE INITIATED BY THIS
FEATURE WILL HAVE 2000+ J/KG OF MLCAPE AND 50 KTS OF BULK SHEAR TO
WORK WITH. IN THIS HIGH CAPE AND SHEAR ENVIRONMENT, LARGE HAIL AND
DAMAGING WINDS ARE A CONCERN. AS WELL, ABUNDANT BOUNDARY LAYER
MOISTURE IS PRESENT IN THE THREAT AREA, WITH DEWPOINTS OF 20 DEGREES
IN THE REGION OVER THE PAST FEW DAYS, AND EXPECTED AGAIN TODAY.
GIVEN THIS, THUNDERSTORMS WILL LIKELY HAVE LOW LCLS AND WITH CURVING
HODOGRAPHS VICINITY OF THE WARM FRONT, THERE IS A CONCERN FOR
TORNADOES. WITH THE ABUNDANT MOISTURE, PWAT VALUES OF 30 TO 40 MM ARE
PROGGED TO BE OVER THE REGION LEADING TO HEAVY RAINFALL CONCERNS.
THERE ARE A FEW CAVEATS TO THUNDERSTORM DEVELOPMENT TODAY...THE
FOREST FIRE SMOKE THAT HAS BEEN OVER THE REGION THE PAST FEW DAYS MAY
ACT TO INHIBIT THUNDERSTORM DEVELOPMENT. THE UPPER RIDGE OVER THE
AREA MAY SUPPRESS THUNDERSTORM DEVELOPMENT, BUT THE AFOREMENTIONED
SURFACE LOW, COUPLED WITH UPPER JET SUPPORT ALONG WITH THE ASSOCIATED
FRONTAL BOUNDARY MAY PROVIDE SUFFICIENT LIFT TO CONTERACT THIS.
A WARM DOME OF AIR IS OVER THE REGION, PARTICULARLY IN THE SOUTH,
WHICH MAY KEEP THINGS CAPPED FOR THE DAY. THUNDERSTORM DEVELOPMENT
MAY BE DELAYED UNTIL THE OVERNIGHT PERIOD WHEN THE AMPLE FORCING AND
DEVELOPING LOW LEVEL JET CAN OVERCOME THESE CAVEATS.
NT...OUR STORM IS SUBSIDING IN THE NORTHWEST TERRITORIES, WITH A
TOTAL OF AROUND 75 MM HAVING FALLEN IN PAULATUK AND A SMALL COATING
OF WET SNOW IN COLVILLE LAKE VISIBLE ON CAMERAS LAST EVENING. IT DOES
HAVE ONE LAST TWIST FOR US THOUGH. AN AFL IS APPARENT ON GUIDANCE AT
SACHS HARBOUR WITH TEMPERATURES THERE EXPECTED TO BE NEAR OR BELOW
ZERO. A RISK OF FREEZING RAIN IS IN THE FORECAST FOR TONIGHT.
SMOKE CONTINUES TO AFFLICT SOME COMMUNITIES IN THE NT, INEVITABLY
WITH SO MANY FIRES, SOME CLOSE TO SOME COMMUNITIES, BUT WITH COOLER
WEATHER AND LIGHT WINDS, SMOKE GUIDANCE IS SHOWING LOW ACTIVITY AND
THERE'S FEW OBS OF ELEVATED AIR QUALITY. WARNINGS AND SMOKE HAVE BEEN
PARED BACK TO THE IMMEDIATE VICINITY OF FIRES.
NU...THE RAIN OVER SOUTHERN BAFFIN ISLAND AND PARTS OF KIVILLIQ WILL
TAPER OFF TODAY, AS THE LOWS DUMBELLING AROUND HUDSON BAY WEAKEN.
TOTAL RAINFALL AMOUNTS FOR THE EVENT WERE IN THE 10 TO 20 MM RANGE.
END/FULTON/PIMISKERN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page