FOCN45 CWWG 091200
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 7:00 AM CDT THURSDAY JULY
9 2026.

ALERTS IN EFFECT...AIR QUALITY WARNING FOR PORTIONS OF NORTHERN
MANITOBA, NORTHERN SASKATCHEWAN, THE NWT AND THE MOUNTAIN PARKS IN
ALBERTA. HEAT WARNING FOR PARTS OF THE NWT AND NU. SEVERE
THUNDERSTORM WATCHES OUT FOR PARTS OF SASKATCHEWAN. SPECIAL WEATHER
STATEMENT FOR HEAT FOR PORTIONS OF SOUTHERN MANITOBA AND
SASKATCHEWAN.

OVERVIEW...MORNING WATER VAPOUR IMAGERY REVEALS A PAIR OF LOWS; ONE
OVER NORTHERN BRITISH COLUMBIA AND A SECOND OVER NORTHERN QUEBEC.
A RIDGE SITS BETWEEN THE TWO LOWS OVER SASKATCHEWAN, EXTENDING NORTH
INTO THE NWT. A SHORTWAVE TROUGH IS TRANSLATING EASTWARD OVER NORTH
DAKOTA. SHORTWAVE TROUGHS ALSO SIT OVER NORTHERN AB AND SOUTHERN NWT.

AT THE SURFACE, A RIDGE OF HIGH PRESSURE EXTENDS THROUGH
SASKATCHEWAN, AND THE NWT TOWARDS VICTORIA ISLAND. AN OCCLUDED 995 MB
LOW SITS OVER NORTHERN QUEBEC. A 1007 MB LOW OVER SOUTHERN AB/SK WITH
AN A WARM FRONT EXTENDING EASTWARD THROUGH SOUTHERN SK, AND A COLD
FRONT EXTENDING SOUTHWARDS INTO MONTANA.

DISCUSSION...

WESTERN PRAIRIES...NUMEROUS WILDFIRES CONTINUE TO BURN BRINGING POOR
AIR QUALITY TO PARTS OF NORTHERN SASKATCHEWAN.

THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE CENTRAL FOOTILLS AND
ALONG A NORTH-SOUTH TROUGH OVER THE SPECIAL AREAS. A LOW WILL
DEVELOP AROUND CALGARY, BRINGING MOIST EARLIES INTO THE FOOTHILLS
AND A BULGING DRYLINE THROUGH THE TRANSCANADA CORIDOR. A HIGHLY
SHEARED ENVIRONMENT WILL EITHER SUPPORT SUPERCELL DEVELOPMENT OR
OVERPOWER THE CAPE, TEARING STORMS APART. IF STORMS CAN PERSIST,
LARGE HAIL IS LIKELY. LIKE YESTERDAY, STRAIGHT HODOGRAPHS WILL BRING
SPLITTING SUPERCELLS AND SHIFTING DEVIANT MOTION. IF STORMS CAN
DEVELOP NEAR THE DRYLINE, THE LOW LEVEL VORTICITY COULD YIELD A
TORNADO.

SMOKE FROM WILDFIRES IN BRITISH COLUMBIA HAS ADVECTED INTO THE
PROVINCE, LEADING TO POOR AIR QUALITY IN THE MOUNTAIN PARKS. AS A
RESULT, AN AIR QUALITY WARNING HAS BEEN ISSUED. DEPENDING ON THE
EXTENT TO WHICH THE SMOKE CONTINUES TO SPREAD EASTWARD AND MIX DOWN
TO THE SURFACE, THESE AIR QUALITY WARNINGS MAY NEED TO BE EXPANDED TO
ADDITIONAL AREAS.

EASTERN PRAIRIES...WILDFIRES CONTINUE OVER NORTHERN MANITOBA AND THUS
WILL THE AIR QUALITY WARNINGS.

THURSDAYS THUNDERSTORM RISK FOCUS SHIFTS EASTWARD TO NEAR THE SK/MB
BORDER, AND PERHAPS AS FAR EAST AS THE RED RIVER VALLEY. THE LOW/
TROUGH COMPLEX WILL MIGRATE TO THIS REGION, PROVIDING THE FOCUS ONCE
AGAIN FOR AFTERNOON AND EVENING THUNDERSTORMS. MOISTURE WILL POOL
NEAR THE TROUGH WITH LOW 20S DEWPOINTS EXPECTED, PRODUCING MLCAPE OF
1500-3000 J/KG. VEERING WIND PROFILES BUT NOT OVERLY LONG HODOGRAPHS
WILL LIKELY LEAD TO MULTICELL OR MARGINAL SUPERCELL STRUCTURES.
OWING TO THE AMOUNT OF MOISTURE AVAILABLE (PWAT APPROACHING 50 MM),
LARGE HAIL WILL BE THE MAIN THREAT WITH THE MORE ORGANIZED CORES, AND
SLOW STORM MOTIONS (310/15 KT) WILL PROMOTE HEAVY RAINFALL. A WIND
GUST AND EVEN A TORNADO OR TWO CANNOT BE RULED OUT, ESPECIALLY WITH
ANY STORMS THAT CAN INTERACT WITH BOUNDARIES LEFT OVER FROM OVERNIGHT
CONVECTION, AS WELL AS ANY STORMS THAT CAN MOVE INTO THE SLIGHTLY
MORE FAVOURABLE LOW-LEVEL ENVIRONMENT IN THE RRV. NOTE THAT THERE IS
UNCERTAINTY IN GUIDANCE WITH RESPECT TO THE LOCATION OF THE LOW AND
RESULTING THUNDERSTORMS, WITH LOCATIONS AS DISPARATE AS CARMAN MB AND
DICKINSON ND. THIS WILL ULTIMATELY DETERMINE THE OUTCOME OF TOMORROWS
CONVECTION. FARTHER WEST, IN SOUTHWESTERN SASKATCHEWAN, ANOTHER
SEVERE THUNDERSTORM THREAT WILL EXIST IN ADVANCE OF A LOW EXPECTED TO
FORM IN SOUTHERN ALBERTA. THIS AREA WILL HAVE MORE SHEAR (40-50 KT)
BUT LESS INSTABILITY (1000-2000 J/KG), AND AS SUCH A HAIL AND WIND
THREAT WILL DOMINATE, BUT STILL A TORNADO CANNOT BE RULED OUT.
THUNDERSTORMS IN BOTH THESE REGIONS ARE EXPECTED TO EXIT THE REGION
INTO THE STATES OVERNIGHT.

AS THE WARMER AIR AND MOISTURE PUSHES FURTHER NORTH IN THE LATTER
HALF OF THE WEEK, A LONG DURATION HEAT EVENT LASTING WELL INTO NEXT
WEEK IS EXPECTED FOR A LARGE SWATH OF THE SOUTHERN PRAIRIES,
ESPECIALLY CLOSER TO THE INTERNATIONAL BORDER. DAYTIME HIGHS ARE
EXPECTED TO REACH INTO THE LOW TO MID 30S, WITH DEWPOINTS REACHING
THE LOW 20S. HUMIDEX VALUES EXCEEDING 45 ARE POSSIBLE, WITH THE
HIGHEST VALUES EXPECTED TO BE THIS WEEKEND. THE SPECIAL WEATHER
STATEMENT CONTINUES THIS MORNING, BUT WILL BE REPLACED BY HEAT
WARNINGS WITH THE AFTERNOON FORECAST ISSUE. IT APPEARS LIKELY THAT
THE HEAT WARNINGS WILL BE ORANGE LEVEL.

WESTERN ARCTIC...SMOKE CONTINUES TO IMPACT COMMUNITIES OVER
NORTHERN NWT.

THE SHORTWAVE TROUGH OVER THE SOUTHERN NWT IS BRINGING ORGANIZED
SHOWERS TO THE UPPER MACKENZIE TODAY. THE HEAVIEST RAIN WILL FALL
OVER THE LIARD BASIN WHERE 25 TO 50 MM IS FORECAST BY SATURDAY
MORNING.

WARM TEMPERATURES WILL CONTINUE OVER THE CENTRAL MACKENZIE VALLEY
TODAY. HEAT WARNINGS ARE IN EFFECT FOR PARTS OF THE SAHTU, WHERE
TEMPERATURES IN THE HIGH 20S MAY WELL PERSIST INTO THE WEEKEND.
WILDFIRE SMOKE IN THESE AREAS MAY SUPPRESS DAYTIME HIGHS.

EASTERN ARCTIC...THE RIDGE OVER THE NWT WILL PUSH EAST INTO THE
KIVALLIQ TODAY, BRINGING BACK ABOVE SEASONAL TEMPERATURES.
TEMPERATURES ARE EXPECTED TO HOVER AROUND 20 DEGREES TODAY, BUT WILL
APPROACH MID 20'S BY THURSDAY PROMPTING ANOTHER ROUND OF HEAT ALERTS
FOR PORTIONS OF THE KIVALLIQ INCLUDING CORAL HARBOUR. ABOVE SEASONAL
TEMPERATURES ARE EXPECTED TO PERSIST INTO THE WEEKEND.

END/CARLSEN/PATTEN