FOCN45 CWWG 091900
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 2:00 PM CDT THURSDAY JULY
9 2026.

ALERTS IN EFFECT...AIR QUALITY WARNINGS 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 ALBERTA SPECIAL WEATHER
STATEMENT FOR HEAT FOR SOUTHERN MANITOBA AND SOUTHERN SASKATCHEWAN.
HEAT WARNINGS TO COME.

OVERVIEW...ALOFT, WATER VAPOUR IMAGERY REVEALS A TRIO OF UPPER LOWS;
ONE OVER THE NORTHEAST PACIFIC OCEAN, ONE OVER NORTHERN ALBERTA AND A
THIRD OVER THE UNGAVA PENINSULA. AN UPPER RIDGE SITS BETWEEN THE
ALBERTA AND QUEBEC LOWS OVER MANITOBA, EXTENDING NORTH INTO SOUTHERN
NUNAVUT. A PAIR OF SHORTWAVE TROUGHS SIT EMBEDDED IN THE ZONAL FLOW
OVER THE CENTRAL PRAIRIES; ONE OVER WEST CENTRAL SASKATCHEWAN AND
ANOTHER OF WEST-CENTRAL MANITOBA.

AT THE SURFACE, A RIDGE OF HIGH PRESSURE EXTENDS THROUGH EASTERN
MANITOBA NORTHWARD THROUGH SOUTHERN NUNAVUT TOWARDS VICTORIA ISLAND.
AN OCCLUDED 995 MB LOW SITS OVER NORTHERN QUEBEC. A WEAK LOW SITS
OVER WESTERN MANITOBA WITH A WARM FRONT EXTENDING SOUTHEASTWARD
THROUGH SOUTHERN MANITOBA, AND A COLD FRONT EXTENDING WESTWARD
THROUGH SOUTHERN SASKATCHEWAN CONNECTING TO A DEVELOPING FRONTAL
WAVE, WITH A NEW LEE LOW FORMING IN SOUTHERN ALBERTA.

DISCUSSION...

WESTERN PRAIRIES...THUNDERSTORMS ARE EXPECTED TO DEVELOP AGAIN TODAY,
WITH SOME INITIATING ALONG THE ALONG THE CENTRAL FOOTILLS, WHILE
OTHERS ARE EXPECTED TO BE TRIGGERED BY SHORTWAVES TRUNDLING THROUGH
ALBERTA.

INITIAL THINKING IS THAT A LOW WILL DEVELOP AROUND CALGARY, BRINGING
MOIST EARLIES INTO THE FOOTHILLS AND A BULGING DRYLINE THROUGH THE
EXTREME SOUTH. 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. AN AIR
QUALITY WARNING REMAINS IN EFFECT. 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.

NUMEROUS WILDFIRES ALSO CONTINUE TO BURN AND GENERATE POOR AIR
QUALITY TO PARTS OF NORTHERN SASKATCHEWAN.

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

TODAYS 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 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 FORMING 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 TO END OFF 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 ON SUNDAY. DAYTIME HIGHS ON FRIDAY IN THE RED RIVER
VALLEY ARE EXPECTED TO BE IN THE 28-30 DEGREE RANGE, WITH HUMIDEX
VALUES IN THE LOW TO MID 30S. WITH TEMPERATURES EXPECTED TO REACH THE
32 DEGREE THRESHOLD TOMORROW IN SOUTHERN SASKATCHEWAN, THE SPECIAL
WEATHER STATEMENT CONTINUES FOR MANITOBA FOR ANOTHER DAY, BUT THE
SASKATCHEWAN STATEMENT WILL BE REPLACED BY HEAT WARNINGS WITH THE
AFTERNOON FORECAST ISSUE. IT APPEARS LIKELY THAT ORANGE LEVEL HEAT
WARNINGS WILL BE ISSUED FROM MOOSE JAW EAST TO THE RED RIVER VALLEY,
AND FROM YORKTON SOUTH TO THE INTERNATIONAL BORDER, WITH YELLOW LEVEL
WARNINGS RADIATING OUTWARD FROM THOSE REGIONS.

THE SEVERE WEATHER THREAT OVER THE EASTERN PRAIRIES SHIFTS TO
SOUTHERN SASKATCHEWAN AS THE MOISTURE AND HEAT AXIS EXTENDS SOUTH OF
A FRONTAL WAVE NEAR THE BATTLEFORDS. LARGE HAIL AND STRONG WINDS ARE
POSSIBLE ALONG A SWATH FROM SASKATOON SOUTHWARD THROUGH MOOSE JAW AND
REGINA, WITH A TORNADO ALSO POSSIBLE IN THIS AREA AS WELL.

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 WERE EXPECTED TO CONTINUE TODAY OVER THE CENTRAL.
MACKENZIE VALLEY (WHERE HEAT WARNINGS REMAIN IN EFFECT), HOWEVER
WILDFIRE SMOKE SO FAR HAS LIMITED TEMPERATURES TO LOW-TO-MID
20S. THIS WILL CONTINUE TO BE MONITORED.

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/COLANGELO/PATTEN/PIMISKERN