726
FOCN45 CWWG 291900
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 2:00 PM CDT MONDAY JUNE
29 2026.
ALERTS IN EFFECT...RAINFALL WARNING FOR MOST OF SOUTHERN ALBERTA.
HEAT WARNINGS FOR PARTS OF THE NORTHWEST TERRITORIES, NORTHERN
ALBERTA, AND NORTHERN SASKATCHEWAN. AIR QUALITY WARNING FOR
PORTIONS OF THE NWT AND PORTIONS OF NORTHERN ALBERTA/SASKATCHEWAN.
SEVERE THUNDERSTORM WATCHES LIKELY LATER THIS AFTERNOON FOR SOUTHERN
MB/SE SASKATCHEWAN, WITH TORNADO WATCHES POSSIBLE OVER THE RED RIVER
VALLEY/EASTERN MB. RAINFALL WARNINGS BEING CONTEMPLATED FOR
EAST-CENTRAL SK/WEST-CENTRAL MB.
OVERVIEW...ALOFT, AN UPPER LOW IS OVER ALASKA WITH TROUGHING
SOUTHWARD. AN UPPER RIDGE OF HIGH PRESSURE EXTENDS FROM THE EASTERN
PACIFIC THROUGH CENTRAL BC AND INTO NORTHERN ALBERTA AND THE CENTRAL
ARCTIC. A COMPLEX OF UPPER LOWS WITH VARIOUS EMBEDDED SHORTWAVES ARE
OVER SASKATCHEWAN STREAMING TOWARDS ALBERTA. A STRONG
SOUTHWESTERLY JET IS LOCATED OVER THE AMERICAN GREAT PLAINS AND
EXTENDS INTO SOUTHWESTERN MANITOBA. AN UPPER RIDGE OF HIGH PRESSURE
IS OVER ONTARIO AND QUEBEC. AN UPPER LOW IS OVER THE HIGH ARCTIC WITH
TROUGHING SOUTHWARD THROUGH DAVIS STRAIT. ANOTHER UPPER LOW IS OVER
THE SOUTHERN TIP OF GREENLAND.
AT THE SURFACE, RIDGING DOMINATES THE EASTERN PACIFIC. AN OCCLUDED
998 MB LOW IS OVER THE SK/MT BORDER. THE APEX OF THE FRONTAL WAVE IS
OVER EXTREME SOUTHWESTERN MANITOBA, THE WARM FRONT EXTENDS EASTWARD
THROUGH SOUTHERN MANITOBA AND THE COLD FRONT STRETCHES SOUTHWARD
THROUGH THE DAKOTS. A DEVELOPING LOW PRESSURE CENTER IS OVER NEBRASKA
WITH A WARM FRONT EXTENDING NORTHEASTWARD THROUGH SOUTHERN SOUTH
DAKOTA AND SOUTHERN MINNESOTA. LOW PRESSURE IS OVER WESTERN NWT.
HIGH PRESSURE IS OVER HUDSON BAY WITH A RIDGE THAT EXTENDS INTO
KIVALLIQ AND THE CENTRAL ARCTIC. LOW PRESSURE IS OVER BAFFIN ISLAND.
DISCUSSION...
AB/NRN SK...THE RAINFALL OVER SOUTHERN ALBERTA WILL TAPER OFF OVER
THE NEXT 24 HOURS. MOST OF THE RAIN IS FALLING AS INTERMITTENT
SHOWERS WITH MORE ORGANIZATION ALONG THE EASTERN SLOPES OF THE
ROCKIES. THE FOOTHILLS ARE EXPECTED TO SEE ANOTHER 10 TO 40 MM AND
THE PLAINS AROUND 5 TO 10 MM BY TOMORROW MORNING. AMOUNTS WILL BE
HIGHER IN THUNDERSTORMS.
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE EDGE OF A
RETROGRADING SHORT WAVE TROUGH AND ALONG A TROUGH RUNNING ALONG THE
FOOTHILLS, THROUGH THE MACKENZIE VALLEY TO VICTORIA ISLAND. THE
ENVIRONMENT WILL HAVE 500-1500 J/KG OF CAPE AND GENERALLY WEAK
DYNAMICS. THE PRIMARY THREAT WILL THEREFORE BE RAINFALL, HOWEVER,
GIVEN THE SOGGY ANTECEDENT CONDITIONS, THIS HAZARD COULD STILL BE
IMPACTFUL. THERE IS ALSO THE CHANCE OF FUNNEL CLOUDS OVER
SOUTHEASTERN ALBERTA.
HEAT WARNINGS REMAIN IN EFFECT OVER NORTHERN REGIONS. THIS HEAT
EVENT IS EXPECTED TO END AROUND MID-WEEK.
EASTERLY FLOW NORTH OF THE DEPARTING LOW WILL SWEEP WILDFIRE SMOKE
FROM THE NORTHERN SK/MB INTO MUCH OF ALBERTA TODAY. AIR QUALITY
FOR ALBERTA WILL BE AT IT'S WORSE THIS EVENING INTO TOMORROW
MORNING. AQHI VALUES MAY APPROACH 7 FOR CENTRAL AND SOUTHERN
ALBERTA. AIR QUALITY WARNINGS ARE IN EFFECT AS A RESULT IN NORTHERN
SASKATCHEWAN AND NORTHERN ALBERTA.
SK/MB...SIGNIFICANT SEVERE WEATHER POTENTIAL CONTINUES TODAY FOR
PARTS OF SOUTHERN MANITOBA.
FOR TODAY'S SEVERE THUNDERSTORM SETUP, THE AREA OF CONCERN
ENCOMPASSES MUCH OF SOUTHERN MANITOBA, WITH ALL MODES OF SEVERE
WEATHER POSSIBLE. THE UPPER LOW COMPLEX WITH SEVERAL EMBEDDED
VORTICIES WILL REMAIN ANCHORED OVER SOUTHERN SASKATCHEWAN WITH THE
STRONG SOUTHWESTERLY JET MOVING OVER THE RED RIVER VALLEY AND
SOUTHEASTERN MANITOBA BY THIS AFTERNOON, WITH BULK SHEAR VALUES OF
40 TO 50 KTS OVER MUCH OF SOUTHERN MANITOBA. WITH THIS BEING THE
FOURTH DAY OF PERSISTANT SOUTHERLY FLOW CONTINUING TO PUMP HEAT AND
MOISTURE NORTHWARD, HEAT AND HUMIDITY CONTINUE TO INCREASE WITH
DAYTIME HIGHS ONCE AGAIN FORECAST TO BE IN THE MID TWENTIES, AND
DEWPOINTS PROGGED TO BE IN THE HIGH TEENS TO NEAR 20 WITH MLCAPE
VALUES OF 1000 TO 2500 J/KG EXPECTED TO BE OVER THE AREA. ONCE
AGAIN, WITH THE EXPECTED CAPE VALUES TODAY, AND AMPLE SHEAR, STRONG
WIND AND LARGE HAIL ARE NOTABLE SEVERE WEATHER THREATS. AND, WITH THE
PERSISTENT TRANSPORT OF MOISTURE NORTHWARD, HIGH PWAT VALUES OF 40+
MM ARE LEADING TO HEAVY RAINFALL CONCERNS OVER ALREADY MOIST AREAS.
THE FOCUS FOR SEVERE CONVECTION, TODAY, WILL BE THE DEVELOPING LOW
OVER NEBRASKA AND SUPPORTING SHORTWAVE THAT IS EXPECTED TO TRACK
NORTHWARD THROUGH THE DAKOTAS THIS AFTERNOON AND INTO MANITOBA THIS
EVENING. SEVERE CONVECTION WILL INITIATE WITH THIS LOW THIS
AFTERNOON IN THE US AND THEN IS EXPECTED TO TRACK INTO SOUTHERN
MANITOBA LATE AFTERNOON/EVENING. THE WARM FRONT ASSOCIATED WITH THIS
LOW IS PROGGED TO BE ARCHING INTO SOUTHEASTERN MANITOBA THIS
AFTERNOON. ANY THUNDERSTORMS THAT LATCH ONTO THIS WARM FRONT WILL
HAVE THE CAPABILITY TO PRODUCE TORNADOES. RAPID UPSCALE GROWTH IS
ANTICIPATED THROUGH THE EVENING THROUGH SOUTHERN MANITOBA AS THE LOW
AND SHORTWAVE TRACK THROUGH THE AREA. THUNDERSTORMS ARE EXPECTED TO
PERSIST THROUGH THE NIGHT.
AS THE LOW WRAPS UP TONIGHT INTO TUESDAY, HEAVY RAIN BECOMES A
THREAT FOR WEST-CENTRAL MB/EAST-CENTRAL SK, WITH WIDESPREAD
ACCUMULATIONS OF 50-70 MM EXPECTED BY TUESDAY EVENING. THIS AREA HAS
ALREADY SUFFERED CONSIDERABLE RAINFALL THIS YEAR. RAINFALL WARNING
LIKELY HERE IF TRENDS PERSIST.
OVER SASKATCHEWAN, THUNDERSTORMS ARE ONCE AGAIN EXPECTED OVER MUCH
OF THE PROVINCE, BUT ARE NOT EXPECTED TO REACH SEVERE LIMITS. ONE
NOTE OF HEIGHTENED INTEREST IS OVER CENTRAL AND WEST-CENTRAL
SASKATCHEWAN WHERE THE ENVIRONMENT IS FAVOURABLE FOR FUNNEL CLOUD
DEVELOPMENT THIS AFTERNOON, AS THE UPPER LOW AND VARIOUS SHORTWAVES
REMAIN OVER THE REGION AND A SURFACE TROUGH IS LINGERING THROUGH
THE AREA, AS WELL.
IN NORTHERN MANITOBA, SCATTERED AIR-MASS THUNDERSTORMS ARE POSSIBLE
AGAIN THIS AFTERNOON AS A WEAK UPPER LOW/UPPER TROUGH CONTINUES TO
SIT OVER THE REGION.
IN NORTHERN MANITOBA, WILDFIRE SMOKE WILL CONTINUE TO PROPAGATE
THROUGH MUCH OF THE REGION, GRADUALLY SHIFTING TO BE A CONCERN FOR A
COUPLE AREAS ALONG THE SASKATCHEWAN BORDER AS AN EASTERLY FLOW
DEVELOPS -- MAINLY PARTS OF THE THOMPSON, LYNN LAKE, AND FLIN FLON
REGIONS.
NUNAVUT...ABOVE SEASONAL TEMPERATURES WILL CONTINUE WELL INTO NEXT
WEEK, BUT MOST SITES LOOK TO REMAIN BELOW HEAT WARNING
LEVEL THRESHOLDS.
MORE SHOWERS AND THUNDERSHOWERS WILL DEVELOP ALONG THE WEST SIDE OF
THE UPPER HIGH OVER THE KIVALLIQ MAINLAND AND EASTERN NWT FOR THE
NEXT FEW DAYS. THERE WILL BE ONLY 10 TO 15 KNOTS OF 0-6 KM BULK
SHEAR, SO EXPECTING PULSE THUNDERSHOWERS WITH SOME HEAVIER RAIN.
NWT...HEAT WARNINGS REMAIN IN EFFECT AROUND GREAT SLAVE LAKE. COOLER
TEMPERATURES ARE EXPECTED BY WEDNESDAY. POOR AIR QUALITY IS
EXPECTED AT MANY SITES SOUTH OF THE TREELINE OVER THE COMING DAYS.
SCATTERED THUNDERSTORMS ARE EXPECTED AGAIN TODAY FROM FORT LIARD TO
VICTORIA ISLAND. GIVEN THE AMPLE MLCAPE VALUES, 30 TO 50 KT OF
EFFECTIVE SHEAR, AND A PROVEN TRIGGER, STORMS ARE LIKELY TO
BECOME SEVERE. GUSTY WINDS AND HAIL ARE THE PRIMARY CONCERN.
END/FULTON/ALBERS
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