401
FOCN45 CWWG 291900
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 2:00 PM CDT THURSDAY MAY
29 2025.
ALERTS IN EFFECT...AIR QUALITY WARNINGS FOR PARTS OF SOUTHEASTERN AND
WEST CENTRAL MANITOBA AND NORTHERN SASKATCHEWAN. SPECIAL AIR QUALITY
STATEMENTS FOR MUCH OF MANITOBA AND PARTS OF CENTRAL SASKATCHEWAN,
ALBERTA AND THE NWT. HEAT WARNING FOR MUCH OF ALBERTA.
SYNOPTIC OVERVIEW...ALOFT, AN UPPER LOW IS OVER THE GULF OF ALASKA
WITH A TROUGH ALONG THE WEST COAST AND A BROAD UPPER RIDGE OVER THE
PRAIRIES. AN UPPER LOW LIES OVER LAKE SUPERIOR. OVER THE ARCTIC, A
SHORTWAVE TROUGH IS APPROACHING RESOLUTE WITH ANOTHER OVER WESTERN
HUDSON STRAIT.
AT THE SURFACE, A DEVELOPING LOW LIES OVER THE WESTERN NWT WITH
TROUGH SOUTHWARD THROUGH ALBERTA. A SPRAWLING AREA OF HIGH PRESSURE
LIES OVER THE NORTHERN US PLAINS AND ACROSS THE EASTERN PRAIRIES. A
996 MB LOW LIES OVER NORTHERN QUEBEC. HIGH PRESSURE LIES ACROSS
NORTHERN BAFFIN ISLAND THROUGH THE KIVALLIQ COAST.
DISCUSSION...
AB/NT...MOST OF AB AND SOUTHERN NT WILL HIT 30C TODAY BEFORE THE COLD
FRONT FROM THE NT LOW MOVES THROUGH. MLCAPE OF 500 TO 1400 J/KG WITH
EBWD OF 30-40 KT WILL PROVIDE INGREDIENTS FOR SEVERE THUNDERSTORMS,
ESPECIALLY VERY STRONG WIND GUSTS, THIS AFTERNOON AND EVENING FROM
GREAT BEAR LAKE TO THE US BORDER.
A NUMBER OF WILDFIRES WERE PRODUCING NOTABLE SMOKE SINCE YESTERDAY IN
NORTHERN AB AND NE BC. A FEW SAQS WERE ISSUED TO COVER REGIONS
REPORTING POOR AQ. THE COLD FRONTAL PASSAGE WILL LIKELY IMPROVE
CONDITIONS IN SOME REGIONS, BUT MOVE THE SMOKE AROUND TO OTHER
REGIONS. AQ ALERTS WILL BE UPDATED AS NECESSARY.
SK/MB...UPPER RIDGING CONTINUES TO DOMINATE BOTH SASKATCHEWAN AND
MANITOBA THIS WEEK, LEADING TO WARM, DRY CONDITIONS WHICH HAVE
FUELED FOREST FIRE ACTIVITY. WILDFIRES EJECTED MASS AMOUNTS OF SMOKE
INTO PARTS OF NORTHERN SASKATCHEWAN AND MANITOBA OVER THE PAST FEW
DAYS AND THESE CONDITIONS LOOK TO CONTINUE FOR THE REMAINDER OF THE
WEEK. THE COLD FRONT THAT MOVED THROUGH NORTHERN MANITOBA YESTERDAY
SHIFTED WINDS AND PUSHED SMOKE TO THE SOUTHEAST ACROSS CENTRAL
MANITOBA. OVER NORTHERN SK A SOUTHERLY FLOW WILL RETURN PUSHING
SMOKE BACK NORTHWARD. ALERTS FOR POOR AIR QUALITY WILL LIKELY NEED
TO BE EXPANDED, UNTIL FRIDAY WHEN THE COLD FRONT MOVES THROUGH.
PARTS OF WESTERN SASKATCHEWAN WILL FLIRT WITH HEAT WARNING CRITERIA
OVER THE COMING DAYS. THIS HEAT WILL MOVE EASTWARD THROUGH THE WEEK,
LYING OVER MANITOBA LATE WEEK INTO THE WEEKEND. WHILE DAYTIME HIGHS
WILL BE CLOSE TO HEAT WARNING CRITERIA, OVERNIGHT LOWS LOOK TO DIP A
FEW DEGREES BELOW CRITERIA SO WIDESPREAD HEAT WARNINGS ARE NOT
EXPECTED AT PRESENT TIME.
THE ALBERTA TROUGH MAY SEE SCATTERED SHOWERS WITH A FEW EMBEDDED
LIGHTNING STRIKES ENTER WESTERN AND CENTRAL SASKATCHEWAN OVERNIGHT
THURSDAY INTO FRIDAY MORNING. ANY THUNDERSTORMS WILL BE NON-SEVERE IN
NATURE WITH GUSTY WINDS THE PRIMARY THREAT. THE THUNDERSTORM THREAT
WILL SHIFT INTO NORTHEASTERN SASKATCHEWAN AND WEST CENTRAL MANITOBA
ON FRIDAY.
THE HEAT ACROSS THE SOUTH WILL LAST INTO EARLY NEXT WEEK.
NORTHWESTERLY WINDS BEHIND FRIDAY'S TROUGH MAY BRING WILDFIRE SMOKE
SOUTHEASTWARDS ACROSS THE SOUTHERN PRAIRIES FOR SATURDAY INTO SUNDAY.
NU...THE SHORTWAVE TROUGH HEADING TOWARDS RESOLUTE WILL BRING A RISK
OF FREEZING RAIN TONIGHT.
GUSTY WINDS IN THE WAKE OF THE LOW PRESSURE SYSTEM NOW OVER NORTHERN
QUEBEC WILL QUICKLY SUBSIDE ON THURSDAY. WINDS WILL INCREASE OUT OF
THE SOUTH ON FRIDAY AFTERNOON ACROSS THE KIVALLIQ AHEAD OF AN
APPROACHING TROUGH OF LOW PRESSURE.
END/STAMMERS/MOODIE/GREENHOUGH
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