FOCN45 CWWG 051900

SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM

PREDICTION CENTRE OF ENVIRONMENT CANADA AT 2:00 PM CDT WEDNESDAY

AUGUST 5 2026.



ALERTS IN EFFECT...RAINFALL WARNING FOR KIMMIRUT. AIR QUALITY WARNING

IN FORT SIMPSON.



OVERVIEW...THE UPPER ANALYSES REVEALED A BIG LOW COMPLEX OVER HUDSON

BAY WITH A RIDGE OVER THE WEST COAST AND ANOTHER RIDGE OVER QUEBEC

AND BAFFIN ISLAND. A VIGOROUS SHORT WAVE TROUGH IS RIDING

SOUTHEASTWARD THROUGH THE FLOW OVER SOUTHERN SASKATCHEWAN AND ANOTHER

IS EVIDENT OVER THE SOUTHERN NWT.



THE SURFACE ANALYSIS SHOWS A BIG LOW OVER HUDSON BAY, AND HIGHS OVER

THE EASTERN PACIFIC AND THE HIGH ARCTIC.



DISCUSSION...



WESTERN PRAIRIES...A SERIES OF SHORTWAVE TROUGHS WILL IMPACT NORTHERN

ALBERTA AND SASKATCHEWAN OVER THE NEXT 36 HOURS. THE FIRST IS OVER

NORTHERN SASKATCHEWAN NOW, AND WILL BRING SHOWERS AND SUB-SEVERE

THUNDERSTORMS TO THAT REGION TODAY AS IT CONTINUES TO PUSH EASTWARD.

THE SECOND TROUGH WILL MOVE INTO NORTHERN ALBERTA THIS AFTERNOON INTO

TONIGHT, BRINGING STEADY SHOWERS AND A RISK OF (AGAIN) SUB-SEVERE

THUNDERSTORMS AS IT MOVES THROUGH.



THIS SYSTEM COULD BRING SOME HEAVY RAINFALL TO PORTIONS OF NORTHEAST

ALBERTA AND NORTHWEST SASKATCHEWAN TONIGHT AND INTO THURSDAY.

CANADIAN GUIDANCE CONTINUES TO BE THE MOST BULLISH WITH AMOUNTS,

HINTING AT BULLSEYES NEAR 50 MM SOMEWHERE BETWEEN FORT MCMURRAY AND

BUFFALO NARROWS, WHILE FOREIGN GUIDANCE IS MUCH LESS AGGRESSIVE.

GIVEN THE SOMEWHAT CONVECTIVE NATURE OF THE SYSTEM AND THE

DISCREPENCY IN INTENSITY BETWEEN MODELS, CONFIDENCE ON WARNING LEVEL

RAINFALL IS QUITE LOW. FORECAST AMOUNTS ARE IN THE 20-30 MM RANGE.



SIMILARLY, STRONG WINDS WILL DEVELOP ALONG AND BEHIND THE COLD FRONT

AS IT MOVES THROUGH TONIHHT AND THURSDAY. AGAIN, CANADIAN GUIDANCE IS

MORE AGGRESSIVE THAN FOREIGN GUIDANCE, HINTING AT GUSTS ABOVE

70 KM/H, AND AGAIN, CONFIDENCE IN THIS IS RELATIVELY LOW.



EASTERN PRAIRIES...THE SASKATCHEWAN TROUGH SHOULD ZOOM EASTWARD TO BE

OVER SOUTHERN AND SOUTH-CENTRAL MANITOBA THIS AFTERNOON, HELPING

INITIATE THUNDERSTORMS. MODEST SHEAR, ON THE ORDER OF 30 KNOTS EBWD,

WILL BE IN PLACE, SO A COUPLE OF SEVERE REPORTS OF HAIL AND WIND MAY

OCCUR. ANOTHER TROUGH LOOKS TO MOVE THROUGH SOUTHERN MANITOBA ON

THURSDAY AFTERNOON, SO A REPEAT OF TODAY'S CONDITIONS MAY BE ON TAP.



HAZY CONDITIONS WILL CONTINUE ACROSS MUCH OF THE PRAIRIES AS THE

UPPER-LEVEL FLOW CONTINUES TO SPREAD WILDFIRE SMOKE THROUGH MUCH OF

THE UPPER ATMOSPHERE OVER THE NEXT COUPLE OF DAYS. AIR QUALITY SHOULD

BE MOSTLY UNAFFECTED, HOWEVER, AS THE SMOKE IS EXPECTED TO LARGELY

STAY ALOFT.



ON THURSDAY, ANOTHER, STRONGER UPPER IMPULSE WILL TRACK SOUTHWARD IN

THE NORTHWESTERLY FLOW, ENTERING MANITOBA BY THURDAY AFTERNOON.

SLIGHTLY HIGHER INSTABILITY COMBINED WITH MUCH HIGHER DYNAMICS WILL

GIVE A RISK OF SEVERE THUNDERSTORMS TO MUCH OF SOUTHERN AND CENTRAL

MANITOBA ON THURSDAY AFTERNOON. PRIMARY THREATS WILL BE 2-4 CM HAIL

AND 90-100 KM/H WIND GUSTS. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE

ALONG THE LOW TRACK OVER THE NORTHERN GRAIN BELT OF SASKATCHEWAN

BEFORE TRACKING INTO CENTRAL MANITOBA. LOCAL ACCUMULATIONS OF 20 TO

30 MM WILL BE POSSIBLE HERE. FINALLY, ASIDE FROM THE SEVERE

CONVECTIVE GUST POTENITAL, SYNOPTIC GUSTS MAY REACH 80 KM/H OVER

PORTIONS OF EAST CENTRAL SASKATCHEWAN ON THURSDAY AFTERNOON.



NT...SOME WEAK THUNDERSTORMS ARE POSSIBLE AGAIN THIS AFTERNOON AND

EVENING OVER SOUTHER PORTIONS OF THE TERRITORY.



AN AIR QUALITY WARNING REMAINS IN EFFECT FOR THE FORT SIMPSON REGION,

WHERE CONDITIONS HAVE PERIODICALLY BEEN QUITE POOR DUE TO FOREST

FIRES UPWIND OF THE COMMUNITY.



NU...MOISTURE WILL BE FUNNELED TOWARD KIMMIRUT AND IQALUIT OVER THE

NEXT DAY OR SO. GUIDANCE IS IN GOOD AGREEMENT THAT RAINFALL WILL BE

FAIRLY STEADY AND WILL ACCUMULATE ENOUGH TO WARRANT A BULLETIN AT

KIMMIRUT. A RAINFALL WARNING CONTINUES HERE, AS 30-50 MM OF STORM

TOTAL IS LIKELY BY THIS EVENING. AT IQALUIT, LESSER RAINFALL AMOUNTS

ARE EXPECTED TODAY AND TONIGHT, SO WE HAVE HELD OFF ON A BULLETIN,

BUT THE FORECAST REFLECTS AMOUNTS APPROACHING WARNING LEVELS.

OTHERWISE THE EASTERN ARCTIC WILL BE FAIRLY BENIGN THIS FORECAST

PERIOD.



END/STAMMERS/CARLSEN/GRIFFITH/PIMISKERN