FOCN45 CWWG 181200
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 7:00 AM CDT MONDAY MAY
18 2026.

ALERTS IN EFFECT...FROST ADVISORIES FOR PORTIONS OF ALBERTA AND
WESTERN SASKATCHEWAN.

OVERVIEW...ALOFT THIS MORNING, A SHARP UPPER RIDGE SITS OVER BRITISH
COLUMBIA AND YUKON THAT DIGS INTO A SHARP TROUGH THAT EXTENDS FROM AN
UPPER LOW NEAR THE UNGAVA PENINSULA SOUTHWEST TO NORTHERN
SASKATCHEWAN THEN DROPS SOUTH INTO THE WESTERN UNITED STATES. THE
FLOW REBOUNDS IN A BROAD UPPER RIDGE OVER ONTARIO, QUEBEC, AND
SOUTHERN HUDSON BAY, THEN DIPS INTO ANOTHER UPPER TROUGH THAT EXTENDS
FROM AN UPPER LOW ALONG THE LABRADOR COAST SOUTHWEST OVER
NEWFOUNDLAND. IN THE FAR NORTH, AN UPPER LOW SITS OVER THE
NORTHERNMOST PORTION OF THE CANADIAN ARCTIC ARCHIPELAGO WITH A WEAK
UPPER RIDGE OVER ITS SOUTHERN AND CENTRAL PORTIONS.

AT THE SURFACE, A TROUGH OF LOW PRESSURE EXTENDS FROM NORTHERN YUKON
SOUTH ALONG THE LEE OF THE ROCKIES INTO CENTRAL ALBERTA; A WARM FRONT
SITS EAST OF THIS, CUTTING SOUTH THROUGH WESTERN NORTHWEST
TERRITORIES AND INTO EASTERN ALBERTA BEFORE DEFLECTING SOUTHWEST INTO
MONTANA. EAST OF THIS, A 1028 MB HIGH CENTRE SITS OVER NORTHERN
MANITOBA WITH RIDGING NORTH THROUGH THE KIVALLIQ AND EAST-SOUTHEAST
ACROSS SOUTHERN HUDSON BAY. A WEAK RIDGE ALSO EXTENDS SOUTHWEST
ACROSS SOUTHERN SASKATCHEWAN INTO MONTANA. SOUTH OF THIS, A 1004 MB
LOW SITS ALONG THE MINNESOTA/WISCONSIN BORDER WITH A WARM FRONT EAST
AND A COLD FRONT SOUTHWEST. LASTLY, A 1000 MB LOW SITS OFF THE COAST
OF NEWFOUNDLAND WITH A TROUGH NORTHWEST TO A DECAYING 1003 MB LOW OFF
THE NORTHERN COAST OF LABRADOR AND CONTINUING TO SOUTHERN BAFFIN
ISLAND.

DISCUSSION...

ALBERTA...A COOL MORNING ACROSS MUCH OF CENTRAL AND SOUTHERN ALBERTA
WITH TEMPERATURES BETWEEN -3 AND +4. FROST POTENTIAL AGAIN TONIGHT
THROUGH MOST AREAS SOUTH AND EAST OF EDMONTON.

THUNDERSTORMS POSSIBLE AGAIN TODAY ALONG THE FOOTHILLS AND IN
CENTRAL ALBERTA. BETTER POTENTIAL TOMORROW WITH AN UPPER LOW MOVING
INTO NORTHWESTERN ALBERTA DESTABALIZING MUCH OF THE NORTH AND
CENTRAL ALBERT AGAIN. CAPES TODAY ARE GENERALLY BELOW 300 J/KG.
TOMORROW SOME AREAS APPROACH 500J/KG.

MANITOBA/SASKATCHEWAN...PRECIPITATION WILL TAPER OFF ACROSS THE
SOUTHERN PRAIRIE TODAY, WITH SNOW GRADUALLY CHANGING TO RAIN OVER
PORTIONS OF SOUTHERN SASKATCHEWAN AND WESTERN MANITOBA AS MORNING
PROGRESSES. MUCH OF THE RAIN WILL TAPER OFF BY THE AFTERNOON WITH A
FEW PATCHES OF LIGHT RAIN OR DRIZZLE POSSIBLE INTO THE EVENING AS THE
LAST OF THE PRECIPITATION DRIFTS ACROSS MANITOBAA�A��A��S INTERLAKE
AND RED RIVER VALLEY. FURTHER WEST, A FEW SHOWERS WILL CONTINUE TO
LINGER ACROSS PORTIONS OF WESTERN SASKATCHEWAN TODAY.

THE NEXT SYSTEM TO IMPACT SOUTHERN MANITOBA WILL CLIP BY THE REGION
OVERNIGHT AS ANOTHER SURFACE LOW LIFTS NORTHEAST THROUGH MINNESOTA.
IT WILL SPREAD AN AREA OF RAIN ACROSS SOUTHEAST MANITOBA OVERNIGHT
WITH 2 TO 5 MM FOR THE SOUTHEAST CORNER OF THE PROVINCE.

AFTER THAT, TUESDAY WILL BE A QUIETER DAY, THEN AN IMPULSE PUSHING
INTO SOUTHERN SASKATCHEWAN WILL BRING RAIN SHOWERS WITH A RISK OF
THUNDERSTORMS TO THE REGION ON WEDNESDAY.

NWT/NU...THE SURFACE LOW OFF THE COAST OF LABRADOR WILL CONTINUE TO
SPREAD SNOW INTO PORTIONS OF SOUTHERN BAFFIN ISLAND OVER THE NEXT 24
TO 36 HOURS. THIS WILL BRING 5 TO 10 CM OF NEW SNOW TO IQALUIT AND
LESSER AMOUNTS TO KIMMIRUT.

OTHERWISE, NIL SIG WX FOR THE EASTERN ARCTIC.

LOW NORTH OF BANKS ISLAND WILL SLOWLY MOVE TO THE NORTHEAST BRINGING
SNOW AND WINDS UP TO 60 KM/H TO RESOLUTE. A VERY WIDE RANGE IN
SNOWFALL AMOUNTS BETWEEN MODELS. MOST MODELS INDICATE 10 CM OF SNOW
HOWEVER CANADIAN MODELS ARE SHOWING CLOSER TO 20 CM. WITH SNOW
DEVELOPING TONIGHT WE ARE HOPING TO GET A BETTER CONSENSUS.
TEMPERATURES WILL BE NEAR -3 WHEN SNOW AND WINDS COMBINE.

OTHERWISE A VERY SLIGHT CHANCE OF FZRA THROUGH THE WESTERN ARCTIC AT
THE COASTAL COMUNITIES.


END/VROLIJK/WIELKI