FOCN45 CWWG 191200
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 7:00 AM CDT TUESDAY MAY
19 2026.

ALERTS IN EFFECT...NONE AT THIS TIME.

OVERVIEW...ALOFT THIS MORNING, A BROAD UPPER RIDGE SITS OVER THE
EASTERN PACIFIC, DIPPING SOUTH ALONG THE BRITISH COLUMBIA COAST INTO
AN UPPER TROUGH THAT EXTENDS FROM HUDSON BAY SOUTHWEST THROUGH
NORTHERN MANITOBA THEN SOUTH INTO THE WESTERN DAKOTAS. A VIGOROUS
SHORTWAVE IS LIFTING NORTHEAST ACROSS NW ONTARIO WHERE THE UPPER FLOW
REBOUNDS INTO A BROAD UPPER RIDGE WITH AXIS FROM SOUTHERN QUEBEC TO
SOUTHERN HUDSON BAY. NORTH OF THIS, AN UPPER LOW SITS NEAR THE
NORTHERN EXTENT OF LABRADOR WITH A TROUGH WEST-SOUTHWEST INTO HUDSON
BAY. THE REMAINING UPPER FEATURES IN THE ARCTIC ARE A LONG-WAVE
TROUGH THAT EXTENDS FROM NORTHERN ALASKA ACROSS YUKON INTO
NORTHEASTERN BRITISH COLUMBIA, A COMPACT UPPER RIDGE THAT EXTENDS
FROM NORTHERN ALBERTA THROUGH EASTERN NORTHWEST TERRITORIES. AN UPPER
TROUGH SITS OVER THE WESTERN CANADIAN ARCTIC ARCHIPELAGO.

AT THE SURFACE, A RIDGE OF HIGH PRESSURE EXTENDS FROM THE EASTERN
PACIFIC NORTH THROUGH ALASKA AND YUKON TO A BROAD HIGH OVER THE
ARCTIC OCEAN. EAST OF THIS, A 1005 MB LOW SITS NORTHWEST OF GREAT
SLAVE LAKE WITH A FRONT DRAPED NORTHWEST INTO NORTHERN YUKON AND A
WARM FRONT THAT ARCS SOUTH THROUGH SASKATCHEWAN INTO MONTANA. EAST OF
THIS, A 1027 MB HIGH SITS OVER SOUTHWEST HUDSON BAY WITH RIDGING
SOUTHWEST ACROSS MANITOBA AND THE NORTHERN PLAINS TO A 1032 MB HIGH
OVER COLORADO. THE HUDSON BAY HIGH ALSO HAS RIDGING EAST ACROSS
NORTHERN QUEBEC TO LABRADOR AND NORTH OVER SOUTHAMPTON ISLAND TO
NORTHERN BAFFIN ISLAND. SOUTH OF THIS, A 1004 MB LOW SITS OVER LAKE
SUPERIOR WITH A COLD FRONT SOUTHWEST AND A WARM FRONT EAST TO A 1011
MB LOW OVER SOUTHERN QUEBEC, THEN ONWARDS. IN THE NORTH, A 1002 MB
LOW SITS OVER THE NORTHERN CANADIAN ARCTIC ARCHIPELAGO WITH A TROUGH
SOUTH TO A WEAKER SECONDARY LOW OVER VICTORIA ISLAND. LASTLY, A 998
MB LOW SITS OVER THE BREVOORTS OFF THE COAST OF SOUTHERN BAFFIN
ISLAND.

DISCUSSION...

ALBERTA...TODAY WITH BE UNSETTLED WITH AN UPPER TROUGH MOVING INTO
THE REGION. THE BEST AREA FOR THUNDERSTORMS IS LIKELY TO THE WEST
OF EDMONTON WHERE STORMS WILL FORM NEAR THE 500 JET. THIS AREA LOOKS
TO BECOME ORGANIZED AND MOVE INTO EDMONTON EARLY IN THE EVENING
WITH POTENTIAL FOR GUSTS NEAR 70 TO 90 KM/H AND SMALL HAIL. MLCAPES
OF 500 TO 750 J/KG HERE.

THE SECOND AREA FOR STORMS IS FROM HAY RIVER TO WAINWRIGHT. LOWER
CAPES THAN THE PREVIOUS AREA BUT COULD SEE FUNNELS POTENTIALLY
SIMILAR TO THE LAST FEW DAYS. STORMS THAT FORM CLOSE TO THE NWT
BORDER WILL HAVE VERY SLOW MOTION.

LATE TODAY A LEE LOW DEVELOPS NEAR CALGARY AND MOVES TOWARDS
KINDERSLEY BY WEDNESDAY MORNING. CONVECTION WITH THIS FEATURE IS
LIKELY TO GO THROUGH THE NIGHT AND MOST MODELS ARE SHOWING OVER 25
MM WITH IT NEAR LLOYDMINSTER WEDNESDAY.

MANITOBA/SASKATCHEWAN...INSTABILITY WILL DEVELOP WITH DAYTIME HEATING
ACROSS PORTIONS OF CENTRAL AND SOUTHERN SASKATCHEWAN TODAY; SBCAPE
VALUES WILL CLIMB INTO THE 400 TO 500 J/KG RANGE WITH BULK SHEAR
VALUES IN THE 25 TO 35 KNOT RANGE. DRIER LOW-LEVELS WILL RESULT IN
INVERTED-V PROFILES AND DCAPE NEAR 500 J/KG; AS A RESULT WIND GUSTS
OF 70 TO 90 KM/H MAY BE POSSIBLE WITH ANY THUNDERSHOWERS THAT DEVELOP
TODAY. THERE WILL BE NO ORGANIZED SEVERE WEATHER RISK TODAY.

OTHERWISE, LINGERING RAIN SHOWERS AND DRIZZLE WILL TAPER OFF THIS
MORNING OVER SOUTHERN MANITOBA WITH A FEW AFTERNOON SHOWERS LIKELY
REDEVELOPING OVER THE SOUTHERN AND SOUTHEASTERN PORTIONS OF THE
PROVINCE THIS AFTERNOON, DRIFTING SOUTHEAST, THEN DIMINISHING IN THE
EVENING.

SCATTERED SHOWERS WILL BE POSSIBLE OVER PORTIONS OF NORTHERN
SASKATCHEWAN AND CENTRAL MANITOBA THIS AFTERNOON; NO SIGNIFICANT
RAINFALL ACCUMULATIONS ARE EXPECTED WITH THEM.

FROST ADVISORIES ARE LIKELY TONIGHT OVER PORTIONS OF SOUTHERN
MANITOBA AS TEMPERATURES DIP TO NEAR OR BELOW FREEZING UNDER THE
SURFACE RIDGE CROSSING THE REGION TONIGHT. THIS SHOULD BRING AN END
TO THE BELOW-NORMAL TEMPERATURES ACROSS THE REGION WITH A RETURN TO
NEAR-SEASONAL DAYTIME HIGHS EXPECTED FOR THE EASTERN PRAIRIES ON
WEDNESDAY.

ON WEDNESDAY, A MORE WIDESPREAD THUNDERSTORM RISK WILL MATERIALIZE
ACROSS SOUTHERN SASKATCHEWAN AS A DEVELOPING LOW PRESSURE SYSTEM
PUSHES INTO THE PROVINCE. SBCAPE VALUES WILL CLIMB INTO THE 500 TO
1,000 J/KG RANGE OVER PORTIONS OF SOUTHERN SASKATCHEWAN WITH BULK
SHEAR VALUES LIMITED AT 15 TO 25 KNOTS. ENHANCE SURFACE CONVERGENCE
WILL COMPENSATE SOMEWHAT FOR THE DIMINISHED SHEAR VALUES, AS WILL A
BROADER PATTERN OF FALLING HEIGHTS ACROSS THE REGION. SCATTERED
THUNDERSTORM ACTIVITY WILL DEVELOP WEDNESDAY AFTERNOON ACROSS MUCH OF
SOUTHERN SASKATCHEWAN; THE RISK OF SEVERE WEATHER REMAINS LOW BUT IT
MAY END UP ONE OF THE MORE ORGANIZED CONVECTIVE EVENTS OF THE SEASON
THUS FAR.

NWT/NU...SNOW WILL TAPER OFF OVER SOUTHERN BAFFIN ISLAND OVER THE
NEXT 12 TO 24 HOURS AS THE OFFSHORE LOW PRESSURE SYSTEM SHIFTS SOUTH
AND DISSIPATES TODAY. FURTHER ACCUMULATIONS IN ANY TOWNSITES WILL BE
MINIMAL WHILE HIGHER TERRAIN ALONG THE SOUTHEASTERN COAST COULD SEE
AS MUCH AS 5 TO 10 MORE CENTIMETRES.

OTHERWISE, NIL SIG WX FOR THE EASTERN ARCTIC.

LOW NORTHEAST OF BANKS ISLAND WILL SLOWLY MOVE TO THE NORTHEAST
BRINGING SNOW AND SUSTAINED WINDS UP TO 40 KM/H TO RESOLUTE TODAY.
CANADIAN MODELS HAVE STARTED TO COME INTO LINE WITH OTHER GUIDANCE.
TOTAL AMOUNTS LOOK TO BE CLOSE TO 10 CM OF SNOW. LOWER VISIBILITIES
IN BLOWING SNOW ARE LIKELY THIS MORNING (MOSTLY FOR SNOW
BLOWING SIDEWAYS VS SNOW BEING LOFTED).

OTHERWISE A CHANCE OF FZRA IN GJOA HAVEN AND TALOYOAK TONIGHT AROUND
6Z.

END/VROLIJK/WIELKI