370
FOCN45 CWWG 141900
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 2:00 PM CDT TUESDAY JULY
14 2026.
ALERTS IN EFFECT...AIR QUALITY WARNINGS FOR PORTIONS OF THE NWT AND
PORTIONS OF NORTHERN SK AND MB. HEAT WARNINGS FOR PARTS OF NORTHERN
MB AND THE NWT. FOG ADVISORY FOR MELVILLE PENINSULA.
OVERVIEW...ALOFT, A LOW SPINS SOUTHWEST OF VANCOUVER ISLAND.
TWO UPPER HIGHS SIT OVER THE CENTRAL UNITED STATES WITH RIDGING OVER
AB AND INTO THE NWT. THERE IS MAINLY ZONAL FLOW OVER THE SOUTHEASTERN
PRAIRIES THAT CONTINUES INTO ONTARIO. THERE ARE TWO SHORTWAVES IN THE
FLOW OVER THE NORTHERN PRAIRIES; ONE OVER THE AB/SK BORDER AND THE
OTHER NEAR THE SK/MB BORDER. AN UPPER TROUGH EXISTS OVER THE ARCTIC
ISLANDS WITH AN UPPER LOW DEVELOPING SOUTH OF BOOTHIA PENINSULA.
ANOTHER LOW SPINS OVER NORTHERN QC.
AT THE SURFACE, A RIDGE FROM THE PACIFIC OCEAN STRETCHES EAST OVER BC
AND MEETS A HIGH PRESSURE OVER CENTRAL AB. THE RIDGE CONTINUES
THROUGH SOUTH-CENTRAL SK AND INTO SOUTHERN MB. A LOW SITS OVER
EASTERN MONTANA. FURTHER NORTH, THERE IS A TROUGH ALONG THE NORTHERN
ALASKAN COAST AND A HIGH PRESSURE CENTRE OVER VICTORIA ISLAND.
A STRONG LOW PRESSURE SYSTEM SPINS OVER NORTHERN QC CREATING CYCLONIC
FLOW OVER EASTERN CANADA. A NOTABLE LOW PRESSURE IS EMBEDDED IN THE
FLOW NEAR THE NORTHERN KIVALLIQ COAST.
DISCUSSION...
AB...SEVERE THUNDERSTORMS ARE POSSIBLE TODAY AND TOMORROW. EASTERLY
FLOW IS SETTING UP AND DEWPOINTS ARE RECOVERING. EXPECTING DEWS TO
REACH THE HIGH TEENS BY LATE THIS AFTERNOON. A H500 40 KT JET IN
CONJUNCTION WITH NEAR SURFACE FLOW OF 10 KTS SUGGESTING BWD VALUES
CLOSE TO 50 KTS. SUPERCELLS WILL BE THE DOMINANT MODE, PERHAPS
INTERACTING WITH OFBS NEAR THE YELLOWHEAD CORRIDOR DUE TO WEAK
CONVECTION EARLY THIS MORNING. MAIN THREATS WILL BE LARGE HAIL BUT AN
ISOLATED TORNADO CANNOT BE RULED OUT, PARTICULARLY FOR AREAS SW OF
EDMONTON WHERE PARAMETERS ARE LIKELY TO BE MAXIMIZED.
FOR DAY 2, NOT MUCH CHANGE ALOFT. THE MAIN TRIGGER WILL BE A SFC TROF
ORIENTED SW-NE TO THE WEST OF EDMONTON. A SECONDARY TRIGGER IS A
SHORTWAVE OVER SE AB. ALL HAZARDS WILL BE POSSIBLE. THE MAIN CONCERN
IS CONVECTION WHICH WILL TRACK ALONG THIS BOUNDARY AND FIRING OFF OF
THE MAIN JET. ANY STORMS THAT REMAIN DISCRETE WILL BE SUPERCELLULAR
AND LIKELY CARRY A TORNADO RISK IN ADDITION TO VERY LARGE HAIL.
SK/MB...WITH THE PASSAGE OF A COLD FRONT MONDAY FROM THE LOW OVER
NORTHERN QC, THE SOUTHERN PRAIRIES WILL EXPERIENCE SOME REPRIEVE FROM
THE INTENSE HEAT AND HUMIDITY THAT OCCURRED OVER THE PAST FEW DAYS.
HEAT WARNINGS HAVE ENDED FOR THE SOUTHERN PRAIRIES. HOWEVER, THE
UPPER HIGH REMAINS IN PLACE AND TEMPERATURES ARE EXPECTED TO REMAIN
IN THE UPPER 20S FOR THE REMAINDER OF THE WEEK. WITH THAT, HEAT
WARNINGS REMAIN IN EFFECT FOR SOME AREAS IN NORTHERN MB.
ALONG THE UPPER RIDGE OVER AB, THERE IS A JET THAT FLOWS OVER INTO
SOUTHERN SK WHICH WILL TRIGGER SHOWERS AND NON-SEVERE THUNDERSTORMS
TODAY WHICH WILL PUSH INTO SOUTHWEST MB THIS AFTERNOON.
ADDITIONALLY, A SOUTHWEST JET SETS UP THIS AFTERNOON FROM MONTANA
INTO SOUTHWEST SK. CONVECTION WILL INITIATE ALONG THE JET IN
SOUTHWEST SK LATE THIS AFTERNOON. SHOWERS AND THUNDERSTORMS WILL
CONTINUE THROUGH THE NIGHT AND SPREAD INTO SOUTHEAST SK AND
SOUTHWEST MB. THERE IS A CHANCE OF A SEVERE THUNDERSTORM OVERNIGHT
IN SOUTHEAST SK AND SOUTHWEST SK. THE MAIN SEVERE THREATS WITH THESE
THUNDERSTORMS WILL BE WIND AND RAINFALL.
WILDFIRES HAVE BECOME MORE ACTIVE WITH CLEARING SKIES IN NORTHERN MB
AND SK, SPECIFICALLY SOUTH OF REINDEER LAKE. AIR QUALITY WARNINGS
HAVE BEEN ISSUED DUE TO SMOKE IN AREAS DOWNWIND OF THE FIRES. WITH
PREDOMINATELY NORTHWEST FLOW AND NO SIGNIFICANT RAINFALL IN THE
FORECAST, THE WILDFIRES WILL CONTINUE TO REDUCE AIR QUALITY FOR
PARTS OF NORTHERN SK AND MB. PERHAPS BY THURSDAY, THE FLOW WILL
SHIFT TO SOUTHWEST AND SOME SHOWERS WILL MOVE INTO THE AREA WHICH
SHOULD HELP DAMPER THE WILDFIRES AND IMPROVE AIR QUALITY IN THESE
AREAS. HOWEVER, THE SMOKE PLUMES MAY JUST SWITCH DIRECTIONS AND
AFFECT THE AIR QUALITY IN AREAS TO THE NORTHEAST.
NT...SMOKE CONTINUES TO IMPACT AREAS AROUND GREAT SLAVE LAKE. ON
WEDNESDAY A SOUTHERLY FLOW IS FORECAST TO PUSH SMOKE MORE TO THE
NORTH. TEMPERATURES NEAR 30C ARE EXPECTED FOR PARTS OF THE SOUTH
THROUGH THE WEEK, HOWEVER, SMOKE MAY HINDER TODAY'S HIGHS SOMEWHAT.
SOUTHWEST OF GREAT BEAR LAKE HAS SOME POTENTIAL FOR SEVERE
THUNDERSTORMS TODAY WITH MLCAPE VALUES NEAR 1500 J/KG AND 25 KT
EBWD.
NU...THE LOW OVER THE KIVALLIQ COAST WILL DEVELOP A SLOW-MOVING BAND
OF RAIN THAT PIVOTS OVER THE MELVILLE PENINSULA AND NORTHERN BAFFIN
ISLAND TODAY TO WEDNESDAY MORNING. 10 TO 15 MM OF RAIN IS LIKELY
ALONG A LINE FROM NAUJAAT TO POND INLET. BOTH SANIRAJAK AND IGLOOLIK
MAY ESCAPE WITH THE RAIN POSSIBLY FALLING TO THEIR WEST.
A BANK OF STRATUS AND FOG OVER FOXE BASIN HAS MADE ITS WAY INTO
SANIRAJAK AND IGLOOLIK. A FOG ADVISORY HAS BEEN ISSUED FOR THESE
SITES. FOG MAY LIFT AT TIMES TODAY HOWEVER, IT IS EXPECTED TO
RETURN THIS EVENING. WITH PREDOMINATELY ONSHORE FLOW EXPECTED FOR
THESE SITES, FOG IS EXPECTED TO STICK AROUND UNTIL WEDNESDAY, WHEN
THE WIND SHIFTS.
END/SPC-WPG/VAN LOCHEM
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