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FOCN45 CWWG 271200
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 7:00 AM CDT FRIDAY JUNE
27 2025.
ALERTS IN EFFECT...AIR QUALITY WARNING FOR FORT LAIRD. SPECIAL AIR
QUALITY STATEMENTS FOR FORT SIMPSON AND FAR NORTHWEST ALBERTA.
SYNOPTIC OVERVIEW...00Z UPPER AIR AND WATER VAPOUR ANALYSIS REVEALS
POSITIVELY TILTED TROUGHING ACROSS WESTERN NORTH AMERICA WITH
MULTIPLE EMBEDDED SHORT WAVES; POTENT VORT CENTER THAT WILL IMPACT
TS DEVELOPMENT TODAY NOW LOCATED AT THE NOSE OF THE 250 MB JET IN
CENTRAL WASHINGTON TRACKING EAST.
AT THE SURFACE...BROAD TROUGHING ACROSS MUCH OF THE PRAIRIES. A FEW
WEAK LOWS, ALTHOUGH A PRETTY FLAT PATTERN. BROAD QS BAROCLINIC ZONE
EXTENDS WEST TO EAST FROM ALASKA TO CHURCHILL. SECOND BAROCLINIC
ZONE WEAVES ACROSS THE NORTHERN US PLAINS. WEAK 1001 MB SURFACE LOW
JUST SOUTH OF STONY RAPIDS WITH ASSOCIATED WEAK OCCLUDING FRONTAL
WAVE; WARM FRONT TO THE SOUTHEAST THROUGH MANITOBA AND COLD FRONT TO
THE SOUTHWEST THROUGH SOUTHERN SK. NORTH TO SOUTH SURFACE TROUGH IN
SOUTHEASTERN SK.
DISCUSSION...
AB... UNSTABLE THROUGH MUCH OF THE PROVINCE TODAY. THUNDERSTORMS
SHOULD BE FOCUSED OVER THE FAR NORTH AND EAST. IN THE EAST A
VORTICITY CENTRE OVER SOUTHERN B.C. WILL MOVE TOWARD
DRUMHELLER/CORONATION AREA THIS AFTERNOON. WITH IT SOME CAPE VALUES
NEAR 900 J/KG AND VORTICITY GIVE A SLIGHT RISK OF FUNNEL CLOUDS AND
POSSIBLY LOCAL HEAVY RAIN. STORMS WILL BE SLOW MOVING HERE AND
LIKELY TO PERSIST THROUGH THE NIGHT.
POTENTIAL FOR SMOKE FROM HIGH LEVEL AND FORT NELSON TO PUSH
EASTWARDS TO FORT CHIPEWYAN AND SOUTH OF GREAT SLAVE LAKE SATURDAY.
LIMITED CONFIDENCE HERE AS AQ VALUES ARE GENERALLY MODERATE AT THE
MOMENT WITH NO HIGH READINGS.
SK/MB... AS THE UPPER TROUGH CONTINUES ITS PROGRESSION EAST, WE
HAVE ANOTHER SEVERE THUNDERSTORM DAY ON TAP FOR THE SOUTHERN
PRAIRIES. A BROAD AREA OF INSTABILITY IS EXPECTED TO DEVELOP
ACROSS SE SK AND SW MB OF ABOUT 1200 TO 1700 J/KG ML CAPES WITH
GENERALLY 30-35 KT 0-6 KM SHEAR. NAM SOUNDINGS AND HODOGRAPHS LOOK
TO BE MORE FAVORABLE FOR SEVERE POTENTIAL THAN THE RDPS SOUNDINGS.
THUNDERSTORMS ARE EXPECTED TO BE SUPERCELL IN STRUCTURE AND ARE
EXPECTED TO DEVELOP ALONG THE SURFACE TROUGH AND COLD FRONT. THE
WEAK SURFACE LOW AND ASSOCIATED FRONTAL WAVE MAY OCCLUDE SOUTH IN TO
NORTH DAKOTA WHERE THERE IS BETTER UPPER SUPPORT AND ENERGY. THE
WESTERLY UPPER JET LIES JUST SOUTH OF THE US BORDER. UPPER SHORT
WAVES LIFT NORTHEAST INTO THE SOUTHERN PRAIRIES THIS AFTRERNOON
WHICH MAY BE A MORE LIKELY TRIGGER FOR THUNDERSTORMS DEVELOPMENT
NORTH OF THE US BORDER. REGARDLESS, SOUNDING ANALOGUES SHOW GOOD
MATCHES FOR SUPERCELLS WITH POTENTIALLY LARGE HAIL UP TO 6 CM WITH
THE RISK OF A TORNADO. A FLY IN THE OINTMENT MAY BE THE LINGERING
SHOWERS AND CLOUD FROM LAST NIGHT'S CONVECTION-THIS WILL ACT TO CAP
INITIATION FROM OCCURRING TOO EARLY IN THE DAY, BUT ALSO COULD KEEP
TEMPERATURE AND ENERGY LOWER THAN CURRENTLY FORECASTED.
THUNDERSTORMS ARE EXPECTED TO CONTINUE INTO THE OVERNIGHT HOURS IN
SOUTHERN MANITOBA WITH THE UPPER SHORT WAVE TRACKING INTO THE AREA.
ARCTIC...LOW TO THE EAST OF GRISE FIORD GIVES A CHANCE OF GUSTY
NORTHERLY WINDS TONIGHT. INVERSION IS A BIT HIGHER THAN PAST CASES
BUT A STRONG FLOW AND GOOD DIRECTION COULD BRING WINDS OVER 50 KMH.
END/DYCK/WIELKI
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