FOCN45 CWWG 181900
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 2:00 PM CDT FRIDAY OCTOBER
18 2024.

ALERTS IN EFFECT...WIND WARNINGS FOR MUCH OF THE KIVALLIQ. WINTER
STORM WARNINGS FOR IGLOOLIK AND SANIRAJAK. BLIZZARD WARNINGS FOR
CAMBRIDGE BAY, GJOA HAVEN, TALOYOAK, AND KUGAARUK. SNOWFALL WARNING
FOR FT LIARD AND TUKTOYAKTUK.

SYNOPTIC OVERVIEW...ALOFT, AN UPPER LOW IS OVER THE HIGH ARCTIC WITH
A BROAD TROUGH SOUTHWARD ACROSS WESTERN CANADA, AND SEVERAL
SHORTWAVES EMBEDDED WITHIN. THE MOST NOTABLE SHORTWAVE IS OVER SOUTH
NUNAVUT. AN UPPER RIDGE EXTENDS NORTHWARD FROM THE CENTRAL US,
THROUGH HUDSON BAY, TO NORTHERN BAFFIN ISLAND.

AT THE SURFACE, AN ELONGATED TROUGH EXTENDS FROM THE WESTERN ARCTIC,
SOUTHEAST THROUGH NORTHERN MANITOBA, AND INTO NORTHERN ONTARIO, WITH
AN EMBEDDED 980 HPA LOW NEAR BAKER LAKE. A RIDGE OF HIGH PRESSURE
STRETCHES FROM THE YUKON SOUTHEASTWARD INTO THE WESTERN PRAIRIES.

DISCUSSION...

WESTERN PRAIRIES...FAIRLY QUIET ON THE WESTERN FRONT TODAY BEFORE THE
NEXT SYSTEM BEGINS TO THE MOVE INTO THE NORTHERN PORTIONS OF ALBERTA
TONIGHT. AHEAD OF THIS SYSTEM, A RIDGE-TROUGH COUPLET WILL DEVELOP
ALONG THE ALBERTA FOOTHILLS COINCIDING WITH STRONG H5 AND H7 JETS
(RANGING IN STRENGTH FROM 50-70 KTS). THESE FEATURES COMBINED WITH A
DECENT INVERSION ARE FORECAST TO GENERATE SOME STRONG WINDS WITH
GUSTS UP TO 90 TO 100 KM/H OVERNIGHT TONIGHT INTO SATURDAY. WHILE THE
SET-UP ISN'T PERFECT, WHAT WITH WIND SHEAR/CAPPING INVERSION NOT
BEING AS STRONG AS IN PAST CASES, WE STILL FEEL THERE IS A DECENT
CHANCE OF STRONG, POTENTIALLY HAZARDOUS GUSTS OCCURRING OVER THE
REGIONS. A WIND WARNING WILL BE ISSUED WITH THE AFTERNOON FORECAST
ISSUE.

THE LOW PRESSURE SYSTEM ITSELF WILL TRANSVERSE THROUGH THE NORTHERN
PRAIRIES TONIGHT AND INTO SATURDAY, BRINGING MIXED PRECIPITATION AND
SNOWFALL AMOUNTS TO PARTS OF NORTHERN AB. THERE IS ALSO A SLIGHT
CHANCE OF A WEAK THUNDERSTORM OR TWO OVER WEST-CENTRAL ALBERTA ON
SATURDAY AFTERNOON AS WELL AS SOME POSSIBLE HEAVIER CONVECTIVE SNOW
SHOWERS OVER THE ICEFIELDS PARKWAY ON SATURDAY. SNOW LEVELS OVER
HIGHWAY 93 ON SATURDAY WILL GRADUALLY RISE, BUT PRIOR TO DOING SO,
PARTS OF THE HIGHWAY WILL LIKELY SEE SNOW. WE'VE ADDED SNOWFALL
AMOUNTS TO THE FORECASTS TO ACCOUNT FOR THE ACCUMULATION POSSIBILITY.

EASTERN PRAIRIES...A FEW MORE SEASONAL DAYS ARE IN STORE BEFORE
TEMPERATURES REBOUND INTO THE UPPER TEENS OR HIGHER FOR THE WEEKEND.

THE LOW THAT HAS EXITED THE PRAIRIES, NOW NEAR BAKER LAKE, HAS SOME
RAIN LINGERING OVER NORTHERN MANITOBA THAT WILL MOVE OUT THIS
AFTERNOON. RAIN ACROSS SOUTHEASTERN MANITOBA, 5 TO 10 MM, ASSOCIATED
WITH THE COLD FRONT WILL ALSO MOVE OUT THIS AFTERNOON.

WESTERN ARCTIC...AS THE NEXT LOW PRESSURE SYSTEM BEGINS TO MOVE INTO
NORTHERN ALBERTA AND THE SOUTHERN NT, HEAVY SNOW WILL BEGIN TO MOVE
INTO THE FORT LIARD AREA TONIGHT. A NORTHEASTERLY UPSLOPE FLOW WILL
BEGIN TO ENHANCE SNOWFALL AMOUNTS. SNOW WILL CONTINUE THROUGH THE DAY
ON SATURDAY. A MORE FAVOURABLE DGZ AND CONTINUED UPSLOPE FLOW IS
LIKELY TO BRING THE HEAVIEST SNOW TO THE REGION OVERNIGHT FRIDAY AND
INTO SATURDAY MORNING WITH THE SNOW SLOWLY TAPERING OFF BY LATE DAY
SATURDAY. TOTAL SNOWFALL AMOUNTS WILL LIKELY VERY ACROSS THE REGION
WITH THE HEAVIEST SNOW ACCUMULATING WITH TOTALS UP TO 20 CM IN THE
UPSLOPE ENHANCED REGIONS.

THE EASTERLY, UNSTABLE FLOW OVER GREAT SLAVE LAKE MAY ALSO GENERATE
LOCALIZED SNOW SQUALLS WEST OF THE HAY RIVER COMMUNITY, GIVING
LOCALIZED AMOUNTS OF 10+CM/12 HRS TONIGHT INTO SATURDAY. A WATCH IS
BEING CONSIDERED WITH THE AFTERNOON FORECAST ISSUE.

FLURRIES WILL ALSO NOT BE SHORT LIVED ALONG THE BEAUFORT COAST, WHERE
SFC-850 DELTA-T'S WILL BE ON THE ORDER OF 10-15 DEG C. WIDESPREAD SEA
EFFECT SNOW SHOWERS COULD BRING UP TO 10 CM OF SNOW PER 12 HRS TO THE
TUKTOYAKTUK AREA, WHICH COMBINED WITH A STRONG NW FLOW, WILL MAKE FOR
A PRETTY RAW COUPLE OF DAYS AHEAD. HEAVIEST SNOW IS LIKELY TO OCCUR
TODAY HOWEVER LOCALIZED AMOUNTS OF 5-10 CM ARE POSSIBLE TONIGHT AND
SATURDAY IN THE SNOW BANDS.

EASTERN ARCTIC...WINDS WILL CONTINUE TO BE A CONCERN WITH THE LOW
PRESSURE SYSTEM DEEPENING OVER THE SOUTHERN KIVALLIQ. AS THE LOW
CONTINUES TO DEEPEN, STRONG TO SEVERE SOUTHEASTERLIES WILL BE
POSSIBLE AT NAUJAAT TODAY WHILE SEVERE WESTERLY/NORTHWESTERLY GUSTS
OF 70G90 KM/H OR HIGHER WILL DEVELOP ACROSS THE REST OF THE KIVALLIQ
LATE THIS EVENING INTO OVERNIGHT. ANY SNOW FALLING WILL OF COURSE
CAUSE REDUCED VISIBILITIES IN BLOWING SNOW. A WIND WARNING AS BEEN
ISSUED FOR MUCH OF THE KIVALLIQ AND PORTIONS OF THE SOUTHERN
QIKIKTAALUK. A WINTER STORM WARNING HAS BEEN ISSUED FOR THE MELVILLE
PENINSULA SITES FOR A COMBINATION OF STRONG WINDS AND HEAVY SNOW.
PRECIPITATION TYPING HAS BEEN A SIGNIFICANT CHALLENGE FOR THIS
SYSTEM. IF THE WARM AIR ADVECTION IS ABLE TO KEEP THE PRECIP AS RAIN
THEN WINTER STORM CONDITIONS WILL NOT BE MET. AS THE SYSTEM HEADS TO
BAFFIN ISLAND, PANGNIRTUNG COULD SEE HEAVY SNOW THROUGH THE WEEKEND.
AGAIN, IF CONDITIONS ARE TOO WARM THEN ACCUMULATIONS WILL BE LIMITED.

A BLIZZARD WARNING REMAINS IN EFFECT FOR FOR GJOA HAVEN, TALOYOAK AND
KUGAARUK IN CONNECTION WITH THE KIVALLIQ SYSTEM. SNOWFALL AMOUNTS
POSSIBLY EXCEEDING 10 CM AND WIND GUSTS OF 80+ KM/H WILL RESULT IN
SIGNIFICANTLY REDUCED VISIBILITY AND BLIZZARD CONDITIONS TODAY.
CONDITIONS ARE EXPECTED TO IMPROVE LATE THIS AFTERNOON FOR GJOA HAVEN
AND THIS EVENING FOR KUGAARUK AND TALOYOAK. IN ADDITION, A BLIZZARD
WARNING WAS ALSO ISSUED FOR CAMBRIDGE BAY FOR STRONG NORTHWESTERLY
WINDS AND FALLING SNOW BEGINNING TONIGHT AND PERSISTING INTO SATURDAY
AFTERNOON. SOME STRONG EASTERLY WINDS ARE ALSO ANTICIPATED WITH THIS
SYSTEM FOR RESOLUTE AND GRISE FIORD WHERE WINDS ARE LIKELY TO GUST UP
TO 70 KM/H TONIGHT AND INTO SATURDAY.

END/VALLEE/MARK/PIMISKERN