FOCN45 CWWG 181200
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 7:00 AM CDT FRIDAY OCTOBER
18 2024.

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

SYNOPTIC OVERVIEW...ALOFT, AN UPPER LOW IS OVER THE HIGH ARCTIC WITH
TROUGHING SOUTHWARD THROUGH WESTERN CANADA. SEVERAL SHORTWAVES ARE
EMBEDDED WITHING THE TROUGHS, WITH THE MOST NOTABLE OVER SOUTHEASTERN
NWT. AN UPPER RIDGE EXTENDS NORTHWARD FROM THE US MIDWEST, THROUGH
HUDSON BAY TO NORTHERN BAFFIN.

AT THE SURFACE, TROUGHING STRETCHES FROM THE SOUTHERN NWT/NU
BORDER THROUGH MANITOBA AND ONTARIO WITH AN EMBEDDED 988 MB LOW NEAR
ROBERTSON LAKE. A RIDGE OF HIGH PRESSURE STRETCHES FROM THE CENTRAL
ARCTIC SOUTHEASTWARD THROUGH FOXE BASIN, QUEBEC, AND INTO THE EASTERN
US.

DISCUSSION...

WESTERN PRAIRIES...FAIRLY QUIET ON THE WESTERN FRONT TODAY BEFORE
THE NEXT SYSTEM BEGINS TO THE MOVE INTO THE NORTHERN PORTIONS OF
ALBERTA OVERNIGHT 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 KM/H OVERNIGHT TONIGHT INTO
SATURDAY MORNING FOR THE EXTREME SOUTHWEST, AND GUSTS TO 80 KM/H,
ALONG THE FOOTHILLS TO THE NORTH. THERE IS A SLIGHT PROBABILITY THAT
WINDS COULD REACH WARNING CRITERIA FOR A FEW REGIONS ALONG THE
SOUTHERN FOOTHILLS BUT CONFIDENCE IS SOMEWHAT LOW FOR THIS SCENARIO.
WITH THE 700 MB FLOW BEING SLIGHTLY WEAKER IN THE 00Z MODEL RUN, AND
THE WIND SHEAR BEING WEAK WITHIN THE CAPPING INVERSION ABOVE 700 MB,
THERE WILL BE A LACK OF A STRONG CRITICAL LAYER TO FORCE THE WINDS
ALOFT TO THE SURFACE. WIND GUSTS  ARE LIKELY TO BE VERY NEAR WARNING
LEVELS, BUT NOT HIGH ENOUGH TO TRIGGER A WIND WARNING. THIS SCENARIO
WILL HAVE TO BE CLOSELY WATCHED HOWEVER, AS THERE IS STILL A
POSSIBILITY THAT A WARNING MAY NEED TO BE ISSUED.

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.

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 NORTH OF 60 HAS SOME RAIN
LINGERING OVER NORTHERN MANITOBA THAT WILL MOVE OUT THIS MORNING.
SCATTERED SHOWERS ARE POSSIBLE ACROSS SOUTHEASTERN MANITOBA AS THE
ASSOCIATED COLD FRONT BECOMES MORE ACTIVE.

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.

FLURRIES WILL 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. ADDITIONALLY, A WINTER STORM WATCH HAS BEEN ISSUED FOR
BAKER LAKE AND THE MELVILLE PENINSULA SITES. PRECIPITATION TYPING HAS
BEEN A SIGNIFICANT CHALLENGE FOR THIS SYSTEM, AND IT CONTINUES IN THE
FINAL STRETCH AS THE SYSTEM PLOWS AHEAD. UNCERTAINTY LAYS AHEAD OF
HOW THE PRECIPITATION WILL END UP FALLING, WHICH WILL DIRECTLY IMPACT
THE VISIBILITY AT THESE SITES.

A BLIZZARD WARNING HAS BEEN ISSUED FOR FOR GJOA HAVEN, TALOYOAK AND
KUGAARUK IN CONNECTION WITH THIS UPCOMING SYSTEM. SNOWFALL AMOUNTS
POSSIBLY EXCEEDING 10 CM AND WIND GUSTS OF 80+ KM/H WILL RESULT IN
SIGNIFICANTLY REDUCED VISIBILITY AND BLIZZARD CONDITIONS BEGINNING
THIS MORNING. 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/CARLSEN/GREENHOUGH