207  
FOCN45 CWWG 061900  
SIGNIFICANT WEATHER DISCUSSION ISSUED BY THE PRAIRIE AND ARCTIC STORM  
PREDICTION CENTRE OF ENVIRONMENT CANADA AT 2:00 PM CDT THURSDAY MAY  
6 2021.  
 
ALERTS IN EFFECT...NONE.  
 
SYNOPTIC OVERVIEW...ALOFT, AN UPPER LOW IS WEST OF HAIDA GWAII WITH A  
TROUGH SOUTHWARD. AN UPPER RIDGE RUNS ALONG THE BC/ALBERTA BORDER AND  
STRETCHES NORTHWARD THROUGH THE YUKON AND THE NWT. AN UPPER LOW IS  
NORTH OF ELLESMERE ISLAND WITH A TROUGH SOUTHWARD TO ANOTHER UPPER  
LOW OVER SOUTHERN HUDSON BAY WITH A SERIES OF SHORTWAVES PASSING  
THROUGH THE HIGH ARCTIC. A RIDGE IS OVER EASTERN CANADA AND EXTENDS  
NORTHWARD TO BAFFIN BAY.  
 
AT THE SURFACE, A LOW IS OFF THE COAST OF HAIDA GWAII WITH A LEE  
TROUGH DEVELOPING OVER WESTERN AB. HIGH PRESSURE EXTENDS FROM THE  
BEAUFORT SEA EAST THEN SOUTHWARD THROUGH THE CENTRAL PRAIRIES INTO  
THE U.S. GREAT PLAINS. A 1005 MB LOW IS OVER NORTHERN QUEBEC WITH A  
TROUGH NORTHWARD THROUGH FOXE BASIN AND ANOTHER TROUGH SOUTHWESTWARD  
INTO SOUTHEASTERN MB. A RIDGE OF HIGH PRESSURE IS OVER EASTERN BAFFIN  
ISLAND.  
 
DISCUSSION...  
 
ALBERTA...UPPER TROUGH OFF THE BC COAST WILL PIVOT INTO BC FRIDAY  
WITH A LOW DEVELOPING NEAR SUNDRE, AB LATE FRIDAY. ALONG THE TROUGH,  
NORTH FROM THE LOW, THERE WILL BE POTENTIAL FOR THUNDERSTORMS  
STARTING FRIDAY AFTERNOON. IN THE HIGHER ELEVATIONS ALONG HIGHWAY 93  
THERE IS POTENTIAL FOR POCKETS OF 10+ CM OF SNOW BY SATURDAY MORNING.  
SNOW WILL LIKELY SPREAD EAST ONTO THE FOOTHILLS THROUGH FRIDAY NIGHT.  
THERE IS STILL CONSIDERABLE MODEL DISAGREEMENT, HOWEVER, AREAS WEST  
OF EDMONTON MAY SEE AT LEAST 10-30 MM OF PRECIPITATION ON FRIDAY  
NIGHT.  
 
AHEAD OF THE LOW STRONG SOUTHEASTERLIES ARE FORECAST. GENERALLY GUSTS  
NEAR 60 KM/H ARE EXPECTED HOWEVER NORTH OF THE CYPRESS HILLS  
DOWNSLOPE WINDS ARE LIKELY TO GIVE GUSTS IN THE 70-80 KM/H RANGE  
FRIDAY MORNING.  
 
SASKATCHEWAN AND SRN MANITOBA...GENERALLY CLEAR CONDITIONS UNDER THE  
INFLUENCE OF THE SURFACE RIDGE. DEVELOPING LOW NEAR SUNDRE ON FRIDAY  
WILL MOVE INTO SOUTHERN SK ON SATURDAY BRINGING SIGNIFICANT MOISTURE  
TO A MUCH NEEDED AREA. PRECIPITATION WILL LIKELY FALL AS MOSTLY RAIN,  
HOWEVER, ONE MODEL RUN SUGGESTS POSSIBLE SNOWFALL WARNINGS IN SW SK  
SOUTH OF THE TRANS CANADA AND IT WILL BE SOMETHING WE NEED TO  
MONITOR.  
 
NRN MANITOBA...A SHORTWAVE ROTATING AROUND THE UPPER LOW OVER  
SOUTHERN HUDSON BAY IS SUPPORTING AN AREA OF SNOW THROUGH  
NORTHEASTERN MANITOBA. AMOUNTS WILL BE NEGLIGIBLE DUE TO MELTING AS  
TEMPERATURES WILL BE NEAR THE ZERO MARK, OR SLIGHTLY ABOVE.  
 
ARCTIC...BOUNDARY LAYER CLOUD CONTINUES TO DOMINATE THE WEATHER  
PICTURE ACROSS A LARGE PORTION OF THE ARCTIC. OCCASIONAL FLURRIES,  
FOG, DRIZZLE OR FREEZING DRIZZLE PERSIST ESPECIALLY OVER COASTAL  
AREAS WHERE WINDS BLOW ONSHORE. PERSISTENT FOG IN KINNGAIT IS  
EXPECTED TO LIFT THIS AFTERNOON.  
 
END/LUZNY/ROMBOUGH  
 
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