Prairie Weather (Rural Roots Canada) – Heavy Rain for Alberta, moderate rain elsewhere, and that’s just Monday…

Showers and storms in Alberta Sunday marked the start of a wet weather period across the three prairie provinces.  The farther west you are, the wetter it will be.   An upslope rain event will soak the southern Alberta foothills on Monday.   The map below shows rain expected by the end of the day Monday:

 

 

Areas from Nordegg south to Pincher Creek could see 50-80 mm of rain, with the heaviest totals likely near Kananaskis.   The rain extends all the way east to Regina,  with Manitoba receiving much lesser amounts of precipitation in showers and possible thundershowers.

It’s almost an embarrassment of riches for Alberta.   As we mentioned in a post last week, the Canadian Drought Monitor shows drought conditions have eased in parts of Alberta, while they’ve worsened across the rest of the prairies.   Much of the rain that falls Monday and for the rest of the week will land in areas that need it least.

While most of this week’s rain will fall Monday, there will be more precipitation in the form of showers and thundershowers in the days ahead.  The two maps below show how much rain COULD accumulate up to the end of the afternoon, Sunday July 20.

 

 

 

There is considerable uncertainty over the numbers shown in the above maps.   For example, the maps show Calgary could get 102 mm of rain this week.   While that’s possible, it is more likely the amount will be revised downward as the week goes on.    The maps are more useful if they are interpreted as showing where heavier vs. lighter amounts of  rain will fall, without focusing on the actual numbers.

What is clear is that significant rain will fall this week in Alberta and Saskatchewan south of the Yellowhead Highway.   And, the vast majority of that falls Monday.  Manitoba, which has suffered through below average precipitation across the province all summer, can expect only a few mm of rain this week.   Rain is badly needed, with a considerable number of crops in poor condition. The Manitoba Crop Report says dairy producers in the Interlake say there won’t be a second cut harvest this year unless substantial rainfall occurs.   And that’s not expected to happen this week.

 

Monday

Alberta

An upper level low from the Gulf of Alaska will dip into southern BC, then move across the central prairies, bringing in much cooler air to go along with the wet weather described above.   Watch for rainfall warnings as an upslope rain event produces heavy rainfall in the Alberta foothills, and considerable precipitation east to Saskatchewan.

This will not be the only wet day this week, but it will be the wettest.   While central Alberta doesn’t necessarily need the coming rain, it is needed in southern Alberta, and soils and developing crops in that area should benefit from this rain.   A careful look at the maps above, though, shows the area from Milk River to Manyberries, along the US border,  may miss out on the heavier rain.

With the rain, it will be a chilly day.  South of Calgary, highs will only reach 10-15 degrees, and it will be even cooler in the foothills, with highs from 0 to 10, depending on elevation and rain intensity.

Saskatchewan

Considerable rain is forecast for southern Saskatchewan, west of Regina, west along the Trans Canada Highway corridor.    East of Regina, it should be mainly dry, with a few showers, all the way into Manitoba.   Some of the moisture will fall in the parched regions of southwestern Saskatchewan.  As noted in earlier posts, that area is in extreme drought, and it’s likely too late for Monday’s rain to do much good.  Across Saskatchewan, highs will only reach the mid teens, and west of Regina, in the rain, it will be about five degrees cooler.

Manitoba

Expect scattered showers in southern Manitoba and the interlake through much of the day Monday.  Rainfall amounts will be light, and it will be warm.  Temperatures will reach    the mid to high twenties.  In Central Manitoba, at the north end of the lakes, the rain may be somewhat more intense during the afternoon, and highs will be somewhat suppressed, only reaching 10-15 degrees.

 

Tuesday

Alberta

Surface high pressure will build down from the north on Tuesday, pushing the rain into the United States.  Early in the morning, the rain will be over for most areas, except the foothills, with upslope conditions providing heavy early morning rain to the Waterton area.   As the day goes on, the rain will move south, and, eventually, the sky will clear.   However, the high pressure system is of northern origin.   In the winter, we’d call it an Arctic high, and it would bring us very cold weather.    In the summer, the high will modify the air mass, and it will be cool, with highs of only 5-10 degrees in southwestern Alberta.

Southern and south central Alberta can expect highs of 10-15, and to the north, temperatures will be more seasonable, in the low to mid 20s.

Saskatchewan

High pressure building from the north rids the region of rain, but it is a chilly air mass.  The high will clear the sky, and there will be sunshine, except perhaps for southwestern Saskatchewan.   Despite the sun, temperatures in this colder air mass will peak somewhere near 15-20 degrees.   No significant weather is expected.

Manitoba

No significant weather threats exist for Manitoba on Tuesday, as the large high pressure system continues to clear out the prairies.  As mentioned above, this is the summer equivalent of an Arctic winter high, so it will introduce cooler weather to the province.   It will be colder than average across Manitoba Tuesday, with highs between 15 and 20 degrees.

 

Wednesday

Alberta

There is a chance for afternoon rain over the Cypress Hills, and early evening rain near Jasper.   In the evening, some upslope rain will develop in the central foothills from Sundre to Grande Prairie.  There will likely be thunderstorms in that area,  and some may become severe.   On the flatter terrain, most agricultural areas of Alberta will have another dry day Wednesday.  Highs across the province will range from the high teens to the low 20s.

Saskatchewan

Other than a few morning showers in the parched Cypress Hills, Saskatchewan should be rain free Wednesday, as it remains under the influence of the cool area of high pressure.   Most of Saskatchewan will experience  plenty of sunshine, with highs rebounding to the low 20.   South of the Trans Canada Highway, it will be  a bit cooler, with highs between 15 and 20 degrees.

Manitoba

Due to the continued domination of the chilly area of high pressure, Manitoba will have another uneventful day.    It will be mainly sunny, with highs reaching the low 20s across the province.

 

Thursday

Alberta

Thursday brought a return of active weather to Alberta, with rain, thunderstorms, and a slight chance of severe weather.    The animated map below shows a system developing near Jasper early in the morning, then quickly intensifying as it moves south through Alberta Thursday and Friday.   By the end of the loop, it’s Sunday, and the system is in eastern Manitoba, with another one forming near Jasper, to follow the same path next week.

 

This system could produce up to 30 mm of rain in parts of southern Alberta on Thursday.   However the rainfall won’t be distributed evenly, and some areas may get more than others.  Thunderstorms are likely to form in the southern part of the province.  These storms are packing enough energy to produce large hail. Around southeastern Alberta, there’s also a chance for funnel clouds to form.  With the rain, highs in southern agricultural regions will only reach 10 to 15 degrees.   In the Peace region and across northern Alberta, where it will be drier, it will also be warmer, with highs reaching the mid to high 20s.

Saskatchewan

The “arctic” high pressure system that dominated Saskatchewan’s weather Tuesday and Wednesday, lingers on Thursday,  but disturbances will go through the ridge, providing  some rain to the Cypress Hills in the afternoon, then moving east along the US border through the evening.   Pop-up showers can be expected in central Saskatchewan throughout the day, but there won’t be any organized, significant rainfall.  It will remain quite cool, though, with highs of 15 to 20 in southern Saskatchewan.  To the north, it will be warmer, with highs in the low to mid 20s.

Manitoba

As the high pressure system moves south, it leaves behind cooler than average weather for Manitoba.  No precipitation is expected anywhere in the province on Thursday, but there will be increasing cloud as the day goes on.  Highs should reach the high teens to low 20s in agricultural areas.

 

Friday

Things settle down a bit across the Prairies, but a large weather system from the Gulf of Alaska will start creeping closer to British Columbia. It won’t directly impact the Prairies yet, but it’s setting the stage for more active weather over the weekend.

Alberta

The rain that began in southern Alberta Thursday will be gone by Friday morning.   Expect midday sun as high pressure rebuilds over Saskatchewan, clearing the sky across most of the prairies.  The dry weather will be short lived, as a surface low develops north of Jasper, and rain begins in the afternoon along the Rockies and the foothills.   By evening,  the rain will spread eastward across central and southern Alberta, intensifying through the night.   Ahead of the wet weather,  highs across the province will climb to the mid to high 20s, with some areas in the far north potentially reaching 30.

Saskatchewan

With high pressure continuing to linger over Saskatchewan, it will be a quiet weather day, with a mainly sunny sky across the entire province.   With some instability, there is a chance of pop up showers and storms in east central Saskatchewan, close to the Manitoba boundary.    Friday’s highs should reach the low to mid 20s.

Manitoba

Highs in western Manitoba should reach the low 20s.   As high pressure in Saskatchewan continues to dominate the weather across the prairies, only a few showers or thundershowers are possible in the interlake, with conditions remaining dry elsewhere.   No organized precipitation, and no significant rainfall accumulations are anticipated.

 

Saturday

Alberta

It will be a wet morning in much of central and southeastern Alberta.   A low centered over Edmonton will spread rain northwest to Grande Centre,  with significant accumulations possible.  Thunderstorms are likely, and some could turn severe.    That same low will also produce rain to the southeast from Edmonton to Medicine Hat, with heavy rain possible between Edmonton and Stettler.  By noon, the Low moves into the Medicine Hat area, and the rainfall continues, though pushing eastward toward Saskatchewan.   Later in the afternoon, scattered showers and storms will likely form across most of southern Alberta.    With all this wet weather, it will be cool across central Alberta, highs of only 10 to 15 degrees.   Before the rain expands late in the day to southern Alberta, highs in the area should reach the mid 20s.

Saskatchewan

Rain will push into the province from west to east, originating with a Low in Alberta that will travel from Edmonton to Medicine Hat through the day.  By noon, the rain will be close to Moose Jaw,  reaching Regina in the afternoon.   Thunderstorms are possible.   The map below shows rainfall totals between 6:00 pm Friday and 6:00 pm Saturday:

 

The map is valid at 6:00 pm Saturday.   After that time, rain will continue to progress eastward to Moosomin by midnight.  Where it rains, high temperatures will reach only 10-15 degrees.  It will be somewhat warmer in the southwest, and the north, where highs will climb to the mid 20s.

Manitoba

As the map above shows, Manitoba will be dry on Saturday, with highs across the province in the mid to high 20s.   High pressure centered over the interlake will keep the province dry and mainly sunny throughout the day.

 

Sunday

Wet weather continues in Alberta and Saskatchewan on Sunday.   Significant rain will fall in parts of south central Alberta, and in central and southern Saskatchewan, while Manitoba will have another dry day – except along the Saskatchewan boundary.   The map below shows rain totals expected between 6:00 pm Saturday and 6:00 pm Sunday:

 

Temperatures will be cooler than long term averages, with highs in the mid teens  across the rainy regions.  Manitoba’s highs will peak in the low to mid 2os.

 

SEE:  Mitigating the Effect of Weather During Haying Season