Prairie Weather (Rural Roots Canada) – Don’t look now, but September is almost over, and many areas on the southern Canadian prairies have yet to see their first frost.   That will change this week, as many areas are expected to drop below zero overnight, with the real threat of a killing frost.   Keep up to date with daily weather forecasts to determine whether you’ll need to take any precautions on any given night.

This first map shows frost potential before sunrise Tuesday morning, just northeast of Calgary, in the Cypress Hills of Saskatchewan, and in northwestern Alberta.   The areas shaded in red show where the temperature could drop to 0.  The areas shaded in blue show areas that could drop to -5.

The following morning, Wednesday, frost will become more widespread across the Alberta foothills, in northern Alberta and Saskatchewan, and in northwestern Manitoba.   The southern agricultural regions of all three prairie provinces will continue to escape the frost.

Further into the week, there will be even greatrer chances for frost.   Check out the daily forecasts below.

As October begins, some producers in the southern prairies may have to start worrying about rushing the harvest to beat the frost, especially in Alberta and Saskatchewan.   Efforts to get the crop in quickly, though, will be hampered by occasional precipitation, as outlined in the daily forecasts below.

In Alberta, the harvest is still running ahead of the long term average, though it has been interrupted by rain over the past couple of weeks.  The rain has helped to improve soil moisture, but according to the Alberta Crop Report, the rain may also have lowered the quality of yet-to-be-harvested cereal crops.

The situation is similar in Saskatchewan, where, despite rain delays, the harvest is also running ahead of normal.  The rainfall was welcome in the pastures.   The Saskatchewan Crop Report says the rainfall “helped alleviate some producer concerns relating to fall pasture conditions”.

In Manitoba, it’s pretty much the same story.   Rainfall over the past few weeks has interrupted the harvest, but has produced a postive pasture picture.  From the Manitoba Crop Report: “Cattle on pasture are in beautiful condition. Well managed pastures are looking excellent for this time of year, however grass growth appears to be slowing down. Some producers are beginning to supplement animals with hay on pasture. The animals are nibbling on the bales largely because it’s something different rather than because grass is limited. Water levels in dugouts remain adequate. Pastures rarely look this great in September.”

For this growing season, there has been an abundance of moisture in most parts of the agricultural south.   The map below shows areas of above and below average rainfall.   In the blue/green/purple areas, rainfall has been above average.   The brown areas show where there has been a shortage of rainfall.   Central Alberta has been particularly hard hit by the lack of moisture,  as have parts of southern Saskatchewan and the area north of Dauphin, Manitoba.

RELATED: Hail Report: Minor Storms Still Causing Crop Damage

This week’s weather:

Monday

Alberta

Snow is possible in the foothills west and northwest of Sundre early in the morning, as an upper level trough digs into Alberta.   A surface low will generate rain before sunrise across most of Alberta east of highway 2   The ground in these areas will be quite wet first thing in the morning, but by noon, the rain will have moved into Saskatchewan, and there may be sufficient drying to resume harvesting in the afternoon.  It will be chilly, with temperatures peaking only around 10-15 degrees.  A northwest wind will make it feel even cooler.

Saskatchewan

Most of Saskatchewan will receive rain on Monday, and there will be a strong northwest wind.   You’ll likely park your combines and swathers, as the rain will cross the province from west to east throughout most of the day.   The rain is being generated along the back side of a surface Low pressure system in northern Manitoba.   The Low will also draw cool air into Saskatchewan, with daytime highs barely in the double digits.

Manitoba

The aforementioned Low in northern Manitoba that generates Saskatchewan’s rain will do the same for Manitoba, but a bit later in the day.   There may be a few light showers south of the lakes in the morning, but as the Low progresses, and tracks across the province, heavier rain will develop in the late afternoon across the interlake and the north.   Southern Manitoba may stay relatively dry, but it will be windy there, and across the rest of the province.   Temperatures will peak in the low double digits.

Tuesday

Alberta

With the exception of the Grande Prairie/Peace regions, Alberta should be dry and rather windy.   There’s a Low pressure system off the BC coast, pumping plenty of moisture onshore.   The moisture will be wrung out over the Rockies, leaving the prairies dry.   Rain will fall between Edmonton and Grande Prairie.   North of there, snow will be possible in the midday and afternoon. The jetstream will be right on top of the southern prairies, and surface wind may also be quite strong.  The warm, drying westerly wind will boost temperatures in southern Alberta to the high teens or low 20s.  Meantime, a weak low will form in southern Alberta, and as it heads toward Saskatchewan, it could drag some of the northern rainfall south across central Alberta late at night or early Wednesday morning.

Saskatchewan

Almost all of Saskatchewan, except for the far north, will have a dry day, and that will be an excellent opportunity to get back to the harvest.  A light to moderate wind will come out of the west, and afternoon temperatures will climb to nearly 20 degrees.

Manitoba

The Interlake rain will continue moving east, and there may be some residual showers for most of the day east and north of Lake Winnipeg.   The low producing the showers will move well into Nunavut, where it will become a major rain and snow storm.  Manitoba’s agricultural south will remain dry with a southwesterly wind, but it will be a bit cooler, with highs hitting only the low double digits.

Wednesday

Alberta

The Pacific flow will weaken, and things will become a bit more unsettled.   Rain is expected in central Alberta before sunrise.   The north and the south will stay dry.  By noon, just a few sprinkles are left in central Alberta, but isolated, scattered snow flurries are possible north of Edmonton.   With a northwesterly wind across Alberta, it will be chilly.  As mentioned above, morning frost is likely in northern Alberta, and across the province, afternoon highs will only reach the low to mid double digits.  Rain showers will redevelop over parts of central Alberta in the evening, though amounts should be fairly insignificant.

Saskatchewan

The day begins with rain north of the Trans Canada highway to Prince Albert.   Closer to the Territories’ border, there will be snow.   A brisk WNW wind will develop as the central Saskatchewan rain eases off by the end of the day.   The snow in the north will continue, but will not impact any agricultural territory.  It may turn out to be a reverse temperature trend day, where it cools down in the afternoon, with temperatures ending up below 10 degrees.

Manitoba

It’s a rather uneventful day for southern Manitoba.   While rain will fall periodically in the interlake, and snow in the far north, the weather in the agricultural south will be quite benign.   There is one possible exception, with some midday rain showers possible near Neepawa and Minnedosa.   Otherwise it’ll be dry and seasonably cool, with temperatures reaching 20 at best south of the Trans Canada highway.

Thursday

Alberta

Much of Alberta was hit with a light frost early Thursday morning, but in some areas, particularly south and west of Calgary, temperatures dropped to -4 or -5.  The map below shows temperatures at 2:12 AM Thursday morning.   It is doubtful there was a killing frost, as temperatires of -4 in Foothlls County and -5 in Wheatland County didn’t last long enough.

For the rest of the day,  a surface high pressure system will provide dry weather.   It will stay cool all day, with afternoon temperatures in Alberta reaching only the low double digits.

Saskatchewan

It will be a dry day in Saskatchewan, but the weather pattern will be cold, with temperatures reaching afternoon highs of only about 10 degrees in southwestern Saskatchewan,  5-10 degrees in southeastern Saskatchewan, and low single digit highs in the north.  No significant weather is expected.  It may be cool, but it’s a great day for harvesting operations.

Manitoba

A Low in the northern reaches of Hudson Bay will produce snow through most of the day in Northern Manitoba.   It looks like the agricultural south escaped morning frost.  Despite cool weather, conditions should be good for the harvest to continue in the south, as temperatures stay in the low single digits.

Friday

Alberta

A surface high develops in southeastern BC, with a trough of low pressure on the Alberta side of the Rockies.   This is a setup for dry weather.  From the trough, a centre of Low pressure will develop near Jasper in the midday, moving toward Red Deer by sunset.   The only precipitation to come out of the low will be in the late afternoon near Grande Prairie and the Peace Region. There will be widespread frost across the province Friday morning,  and this may bring a killing frost to areas that survived the Thursday morning freeze.   There will be a big rebound in temperatures in the afternoon, with 15-20 degree highs expected south of Edmonton.    There will be a terrific opportunity to bring in the crops that have survived the freezing cold mornings.

Saskatchewan

Expect widespread frost in the early morning, and the chance is very good that this will be a killing frost.   If so, it would be unfortunate, as no precipitation is expected at all, anywhere in Saskatchewan on Friday, and it would be a terrific day to work the fields.   Southwestern Saskatchewan will see temperatures rising to the high teens.  It will be progressively cooler heading east, with only single digit highs expected near the Manitoba boundary.

Manitoba

Southwestern Manitoba, west of Portage La Prairie, can expect its first frost Friday morning, and it will be a killing frost in some areas.    The remainder of the day will be cold, with temperatures peaking only between 5 and 10 degrees.  Under the influence of high pressure, the province will remain dry all day, and with frost now a genuine threat, the harvest, where possible, should be rushed to completion.

Saturday and Sunday

The Low in Alberta will move across central Saskatchewan, and as it does, it will deposit rain to most of Alberta north of Edmonton.   The rain will become more intense and widespread in Saskatchewan Saturday morning, and will continue there through most of the day.  The rain will move east as the Low heads to the Manitoba lakes.   As it does, the Low will further intensify,  and rain will fall Saturday afternoon and Sunday morning from York Factory to North Dakota.   The rest of the prairies will stay dry through the weekend.

Event Forecasts

Smoky Lake Great White North Weigh Off and Fair,  October 5, Smoky Lake, AB

Partly cloudy,  high 10

Farm Day in the City, October 6, Humboldt, SK

Mainly sunny, high 15

COMPARE TO LAST WEEK: Prairie Weather This Week – September 23