A couple of issues back, we discussed how we get large undulations of cold air sagging southwards from the North Pole (we are just talking about the Northern Hemisphere). These undulations create something called long waves and at any given moment there are usually three to six long waves circling our planet. These waves usually move steadily along giving us periodic shots of warm and cool air with unsettled conditions developing during the transitions. We also learned that sometimes these long waves can get stuck, and we refer to this as a blocking pattern.

So let’s continue our look at blocking patterns and heatwaves. But first I figured we should first define what a heat wave is, then look at the criteria that Environment Canada uses to define heat events.

Looking at several different definitions, I found a couple that were good: a generalized one and an official one from the World Meteorological Organization.

“A basic definition of a heat wave implies that it is an extended period of unusually high atmosphere-related heat stress, which causes temporary modifications in lifestyle and which may have adverse health consequences for the affected population.” – University of North Carolina at Chapel Hill, N.C.

“A heatwave occurs when the daily maximum temperature of more than five consecutive days exceeds the average maximum temperature of (five degrees Celsius), based on the normal climate of the region.” – WMO

These basically state that while a heat wave is a meteorological event (abnormally warm temperatures), it is the impact that the heat has on people that is key.

Heat warning thresholds

If you check Environment Canada’s website for a list of criteria for public weather alerts, you would find the following heat-related alerts for the Prairie provinces. In southern Manitoba and Saskatchewan, a heat warning or advisory is issued when two or more consecutive daytime maximum temperatures are expected to reach 32 C or warmer, and nighttime minimum temperatures are expected to remain at or above 16 C.

Or, when two or more consecutive days of humidex values are expected to reach 38 C or higher. In southern Alberta, it is the same criteria as southern Manitoba and Saskatchewan, but without the mention of humidex values as this region rarely sees high humidity.

Over more northern regions, the values in Manitoba are two or more days with daytime highs warmer than 29 C (and 16 C or warmer at night) or humidex values greater than 34 C. In northern Saskatchewan and Alberta, it is 29 C during the day and 14 C at night.

What causes a heat wave?

We now know the criteria, but what conditions need to come together to give us a heat wave? There are several different scenarios that can come together to give us conditions that will prompt a heat warning, but what I want to look at are the conditions that lead to not just a couple of days of heat, but the big heat waves that last for several days.

To get the long lasting, intense, record-breaking heat waves, a couple of meteorological events must come together. First, we usually need a blocking pattern to develop, and as I pointed out in the last issue, the most typical pattern is the Omega block. This pattern has upper-level lows sitting to our west and east with a ridge of high pressure in the middle. This is important because this pattern, as the name suggests, can become fairly stable and tend to sit in one place for several days allowing for temperature to build up.

The ridge of high pressure allows for a couple of things to happen. First, the descending air inhibits the growth of clouds. This in turn means plenty of sunshine, and in the summer, sunshine means heat. On their own, sunny skies do not mean a heat wave, we see plenty of sunny days in a row without experiencing a heat wave. The next part has to do with the strength of the high. When the high is strong we get very strong subsidence or sinking of air. As this air is pushed downwards, it hits the ground and is compressed. Now, anyone who has used an air compressor or even just a hand pump knows that as you compress air, you are forcing the air particles closer together, this in turn increases the rate of particle collisions, and these collisions transfer energy which we feel as heat. Don’t believe me? Grab a bike pump, give it 20 or so pumps and then feel the bottom of the pump, it’s hot due to the compression of air.

So, when there is a strong ridge of high pressure over us, the compression of sinking air can dramatically heat the air and give us some truly warm days. Now, if the upper high is not that warm, then all this compressing and heating of the air won’t do that much to give us record-breaking temperatures. If the upper high is warm to begin with, then this compression of air, combined with the additional heating of the sun, can really push the temperatures up. This is something we have seen over the last several years. We have been seeing some remarkable warm days even when the upper high has not been that strong. This is largely due to a generally warmer atmosphere. I’ve caught myself several times saying after a particularly hot day or two that the atmospheric setup should not have led to such warm temperatures.

So far this summer we have not seen strong blocking patterns develop, but that doesn’t mean it still can’t happen. In the next issue I promise we will begin out look at extreme rainfall events.

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Eventually we’ll also have to deal with the first frost of the season, I just don’t think it will be during this forecast period – except for maybe the north half of Alberta. Just saying.

To start this forecast period, we have a building ridge of high pressure that will bring at least one more day of sunny, warm fall weather to Alberta. Several days of the same sunny and warm weather are expected in Saskatchewan and Manitoba as the ridge moves eastwards. Alberta will likely see clouds and showers, with maybe even a few thundershowers on Thursday as an area of low-pressure zips northeastwards through the province. Along with the showers, temperatures will cool as the low collapses the ridge of high pressure to the south and east.

The flow across the Prairies then looks to become zonal on Friday and Saturday—a fancy term meaning a west to east flow. By Sunday morning the weather models are showing an area of low pressure developing over southern Alberta which will then quickly move off to lie over northern Manitoba by Sunday evening. Central and northern parts of Alberta and Saskatchewan may see a few showers from this system, but the main impact will be cooler temperatures moving in behind the low. The weather models then show another ridge of high pressure building over the Prairies early next week, which would mean a return to sunny and warm conditions for the start of October.

Alberta

Alberta will see one more day of summer-like temperatures before a developing area of low pressure brings increasing clouds and the chance of showers or thundershowers on Thursday. Temperatures will start in the mid to upper twenties on Wednesday and then cool down into the upper teens to low twenties on Thursday and Friday over southern and central regions. Temperatures in the mid teens are expected over more northern regions.

Mostly sunny skies and seasonable temperatures are expected over the weekend as the flow becomes zonal across the region. The weather models are showing an area of low pressure quickly developing over southern Alberta on Sunday a swiftly moving off to the northeast. This low may bring the odd shower over central regions later in the day on Sunday but confidence in this fast-moving system is low.

Temperatures look to cool down early next week with the weather models showing daytime highs in the low to mid teens and overnight lows falling to around the 2 to 4 C range. Frost can’t be ruled out. It then looks like there will be a return to above average temperatures as a ridge of high pressure is forecasted to rebuild across the region.

Saskatchewan and Manitoba

These two regions look to see plenty of sunshine and warm temperatures thanks to a building ridge of high pressure. Expect daytime highs from Wednesday to Friday to be in the mid or even upper twenties with overnight lows only falling into the low teens. Saturday still looks to be nice but with the Alberta low tracking by to the north helping to collapse the upper ridge, temperatures will likely be a few degrees cooler.

Late Saturday and into Sunday, central Saskatchewan could see the odd scattered shower as the low tracks through but with the speed of the system it doesn’t look like there will be any significant rainfall. Southern and central regions of Manitoba look to miss out on any rainfall from this system. Cooler air will work southwards behind the low and will drop daytime highs into the mid-teens with overnight lows falling to 3 to 5 C range. The coldest temperatures are expected on Monday morning.

Temperatures look to rebound early next week as the weather models are showing a ridge of high-pressure rebuilding across the Prairies. Expect daytime highs by Wednesday to be back into the low twenties. So far, the weather models are not showing any signs of a big outbreak of cold air. Let’s keep our fingers crossed!

— Daniel Bezte is a teacher by profession with a B.A. (Hon.) in geography, specializing in climatology from the University of Winnipeg. He operates a computerized weather station near Birds Hill Park, Man. Contact him via email with your questions and comments. 

The post Prairie forecast: Cooler, but still warmer than average appeared first on Alberta Farmer Express.

We’re seeing periodic troughing develop along the West Coast. This places us in a southwesterly flow. Areas of low pressure then spin up in the flow and lift northwards. Over to the east, there continues to be high pressure locked in place which is making it difficult for the western low to push eastwards. Instead, the lows lift to the north or northeast before sliding east over the northern Prairies. The slow progress of these lows allowed for plenty of moisture to move northwards. This moisture has been feeding the development of late season thunderstorms.

Typically, with this type of setup, the slow motion of the low allows it to pull moisture, warm up from the south and, as the lows lift northwards, they will tap into cold air and push it southwards. So far, we have not seen much of this.  Colder temperatures have only made it to the far northern Prairies. The weather models keep hinting at this cold air plunging southwards before pulling back their predictions.

This forecast period starts with one of the northwestern U.S. lows slowly lifting northwards. The unsettled weather that started the week across parts of Saskatchewan and much of southern Manitoba looks to continue. It appears the low will only move out late Friday or early Saturday. Even parts of southern Alberta my see some rainfall from this low on Wednesday.

Over the weekend and early next week, it looks a bit more like fall like across the Prairies as cooler air tries to work southward behind the departing low. The coolest readings look to be over the northern half of Alberta and Saskatchewan. The southern Prairies will likely see slightly above average temperatures. The weather models are then showing another area of low pressure developing around mid week, but this time further north over Alberta. Considering the pattern we are in, there’s a good chance of seeing more unsettled weather during the second half of next week.

Alberta

As mentioned, a developing Montana low will bring the chance of showers on Wednesday to parts of southeastern Alberta, while areas to the west and north should see sunny to partly cloudy skies. Temperatures look to be seasonably mild with daytime highs in the upper teens and overnight lows falling to around 7 C.

A couple of weak disturbances are forecasted to ripple through the province, with the first one expected on Friday and the second around Monday. These systems will bring a mix of sun and clouds and the chance of a few showers. Temperatures will continue to be seasonable with highs in the mid to upper teens and overnight lows in the 5 to 8 C range.

A stronger area of low pressure if forecasted to come ashore over central B.C. and to help spin up a lee side low over central Alberta around Wednesday. The southerly flow ahead of this feature should help to moderate temperatures. Daytime highs are forecasted to be in the low twenties with overnight low falling to around 12 C. This low will likely bring more precipitation during the second half of the week to central and northern regions.

Saskatchewan and Manitoba

Both regions are going to have to deal with at least a couple more days of unsettled weather. The main Montana low will lift northeastwards through southern Saskatchewan on Wednesday and into northern Manitoba by Friday. There will be plenty of moisture and warm air in place for more thunderstorms. The best chance of storms is over Saskatchewan on Wednesday, with a slightly lower chance of thunderstorms over Manitoba later Wednesday and Wednesday night.

The low will slowly lift northeastward which will result in cloudy skies and scattered showers on Thursday. Skies should start to clear out over Saskatchewan early on Friday with Manitoba clearing out later in the day. Despite the clouds and showers, temperatures look to be seasonable with daytime highs in the low twenties on Wednesday, falling to around 20 C mark on Thursday. Expect overnight lows to remain mild.

Over the weekend and into the first half of next week, the weather models show a couple of weak systems rippling across the Prairies. These are predicted to bring a mix of sun and clouds and a few showers. The exact timing of these systems will be a bit difficult. The first system is forecasted to drift through on Saturday and the second system on Monday or Tuesday.

With the clouds and showers, expect daytime highs to be in the upper teens with overnight lows falling to around 10 C.

— Daniel Bezte is a teacher by profession with a B.A. (Hon.) in geography, specializing in climatology from the University of Winnipeg. He operates a computerized weather station near Birds Hill Park, Man. Contact him via email with your questions and comments. 

The post Prairie forecast: Weather pattern has undergone a shift appeared first on Alberta Farmer Express.

For those of you in Alberta, this will mean cooler and wetter conditions. In Manitoba, it looks like summer will continue for at least one more week. If you are in Saskatchewan, well, you will be stuck in the middle of these two features. It will all depend on how the pattern sets up and where you live.

Currently there’s an area of low-pressure lifting northeastwards out of the southern Nunavut. Behind this low an area of high pressure is sliding southeastwards across the northern Prairies. This high will somewhat cool the central and eastern Prairies on Wednesday.

Further west, a couple of areas of low pressure are forecasted to drop down the coast from the Gulf of Alaska, which will help to slowly dig a sizable trough of low pressure across that region. Over eastern Canada and the northeastern U.S., the weather models show an area of high pressure building and stalling out during this forecast period.

Putting this all together this is what look to happen: the eastern high will block the eastern movement of systems. The first area of low pressure dropping down the West Coast should move inland and strengthen over Montana. This low is then forecasted to move nearly due north thanks to the blocking ridge in the east. The question is just where the blocking boundary set up.

Currently it looks like  it will lift northwards and track from southern Alberta towards northern Saskatchewan. Areas to the north and west of this low track will see shower and/or rain and cool temperatures. Areas to the east will see sunny to partly cloudy skies and continued summery temperatures. This low should move out by Saturday or Sunday.

Early next week, the weather models are showing a second low tracking down the West Coast, coming inland, the then strengthening – very similar to the first low. The one difference is that this low is predicted to track a little further east before lifting north. This means that Saskatchewan will have the best chance of seeing precipitation from this system.

Alberta

Central and northern regions should start this forecast period with partly to mostly cloudy skies and near seasonal temperatures. Southern regions will be cloudy and cool with showers or rain developing late in the day. This precipitation will work northwards on Thursday as the low begin to lift northeastwards. The slow speed of this low means that showers and rain may stick around until at least Friday across most of the province.

It looks like there will be a bit of a break over the weekend with skies become partly cloudy and highs in most regions expected to be in the upper teens to low twenties. Overnight lows will fall into the upper single digits.

By late Sunday or early Monday, a second area of low pressure is forecasted to begin strengthening over Montana and begin lifting northeastwards. Currently it looks like this low will track a little further east into Saskatchewan with only southern and far eastern regions likely to see any precipitation. With the rest of the province being on the back side of the low, expect to see cloudy to partly cloudy skies and cool temperatures. Daytime highs are forecasted to be in the mid-teens with overnight lows falling into the upper single digits.

Saskatchewan and Manitoba

This forecast period will start with a bit of a cool down as a cool area of high-pressure tracks across northern Saskatchewan and Manitoba. This won’t last for more than a day as a large area of low pressure develops over the northwestern U.S. The circulation around this low will pull warm air northwards. By Thursday, highs across southern Saskatchewan and Manitoba are forecast to push into the upper twenties with lows only falling into the mid-teens.

As the U.S. low lift northeastwards, a strong southerly flow ahead of it will bring mild air northwards. Manitoba will see the most sunshine and the warmest temperatures as the main low and clouds stay well to the west. Expect daytime highs to continue in the mid to upper twenties and overnight lows to only fall to the low to mid-teens. Across Saskatchewan, the southeast part will be the warmest with temperatures decreasing and cloud cover increasing as you move to the northwest. The best chance of rainfall looks to be on Friday over the western half of the province.

The weekend looks to be dry and warm with sunny to partly cloudy skies and daytime highs ranging from the mid-twenties across Saskatchewan and into the upper twenties across Manitoba. By early next week a second area of low pressure is forecasted to lift northeastwards out of the northwestern U.S. This low looks to track into Saskatchewan. It brings a good chance of showers and even some thundershowers starting on Monday and lasting through Tuesday.

Across Manitoba, the chance of showers and thundershowers should begin on Tuesday and last through Wednesday as the low lifts to the northeast. As I always, I’d like to point out that this system is still a fair way off and much can happen between now and then. I haven’t had to do a forecast update in quite awhile, but if there are big changes to this second system watch for an update early next week.

— Daniel Bezte is a teacher by profession with a B.A. (Hon.) in geography, specializing in climatology from the University of Winnipeg. He operates a computerized weather station near Birds Hill Park, Man. Contact him via email with your questions and comments. 

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Before that weather moves in, there’s an area of low pressure over Montana with an associated upper low over southern Alberta. This is bringing periods of rain and cool temperatures. Southern and central Alberta will be dealing with this on Wednesday before it moves into Saskatchewan Wednesday afternoon and then into Manitoba on Thursday.

Once this system departs to the northeast on Friday, the stage will be set for a ridge of high pressure to build across the Prairies. This ridge will bring sunny skies and warming temperatures for the start of the school year. Daytime highs across the Prairies will be pushing into the upper twenties and even low thirties by the middle of next week.

Alberta

This forecast period starts with an area of low pressure over Montana and an associated upper low over southern Alberta. This feature will bring widespread rains to southern regions and rain and/or showers over central regions on Wednesday. With the clouds and precipitation, temperatures will be on the cool side with daytime highs forecasted to be in the 13 to 16 C range.

The Montana low is forecasted to move into Saskatchewan late today but there is some indication that eastern regions may see some lingering showers on Thursday. By Friday, surface high pressure will move in and bring plenty of sunshine and seasonable temperatures. Over the weekend and into next week, the weather models are showing an upper ridge building over B.C. and Alberta and then slowly transitioning eastwards. This will allow sunny skies to continue with temperatures warming into the upper twenties to low thirties by Sunday or Monday. These conditions look to continue through much of next week.

Saskatchewan and Manitoba

Saskatchewan will feel the impact of the approaching upper low by Wednesday afternoon with increasing clouds and the chance of showers and thundershowers. These showers and thundershowers will continue overnight before they move off to the east by Thursday afternoon.

Currently it looks like there will be a mix of sun and clouds, which will allow temperatures to warm into the upper teens to around twenty degrees. In Manitoba, this same area of low pressure will begin to push clouds, showers, and thundershowers into southern and central regions beginning late this evening and lasting through Thursday.

The models are showing the upper low speeding up as it moves through the province which means that thing should clear by Friday. But as we know, upper lows often like to stick around a little longer than expect.

On Friday, skies will have cleared out across Saskatchewan and hopefully across Manitoba as surface high pressure pushes in from the west. With high pressure in place over the weekend, and with plenty of sunshine, expect temperatures to warm into the low twenties with overnight lows falling to around 10 C.

To start the first week of September, a building upper ridge over Alberta will begin to slowly move eastwards. This upper ridge will continue to support clear skies and will help to boost temperatures. Expect daytime highs across southern and central Saskatchewan to push into the mid twenties by Monday with upper twenties to thirty degrees expected on Tuesday or Wednesday. Similar temperatures are expected in Manitoba, but it will take an extra day or two to arrive.

— Daniel Bezte is a teacher by profession with a B.A. (Hon.) in geography, specializing in climatology from the University of Winnipeg. He operates a computerized weather station near Birds Hill Park, Man. Contact him via email with your questions and comments. 

The post Prairie forecast: Summer weather not over yet appeared first on Alberta Farmer Express.

Also of interest, even though the overall pattern wasn’t that warm, we still saw some hot temperatures.

Looking at this forecast period, and as we near the end of meteorological summer, it’s still looking like summery temperatures will stick around. Along with those warm temperatures we will continue to see the chance of thundershowers and storms.

We start with a weak trough of low pressure over the eastern Prairies that is slowly pushing an upper ridge eastward out of the region. This trough has been the focus of scattered thunderstorms and looks to continue this over the next couple of days. Over the western Prairies we are starting with high pressure building in from the west. This may trigger a few thunderstorms as it pushes in before bringing several days of quiet weather.

Over the weekend the weather models are showing an area of low pressure developing over Montana, tracking due north through Alberta and then either stalling out over the Northwest Territories on Monday or tracking eastwards. There’s uncertainty the behaviour of this low, which could have a significant impact on the weather near the end of this forecast period.

This system will bring a good chance of clouds, showers, thunderstorms, and cooler temperatures to parts of Alberta and northern Saskatchewan. Over the eastern Prairies, the southerly flow ahead of this low will bring warm temperatures with a small chance of thunderstorms late in the weekend as a warm front from the low lifts northwards. Quieter and more seasonable temperatures look to be on tap for the first half of next week as the flow across the Prairies becomes more westerly.

Alberta

High pressure is forecasted to build in from the northwest over the next couple of days. Ahead of this high the weather models are showing a weak trough of low pressure being pushed southwards. This system will bring the chance of showers and thunderstorms with the best chance being over central and western regions. Temperatures will be a little cooler on Wednesday before warming up on Thursday and Friday under plenty of sunshine. Expect daytime highs to be in the low twenties on Wednesday, warming into the upper twenties to around thirty degrees by Friday.

Over the weekend, an area of low pressure is forecasted to develop over Montana and lift northwards. It looks like most precipitation accompanying this low will be over western and northern regions on Saturday and Sunday. There is the possibility of a secondary area of low pressure spinning up over north-central Saskatchewan on Sunday. Should this happen, eastern regions could see some measurable precipitation on Monday.

The weather models are not sure what will happen with this low as they have been showing it both stalling out over Great Slave Lake and being more progressive and sliding off to the east. Should it stall, the flow around the low will push cool unstable air into the north half of the province. Most days would a mix of sun and clouds with the chance of afternoon showers and thundershowers. Daytime highs will be in the upper teens with overnight lows dropping to around 8 C. If it doesn’t stall, temperatures will be milder with less chance of clouds and showers. Further south, skies should be sunny to partly cloudy with daytime highs in the low twenties and overnight lows in the 10 C range.

Saskatchewan and Manitoba

This region will continue to see scattered thunderstorms over the next couple of days as weak areas of low pressure ride up the western side of the departing upper ridge. The main focus looks to be over eastern Saskatchewan and western Manitoba on Wednesday with the weather models showing the possibility of some severe storms. This activity will push into southern and central Manitoba on Thursday and bring with plenty of clouds and a good chance of showers and occasional thundershowers. With the clouds and precipitation, expect daytime highs to only be in the low twenties.

By Friday Saskatchewan will have cleared out with Manitoba clearing out during the day. Over the weekend a fairly strong southerly flow will develop ahead of the Alberta low. This will bring sunny, hot, and windy conditions with daytime highs pushing thirty degrees and overnight lows only falling into the mid teens. The weather models are hinting at a secondary area of low pressure developing over north-central Saskatchewan on Sunday. Should this materialize, there will be the chance of late thundershowers or storms over central Saskatchewan and over much of southern and central Manitoba.

On Monday the flow across the Prairies is forecasted to become westerly. This will bring sunny to partly cloudy skies along with seasonable temperatures. Expect daytime highs to be in the low to possibly mid twenties with overnight lows falling to around 10 C.

— Daniel Bezte is a teacher by profession with a B.A. (Hon.) in geography, specializing in climatology from the University of Winnipeg. He operates a computerized weather station near Birds Hill Park, Man. Contact him via email with your questions and comments. 

The post Prairie forecast: Warm but unsettled weather appeared first on Alberta Farmer Express.

This forecast period starts with high pressure slowly sliding to the east of the Prairies, an area of low pressure over northern Saskatchewan and another area of low-pressure moving northeastward into North Dakota. There’s also some weak ridging over Alberta and western Saskatchewan.

The low over northern Saskatchewan and its accompanied warm front near the Saskatchewan-Manitoba border will be the focus of showers and thunderstorms as it slowly tracks eastwards. The North Dakota low may trap some of the moisture moving northwards , which would keep the heaviest rainfall to our south but provide plenty of clouds.

As the weekend approaches, weak upper-level ridging will be in place across the central and eastern Prairies while over Alberta a weak upper low will be tracking southeastwards out of the Yukon. This upper low will set the stage for showers and thunderstorms on Friday and Saturday before it moves into Saskatchewan and Manitoba by Sunday or Monday.

The slack or weak pattern looks to continue into much of next week, which makes it difficult to pinpoint which areas could see showers or thunderstorms, and on which days. Best chances for precipitation look to be over the eastern Prairies. This type of pattern also makes it difficult to predict where forest fire smoke will be.

Alberta

Weak upper-level ridging will bring sunny to partly cloudy skies on Wednesday and Thursday with northern regions seeing a good chance of smoke. Temperatures will be in the mid to upper twenties with overnight lows falling into the mid-teens.

On Friday, a weak upper low or disturbance is forecasted to begin dropping southeastwards out of the Yukon. This feature will destabilize the atmosphere, which should result in a good chance of showers, thundershowers, and a few thunderstorms. With all the clouds and precipitation, expect cooler temperatures. Daytime highs are forecasted to be around 20 C with overnight lows falling to around 12 C. This system should move off east by Sunday.

The weather models are showing weak upper-level ridging rebuilding over Alberta early next week. This should bring sunny to partly cloudy skies along with seasonable temperatures. Expect daytime highs to be in the mid-twenties with overnight lows in the 10 to 14 C range. Southern regions could see the odd afternoon shower or thundershower on Monday as a weak system skirts by to the south, but confidence in this feature is low.

Saskatchewan and Manitoba

As stated earlier, this region will be the focus for showers and thunderstorms to start this forecast period as an area of low pressure over northern Saskatchewan slowly slides to the east. This low will push a warm front through eastern Saskatchewan and into southwestern Manitoba during the day on Wednesday and through eastern regions of Manitoba by Wednesday night and into Thursday. The front will be the focus for showers and thunderstorms as it pushes through.

Timing of the front will determine the amount of rainfall. If the front moves through later in the day, there’ll be the best chance of seeing heavier rain amounts. Currently the weather models are showing total amounts from storms in the 10 to 15 mm range, but the slow motion of some storms could result in locally higher amounts. Even with the clouds and possible precipitation, daytime highs will continue to be in the mid to upper twenties.

Behind the front, weak upper-level ridging will begin to re-establish itself, which will bring sunny to partly cloudy skies over much of Saskatchewan and Manitoba on Friday and Saturday. A disturbance moving out of Alberta will bring increasing clouds and the good chance of scattered showers or thundershowers to Saskatchewan late Saturday and into Sunday morning. This feature should move into Manitoba on Sunday.

Skies should clear on Monday as weak high pressure works in, but another weak disturbance is forecasted to track by to our south on Tuesday and Wednesday. This should bring a return to partly cloudy skies along with the chance of widely scattered showers or thundershowers. Temperatures look to remain seasonable during this period with daytime highs in the mid-twenties and overnight lows in the low teens.

— Daniel Bezte is a teacher by profession with a B.A. (Hon.) in geography, specializing in climatology from the University of Winnipeg. He operates a computerized weather station near Birds Hill Park, Man. Contact him via email with your questions and comments. 

The post Prairie forecast: Weak systems make for tricky forecast appeared first on Alberta Farmer Express.

For this forecast period, it’s looking like the forecasted strong area of high pressure is going to dominate the weather across the Prairies. This should bring plenty of sunshine and warming temperatures. Overnight lows look to be seasonable, so at this point it doesn’t look like we’ll see heat warnings—but as usual you just never know.

The high pressure is forecasted to drop southwards into northern Saskatchewan on Wednesday and continue slowly dropping southwards and strengthening as the week progresses. By Friday, the center of the high is expected to be over southern Saskatchewan with a ridge of high-pressure stretching northwards into the territories. This surface high and ridge will continue to drop southeastwards over the weekend into next week.

With high pressure firmly in place, the only chances for precipitation will be over Manitoba on Wednesday and Thursday as the Prairie low departs, and then over Alberta later in the forecast period with widely scattered thundershowers or storms.

Alberta

Much of Alberta will see sunny to partly cloudy skies as a ridge of high pressure builds southeastwards out of the Territories. This high will bring warm temperatures to the northern half of the province. Temperatures are forecasted to be in the mid twenties on most days. Southern regions will not feel as strong as an influence from the high, which will make for slightly cooler temperatures.

The weather models are not showing any strong areas of low pressure impacting the province during this period. A southeasterly flow is forecasted to develop, which will bring some moisture into the southern half of the province starting over the weekend. The southeasterly winds and moisture will combine to trigger scattered afternoon thundershowers. The odd thunderstorm cannot be ruled out. Coverage and amount look light, but there’s always the possibility of a few localized heavier rain events. This pattern looks to continue into the first half of next week.

Saskatchewan and Manitoba

Saskatchewan will see one last day of cloudy or partly cloudy skies before an area of low pressure moves off east. This low will bring those same cloudy to partly cloudy skies to Manitoba on Wednesday and Thursday before that it tracks off into northwestern Ontario. Along with the clouds there will be the occasional shower or thundershower, but not much in the way of accumulations are expected. For those areas that see thundershowers, a quick 10-20 mm can not be ruled out.

By Friday, high pressure building southwards will bring sunny skies, light winds and seasonable temperatures. Expected daytime highs to be on the low twenties on Friday, warming into the mid twenties over the weekend. Overnight lows will also be seasonable and make for some nice sleeping weather. Expect lows to start off around 10 C warming towards 14 C by Sunday.

Sunny skies and seasonable temperatures are forecasted to last until at least Tuesday. At this point, the weather models are showing an area of low pressure developing over Montana and then lifting northeastwards. This brings a good chance of showers and thundershowers to Saskatchewan on Tuesday and Manitoba on Wednesday. Confidence in this system is low at this point.

— Daniel Bezte is a teacher by profession with a B.A. (Hon.) in geography, specializing in climatology from the University of Winnipeg. He operates a computerized weather station near Birds Hill Park, Man. Contact him via email with your questions and comments. 

The post Prairie forecast: Temperatures to warm up appeared first on Alberta Farmer Express.

To start this forecast period, we still have some weak upper-level ridging in place that will continue to bring mostly sunny skies and hot temperature to the southern Prairies. This ridge is forecasted to weaken and collapse by Friday. This will result in a zonal (west-to-east) flow across the Prairies and a rather weak pressure pattern with no strong areas of low pressure or high pressure dominating the picture.

Early next week the weather models are showing a strong surface high dropping southwards out of the Northwest Territories. This will bring a continuation of sunny to partly cloudy skies and nice, summery temperatures. Usually these northern highs bring cooler conditions but the source region of this high is warm thanks to it being the peak heating period of the year.

Alberta

Southern regions will see a couple more days of sunny and hot conditions. Expect daytime highs to be in the low to mid-thirties with overnight lows falling to around 15 C. Further north, temperatures will continue to be warm with daytime highs in the upper twenties. A weak system tracking in from B.C. could trigger some afternoon thunderstorms on both Wednesday and Thursday before moving off into northern Saskatchewan.

Over the weekend, an area of low pressure is forecasted to begin forming over the northwestern U.S. The counterclockwise flow around this low, combined with the clockwise flow around an area of high pressure over northern regions, will pull moisture into the southern half of the province and push it up against the mountains.

Expecting increasing clouds on Sunday, along with the good chance of showers and thundershowers late Sunday and into Monday. With the clouds and showers, expect temperatures to peak in the low twenties. Northern regions, thanks to an area of high pressure, will see sunny to partly cloudy skies and daytime highs in the mid-twenties. Overnight lows will fall into the low teens. This forecast period will end with clearing skies across the south along with seasonable temperatures.

Saskatchewan and Manitoba

A short forecast for this period. Southern and central regions will see at least three more days of hot and sunny conditions thanks to the slowly collapsing upper ridge. Most regions will see daytime highs in the low thirties with Saskatchewan seeing the best chance of some mid-thirties highs. Overnight lows look to remain in the 15 to 18 C range.

An area of low pressure tracking across the far northern Prairies is forecasted to drag a weak cold front southward late on Friday. This front may be enough to trigger the odd thunderstorm with the best chance of storms being over Manitoba.

Skies should quickly clear on Saturday with daytime highs dropping into a more comfortable mid twenty-degree range. Along with cooler daytime highs, overnight lows will also be more comfortable, falling into the 10 to 14 C range.

The first couple of days of the long weekend look to see sunny or partly cloudy skies with a continuation of seasonable temperatures.

On Monday the northwestern U.S. low is forecasted to track eastwards and bring cloudy skies to Saskatchewan along with a good chance of showers and thundershowers. This low will move into Manitoba late on Monday bringing showers and thundershowers overnight Monday and into Tuesday.

— Daniel Bezte is a teacher by profession with a B.A. (Hon.) in geography, specializing in climatology from the University of Winnipeg. He operates a computerized weather station near Birds Hill Park, Man. Contact him via email with your questions and comments.

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While camping, I’ve been keeping an eye on the weather and have been getting updates from my kids and some of my readers. The forecasted heatwave occurred pretty close to what was forecasted, with the main exception being Manitoba which didn’t end up seeing the really intense heat that Alberta and much of Saskatchewan saw.

This forecast period will start with an area of low pressure forming over southern Alberta. This low is forecasted to slowly lift northwards, continue its slow trek eastwards across the northern Prairies, before finally exiting our region sometime over the weekend.

This system looks like it’ll bring much-needed rains to central and northern Alberta, northern Saskatchewan and to a lesser extent, Manitoba. Along with the clouds and rain, these regions will see much cooler temperatures.

Southern Alberta, southern and central Saskatchewan and Manitoba will see another day or two of hot weather before the northern low drags a cold front southward, which will bring an end to this extended heatwave.

It doesn’t look like the cooler temperatures will stick around for long, as a weak upper ridge is forecasted to develop early next week. This should bring a return to warm/hot temperatures, but at this point it’s not looking like another prolonged heatwave.

Alberta

As mentioned, the weather models are showing an area of low pressure developing over southern regions on Wednesday. This low is forecasted to slowly drift northwards, taking until late Friday or Saturday to finally exit the province.

Central and northern regions will see extensive cloud cover with showers and thundershowers. It looks like most regions will see between 10 to 20 mm of rain, but there are some indications that western regions could see significantly more. I will leave that up to Environment Canada. Temperatures will be on the cool side with daytime highs forecasted to be in the 18 C range and overnight lows falling to around 12 C.

In the south, it looks like there will be one or two more days of heat before cooler temperatures moving in. Expect daytime highs to cool back into the low to mid-twenties by Friday except for extreme southern regions which will likely only cool down into the upper twenties. Skies look to remain mainly clear with no real chances for rain.

To start next week, the weather models show sunny to partly cloudy skies across the province as a weak upper ridge builds in.

Temperatures will warm over central and northern regions with daytime highs forecasted to be in the mid to upper twenties and overnight lows falling into the low to mid-teens. Further south, expect daytime highs in the upper twenties or low thirties. There’s a hint that an area of low pressure could bring some widely scattered thunderstorms to southern and central regions on Wednesday but confidence in this is low.

Saskatchewan

This region will see a couple of more days of extreme heats as the upper ridge responsible for it slowly moves eastwards and breaks down.

By Friday, all the heat warnings should be over with forecasted highs dropping down into the mid-twenties with overnight lows falling into the low to mid-teens. These cooler temperatures should last through the weekend and into the early part of next week before another upper ridge is forecasted to develop. This should bring a return to hot temperatures.

Fortunately it looks like these hot temperatures will only last a few days before cooler air moves back in. As for precipitation, the weather models are only showing a slight chance of showers or thunderstorms over central regions late on Friday and into Saturday as the Alberta low tracks across the northern part of the province.

Manitoba

Southern and central regions are forecasted to see a return to hot temperatures after cooler air pushed into the region earlier this week. As the western upper ridge pushes eastwards, expect mostly sunny skies and daytime highs in the low thirties on Thursday and Friday. The hottest temperatures are expected to be over western regions.

As the upper ridge continues to slide east and weaken, the weather models are showing a weak cold front associated with the northern Prairie low moving through late on Friday or early Saturday. With plenty of moisture in place, this front could trigger some thunderstorms—it depends on its timing.

Cooler air will move in behind this front. Daytime highs on Sunday and Monday are expected to be in the low to mid-twenties with overnight lows falling to around 12 C.

Sunday and Monday look to be a little unsettled thanks to a cool pocket of air in the upper atmosphere. This means there will be a good chance of seeing some widely scattered afternoon and early evening thundershowers. By Wednesday, the weather models are showing an upper ridge developing which will bring a return to sunny skies and warm/hot temperatures. We will have to wait and see how long the heat will last but current indications are for only a few days of hot temperatures.

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