**3. Analysis of Regional Weather**

Given its large geographic area, northerly latitude, and distance from any major body of wa‐ ter, the province of Saskatchewan is prone to considerable weather diversity. The province transitions its climates from humid continental in the south to subarctic in the north. Precipi‐ tation patterns vary considerably, typically decreasing from northeast to southwest. The summers are hot and dry while the winters are frigid.

Wind chill statistics for each of the twelve load centres examined in this chapter were analyzed and compared. Regional weather data were recorded and analyzed from January 2005 to No‐ vember 2011. Sufficient weather diversity was identified within the analysis for all the load centres to warrant adopting a multi-region approach to modelling. Thirteen weather variables were analyzed, which included: temperature (°C), relative humidity (%), pressure (millibars), wind direction (compass degrees), wind speed (km/hr), wind gust (km/hr), cloud cover (%), normal cloud cover (%), cloud ceiling (metres), visibility (km), low-lying cloud coverage (%), middle-lying cloud coverage (%), and high-lying cloud coverage (%). Based on sensitivity and statistical analysis conducted independently on the thirteen quantitative weather variables, only the variables of temperature, humidity, and wind speed were identified as statistically significant factors for explaining load variation due to weather. These three variables were in‐ cluded in the prediction models and the other weather-related variables were ignored because insignificant improvement was found from their inclusion in the model.

**Region Code Mean (°C) Maximum (°C) Minimum (°C)**

Area01 -1.48 36.66 -53.88 Area02 -1.59 36.89 -52.77 Area03 -1.48 36.53 -53.89 Area04 -1.52 34.46 -51.66 Area05 0.11 38.33 -50.23 Area06 -1.58 36.61 -52.85 Area07 -1.67 35.09 -51.11 Area08 2.56 41.66 -46.66 Area09 -2.68 33.89 -52.22 Area10 -2.65 33.88 -52.28 Area11 -1.51 34.44 -52.77 Area12 -2.04 32.77 -52.23 Regional Average -1.29 35.93 -51.87

> **Summer Average Daily Wind Chill**

**Region Code Max (°C) Min (°C) Max (°C) Min (°C)** Area01 18.77 5.05 -11.11 -23.92 Area02 19.66 4.68 -11.21 -24.75 Area03 19.87 5.02 -11.38 -24.95 Area04 17.71 4.83 -10.51 -23.21 Area05 20.35 5.69 -8.56 -21.47 Area06 20.71 4.14 -11.17 -24.53 Area07 18.38 5.98 -11.87 -23.92 Area08 22.84 7.84 -5.26 -18.89 Area09 16.70 7.04 -13.32 -25.16 Area10 17.16 6.88 -13.45 -25.05 Area11 19.52 5.85 -11.81 -24.91 Area12 17.06 4.28 -11.25 -23.01 Regional Average 19.06 5.61 -10.89 -23.64

**Table 2.** Average Daily Wind Chill Temperatures During Summer and Winter Months (Jan. 2005 – Nov. 2011).

**Winter Average Daily Wind Chill**

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**Table 1.** Wind Chill Temperature Statistics Across Load Centres.

#### **3.1. The Weather of Saskatchewan**

Saskatchewan is a land-locked prairie province, bordered east and west by the provinces of Manitoba and Alberta, respectively. Its northern border connects with that of the Northwest Territories and its southern border is divided between the American states of Montana and North Dakota. Saskatchewan is a land of geographic diversity.

Containing an area of 651,900 square kilometres [6], Saskatchewan is immense. Much of Sas‐ katchewan lies within the Great Plains and Interior Plains regions of North America, which comprise nearly half of the area of Saskatchewan, while the Canadian Shield dominates the northern half of the province.

Over 52% of Saskatchewan is covered by boreal forest, largely in the north, while arable land in the south represents roughly half of Saskatchewan's total land area [6]. Due to its geography and location, Saskatchewan is further differentiated by its climate.

The dominant climates of Saskatchewan include: semi-arid in the southwest, humid conti‐ nental in the south and central, and sub-arctic in the north [6]. The south is typically drier and the north is typically colder. Due to its northern location, distance from any major bod‐ ies of water, and relatively flat topography, Saskatchewan has a radical climate.

Summers are hot and short, though temperatures exceeding 32°C are not uncommon during the day, but the nights may quickly cool to near freezing. Humidity decreases from north‐ east to southwest due to the pacific westerlies. Winters are cold and long; often tempera‐ tures do not exceed -17°C for weeks at a time. The average summer temperature for the cities of Saskatchewan see highs of 25°C and lows of 11°C; while the average winter highs and lows are -12°C and -23°C respectively [6].

#### **3.2. Weather-Diversity Analysis**

To assess weather-diversity across Saskatchewan, climactic differences across the regions ex‐ amined were empirically identified. Wind chill statistics for each of the twelve load centres were analyzed and compared. Table 1 contrasts the mean, maximum, and minimum tem‐ peratures observed in each of the load centres throughout the period of investigation, which is from January 2005 to December 2011.


**Table 1.** Wind Chill Temperature Statistics Across Load Centres.

centres to warrant adopting a multi-region approach to modelling. Thirteen weather variables were analyzed, which included: temperature (°C), relative humidity (%), pressure (millibars), wind direction (compass degrees), wind speed (km/hr), wind gust (km/hr), cloud cover (%), normal cloud cover (%), cloud ceiling (metres), visibility (km), low-lying cloud coverage (%), middle-lying cloud coverage (%), and high-lying cloud coverage (%). Based on sensitivity and statistical analysis conducted independently on the thirteen quantitative weather variables, only the variables of temperature, humidity, and wind speed were identified as statistically significant factors for explaining load variation due to weather. These three variables were in‐ cluded in the prediction models and the other weather-related variables were ignored because

Saskatchewan is a land-locked prairie province, bordered east and west by the provinces of Manitoba and Alberta, respectively. Its northern border connects with that of the Northwest Territories and its southern border is divided between the American states of Montana and

Containing an area of 651,900 square kilometres [6], Saskatchewan is immense. Much of Sas‐ katchewan lies within the Great Plains and Interior Plains regions of North America, which comprise nearly half of the area of Saskatchewan, while the Canadian Shield dominates the

Over 52% of Saskatchewan is covered by boreal forest, largely in the north, while arable land in the south represents roughly half of Saskatchewan's total land area [6]. Due to its

The dominant climates of Saskatchewan include: semi-arid in the southwest, humid conti‐ nental in the south and central, and sub-arctic in the north [6]. The south is typically drier and the north is typically colder. Due to its northern location, distance from any major bod‐

Summers are hot and short, though temperatures exceeding 32°C are not uncommon during the day, but the nights may quickly cool to near freezing. Humidity decreases from north‐ east to southwest due to the pacific westerlies. Winters are cold and long; often tempera‐ tures do not exceed -17°C for weeks at a time. The average summer temperature for the cities of Saskatchewan see highs of 25°C and lows of 11°C; while the average winter highs

To assess weather-diversity across Saskatchewan, climactic differences across the regions ex‐ amined were empirically identified. Wind chill statistics for each of the twelve load centres were analyzed and compared. Table 1 contrasts the mean, maximum, and minimum tem‐ peratures observed in each of the load centres throughout the period of investigation, which

geography and location, Saskatchewan is further differentiated by its climate.

ies of water, and relatively flat topography, Saskatchewan has a radical climate.

insignificant improvement was found from their inclusion in the model.

North Dakota. Saskatchewan is a land of geographic diversity.

**3.1. The Weather of Saskatchewan**

252 Decision Support Systems

northern half of the province.

and lows are -12°C and -23°C respectively [6].

**3.2. Weather-Diversity Analysis**

is from January 2005 to December 2011.


**Table 2.** Average Daily Wind Chill Temperatures During Summer and Winter Months (Jan. 2005 – Nov. 2011).

It can be observed from the dataset that the regions experience different weather conditions at different times such that the temperature distributions and the variances in temperature are not the same. Table 2 lists the seasonal average daily variation of wind chill temperatures expe‐ rienced by each of the twelve load centres during the period of investigation from January 2005 to December 2011. Significant temperature variation exists among the twelve regions and indi‐ vidual load centres experience a considerable range of temperatures in an average day.

To illustrate the load diversity among the regions, the region code, average load, and peak load for the twelve load centres from the period of January 2005 to December 2011

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**Region Code Average Load (MW-hour) Peak Load (MW-minute)**

Area01 205.73 345 Area02 181.46 349 Area03 35.59 60 Area04 36.54 71 Area05 36.48 67 Area06 71.33 221 Area07 25.34 45 Area08 23.86 65 Area09 17.04 74 Area10 14.23 65 Area11 43.93 154 Area12 9.44 16 Aggregate System Load 700.97 1154

**Table 3.** Region Code, Average Load, and Peak Load (January 2005 to December 2011).

It can be seen from Table 3 that the peak load for most load centres tends to be twice the average load, which indicates that considerable load swings are possible within each load centre. The aggregate load model approach would not be able to represent the possible load

To demonstrate the seasonal trends in electricity demand of the load centres, the hourly aggregate electricity demands of the load centres over four years are shown in Figure 2. In this figure, it can be seen that these seasonal patterns correspond to periodic daily, weekly, and monthly variations. Peaks are found in the winter and summer months, while troughs are found in the spring and autumn months. Limited load growth is found during this period, but a considerable variance is possible within each season, which usu‐

The dark black line in Figure 2 indicates the seasonal trends of the system. Peaks are found in the winter and summer months and troughs in spring and autumn. These seasonal pat‐ terns correspond to periodic daily, weekly, and monthly variation. Limited load growth is found during this period, but a considerable variance is possible within each season, which

are listed in Table 3.

swings within each centre.

ally results from significant weather diversity.

usually results from considerable weather diversity.

Thus, it can be seen from Tables 1 and 2 that the weather experienced in each of the twelve re‐ gions vary considerably. Weather diversity was evidenced by the seasonal differences, daily wind chill ranges, and distribution of wind chill temperatures among the regions. The evidence for weather diversity supports our proposal for the development of a multi-region model.
