Synopsis

Map 1: Since the last report, (September 21^th 2022) dry conditions have continued to prevail over most of the province, with many widely scattered areas receiving less than 1 mm of rain and about 80% of the province’s growing areas receiving less than 5 mm (map 1). In contrast some precipitation has fallen in the extreme southwest corner of the province with accumulations ranging up to 20 mm.  Most of this fell during a single event on September 29^th.

The continuation of dry weather this fall has been marked by above average temperatures and has helped speed harvesting. However, many lands have received below normal precipitation accumulations since the beginning of July.  As a result, moisture is needed soon  On a more positive note, often dry spells break with the change of season and as we transition into winter, there is still hope that this holds true.

Recent Precipitation Trends

Maps 2, 3 & 4: This year with warmer than average temperatures and below normal rainfall, most agricultural areas have not seen appreciable rebounds in soil moisture yet. Over the past 60-days, many lands are experiencing once in 12 to 25 year low rainfall accumulations with large parts of the Central and North East regions experiencing less than once in 50-year lows (map 2).  Through the South, Central and North East regions large areas have received less than 40 mm of rainfall over the past 60-days and within this zone, many weather stations have reported less than 20 mm of rain (map 3).

Looking back further, to the beginning of July, some areas have received less than 40 mm of rain over the past 90 days (map 4).  Over this same period, the lowest accumulations (24.4mm) were recorded at the Neir AGDM station, just a few kilometers north west of Airdrie.  These long standing drying trends have left soil moisture reserves well below normal for this time of year, throughout most of our agricultural lands.

Soil Moisture Reserves

Map 5: Across the south, July historically marks the start of a drying trend and for those areas of the province lying north of Olds, the drying trend does not start until late August or early September.  However, as plant water use wanes in late summer and daylight hours diminish, September and October are typically associated with the beginning of the soil moisture recharge cycle, which usually lasts well into early June.

With the warm and dry weather of late, soil moisture reserves are currently well below normal across most agricultural areas with many lands through the Central, North East and North West regions estimated to have reserves this low less than once in 25-years (map 5). 

Perspective

Map 6: As mentioned earlier, we are just at the start of the soil moisture recharge period.  Thus there is still ample time to replenish moisture ahead of the 2023 cropping season, providing that the current drying trend ends soon.  Furthermore, at this time of year soil moisture reserves are near their lowest point in the year, so as such the actual deficits through the driest areas are only nearing about 50 mm (map 6).  This can be quickly reversed with just a few days of wet weather.  Currently rainfall accumulations in the 50-75 mm range will largely bring reserves back to near normal levels.  If this does not happen soon, looking further ahead, near normal winter snows and a slow gradual melt will also help dramatically as well as reasonable moisture in April and May.  Weather patterns can change very rapidly in this province, as we have seen this year and in many others.  Next year’s cropping cycle is still a long way off.