Moisture Updates - October 18, 2023

Synopsis

Maps 1 & 2: Since the last report on October 4th, 2023, reasonable rains, for this time of year, have continued to fall across much of the Southern Region and about 60% of the Central Region along with the west-half of the North West Region. In fact some parts of the Southern Region and Central Regions have received above normal rain fall for this time of year (Map 1). However, this is a normally dry time of year and above average moisture while beneficial, is still not enough to reverse long standing moisture deficits. It does, although bring hope to those that have suffered long running moisture deficits and begins to fuel some optimism for the 2024 cropping season.
Total rainfall accumulations over this time span range as high as 20 to 25 mm in some widely scattered pockets, with a broad swath of the province from the extreme southeast corner of the province, up to Grande Prairie, generally receiving over 10 mm (Map 2). Elsewhere most other areas have received less than 5 mm of moisture and now that harvest is complete, most lands would benefit from some wide spread rain and/or rain snow mix, ahead of the November freeze-up.

30-Day Precipitation Trends as of October 18, 2023

Maps 3 & 4: Looking back over the past 30-days, most of the Southern and Central Regions have seen at least near normal rainfall for this time of year (Map 3). In sharp contrast, lands lying north of the Yellowhead Highway, extending well up into the Peace Region have been drier than normal. For those engaged in harvesting activities this has been beneficial, but the warm and dry harvest weather has taken its toll on moisture reserves. That being said unlike the south, here winter snows are generally retained on the landscape until spring melt and there is ample time to develop reasonable snow packs. This is particularly true for the Peace Region, were winter snows typically account for about 35% of the annual precipitation accumulations, which is more in comparison the extreme south, were only 20% of annual moisture falls in the winter (November to March), and much of this is lost due to evaporation by warm winds and frequent snow melt episodes.

Total precipitation accumulations over the past 30 days, have ranged from well over 35 mm to as high as 50 mm across some of the agricultural lands in the Southern Region, and up to 35 mm across the western parts of the Central Region and well over 50 mm in the Forest protection areas located in the North West Region (Map 4). In contrast many lands, roughly lying east of a diagonal line from Near Rycroft in the Peace Region down to Medicine Hat, have received less than 15 mm. Notably, a large area lying north‑east of Edmonton has received less than 5 mm along with several pockets in the east-central Peace Region.

Soil Moisture Reserves as of October 18, 2023

Map 5: Soil Moisture reserves have recovered to “Near Normal” across much of the southern Region (Map 5), were, it’s normally quite dry this time of year. Elsewhere, the North West Region and parts of Peace Region are near normal, following ample rains in the growing season. In sharp contrast the entire Central Region and parts of the North East Region and the extreme northern Peace Region are below normal with some lands estimated to be this dry, on average at least less than once in 12 to 25 years.

Perspective

Map 6: With winter fast approaching and several months between now and next growing season remaining, there is little to do but wait out the winter and hope that favorable weather patterns dominate the skies. Across the south, April, May and June are the most important months for cropping. Across the Central, North West and North East Regions, May June and July are the most critical months, while across the Peace Region, winter snow accumulations and late May through to early August are the most important moisture bearing times (Map 6).