Agricultural moisture situation depending on what part of Alberta

As of September 11, cool cloudy weather moved into most of the province, lingering for several days, bringing high humidity and poor drying conditions. This was especially true for those lands across the north-half of the province, where light showers and heavy dew likely hampered harvesting efforts for many.

As the skies cleared on Tuesday, the early morning temperatures moved below the freezing mark, ushering in a widespread frost that affected most areas of the province, lying roughly north of the Yellowhead highway but also extending down along the Saskatchewan border as far as the Special Areas. Much drier than normal conditions have continued to persist across southern Alberta, a trend that began in early July, generally following near normal or above moisture through May and June.

8-day precipitation accumulations as of September 16

Across the south-half of the province most areas received less than 1 mm of rain, if any at all. North of the Yellowhead Highway it was cool and moist, with many areas up as far as Manning experiencing bouts of light rain under heavy cloud cover, with total accumulations generally under 5 mm. Through the northern Peace Region conditions were wetter, with many lands receiving as much as 15 mm of rain.

Frost since the last report September 8 to September 16

As the cool, cloudy weather moved off early this week, clearing skies allowed heat to escape from the land, resulting in a widespread frost during the morning of September 16. This affected a large area of the province ranging from the northern Peace Region, all the way down to the Special Areas. Several widely scattered pockets saw the mercury dip to below -4C, with 7-10 consecutive hours remaining below the freezing mark.

For some locales, this marks the third frost event this harvest season, with the first one on occurring on August 31, the second one on September 8 and this last and most severe one on September 16.

Precipitation accumulations over the past 60-days (map) has seen a marked drying trend across most of the province, which includes some of the previously wet areas in parts of the North West (Map 3). The recent trend to below normal rainfall accumulations has had the most negative affect through much of the Southern Region, where it normally dries out markedly in early July. Here, below normal rainfall during a normally dry period has had an adverse affect on crop growth, particularly in pastures and hay land.

Some lands north of Medicine Hat received rainfall totals this low (for the same period), on average less than once in 50-years (Map 3). In contrast, some wet areas through the North East, parts of the Central Region and the extreme northern Peace Region have remained near normal or above.

Generally, most of Southern Alberta has been extremely dry with lands north of Medicine Hat receiving less than 20 mm. This dry zone extends through much of the Southern region were many lands have seen less than 40 mm in 60-days.