Well, that was one heck of a September across pretty much all of Alberta — if you like it warm and dry that is. Looking back at my last article, it seems as if I jumped the gun when I talked about “Indian summer.” Looking across Alberta, it would appear that most regions have experienced nearly all of the conditions for Indian Summer until time of writing last week, but there was one important criterion missing — frost.
On several nights during the middle of September frost warnings were issued across large portions of Alberta, but when I actually checked, I found that few sites had actually recorded below-zero temperatures . Without experiencing a frost it is pretty hard to say that the beautiful weather is a true Indian summer.
Sometimes I think we need to forget about the frost and stick to the textbook definitions and simply say that the last couple of weeks of September were pretty darned amazing.
So, just how nice was September 2012? According to Environment Canada (which is still having trouble with data from several of its stations), September was anywhere from 2 to 4 C above the long-term average, which is a considerable amount to be above average. With monthly temperatures so far above average it implies there were no really cold or even cool periods during the month. Most days saw daytime highs in the low to mid-20s with several days seeing highs in the upper 20s with even the odd 30 C temperature recorded.
Overnight lows followed the same warm trend, with most nights finding the temperature between 5 and 10 C. The coldest temperatures occurred around the Sept. 12, when overnight lows fell to around 1 or 2 C in several locations.
Precipitation during the month was fairly low in most areas as high pressure dominated. Most regions saw below-average to well-below-average precipitation during the month. The only regions that saw near-average amounts were in the far north, thanks to some heavy rains during the second week of September. Over southern regions rainfall was pretty much non-existent, with a large area seeing less than 5 mm. Further north amounts increased, but even in the heaviest areas amounts were still only in the 50 mm range.
The rest of October
So now the big question is, will Alberta continue to see warmer and drier than average conditions or will the weather tide turn and bring cold wet weather for October?
According to the good folks over at Environment Canada, it looks like pretty much all of agricultural Alberta will see a continuation of above-average temperatures, with only the far northeastern regions expected to experience near-average temperatures in October. Precipitation during October, according to Environment Canada, will be average across all but the far southern regions, where less-than-average amounts are expected.
Over at the Old Farmer’s Almanac they are calling for both average temperatures and precipitation amounts in October. The always ambiguous Canadian Farmers Almanac seems to be calling for colder than average temperatures as they mention stormy weather and heavy rain several times. They also call for cold conditions to move on at least two occasions.
Finally, here at Alberta Farmer I am finding it a tough call for the western Prairies. The current weather models are showing strong ridging to dominate over the west coast of North America with a large upper trough over central to eastern North America. If the western ridge is strong enough or it is placed far enough east then most regions will see above-average temperatures. If the ridge is weaker than anticipated or is further west then southern regions will have the best chance of above-average temperatures.
Precipitation is always the toughest part of the long-range forecast but with drought conditions prevailing over much of central North America I don’t see many signs of any significant precipitation over the next month, so I expect the dry conditions to continue through most of October.