Last issue’s forecast wasn’t that great, which shouldn’t be too surprising, as every time the atmosphere undergoes a switch in patterns, things tend to be rather unpredictable. While the details of the forecast were off, the general pattern was on the mark, with the end of the extremely mild weather and the beginning of more seasonable temperatures.
So, the question is, will the colder air start to dominate, or will the mild weather make a comeback? At first glance, it looked like colder air was going to sweep in for the second half of the month, bringing our temperatures back down to more average values. Lately, the weather models have been pulling back on the extent of the cold air, so we may see milder-than-average conditions continue for a while longer yet.
On to the details. The weather models that have been doing the best job handling the forecast over the last while are calling for two weak areas of low pressure to track across our region from Wednesday (Dec. 16) to Friday (Dec. 18). Each of these systems could drop a few centimetres’ worth of snow at the most. The weekend looks to be nice, with light winds, a mix of sun and clouds, and temperatures pushing the freezing mark by Sunday.
To start next week, the weather models predict another weak area of low pressure moving through on Monday (Dec. 21), but it looks as though the models are trending toward a more northerly route for this system. This would result in only a slight chance of snow across southern and south-central regions, along with mild temperatures. Daytime highs are forecast to be around -5 C, with overnight lows around -15 C.
With a rapidly changing pattern, confidence in this forecast is low. The general trend has been toward milder-than-expected weather over the next couple of weeks, but the cold air is not too far to the north and it would not take much to pull it southward.
Usual temperature range for this period: Highs, -19 to -3 C; lows, -28 to -12 C