Last week I noted that the forecast highs for Ottawa over the weekend were too high (9C or higher). Indeed I was correct. The actual highs were 6.5 and 6.3 C for Sat. and Sun. respectively.
Now there is a new specific case: Friday morning low. Currently Env. Can. forecast is for a low of -16C. There are multiple models (GFS, Euro, NAM) with forecast morning low temperatures lower than -20C. I will wager that over the next day or two Env. Can. forecast temperature will get lower. I will take the over/under bet that the Friday morning low will be -20C or lower.