The good news is the heat is here that myself, Travis and bigmt mentioned last week. It is already up in the mid 30’s with the humidex for many locations across Southern and Eastern Ontario today. Tomorrow could be even warmer, however a low pressure system crossing to the northwest through Northern Ontario will spark thunderstorms tomorrow afternoon across Southern, Central and Eastern Ontario. Some of these could become severe with the humidity and instability in the atmosphere. Seaway has some information on his posts and will keep you updated. Interestingly enough, the low pressure moving through Northern Ontario later tonight and tomorrow even brings snow with it up towards Geraldton, Nipigon even across to Timmins. Talk about a wild swing, many of the these locations will experience a 20 degree drop in temperature come tomorrow!
Now the bad news: the heat wont last 😦 Although we don’t drop down well below normal like we have been most of the month, we do drop to near or slightly below normal for the rest of the long weekend, and likely through the rest of the month of May. The trough pattern that has been in place for the first part of the month wants to return; bigmt mentions it towards the end of this article here and you can also note the pattern reversal in the newest Euro weeklies – below normal until June 5th. Here is the outlook from EC out to June 1st.
To soften the blow of the bad news, since our daily high temperatures continue to climb with stronger sunshine and much longer days, below normal doesn’t mean freezing cold days. Our normal high temp around Ontario is now 18c to 21c, so a nice sunny day around 18c is really not all that bad compared to normal. We have also seen some of the models stumble on these 2 meter temperatures lately so you certainly can’t rule out that a sunny day climbs to normal levels.
This normal/cooler pattern also looks to bring more low pressure systems to the area. It looks fairly wet from May 21 through to the 31st with only a day or two break in between rain and showers.