Ben's Weather Blog

The omega block continues to dominate, and we will see even more hot, but not record hot heat for the rest of the week.

Yesterday the high was 24, and today it seems we have 25. Quite hot, knowing the average high for this time of year is 18. It seems we’ll have similar temperatures for Thursday and Friday, but tomorrow and Saturday are going to reach up into the high 20s.

Right now, it’s looking like tomorrow’s high will be something like 28 or 29, a full 10 degrees above normal. For Saturday, maybe something similar. If you’re wondering if we may break a record, then I’d say probably not, but it could happen on Saturday. The record temperature for tomorrow is 33.6, from 1981. On Saturday, it is 29.4 from 1922.

What about the lows? The forecasts for these have been very unreliable, so we’ll probably see a lot of variation. There might be some that are 12 or 13, and others that get to what they were this morning (5.7). For the next 5 nights though, they will for the most part probably end up in the 9-12 degree range.

That’s it! Just a small update on the heat. If you’re wondering what is coming after this and how that pattern seems likely to break soon, check out the post that came out yesterday.

Sorry it’s been a while since the last post on the blog; I was taking a break for the first bit of school. Somehow this heat wave is still going, but there seems to be evidence of it possibly ending soon.

Over the next 6 days, temperatures are going to continue to be quite above normal, with the hottest being Wednesday and Saturday. This heat is because the omega block, which was moving east, but kind of stopped a handful of days ago. Despite such a strong ridge, there actually is a low under it that is giving mainly Saskatchewan and Manitoba quite a few showers right now. This low will likely only give us a shower or two later this week, if anything.

The main thing to talk about here is next week. It seems the temperatures will cool a bit again, with a lot of uncertainty for where they’ll land. For Saturday and Monday, I think something like highs in the low 20s. We might see a bit more heat on Tuesday or Wednesday (It’s appeared on AccuWeather, which recently has usually been the first to find short one-day heat events). It is after this, that we might finally get a cold wave.

Even though this is a very recent thing (It has only really appeared in the last 24 hours), all the models are agreeing a lot about a cold wave late next week into the last weekend of September. It’s on The Weather Network, it’s on Accuweather, it’s on the US weather model, it’s on the European model, it’s even on the AI model. Everywhere temperature forecasts are dropping. I’m still not completely set on this though, because we’re talking a while out.

Currently, what are the models actually saying the reason for this long-awaiting cooldown is? I’ve looked, and it seems to be one thing: The Pacific High. for quite a while the Pacific high has been far out west. Usually it’s only 1-2 thousand kilometres off the west coast of the US, but for a while now it’s been more 3-4. It seems later this week it may actually drift back to its normal position, which when paired with the low in the Gulf of Alaska will really speed up the jet stream, pushing out the block. The low then sends out a trough, and down the temperature goes.

Well, that’s it for now! I will definitely provide more updates later, when confidence is more greatly acquired.

Today, it’s looking like a high a of 34. Or maybe 33. We’ll see. It might feel cooler than yesterday though, because there’s a lot more of a wind. The main discussion in this post though is about what is coming after the heat, which currently is not the most agreed thing.

It looks like our last 30 degree day of the heat wave is going to be Saturday or Sunday. After that, it look like a cooling trend for about two days back to near to slightly above normal. Beyond early next week though, we currently don’t really know what to expect. Here’s why:

A lot of times this summer I’ve mentioned the Pacific high. This is a high that is always in the north Pacific. It never really leaves. There is another one for us to worry about though; and that is the Bermuda high. This one is positioned over the Atlantic Ocean pretty much always between 15 and 60 degrees north. Even though weather systems propagate from west to east, this high does actually affect us a bit, and is one of the more minor reasons we are as hot as we are right now. The Bermuda high for most of the summer has been centred over the western Atlantic. However, about 5 days ago it actually moved significantly for the first time this whole summer break; over to the eastern Atlantic. The main role of this high is basically a roadblock for North American troughs: Whenever a low encounters it, it either stays in place or deteriorates. The high moving to the east opens up more opportunities for troughs to hit eastern Canada and the eastern US.

You’ve probably heard of the many frost advisories in eastern Canada and even parts of the US recently. This is because a big upper-level low has planted itself over there. Because the Pacific and western Canada is all “blocked up” (as I have mentioned in past posts), the lows have nowhere to go but east of here. If the Bermuda high hadn’t moved, a low might have been able to move the block more east, and we could be the one with a frost advisory right now.

So, can we get to the forecast? The high in the rex blocked Pacific is expected to actually move west this weekend (meaning the eastern cold wave will end then), before another high replaces it in the rex block. It does seem following the move of that high, a low above it is going to make a massive shortwave trough down to here, meaning for a very brief period of time, we might end up having below normal temperatures. Early next week, the shortwave trough will grow to a longwave trough, but by then it will be out of the area. This means we will end up sandwiched between systems, and the jet stream will be overhead nearly north-south for 3 or 4 days. We might still end up a little below it, so we’ll probably end up above normal, but far below what we have right now.

After this though, we get to the area of uncertainty. A lot of forecasts past 7-10 days in the last month have been very unreliable, for some reason. What they normally do is they pick up on a pattern and then it comes. But this last month of those forecasts just haven’t found the patterns that we end up getting. For example, this heat wave didn’t show up until only about a week before it! For something this prominent, the usual would be something like 12-20 days before.

There is evidence of the rex block completely breaking down near the end of next week, though that’s not been in every model or every model run. The most likely thing right now is maybe just toughing 30 again near Friday (or something around there) next week, then maybe a cold wave. Could be short, could be longer. The low that could do this is coming enough from the north that it will be on the drier side and might start raising questions about an early frost. Another possibility is an omega block ends up over BC. It’s not the most likely thing, but it could happen. This would probably have us end up in the 25-30 degrees range for highs for a least a handful of days. Anything mentioned in this paragraph is not certain. Right now, don’t trust anything that seems confident past 10 days.

There is one more thing I want to talk about here today. It is more of long-range kind of thing, but also not really. As we head into fall, we will start to see more of our cold wave some from lows farther north. This means they will be drier, but also cooler. As well, at some point soon, we’re going to have to start looking at a transition of lows being cold and highs being warm to highs being cold and lows being warm. This is still far off, but we might start to see some signs of it in the near future. Fall is the most unpredictable season of the year, and we’ll have to see what happens over the next two months, as well as monitor when and how fast the leaves fall. The main thing the trees look for for when to start shedding leaves is the amount of light, but they also take in to account the temperature, humidity, dew point, and much more. If you remember last year, it was pretty late, with most of the leaves falling in late September and into early October.

Anyways, that’s it for now. The next medium-range forecast will be September outlook coming on Sunday or Monday, depending on how much time I have. Keep your eyes peeled for a short long-range update later this week, and a short-range early next week talking about a hopefully more certain version of the same thing that was discussed here.

Temperatures have shot up to possibly 30 today, and low 30 highs and mid teen lows are expected for the rest of the week.

First off, the heat warning. A special weather statement is in affect for most of Alberta, but actually not a heat warning. The only area that has a heat warning is the Edmonton area. Why is this? Pretty much, for a heat warning, we need a high of 29 or above AND a low of 14 or above. Because lows are warmer in cities, Edmonton has just barely warm enough lows for a heat warning, but rural areas don’t. Calgary also doesn’t, because in southern Alberta they have higher criteria for a heat warning, but they are getting only around the same temperatures as us.

Next, records. For this, I’m going to show you two tables. One for highs, one for lows. The Weather Network has been extremely underestimating heat waves this summer, for some reason, so it’s not even on here because at this point it’s basically defunct (It’s been over 3 degrees below AccuWeather and Environment Canada for highs during heat waves since the start of June over a third of the time).

Overall, for high records, I’d say Wednesday, Thursday, and Friday are most likely, and for low records, Thursday is the most likely.

That’s it for the update! There might be another one later this week, but not for sure. What is coming later this week is both a medium- and long-range forecast!

If you remember all the way back to the August outlook, you may remember I was saying near the end of the month, or maybe in early September, there could be a pretty big heat wave. Well, look at where we are now. I guess AccuWeather’s temperature forecast 5 weeks ahead is more reliable than GFS’s precipitation forecast for the next 3 hours.

Right now, as you read this, (If you are reading before Saturday evening) there is a rex block setting up in the Pacific. If you don’t know what a rex block is, it’s pretty much a blocking system where a high sits on top of low, and the jet stream makes a backwards S shape. The rex block itself doesn’t really affect us, but it’s what happens after it that does: The low becomes a cut-off. This is very similar to what we had at the end of July, if you remember that. Just like then, the cut-off low makes the jet stream go really far north, and we heat up quickly.

This pattern is expected to hold for basically a full 5-8 days starting Sunday. The cut-off low looks like it will actually reconnect to the jet stream through the help of another low late next week, and will probably bring an abrupt end to the heat wave right around the end of August or start of September.

I would expect the heat wave to peak on Wednesday or Thursday, with highs likely pushing towards the 30s. Heat records are possible, but not super likely. I would say maybe a 50/50 chance.

Anyways, that’s it for now! Another update on Sunday or Monday!