0.5mm? That's it?

June 23rd, 2010 will hence forth be known as "Wacky Wednesday." What a crazy day. The day started early for me as I arrived at our studios for an 8:30am shoot (of the "What's Happening" report) and my day did not end until well after midnight. Now the previous blog entry (below)covers the earthquake that originated out of the National Capital region, but what followed was a very busy night for forecasters and emergency responders across the province. Unlike the Earthquake (which was unpredictable), active weather was expected last night...but I'll be the first to admit that things were a little more active than anticipated.

Shortly after 8pm, Environemnt Canada started issuing watches and warnings for our area, the most serious of which were torando warnings for most of our viewing region including Peterborough (city and county), CKL, Northumberland, Fenelon Falls, Apsley and Woodview. Fortunately our region was spared from any tornadic activity but Midland Ontario, as I'm sure you've now heard, was not so lucky. The warnings were lifted around midnight as the line of storms continued to push east. At one point all of southern Ontario was under what is known as a "red alert." In the end parts of the city saw heavy showers, high winds and around 7,000 residents were left without power for a number of hours. In short...we were lucky.

One odd little statistic I'll leave you with is that only 0.5mm of rain was reported at Peterborough Municipal Airport for June 23rd. That's right, 0.5mm. 16.5mm fell later in the overnight but for Wednesday evening that's it. That will be the official rainfall total recorded by Environment Canada for June 23rd, 2010. Was that all that fell? No. I've heard reports that as much as 40mm of rain was recorded to the north (much of that falling before midnight) and many people across the city reported very heavy downpours that evening. Precipitation can be very isolated during thunderstorms. Just check out the video below shot durning yesterday's storm.

Shake, Rattle & Roll

What a day! We have active weather moving into the region later this evening (see the blog below) after a moderate size earthquake shook the region this afternoon. At 1:42pm a 5.0 to 5.5 (different reports vary on the magnitude) occurred less than 60km north of Ottawa near Chelsea Quebec. This part of western Quebec is known for mild quake activity but a 5 plus magnitude quake is rare. How rare? The last time a quake this size occurred there was in October of 1990...just 50-60km from the epicenter of today's quake. So what caused it? Earthquakes are not really caused by anything other than stress. Thousands of years ago the Canadian Shield was pushed down by the weight of a massive glacier. That ice has obviously melted and the depression caused by it's weight is now "rebounding." The Earth is rising in this area. The problem is that, unlike squeezing a rubber ball, this rising motion is not fluid. It happens in steps or "slips." As the crust rises it becomes locked along faults as rocks tend to grab one another or bind up (they're jagged not smooth). Pressure builds until finally the rock breaks or moves and a slip occurs. This rapid "readjustment" results in surface waves as all of that energy is released. Where the slip occurs is know as the "hypocenter" and the point directly above the slip at the surface is the "epicenter" which is what you see on the map I've created above.

So we know where the quake occured but how far away was it felt? Earlier I spoke with John Bellini of the U.S.G.S and he told me about reports as far away as Sudbury and as far south as Washington. Wow! So why is this quake such a big deal? While no major damage has been reported this is a very rare event. Peterborough is not located along a tectonic plate boundary (like Los Angeles or Tokyo) so we're simply not used to the ground shaking. That's why a 10-20 second tremor managed to get everybody talking. Full details plus my quick interview with the U.S.G.S. will air tonight on Newswatch @ 6pm. To see a video explanation I gave to the Peterborough This Week newspaper as to why the quake happened click here. Hopefully this video helps answer the question why.

An active night ahead...

Will tonight be a quiet night across the Kawarthas? Not likely. Some active weather is a probability tonight and there is the risk of severe weather. Let's take a look at the latest forecast model run below...





Now I've drawn in the fronts so that this image makes more sense. The first frontal passage will be early this evening as a warm front moves across the region. Rain and some mild (non-severe) activity is possible with this frontal passage but the potential for real active weather will be with the passage of the cold front late this evening. Between 10pm and 12am tonight that cold front looks to push in from the northwest and, after a very warm and humid day, that cold front could trigger some severe weather. Keep in mind that this is only a possibility as no watches or warnings have been issued at the time I write this blog...but there is a very good chance. Cloud heights to the west are in excess of 50 thousand feet which could mean hail and likely very heavy rain. Tornadoes are also possible although I think southwestern Ontario has a better chance of seeing a twister than here in Peterborough...but I'll keep you posted on CHEX and via Twitter if any warnings do pop up. Even though there is just a chance for severe weather it's best to be prepared and cover up the tender vegetation and secure loose patio furniture. Also bring the pets in tonight just in case. I'll have more details for you tonight on Newswatch at 6pm.

Gone tonight. Back tomorrow...the rain that is.

After a sunny start to the day it ended up being a rather wet one. For much of the day the region saw a light but steady rain and, at times, a few moderate showers. Looking at the image above (from our Adonis forecast model here at CHEX) you can see that first system and the cold front that pushed through region already to the east of us by 8pm tonight. With lingering instability, showers are still possible to the west of that "low" but things will clear later tonight. Tomorrow we're likely to see a sunny start to the day but a second "low" (that you can see southwest of Lake Erie) moves in late day. Unlike today which (although humid) was relatively cool, tomorrow looks to be warm and muggy. With all of that potential heat and humidity thundershowers are possible tomorrow night once that second system moves in. Another cold front pushing through the region could be all the that is needed to see an active wrap to the day...so don't let a sunny start tomorrow morning catch you off guard.

One of the best things about having this blog is having the ability to get a little more in-depth with you while "talking weather." The blog wouldn't exist without readers so I want to thank all of you for checking out the weather blog and also to give a "shout out" to one particular reader (and CHEX viewer). Thomas, like myself, is a big "weather nerd" and his birthday wish was to be a Weather Watcher and his wish came true...

















Thomas and his friends spent some time in the CHEX TV studios last night and even had the chance to try out the famous "green screen. As you can see, the kids had a great time. Very cool!

















Afterwards we had the chance to talk about hurricanes, thunderstorms and all things weather. When it comes to weather let's just say Thomas has a bright future in broadcast meteorology. I'm always impressed with how much kids know about weather. Happy birthday Thomas and thanks for watching CHEX TV!