October Thunderstorms?  - Oct 15, 2012

I've had a lot of people asking about the thunderstorms that rolled through over the weekend. October thunderstorms ARE rare.  But, with weather, it's always more about "Conditions" than
the "Calendar". And...when you think about it, maybe October thunderstorms shouldn't be as uncommon.  

In fall, we have a low freezing level (which is favorable for thunderstorm development).
We typically don't have instability as high as it was over the weekend, but with cold air aloft &
significant surface warming, we DID generate a good amount of instability.  Some strong updrafts developed
and...KABOOM.  Lightning, thunder, hail & heavy rain.

That rain has pushed the October rainfall total to 17mm (as of today).
Two weeks into the month & we've already had more rain than all of September (14mm in Edmonton).
The 30year average rainfall is 42mm in Sept & just 11mm in Oct.

There's more rain on the way.  Skies clearing today, but a new system will sweep in from the west tonight.
That'll bring scattered showers overnight & mostly cloudy skies with a good chance of showers again tomorrow.
The heaviest, most organized rain looks like it'll fall north of Edmonton, but the Capital region WILL likely
get some rain.

Looking LONG range:
Temperatures are set to tumble at the end of the week.  Chance of snow & highs near zero by the weekend and into next week.


Edmonton Forecast looks like this:

Today - Clearing to mainly sunny.
High:  14

Tonight - Increasing cloud.  60% chance of a shower late this evening & overnight.
Low: 6

Tuesday - Mostly cloudy.  60% chance of showers.
High:  10

Wednesday - Mix of sun & cloud.
High:  6  

Thursday - Mix of sun & cloud.
High:  8  

Friday - Mostly cloudy.  40% chance of rain turning to snow.
High:  5  

Saturday - Mostly cloudy.  30% chance of flurries.
High:  2