thunderstorms for southern Ontario July 22-24., chance for storms starting tonight. Options

[players1]

there is a chance that some storms maybe sever will start in Ontario tonight and continue until Saturday.

if the MCS that is in the mid-west US continues east tonight it should make for an interesting evening in Southern Ontario.

 centgrtlakes.gif ( 159.17K ) Number of downloads: 1


This is coming in along a warm front which should bump up the temps and dew points for tomorrow and maybe saturday.

the folling is a write up from EC.

ACCN10 CWTO 220859
Convective weather forecast for the province of Ontario
Issued by Environment Canada Ontario region
At 4:59 AM EDT Thursday 22 July 2010.
This forecast is issued at 4 AM and 4.30 PM daily between May 1
And September 30.

This forecast is issued at 4 AM and 4.30 PM daily between May 1
And September 30.

Note: this is not a severe weather watch warning or special weather
Statement.

Discussion of thunderstorm potential.

Today..Scattered non severe thunderstorms are expected across
Northwestern Ontario.

Tonight..A cluster of significant thunderstorms may reach Lake Huron
or Southwestern Ontario overnight ahead of a warm front. There is a
slight risk these storms may be severe with torrential downpours as
the main concern. There is a lesser risk of isolated large hail or
brief damaging winds. Isolated non severe thunderstorms are also
likely across Far Northern Ontario.

Friday..The warm frontal thunderstorms will likely be tracking
eastward across Southwestern Ontario to Niagara or the Golden
Horseshoe in the morning. There is a slight risk that these storms
may be severe with torrential downpours, large hail, damaging winds.
Scattered thunderstorms are likely to regenerate over Southwestern
Ontario towards the Golden Horseshoe Friday afternoon. There
Is a slight risk that the afternoon storms may be severe with
torrential downpours, large hail, damaging winds being the main
threats. An isolated tornado cannot be ruled out. There is a lesser
risk of severe thunderstorms for the Golden Horseshoe Friday
Afternoon. Also..Widely scattered non severe thunderstorms will also
be prevalent across the remainder of the province.

A severe thunderstorm is defined as having one or more of the
following

- wind gusts of 90 km/h or greater.
- hail of 2 centimetres diameter or greater.
- rainfall rate greater than 50 millimetres in 1 hour or less.
- tornadoes

END/OSPC

http://www.weatheroffice.gc.ca/warnings/SW..._e.html?prov=on (source)

This post has been edited by players1: Jul 22 2010, 01:08 PM

[travis3000]

So according to them, anywhere north of the GTA will see no thunderstorms at all.

[Torontoweather]

there is a chance that some storms maybe sever will start in Ontario tonight and continue until Saturday.

if the MCS that is in the mid-west US continues east tonight it should make for an interesting evening in Southern Ontario.

 centgrtlakes.gif ( 159.17K ) Number of downloads: 1


This is coming in along a warm front which should bump up the temps and dew points for tomorrow and maybe saturday.

the folling is a write up from EC.

ACCN10 CWTO 220859
Convective weather forecast for the province of Ontario
Issued by Environment Canada Ontario region
At 4:59 AM EDT Thursday 22 July 2010.
This forecast is issued at 4 AM and 4.30 PM daily between May 1
And September 30.

This forecast is issued at 4 AM and 4.30 PM daily between May 1
And September 30.

Note: this is not a severe weather watch warning or special weather
Statement.

Discussion of thunderstorm potential.

Today..Scattered non severe thunderstorms are expected across
Northwestern Ontario.

Tonight..A cluster of significant thunderstorms may reach Lake Huron
or Southwestern Ontario overnight ahead of a warm front. There is a
slight risk these storms may be severe with torrential downpours as
the main concern. There is a lesser risk of isolated large hail or
brief damaging winds. Isolated non severe thunderstorms are also
likely across Far Northern Ontario.

Friday..The warm frontal thunderstorms will likely be tracking
eastward across Southwestern Ontario to Niagara or the Golden
Horseshoe in the morning. There is a slight risk that these storms
may be severe with torrential downpours, large hail, damaging winds.
Scattered thunderstorms are likely to regenerate over Southwestern
Ontario towards the Golden Horseshoe Friday afternoon. There
Is a slight risk that the afternoon storms may be severe with
torrential downpours, large hail, damaging winds being the main
threats. An isolated tornado cannot be ruled out. There is a lesser
risk of severe thunderstorms for the Golden Horseshoe Friday
Afternoon. Also..Widely scattered non severe thunderstorms will also
be prevalent across the remainder of the province.

A severe thunderstorm is defined as having one or more of the
following

- wind gusts of 90 km/h or greater.
- hail of 2 centimetres diameter or greater.
- rainfall rate greater than 50 millimetres in 1 hour or less.
- tornadoes

END/OSPC

http://www.weatheroffice.gc.ca/warnings/SW..._e.html?prov=on (source)

Indeed, I am looking for this large MCS to move through southern Ontario somewhat slowly in the overnight into the morning with possible high winds, and a less likelier but still a chance for hail and the isolated tornado, then we may have short destabilization period with some sun, before a possible second round of storms tomorrow afternoon-evening. I think Saturday though could be a more significant day for strong-severe storms, with high shear(conducive for strong winds), fairly high EHI values(which could be/would be conducive for tornadoes), fairly decent CAPE values(instability), high dewpoints(into the 70's F likely), high 0-1km and 0-3km helicity(which would also be conducive for strong winds). Could be an interesting 48-72 hours!

[Weather X]

Indeed, I am looking for this large MCS to move through southern Ontario somewhat slowly in the overnight into the morning with possible high winds, and a less likelier but still a chance for hail and the isolated tornado, then we may have short destabilization period with some sun, before a possible second round of storms tomorrow afternoon-evening. I think Saturday though could be a more significant day for strong-severe storms, with high shear(conducive for strong winds), fairly high EHI values(which could be/would be conducive for tornadoes), fairly decent CAPE values(instability), high dewpoints(into the 70's F likely), high 0-1km and 0-3km helicity(which would also be conducive for strong winds). Could be an interesting 48-72 hours!

Hopefully it comes together.

[sumdude86]

Looking at the radar, nothing looks impressive, the rain looks light with a bit of some heavy downpours possible. From what i have seen it doesn't look like anything significant will happen as EC suggested

[TriC]

Looking at the radar, nothing looks impressive, the rain looks light with a bit of some heavy downpours possible. From what i have seen it doesn't look like anything significant will happen as EC suggested

The way this system is setup and the fact that its a warm front. You will likey see the big ones pop up after sunset. into the over night.

This post has been edited by TriC: Jul 22 2010, 06:01 PM

[TriC]

Lots going on in the Southwestern Ontario tonight! Tornado Watch, Thunder storm watch and heavy Rainfall Warning..

[sumdude86]

Lots going on in the Southwestern Ontario tonight! Tornado Watch, Thunder storm watch and heavy Rainfall Warning..

Ya this is crazy!! up to 70 mm possible here in the Southwest, possibly even more with Thunderstorms

[travis3000]

EC was wrong, the heaviest rain turned out to be further north in a band from Goderich and Kinkardine west to Lake Simcoe. Here at my house, 15KM WNW of Alliston, I recorded 40 mm of rain that came down between midnight and 7am . Mount Forest got it even worse with 56mm! The GTA received 20 to 30mm on average with the SW reporting very scattered amounts.

EC issued a special weather statement this morning confirming this, and warned for the risk of severe thunderstorms tomorrow afternoon and evening which are capable of producing tornadoes.

[TriC]

At 8am the humidex in London was 37c.. 40c in Windsor. I can't even see out the windows in the house since they are fogged up on the outside from it being so warm in humid. its going to be a muggy one today the sun is already starting to peek out. any place that has AC their windows have water just running down the outside from the condensation. dew-points around 8am at 24-25c. in Southwestern Ontario looks like we could get some good storms today and tomorrow.

From EC for the SW today
Today..Scattered non severe thunderstorms over south Central Ontario
this morning.
Isolated thunderstorms over Southwestern Ontario today and tonight.
A few of these storms could be locally severe due damaging winds and
large hail during the afternoon and evening hours with an isolated
tornado not to be ruled out. Elsewhere isolated non severe
thunderstorms.

This post has been edited by TriC: Jul 23 2010, 08:27 AM

[sumdude86]

Ya EC messed it up big time, they had the Southwest under a rainfall warning and while we did get some rain and some of it came down heavy at times, we didn't even get close to what they were saying. It is really humid out, windows here are also fogged up

[Weather X]

Ya EC messed it up big time, they had the Southwest under a rainfall warning and while we did get some rain and some of it came down heavy at times, we didn't even get close to what they were saying. It is really humid out, windows here are also fogged up

I'm jealous of ur temps and humidity!!!!

[dsichewski]

Kitchener had a huge thunderstorm pass over it at 8am today.....Heavy amounts of rain (the sod field was flooded with 6" puddles when I left it and that all accumulated in less than 10 min) Bright lightning (sheet and many lightning strikes and lots of thunder! From about 5am till 8 am it was hot out and quite muggy...
Kitchener/Waterloo had reported flooding on many streets, cars were hydro plaining and couple cars landed in the ditch

Ok who's ready for round 2? I am!

[sumdude86]

Humidex is already up to 41 down here, Temps are approaching 30 already!!

[weatherman 23]

The warm air is surging in behind that warm front. Dewpoints are so high!

[sumdude86]

Dark, ominous sky, thunderstorm is about to roll through my area

[dsichewski]

lol i just found this video on the weather network from someone that lives in the core of Kitchener....you can see how much rain we got in so little a time! Canoe ride anyone?

http://www.theweathernetwork.com/your_weat...2555/2/caon0356

[sumdude86]

Pretty good storm rolling through St Thomas, Very heavy rain, i couldn't see across the street, gusty winds was blowing the rain in all directions and dangerous lightning and loud thunder

[Weather X]

So here in Toronto we got into that extreme humidity shortly after I wrote my last comment! We were up to 31C and an amazing humidex of 44C!!!!!! Temps have back off about 4 degrees as the we have clouded over in the past couple of hours.

That kind of humidity warrants some major t-storm action!!!

Dewpoints were at there highest I can remember since August 1, 2006? We had a 25C dewpoint in the afternoon.

[Torontoweather]

There are now 2 tornado signature cells on the map; one in SE Michigan heading towards SW Ontario and one already in SW Ontario. The one already in SW Ontario is alos producing hail of between 5-6cm in diameter!

http://www.wunderground.com/radar/radblast...&rainsnow=0