ShieldsWeather.com Blog

Summertime activities have slowed down my time for blogging but today I thought I’d mention a cold front passage. This image shows the line of rain and storms ahead of the cold front, about to hit the Sault at 6am.

The cold front will work its way west to east today bringing rain and storms across the region. Regions that see the onset of this activity during the afternoon may see some intense storms.

The storm prediction center suggests that regions east of Iron Bridge have a chance of strong storms bringing some hail and strong winds. People in this region should keep a heads up for threatening weather and tune into public warning sources for the latest weather watches and warnings.

I haven’t blogged much in the last couple days as I’ve been working on improving some forecast details for the long range forecast. I’m also working on a pay-for-use service that will get detailed weather information to those needing that service for their work-place activities or personal scheduling. More on these additions once they come online.

For today I want to talk about Lake-Breeze activity. You often read me comment about the products of lake breeze activity. It could be just clouds, rain or even thundershowers.

This map is from Dr. David Sills, a meteorologist from Environment Canada, that specializes in Lake Breeze activity around the Great Lakes. He has more detailed information at http://www.yorku.ca/pat/research/dsills/primer.html .

Lake breezes around Algoma seem to form mostly on the north shore of the North Channel and sometimes east of Lake Superior. Often the lake-breeze can be seen at work by a thin line of clouds that extends along the North Shore just inland of Highway #17.

Sometimes this line can become intense and spawn a shower or even a thundershower. If conditions are primed for severe weather than a lake breeze can act as the catalyst to fire severe storms.

You can see from the diagram that lake-breezes are due to the uneven heating of the cool spring lakes and the neighbouring landmass. It is important for wide-scale windspeeds to be light, or the lake breeze cannot establish.

I bring this topic up today because we have a real chance of lake-breeze clouds and showers over the next couple days. Upper Michigan is great for lake breeze development as Lake Superior and Lake Michigan combine to create the merging of two lake breezes, which enhances the effects even more.

Watch for showers to fire in Upper Michigan today and Saturday and then they may move into Ontario or we may see our own lake breezes start up along the North Shore.

Time to drift away from the cold, wet weather and dream of warm summer days.   Trust me - it’s not too far away.  It has been a cool damp spring but the latest round of long range forecast models suggest that the Canada Day weekend could be Hot!

By late next week the American south-central will be cooking in +40C weather.  A low pressure system should bring that warm moist air into the Great Lakes by next Friday.

This all means we have a good shot at +30C temperatures and humidity for the holiday weekend.  The map shows the extreme heat in purple and bright oranges in our region will translate into upper 20’s and low 30’s.

So this week, while you’re shivering at the kids soccor/baseball games just think of the hot sticky weather that coming next week.

A low pressure system that brought rain and storms this past weekend will park itself well to our northeast.  This positioning will then allow the low to draw cool arctic air into the upper Great Lakes region for the next several days.  Along with the cool temps will come fall-like northwest winds off of Lake Superior.

This image shows surface temperatures and wind for Tuesday afternoon.  You can see how the cold air is pulled across Superior and into onshore locations.  The greens are temperatures below +10C.  Normal temperatures, for this time of year, are on the border of light yellow and light orange.  Near +21C.

This setup for cool air will move east, towards the end of the week.  Until then it’ll be ‘jacket’ weather and fall-like lake effect showers for those close to Superior.

A cold front pushes into the region on Sunday afternoon. This may trigger some thunderstorms during the peak heating hours. These storms could possibly generate hail with relatively low freezing heights.

The storms will move out Sunday night and bring cold, dry air. By Monday and Tuesday we could see rain and unseasonably cold temperatures.

Current projections suggest we could see high temps at or below +10C for Monday and only slightly higher on Tuesday!! Cold air will be channeled into the region on the backside of the low connected with Sunday’s cold front.

Temps warm up by the end of the week but this damp, cool spring just keeps holding on!

An unseasonably deep low pressure system will move into the region over the next couple days.  The depth of this low compared to exiting high pressure will create an impressive pressure gradient.

Pressure gradients indicate wind speeds.  The closer the isobars (line of equal pressure) are together the stronger the wind blows.

The attached image is the forecast pressure gradient for this afternoon.  You can see the closest isobars are over the Sault region (circled) and the orientation suggests a southeast wind as winds blow counter-clock wise around low pressure.

Peak winds could reach over 50km/h today with sustained to 40km/h expected for this afternoon.

A cold front pushed through some more strong storms yesterday afternoon.  I chased a storms into Garden River and north of Echo Bay that brought heavy rain and small hail around 4:40pm yesterday.

Non-severe storms continued to roll across the region until 7pm and then skies cleared as drier air arrived.

Today will see some sunshine before the next system moves in tonight.  There is a slight risk of a shower Thursday morning but the heaviest rain arrives Thursday night with more storms.

Tomorrow could end up windy as the pressure gradient tightens, with the incoming system, and generates winds over 40km/h.

I spoke to Envirnonment Canada today about the damage path, the type of damage and orientation of that damage. Most damage could be attributed to microbursts or a weak F0 tornado but the 7km length of damage has lead EC to declare this a probable F0 (weakest tornado on the Fujita scale, F5 is strongest)

I was told that there was a small hook echo on the Montreal River Radar station. Hook echos are often indicators that a tornado is on the ground or about to touchdown. I am still trying to get a copy of that radar return to post here on the blog.

Thanks to everyone for your information, pictures and stories about this storm. Thank goodness no one was hurt and I hope its heightened awareness to the possibility of severe storms, even tornados, in our region.

Here’s the official statement from Environment Canada…

AWCN12 CWTO 102026
Weather summary for Northern Ontario
Issued by Environment Canada Toronto
At 4:21 PM EDT Tuesday 10 June 2008.

Probable tornado last Friday evening in Sault Ste Marie area.

Severe thunderstorms passed through the Sault Ste Marie area around
6 PM EDT on Friday June 6th. Significant roof damage was reported at
A tractor dealership and a neighbouring house near echo bay.. In
addition to other building and tree damage along a 7 km path
northeastward to bar river in Laird township.  Photographic evidence
suggests most of the damage was rated as Fujita scale zero (f zero)
associated with winds up to 115 km/h. While straight-line winds due
To a microburst may also be a possible explanation.. The relatively
long and narrow path of damage lead Environment Canada to call this a
"probable f0 tornado." as such.. This represents the fourth reported
tornado in Ontario so far this summer. In an average summer Ontario
receives 11 tornadoes.

Further updates may be provided if more information becomes
available.

Please note that this summary contains the observations at
The time of broadcast and does not constitute an official
And final report of the weather events or the high
Impact events attributed to the weather events.

END/KIMBELL/SEIFERT

Environment Canada tried to contact me on Sunday morning about possible tornado at Laird Hill and Bar River. They had been reviewing my photos and wanted to ask my more details about the storm. Much of the damage looks to be micro-bursts and possibly a F0 tornado. The exception was the roof torn off of the building at North Shore Tractor. The damage there suggested winds to 170km/h, which would be a F1 Tornado.

I will be speaking with a meteorologist from Environment Canada(EC) early this week to provide more details and pictures. It is doubtful that EC will send out a team to investigate the damage.

I will forward details of my conversation with EC and post it in this blog.

This is the email I received from Environment Canada on Sunday morning….

I am a meteorologist with EC, and am on your wx email list, and I have to say that I am very impressed with the info you have about the storm near the Sault in your blog. It sounds like you are very keen about severe weather

We likely won’t be sending out a team for a damage survey as likely most of the damage has been cleaned up by now, but I was wondering if you could provide us with your phone number so that we could ask you some questions. It sounds like you have a lot of useful information that could help us out (in determining tornado vs straight line wind).

This bulletin came across my desk this evening. It suggests that Environment Canada is checking into a possible tornado near Laird/Bar River region and that it may have been a F1 tornado, based on the damage pictures of North Shore Tractor.

If this is the case, then this will have been the strongest tornado to hit Ontario this spring season. More to come as information becomes available….

This is from Environment Canada –

AWCN12 CWTO 072323
Weather summary for Northern Ontario
Issued by Environment Canada Toronto at 6:20 PM EDT Saturday 7 June
2008.

Possible tornado Friday evening in Sault Ste Marie area.
————————————————————-
==weather event discussion==

Severe thunderstorms passed through the Sault Ste Marie area on
Friday June 6 near 6 PM EDT. Damage was reported at a tractor
dealership near echo bay. Photographic evidence suggests most of
The damage was rated as Fujita scale zero (f zero) associated
With winds up to 115 km/h. However a roof was torn off a warehouse
suggesting winds in the Fujita one range (f1) between 120 to 170
km/h.

A severe thunderstorm warning was in effect for the Sault Ste Marie
region at the time the damage occurred.

Environment Canada is continuing to investigate this event to
determine whether the damaging winds were associated with a
Tornado or not and will provide updates as more information becomes
available.

Please note that this summary contains the observations at
The time of broadcast and does not constitute an official
And final report of the weather events or the high
Impact events attributed to the weather events.

END/Rodgers/COULSON