Today was one of those days, the morning was cloudy, foggy and cool, the forecast was for thunderstorms and depending on which model you wanted to believe it was bang or bust. The surface observations and meso-analysis data suggested a good amount of shear, low cloud levels thanks to the ample moisture, good visibility but limited energy. The whole forecast was basically based on surface observations and satellite data augmented by the meso scale RAP RTMA data which I like to use to sort of fill in the blanks. At the end of this set I'll get into some technical discussion about what made this storm special and why it did or did not do whatever it did. Anyway, the target was somewhere around Arthur and this storm fired up near Grand Bend along a surface trof riding under a mid level moisture plume. The storm quickly developed and tracked north but really looked like crap on radar, and I mean just CRAP! Dave Patrick and I who met up just north of Aurther raced north on hwy 6 as the storm came into view and were greeted by this rapidly developing wall cloud.

This was really one of those "wow, it going to probably drop a tornado soon, I feel like I'm in Oklahoma" moments. Usually structure this good in Southern Ontario means batten down the hatches and this was really a ground scraping wall cloud!

As the storm continued on, the strong 20km/h southerly inflow quickly turned to a gusty westerly flow as the rear flank downdraft kicked down and around. Look at the way the grass is leaning towards the bottom of the picture, it's leaning towards the right (east) since the photo was taken looking north. Dave was so impressed he was almost wandering around aimlessly in awe, video camera in hand forgetting to record!

The first really great chase day of the May season! I like to make photos interesting, and perspective is key! Just as Dave was pointing up at some of the rotating scud getting sucked in near the rear of the wall cloud I was able to snap this photo of him pointing! This was definitely one of the more awe inspiring weather moments I've had in Southern Ontario!

As the storm chugged along northeast from Mount Forest towards Shelburne it began to undercut itself since the RFD kick was so intense.

Despite this undercutting, the storm was actively cycling and working to produce a new wall cloud and again present another opportunity to produce an elusive Southern Ontario tornado.

Positioning ahead of the storm once again, this time just west of Shelburne in the wind farm area it was amazing to see the storm sucking up moisture and continuing to produce dangly things.

Getting closer to the storm it was doing some crazy stuff, it was neat to see the storm pull in and directly ingest what appeared to be fog from the surface. This really let's you see how a parcel of air get's into the storm and the path it takes. You can see how on the way up the air is twisting and coming in from an angle instead of going straight in and up.

Sadly, the storm was moving quickly and getting into a less chaser friendly area as it neared the edge of the Niagara Escarpment. A couple neat things happened, a combination of tree scud and pooled moisture that was overrun by the warm boundary or forced up the escarpment allowing up slope cooling created dense pools of fog which get sucked into the storm making for some cool skies. (no pun intended) Secondly, while out in what was essentially the middle of nowhere Dave and I ran into Todd Rittinger, or well we were parked and he ran into us! This is the second time I've run into another storm chaser in the field in Southern Ontario this year. It was a brief encounter but nice to meet Todd finally!

While we gave up and storm and watched it wander into the area north of Barrie (and eventually cottage country) I was intrigued by this weak "stuff" moving in from the west.