June 16, 2000
Storm Chase
The
day started when I decided to have a look at some of the severe weather
discussions on various sites. The Storm Prediction Center had a slight
risk out for southern Ontario, and according to the discussions, it
sounded like it was going to be an active day. According to SPC, large-scale
forcing would shift northeastward into southern Ontario. Mid level temperatures
would also be cool to allow the thunderstorms to develop by the early
afternoon as strong severe line segments along and ahead of the cold
front. And according to Environment Canada, a very warm and increasingly
humid air mass would be brought back into the region by southerly breezes.
There was a risk of heavy thunderstorms in many areas, including the
extreme SW. The day before, EC issued the convective weather statement.
They also had a slight risk out for southern Ontario, with damaging
winds, torrential downpours and intense lightning late in the day as
a cold front moves from the west. I decided to pay a visit to the Vortex100
Storm Chase Page as well, and see what Meteorologist Robert Lattery
would be forecasting. According to him, the storm system in the plains
would advance southeastward with isolated severe thunderstorms expected
to reform along the boundary from central Great Lakes to the southern
plains. Moderate instability was expected along and ahead of the cold
front, with lifted indices in the -3 to -6 range from southeastern Michigan
and southern Ontario into Oklahoma and NW Texas. Very good upper level
energy and jet diffluence was expected to mix with very good convergence
and lifting to produce widely scattered intense convection late in the
afternoon and evening. CAPES were forecasted to reach 2000 J/kg, according
to SPC's day one outlook discussion. Weak caps and shear profiles also
suggested that the storms would likely evolve into multicell line segments.
A band of strong low to mid level flow associated with the southern
periphery of jet oriented, perpendicular to the lines, were expected
to provide enough support for storms to produce isolated strong to damaging
wind gusts.
The first severe
thunderstorm watch was issued by EC later that morning, at 11:03 and
was in effect until 6:00 PM. The watch was in effect for many areas
of southern Ontario, then later got extended to the extreme SW and was
in effect until 11:30 PM. Later that afternoon, I emailed EC Severe
Weather Researcher, Dave Sills, and asked him if there were any lake
breeze frontal boundaries that would help initiate the convection. According
to him, there were five boundaries. One of them was extending from Grand
Bend to Collingwood, while another one was extending from western Lake
Erie to Port Huron, Michigan. There was also another boundary from eastern
Lake St. Clair extending to Kitchener. Two other boundaries were east
of me. The Lake Ontario boundary went from Burlington to SE of Lake
Simcoe, and another one from Lake Erie extended from Long Point to Hamilton.
If any of the storms were to enter any of these lake breeze boundaries,
they were sure to fire up explosively. I took the information Dave Sills
gave me, and drew the boundaries on a map to use as a reference. Like
the usual, I ate dinner and logged back into the internet to keep an
eye on this situation. I then looked at radar and compared the location
of the storms to the location of the boundaries. There was a developing
squall line coming off of Lake Huron and entering Bruce county. These
cells were interesting, in that each cell was in a line, but they were
not connected. The line was formed diagonally, NE to SW, and the NE
end cells were less intense than the SW end cells of the line. It seemed
to be developing into an asymmetric case squall line.
I reloaded the radar,
and sure enough that line had changed its shape. It advance eastward,
while some more cells formed over southern Lake Huron. Going by radar,
this was sure to be a squall line event. I had been "burned"
twice this week so far, but Dave Sills mentioned that my luck should
change. A smile went across my face. I was going to have a good chase.
I decided to give
Dave Szozda a call, but unfortunately the line was busy. I guessed he
was on the internet. I emailed him to see if he was on, but no reply.
I got off and called him again on his cell phone and he finally picked
up. I told him of the developing squall line and mentioned that we could
chat about it over the internet. Him and I logged onto Messenger, a
program used to send messages to others, and we discussed the scenario.
I kept reloading the radar to get the latest image. The storms really
started to develop. Him and I concluded that we should go chase. He
logged off, while I was getting my chase gear ready. While waiting for
him to come over, I kept reloading the radar image to get the latest
image. After a little bit, I finally got a new one. Dave arrived, and
I showed him the radar. Then it started to thunder. It turned out that
the storm was coming. Dave, Rita and I left at 6:30 PM. We headed north
on 86, and we could see the darkening western sky. The storm was already
here. I then realized that the line of storms had entered the Grand
Bend to Collingwood lake breeze boundary and fired up. This was a classic
example of how lake breeze boundaries effect the formation of southern
Ontario's severe storms.
When we headed NW
on 86, I looked off to the north and saw some nice inflow features,
including some lowerings. I got out of the "Storm Descender"
and took videos of the features. It then started to rain, so I went
back in the van. There were a few CG's and inner cloud lightning, but
it was not very intense. As we headed toward the updraft region, we
encountered heavy rain at 6:50. We were just west of Elmira. There was
no warning issued yet, and we kept listening to the scanner. We then
remembered that it takes about 15 minutes for the weather bulletins
to get to the weather radio from the internet. So we assumed that the
warning was issued or at least going to be. Sure enough, the warning
came on the weather radio at 7:00. This was the first warning issued
for the day. It continued to rain heavily, so we pulled onto the road's
shoulder. I took some more videos of the deluge. After a few minutes,
the sky started to lighten up and the rain became lighter at around
7:15. By then, the storm seemed to already have moved out of the area,
so we decided to head back and check the radar. This was one of my shortest
chases, and we traveled about 40 km. We arrived home at 7:40. Finally...
finally Mother Nature was kind to me.
Total hours: 1 hour
10 minutes
Distance: approx.
40 km
