April 18, 2002
Storm Chase
It
all began on April 16th when I checked out the SPC Day 3 outlook, for
Thursday. Although it was the Day 3 outlook, I was not going to totally
believe in the forecast just yet because it could change the next time
it is issued. SPC issued a slight risk for the Great Lakes region. Southwestery
mid level winds were expected to be strong, and extend from the southern
Rocky Mountains into the Great Lakes. In this southwestery flow, several
shortwave troughs were excepted. The low was forecast to develop as
it moves across lower Michigan during the afternoon hours. SPC then
stated in their outlook that strong or severe convection would likely
be ongoing in this area and spread eastward during the day. Things were
starting to look like a severe weather setup. This outlook was starting
to get my interest further, when it had said that parameters are favorable
for significant severe weather and possible tornadoes. It almost sounded
too good to be true, especially for a Day 3 outlook!
The next day was
interesting for weather in Southern Ontario. Several supercells had
developed in the afternoon hours. I was at college, unfortunately. Before
my exam, I decided to check out the weather on the Internet. Sure enough,
a severe thunderstorm watch was issued for the area. Great. It just
had to happen during my exams, didn't it? I went outside of the college
and noticed a developing supercell north of Waterloo, at 3:00 pm. It
was building nicely. As it continued to grow, I noticed several pileus
cap clouds. I really wish I was out there. The funny thing is that morning,
I thought to myself that I should have taken my camera with me. Do'h!
Several chasers were on the supercells and reported rotation. Later
on, a tornado warning was issued for Peterborough. There were reports
of a tornado in that area. That evening, I attended the Kitchener-Waterloo
CANWARN meeting. Mark Robinson and I discussed about Thursday's potential
for a chase day. We were planning to chase together. He was still unsure,
and said he would give me a call on Thursday if he was going to pick
me up to go chasing.
On Wednesday, the
SPC Day 2 outlook issued a slight risk. The airmass in the warm sector
of the low was still expected to be moist and unstable with MUCAPE values
ranging from 2500 to 3500 J/Kg. Veering winds were increasing with height,
which was indicating a favorable environment for tornadic supercells.
However, portions of Michigan and Wisconsin were expected to upgrade
to a moderate risk in later outlooks.
Later on I checked
the Day 2 outlook once again. The SPC had upgraded our risk area to
a moderate risk for Thursday. Tornadic supercells were still expected
to develop. The inflow-sector air mass was forecast to be unstable by
the afternoon with MLCAPE ranging from 2000 to 3000 J/Kg, with suface
dew points in the 60s deg F, and 7.5 to 8.5 deg C/Km midlevel lapse
rates.
Friday looked capped.
It just didn't look like things would fire. A severe thunderstorm watch
was issued at 10:35 am for parts of the SW and areas along Lake Huron.
Earlier, ping-pong ball size hail was reported in Little Current and
a tornado was observed northwest of Tobermory. After 2:00 pm, Mark Robinson
called and asked for directions on how to get to my house. I was kinda
surprised because I really wasn't expecting a chase. While I waited,
a severe thunderstorm warning was issued for northern Grey and Bruce
counties. Radar showed an intense storm crossing northern Lake Huron
into that area. Shortly after, Mark showed up in his white car, laden
with antennas and gear, and a "S. Ontario Storm Chaser" sign
on the rear window. He checked out the RUC on Nexlab's site, and noticed
it had updated. Things were starting to set up from what we saw. I noticed
cloud starting to develop over Huron and Perth counties on WeatherTAP's
satellite image. Was the cap going to break? Is this it? While Mark
was setting up his car for the chase, I looked for libraries to use
as data stops.
We left Waterloo
to begin our trek across the countryside at 3:00. We took highway 86
and pulled onto regional road 17. We went through the town of Heidelberg.
Our plan was to take highway 5 once we reached the town of Crosshill,
down to Stratford. On the way, we heard someone mention a tornado watch
on the CANWARN net, on ham radio. We were surprised. Mark exclaimed,
"What?! A tornado watch?!". Ron Gravelle, our nowcastor and
Kitchener-Waterloo CANWARN net controller, corrected the person, saying
that it was a severe thunderstorm watch instead. Oh well, it sounded
good at first! After we reached Stratford, we took highway 8 to Mitchell.
The hot sun was still beating down on us. The heat felt bad for us because
Mark's car, which is very old, had no air conditioning. Ahhhh! It looked
like we would fry up before any storms would develop. In Mitchell, we
took a break at Tim Horton's. I needed a cold drink because we had forgot
to pack our water bottles. Afterwards, we decided that we needed to
head further south. We found ourselves in St. Mary's and began to play
the waiting game. George Kourounis was also out chasing, but he was
much further southwest than we were. Things were not beginning to look
too hopefull anymore. The sky was clear. George and us decided to meet
up in the Fullarton area. On our way up on regional road 163, George
mentioned that he saw TCU starting to build up. We couldn't see anything
from where we were! We looked... and looked... and looked. Then, off
in the distance, I see the TCU that George was speaking of. I pointed
in the direction to show Mark. Yep. We had to go more north than where
we were! As we got closer, the TCU didn't look very healthy. The shear
was evident, however. The smallest TCU would even get knocked over by
the shear because the updrafts were just not strong enough. By now,
Mark and I were starting to lose our hopes of a good severe storm. George
and us decided to meet up in Mitchell. After some difficulty finding
George, we met in a parking lot. We looked at each other's chase vehicles.
We just couldn't do anything else, but wait and hope. We did plenty
of hoping. Later on, we hit the roads again. Mark called Ron on his
cell phone. He wanted us to head north, into Listowel! I could tell
right then Mark didn't feel like doing the distance. A couple of hours
had gone by, and something should have fired up by now. We lost all
hope. On our way towards Listowel, we decided to call the chase quits.
Mark called Ron again. He told Ron that we only saw TCU that just could
not go any higher because of the cap. Ron asked if we wanted to hear
the good news or the bad news first. The bad news? RUC updated and showed
that we lacked moisture at the 850 mb level. The good news? Indices
were classic! CAPE was at 5000 J/Kg, with LI of about -10! Dang. Awesome
indices, and nice blue sky... all because we had lacked the moisture
and lifting force.
We decided to go
to Ron's house. When we arrived at his place at 6:00 pm, we could tell
that Ron was very tired and upset that nothing had fired like we had
originally thought it would. If it would have fired, chances are we
would have had a classic outbreak of severe storms. He said he had analyzed
this storm system for 15 hours straight! That is a lot of work. He saved
about 300 weather images, ranging from satellite to soundings, while
we were out chasing. Ron showed us the RUC that indicated we lacked
moisture. Yuck, no wonder. And not only that... the cap was at 2.5 C!
We all learned. After Ron's hard work of trying to get us in the right
area, we took him and his wife out to dinner as a "thank you"
gift.
Notes: I would like
to give special thanks to Ron Gravelle VA3TVS for his wonderful nowcasting
support. He has tried his best and used what little engergy he had left
to get us in the right spot. In fact, we were in the perfect area! Only
if the storms would have fired, however. Thanks also goes to Mark Robinson
for taking me out on my first chase of the year. At least we had all
tried. We have busted, but we have learned... thanks to the wonderous
cap that would never break. All in all, I still had a good time chasing
with Mark and George.
Total hours: 3 hours
Distance: approx.
250 km
