March 7, 2009
Storm Chase
Southcentral Kansas
Editor: Putnam E. Reiter
Forecast/Setup -
Risk Area: Slight Risk
Initial Target Area: Ponca City, Oklahoma
SPC Products:
SWODY1
16:30z -
Risk
Area -
Tornado Prob -
Hail Prob -
Wind Prob -
LSR Plot
-
LSR
NAM 00z Initialization:
Surface Pressure
- Dewpoints -
CAPE
- MLCAPE
- CIN
- 0-3 Km Helicity -
Surface Temperature
-
850mb Dewpoints
- 850mb Wind -
850mb Vertical
Velocity
- 700mb Wind
- 700mb
Temperatures -
700mb Vertical
Velocity -
700mb Relative Humidity
- 500mb Temperature
- 500mb Wind
-
500mb Vertical
Velocity -
500mb Relative Humidify
- 500mb Vorticity -
250mb Wind
- 250mb Relative
Humidity
SPC Case Review
Last weekend an Arctic front moved through the
region and the Gulf, taking 50F dewpoints almost to
Cuba. The models had been somewhat consistent
on the setup for today as a southern stream
shortwave trof was progged to move east into the
region. However, a big unknown was the ability
of the Gulf to recover. Models seemed pretty
insistent on 50-55F dewpoints moving into Oklahoma
and possibly points north. At the very least,
strong wind fields at the surface and aloft would
create very favorable shear. A big problem was
the subtropical jet and associated cirrus.
This was progged to be over the threat area,
reducing surface heating.
The ultimate setup had the southern stream shortwave
trof moving towards the region Saturday afternoon.
Limited moisture did return with 55F dewpoints in
northern Oklahoma and 50F into northern Kansas.
The surface low as in western Kansas with a dryline
southward just inside the western border of
Oklahoma. This location was well west of the
GFS progs and something the NAM consistently showed.
The cirrus did develop and it did reduce surface
heating, however we still reached the low 70s across
much of the region with CAPE values around 750J/Kg.
The models initialized a little higher but I'm in
the ballpark.
Storms developed around mid-afternoon in
west-central Kansas southwestward to northwest
Oklahoma. There was some linear look to them,
but overall they remained discrete. A storm
did develop just west of Wichita, KS, that got a
tornado warning. Storms in Oklahoma moved
northeast into Kansas with no further development.
In Kansas the storms moved northeast through the
early evening hours.
The Chase -
Team 1 - Brett
LaBare, John Holsenbeck and Putnam Reiter
Miles Driven - 430 - Gas spent $41.00
Departure Time - 14:15 CST
Return Time - 23:50 CST
Track Path
We left the Severe Weather Conf in Norman, heading north on
I-35. Storms had developed in Kansas with SPC issuing a severe
thunderstorm watch. We decided to head up to Highway 11 and evaluate our
options. Getting up there around 4pm, we got gas and talk about the
ongoing activity. A supercell was located near Wichita and we thought
about going after it. After some thought, the best idea was to head west
towards the activity in northwest Oklahoma, southweset Kansas.
We took Highway 11 west and
eventually hit Highway 281. At first we
thought about going south to Alva and then to the
southern most storm. However, the northern
storm of the three rapidly intensified, so we went
towards it. Taking Highway 281 north to
Hardtner, we went west on Hackberry about 2 miles.
Then, we turned north on Gypsy Hill Road and found a
spot to park. The dust in the air made storm
scale viewing tough, but we did have features for
about 10 minutes before we got to our observation
point. When we got out we noted very strong
southerly flow, probably 20-30mph.
Additionally, a rain free base was present and a
briefly organized wall cloud. The RFD cutoff
the updraft region, which attempted to reform just
to our northwest. At this point the storm
appeared to become elevated and accelerated to the
northeast. The middle storm was not of
interest and that left tail-end Charlie, which
happened to be by itself.
We drove south to Hackberry and
south just east of Gypsy Hill Road for a little bit,
watching the final storm approach. Trying to
get better cell coverage and closer to the storm, we
moved a few miles west and sat on a hill. From
here we watched the rain free base approach with
periodic lightning. The storm passed us by and
we thought it had become elevated again, but it was
not outflow dominated. So, not really sure
what we thought had happened. However, we
decided to stay with the storm as it moved northeast
near Medicine Lodge. We went back north on
Gypsy Hill Road and took it to Highway 160. We
eventually got RADAR data back and noted the storm
had re-organized, although not what we'd call a
supercell at the time.
We went east of Highway 160
towards Medicine Lodge, cruising on through the
town. The thinking was we could at least
follow the storm as we headed back to I-35.
There was almost a full moon, so despite sunset,
visibility was really good. We had a good view
of the backside of the storm and periodic lightning
flashes gave us a few of the rain free base.
As we approach Attica, I commented that the base had
risen a little. A few minutes later, just east
of Attica, Jay screams funnel. After a rather
abrupt stop, we all jumped out of the vehicle.
Several lightning flashes revealed a tornado,
although it was brief. Since the tornado was
in open country, there were no power flashes.
And, we didn't get video up quickly as we spent a
few minute attempting to contact the NWS, which we
actually succeeded in doing (relaying information is
always paramount). We started back up at 19:30
CST, although I think the tornado was probably
around 19:27 CST.
We followed the storm on east and
went northeast on Highway 2 past Harper. We
got a few miles northeast and the storm appeared to
have weakened. Watching the storm a little
longer, the rain free base reorganized and lowered.
So, we continued north to Highway 42 near Norwich,
where we sat and watched the storm some more.
The moon light was very impressive here and gave us
a nice view of the updraft base. After
watching the storm a few minutes we noted it was
beginning to race northeast and there was quite a
chill. Our thinking was the storm had become
outflow dominated and most likely elevated. As
we headed back home on Argonia Road through Milton
the temperature was 59F and rose to 66F by the time
we reach Highway 160. This seemed to reinforce
our thinking the storm was done.
We stopped at Penny's Diner in
Wellington, Kansas, a nice/quaint place to eat.
Getting done stuffing our faces, we headed back east
on Highway 160 to the Kansas Turnpike (I-35) and
went south. I dropped Brett off at the Walmart
and headed on home.
This chase was awesome for a
variety of reason. First, I've had an aversion
with going into Kansas. This appears to have
been solved and I'm happy about it. Second,
Brett hasn't seen a tornado and while it was at
night and brief, he's seen one now. Third, I
got to chase with Jay for the first time and that's
after 18 years of knowing him. Fourth, the
Enterprise I had its first chasing voyage and came
back with no hail dents!
Lessons
Learned -
- Nothing that comes to mind, it was a good chase.
Multimedia
-
Hardtner, KS
Supercells - Pictures - WMV Format
Attica, KS Supercell
- Video - WMV Format
Encounters
-
Engaged
Storm: West of Hardtner, KS
Tornado: No
Funnel: No
Hail (larger than 0.75 inches): No
Wall Cloud: No
Wind (above 57.4 mph): No
Engaged
Storm: West of Hardtner, KS
Tornado: Yes - brief near Attica, KS - 19:30 CST
Funnel: Yes - see above
Hail (larger than 0.75 inches): No
Wall Cloud: Yes
Wind (above 57.4 mph): No
