Keep
in mind that this page is hastily updated on a daily basis between
chases. So don't be alarmed by any mistakes.
June 4
2009
Chase
partners: Rosa Finch Discussion
This is a marginal case day, but since this is the
1st day of my chase vacation, I have decided to go ahead and chase. My
initial target area in the Limon-Denver corridor. A cold front has
scoured the moisture out of the central and southern plains. However, a
narrow ribbon of marginal moisture is returning up the high plains.
Also, a weal cool surge through the Limon, Denver and Akron area this
morning may actually help. This region was socked in with low clouds.
The southern edge of this cool/cloudy area should have locally higher
dewpoints. With west-northwest flow at mid and high levels, supercells
should move to the sse.
What happened?
This day turned out to be better than expected. I actually saw 2
supercells and a funnel.
Chase partners: Sean
Lyon and Rosa Finch Discussion
I have more hope today than yesterday. The mid to
high level flow actually has a southerly component today. Therefore,
lee troughing should really increase. Unfortunately, low level moisture
tends to be marginal across the plains. In June, when the moisture is
marginal, you do not want to be on the lower terrain since higher
temperatures and marginal moisture will lead to high cloud bases. It
will also be warmer at 500 and 300mb in the warm sector. I prefer to
chase on elevated terrain on the northwest extremity of the moderate
CAPE area where surface temperatures will be cooler and cloud bases a
little lower. I hope chase forecasters dont accept the the 12z nam.
This model shows a morning MCS over Nebraska and cool outflow over
southeast Wyoming all day. In fact the nam shows surface temperatures
between 50 and 55F in the afternoon to the lee of the Laramie
mountains. This is a model error. My chase target area continues to be
southeast Wyoming where initial cumulus towers should develop on the
Laramie Range. Storms should have about 3 hrs residence time in the
theta-e axis of southeast WY and the western NE panhandle before
moving into lower CAPE in western NE. I think the chances for supercell
storms are very high and there could even be a few tornadoes.The
vertical wind shear profile will be awesome.
What happened?
Our (Sean Lyon and myself) initial target area for initiation was west
of Chugwater, WY. This worked out great. My wife Rosa was along for the
chase as well. Even though I took these pictures, this was a joint
venture. So these pictures are Sean's too as far as I'm
concerned. We drove to the Chugwater area around 1 pm and waited
around for storms to develop. Due to the extensive mountain enhanced
cirrus, it was actually difficult to see the storms developing to our
west/southwest. Two storms developed west/southwest/northwest of
Chugwater. We drove about 5 miles southwest of Chugwater to watch the
storms develop. I enjoy taking temperature/dewpoint readings in my
target area in order to calculate dewpoint depressions and lifted
indices. I have a skewt-log P diagram in the trunk of my car that I
always take chasing. The T/TD at Chugwater (5300 ft) at 2 pm MDT
were 67F/53F. But since 500mb temps were around -10 to -14C at 12 UTC
and progged to be around -12.5 in the Chugwater area at 18 UTC,
500mb/400mb/300mb lifted indices were around -7/-8/-8. This probably
corresponds to about 2000 j/kg surface based CAPE. Given the 40kt 500mb
flow from the west-southwest, 25kt flow at 700mb from the southwest and
80kt winds at 200mb that were progged for the area, I was very excited
about the tornado chances.We focused on the southernmost
storm due
to the fairly
strong 3-6 km flow, we knew that the storm would move no more than
30 deg to the right of the 500mb wind. Our predicted storm
motion
vector was 270 deg at 25 kts. By 252 pm our storm
was getting better organized and had begun to rotate
by 317 pm just ese of Chugwater and turned to the right
(280 deg). This actually worked out fairly well for awhile as the storm
initially moved to the east or east northeast. But I suspected that we
might have to drop south. The
major problem on this chase was the lack of roads east of Chugwater.
Road 313 went east from Chugwater. When the storm was east of
Chugwater, the updraft portion of the storm was just west-southwest of
our location. We started out on this road but we
were keenly aware that we might need to drop south. But there were no
paved roads to the south. Anyway, we did decide drop south since the
forward flank downdraft was getting close to RD 313 and since the meso
seemed to be moving to the east-southeast. We dropped south on Rd 246
as a scary
wall cloud loomed just a few miles to our southwest at 319 pm. We dropped south
on 246 about 6 miles. By 326 pm the meso
was to our north.
Then we took
Rd 153 southeast and
then east as the meso was north of Bear Creek at 350 pm. I am glad that we had the Wyoming Atlas Gazetteer as this
would have been impossible without it. We took this dirt road
through the canyon west of Phillips. Due to the surrounding
cliffs, it was difficult to even the storm
as we traveled east at 352 pm. Due
to the poor road conditions--frequent turns and rough areas, we
actually got on the back side of the meso. Water actually covered the
dirt road in several places, but we managed to drive off the road
slightly to avoid the water. I can't believe that we actually were able
to pull this off. But this was a safe place to be as it was
partly cloudy
to our south and west. We got a clear look at the meso
as it was approaching Bear Creek but still north of RD 153. The first
tornado developed several miles west
of Phillips on Rd 153 along Bear Creek around 357 pm MDT. The
timestamp on my digital camera was 354 pm. But there is a 3 minute
difference between my camera and my cell phone (which has the correct
time). This
tornado started off as a ferociously
rotating column north of Bear Creek with no
discernible condensation funnel even after passing
over Bear Creek. But
the rotation was so dramatic with
this meso that we decided to call this a tornado. Vortex 2 took
pictures of deciduous trees uprooted along Bear Creek It
might be worth searching for tree damage just north of Bear Creek as
this tornado could have started before 357 pm. About 3
minutes later at 400 pm MDT a truncated
cone-shaped tornado
developed. This was somewhere south or
southwest of Phillips. This tornado seems to have lifted but may have just disappeared in the rain. Another tornado
appeared at 403 pm and was wrapped in rain from our vantage point. This rain
wrapped tornado was
still visible
at 408 pm as a large white cone.
The tornado became so wrapped in rain that it became barely visible.
Large hail
also occurred with the storm. We stayed far enough away from the precip
cores to avoid the very large hail. I tried to report these tornadoes
to the NWS but I had no cell/internet coverage. In retrospect, it may have payed
dividends to wait for the storm to approach highway 85 near
Meriden. In fact, those arriving very late from the southeast may
have been rewarded greatly with a higher contrast tornado. But this is
not the way I operate. I always go for initiation, wanting to see
the entire evolution of the storm. Part of the fun for me is making a
storm initiation forecast, driving to the area and then watching the
storms develop. Driving east from Phillips
to La Grange, we saw
another tornado from 423 to 425 pm to
our south.
Then we saw another tornado
partially obscured by rain between 428 and 430 pm. This may have been
the same tornado that started at 423 pm and continued through 430 pm.
This last tornado roped
out at 430 pm and disappeared by 431 pm. We actually
followed this storm well into the Nebraska panhandle. This storm became
a rotating beast again after a brief weakening near the
Nebraska/Wyoming border. We may have
seen 1 or 2 more tornadoes with this storm, but it is possible that
these were just tornado look-
alikes. This particular look alike occurred at 549 pm. The storm
structure was amazing in
the western
Nebraska panhandle. In retrospect, if we had been about 10 miles to the south in the panhandle the view of the truly amazing
storm would have been better.
June 6 2009
Chase partners: Guy Caputo, John Dunne, John Dunne Jr. and Rosa Finch
Discussion:
Warm sector moisture
continues to be problematic. I do expect dewpoints to rise to around
65F in southwest IA today despite lower dewpoints further south. Why is
this? In summer, the boundary later tends to be deeper in the warm
sector of the southern plains--south of the upper jet. However, deeper
into the westerlies, the elevated mixed layer tends to be lower to the
ground so that moisture trapped beneath is confined to a more shallow
layer. This leads to higher mixing ratios further north even though the
precipitable water could be the same. Also, MCS clusters tend to move
along the southern edge of the westerlies. So areas further north often
have a wet ground with lots of evapotranspiration. Evapotranspirated
moisture tends to mix out deep into the warm sector. However, along the
southern part of the westerlies, areas of moisture convergence (such as
ahead of a surface low and shortwave trough) can pile up and
concentrate this evapotranspirated moisture in a small area where
storms later develop. Anyway, I am opting to blow off the eastern
option (southeast NE) in favor of western Nebraska. Mid level
temperature have cooled somewhat overnight. In fact, 500mb temps are
progged to be around -15C from SNY to MHN today. When moisture is
lacking, it pays to be further west on the higher terrain where you
dont need as much moisture and where mid to high level temperatures are
colder.
My target area for today for initiation is the area between Sidney and
Alliance where surface dewpoints should be in the 53-55F range. Mid to
high level winds are progged to be very strong by June standards. The
main limiting factor for significant tornadoes are the weak low level
winds and the narrow theta-e axis. I expect to see supercells but the
tornado chances are low. A storm that develops will have about 2 hours
to produce a tornado before moving into potentially much cooler air.
Update - I have decided to race north to Ellsworth, NE since the
moisture is mixing out per latest surface observation at OGA. The
surface observations look good further north. The towering cumulus also
look crisper.
What happened?
I opted to take the
dreaded Oshkosh-Ellsworth highway northward. This road had plenty
of water in places but I was able to go around the puddles. Also, cows
were walking or laying in the road in several places but my car horn
was very effective at scaring them off. This road is big enough to accommodate
1 car,
thats it. With all the hills, you never know what is going to pop over
the next hill. I could easily invision a head on collision occurring,
Actually, U didnt see 1 car for 40 miles. A moderate cumulus
cloud developed immediately north of us near the Crescent Lake Park
(also note water on road). It was fascinating to watch this cloud
develop into an incipient
thunderstorm , thunderstorm with precip
and then
supercell storm.
I knew that due to the fast storm motion (by June standards) that the
storm would only stay in the higher theta-e air for about 2 hours. So
the storm looked great for awhile. We got several nice pictures of the
storm. I measured a T/TD of 70F/58F at Mullen, NE. This is not
bad give the fairly high elevation of Mullen and the fact that 500mb
temps were around -15C. So surface based CAPE values were surely at or
above 2000 j/kg. However, my fears came true as the storm moved into
more stable air further east and weakened.
June 7 2009
Chase partners: Guy
Caputo, John Dunne, John Dunne Jr. and Rosa Finch Discussion (1030 am) An outflow boundary from
nocturnal convection extends from north of Manhattan to Topeka and into
western MO this morning. A stationary front extended from northern KS
into central IA. A shortwave trough will approach the high plains this
afternoon. The models are forecasting 70-75F dewpoints today in
northeast Kansas. How can this be given that the higherest dewpoints
this morning are in the mid 60sF ? In
summer, the boundary later tends to be deeper in the warm sector of the
southern plains--south of the upper jet. However, deeper into the
westerlies, the elevated mixed layer tends to be lower to the ground so
that moisture trapped beneath is confined to a more shallow layer. This
leads to higher mixing ratios further north even though the
precipitable water could be the same. Also, MCS clusters tend to move
along the southern edge of the westerlies. So areas further north often
have a wet ground with lots of evapotranspiration. Evapotranspirated
moisture tends to mix out deep into the warm sector. However, along the
southern part of the westerlies, areas of moisture convergence (such as
ahead of a surface low and shortwave trough) can pile up and
concentrate this evapotranspirated moisture in a small area where
storms later develop. Storms could develop along the
outflow boundary and along the front or anywhere along a weak N_S
convergence line. I may go down Interstate and reassess around 2 pm.
Given that storms will be moving ene at 35 mph, I dont want to get
caught behind the storms in Kansas with overshooting tops to my
northeast. So I plan to be in Platte City, MO by 2 pm then reassess
from there. After a further loook, we
may head to Horton, KS and wait for initiation (1130 am). What happened?
A storm developed in southern NE by mid afternoon. We opted to
ignore this storm. We were located about 50 miles southeast of the
storm but the sfc winds in our location were about 5 kts. So there was
little inflow into the Nebraska storm that was riding the surface
front. Also, a storm began to develop to our west-southwest on the edge
of the stronger low level winds with better warm sector inflow. We
stayed just ahead of this storm
for several hours. Thisstorm
was awesome
and I dont understand
why there were no
tornadoes. The storm structure
was amazing with frequent rfd dry slots.
June
8 2009
Chase partners: Guy
Caputo, John Dunne, John Dunne Jr. and Rosa Finch Discussion
I opted not to chase
today.
Although a few storms could develop on the higher terrain of Colorado,
these will not produce tornadoes due to a lack of moisture.
June 9 2009
Chase partners: Guy
Caputo, John Dunne, John Dunne Jr. and Rosa Finch Discussion: 1030 pm June 8
I continue to be in the dark about today. Will there be sfc based
convection in the afternoon and evening, or will elevated convection in
the morning persist all day? Models continue to fester elevated
convection all day in southern and central KS and it is not clear when
the transition between elevated and surface based will occur. Target
area continues to be along warm front/outflow boundary in northern OK
and southern KS. A shortwave trough will be approaching by this
afternoon which should provide lift for storm development along the
surface boundaries. The GFS/NAM show a 50-70 kt 500mb jet max entering
southern KS by 00 UTC. The NAM shows 30-40kt southerly 850mb winds
along a OKC to ICT corridor, with P28 and END located along the western
extent of the LLJ. Thefore, wind profiles will be improving during the
afternoon and evening.
We decided to chase in southeast Kansas. We drove to Wichita and then
to Burden. I didnt like the veered out winds further west. Sure storms
could develop out west but the chances for significant tornadoes were
very low there. The low level jet was further east as well as lower
dewpoint depressions and more backed winds. Storms
began developing by 530 pm. A storm developed west of Cambridge
and moved east.
However i didnt like the fact that the boundary was still sagging south
a little. But strong south winds were starting to hold it up. Another storm
developed in the warm sector northwest of Ponca City. We decided to
target this storm but it fell apart. Then another storm developed west
of Ponca City but this storm quickly gusted out. We had
a flat
tire in
the Osage County Indian reservation. We saw a Buffalo
as well. Despite the trials and tribulations, we
still managed to have a good time and see some interesting storms.
Discussion:
940 am June 8
Heading for Anthony, KS.
June
10 2009 Chase partners: Guy
Caputo, John Dunne, John Dunne Jr. and Rosa Finch Discussion:
After a flat tire in the Osage County Indian reservation, we
spent the night in Bartlesville, OK. The target area for today is
southwest Missouri along the east-west surface boundary. Initiation
could be in Dade County MO. However, there is some uncertainty in
exactly where the boundary is since there are no surface observations
between Joplin and Sedalia. Anyway, convective initiation should occur
north of Joplin some distance with storms moving east along the
boundary. Supercell chances look good but we are not sure about tornado
chances. The low level turning is marginal with ssw winds veering to
the west-southwest. I like the 80+ kt 250 mb winds which should help
with convective initiation. There is quite a bit of uncertainty in the
exact wind profile as the ruc and nam seem to change from run to run.
Anyway, we are giving this a shot.
What happened?
We drove north from Joplin in the early afternoon trying to find
the boundary. We knew that towering cumulus would probably be
developing. When we got to Lamar, MO, we saw large towering cumulus
to our north-northwest. This developed into a storm
and another cell was just to the south-southwest. The roads once again
gave us big problems. We tried to maneuver ahead of the storms but
ended up being too far north. So we drove east and then south and got
ahead of the storms. As we did this, another storm exploded ahead of
the 1st too, This storm quickly developed
a funnel
at 532 pm. I reported this to the National Weather Service. Then a tornado
developed to
our south
between 539 and 541 pm which I also reported. I thought we were looking
west so I reported the tornado as being west of Schell City when it was
actually to the south.
This was a picturesque tornado with an obvious debris
cloud starting between 539 and 541 pm. The tornado
lasted for
a few
minutes and
took on
a variety
of shapes.
We decided to stay put and just watch
the
tornado and take pics
instead of trying to maneuver ahead
of the storm.
June 11 2009 Chase partners: Guy
Caputo, John Dunne, John Dunne Jr. and Rosa Finch What happened?
Today didnt work out. I didnt play upslope since the really rich
moisture has not begun to push into Colorado yet. CAPE values will
generally stay at or below 1000 j/kg. We drove to the Texas Panhandle.
A storm developed west of Clarendon and was picturesque for awhile.
However, this storm was never rotating and became anarexic after moving
into a capped environment.
June
12 2009 Chase
partners: Rosa Finch Discussion:
I plan to position myself between 2 possible target areas tonight
(Thursday night). Upslope flow may become a little more unstable by
Friday afternoon. There is also a chance of storms in the Texas
Panhandle. I will probably take my chances around Limon, especially
since the next day should be in Colorado. There is no way I am
traveling to southern OK or north TX and face a daunting drive to
Limon/Akron for Saturday. Colorado here we come!! Actually I may use Friday June 2 as a travel day since
there could be an early show Saturday June 13 around Akron/Limon.
Update: 1130 am June 12
I plan to target the Simla-Limon-Wild Horse-Punkin Center area for
initiation today. Dewpoints are lower further north. Some low level
convergence on the eastern part of the Palmer Ridge along with elevated
heating should allow for storm development. Storm motion vector should
initially be to the east but right turning to the east or southeast is
likely. June
13-15 2009 Discussion: 8 pm June 11
I have high hopes for this period. I plan to spend all 3 days on the
central high plains or front range. My target for Saturday is Cheyenne
to Chugwater to Wheatland and possibly as far north as Douglas, WY.
June
13 2009 Chase partners: Rosa
Finch Discussion: 10 am June 13
I am fairly optimistic about today. At 15 UTC, a cool
surface ridge extended from eastern Nebraska into southeast Colorado.
This ridge may stay in place all day. However, lee troughing was
already occurring across northern CO and southern WY. Winds shifted to
the south and southeast across the high plains overnight. The core of a
jet streak (125kts) will be located over Gunnison, CO by 00 UTC.
Southeast WY will be in the left front quadrant of this jet streak
and should help with lift. Also, surface winds may be more backed
along a corridor from Scottsbluff to Wheatland to Douglas, WY. The
Laramie Mountains may serve as a lifting mechanism as upslope flow
strengthens. I plan to stay away from the effects of the cool surface
ridge in southeast Colorado. There is a chance of tornadic storms in
eastern CO today after storms develop northeast of Denver. But I prefer
to stay further north where upper level temperatures are colder and
where surface based CAPE values may be higher. Also, a surface low will
develop in southern WY in response to the approaching shortwave trough.
This may also help to promote backed low level flow and greater
vertical wind shear. Also, there will be a gradient in 700mb
temperatures between Laramie and Wheatland. Actually, the moist
boundary layer may extend up to near 700mb along the frontrange of
Wyoming. Capping should erode first along the edge of the 700mb warm
plume along the east edge of the Laramie Mountains. I plan to jog north
to Chugwater and Wheatland and wait for initiation near the mountains.
What happened?
Low level inflow was lacking in my target area and winds just above the
boundary layer were rather weak. So storms developed but these were not
tornadic supercells.
June
14 2009 Chase partners: Rosa
Finch Discussion: 10 am June 14
A shortwave trough will approach the high plains of Kansas this
afternoon. A small area of strong 700-500mb flow is progged to emerge
into far southwest KS, the Oklahoma Panhandle and far southeast
Colorado by late afternoon. The GFS/NAM and RUC depict this very well.
700/500mb winds will increase to 35/50kts in this area. An area of
strong low level convergence should develop in the Oklahoma
Panhandle as strong southwest winds develop over northeast New
Mexico and the western OK Panhandle. Surface dewpoints should rise into
the mid 60s by late afternoon with surface based CAPE up to 3000 j/kg.
The new model data do not look good for my initial target area possibly
due to ongoing convection in western Oklahoma generating outflow and
blocking the moisture return. I plan to chase the Palmer ridge east and
southeast of Colorado Springs and hope for a miracle. There could be a
late show between Akron and Burlington.