Welcome everyone to the third iteration
of our Hazardous Weather Testbed
Experimental Warning Program Tales from
the Testbed webinar series. This is for
the satellite and radar convective
applications experiment. I'm Sarah Borg
from WDTD. This week we have four
forecasters and two guests from the US
Air Force to discuss several operational
and experimental products they've been
evaluating this week during real-time
operations. To kick off this presentation
I'd like to introduce one of the
principal investigators of this
experiment Michael Bowlan. He's a
University of Oklahoma CIMMS researcher
with the Storm Prediction Center. Take it
away Michael. Thank you Sarah. So just for
me some of the presentations here just a
little bit about the hwt experiments
warning program or EWP as you'll hear it
referred to for those that might not be
as familiar with it as some others but
the main mission of the EWP is to
improve prediction of severe convective
weather events at the warning scale
looking at that zero to a few hours in
advance timescale. We're able to bring in
forecasters from across the country as
well as this week you'll hear from some
Air Force forecasters. Previous week's
we've brought in broadcasters and others
so we aim to serve all people across the
country National Weather Service
weather forecast offices as well as CWSU's
nationwide to get a feedback on
experimental and operational products as
well to hopefully help improve those
algorithms and products for future use
in operations to help improve the
prediction of severe convective weather on that warning scale so you can
consider it a vital component in the
research to operations process as well as
getting the feedback from operational
users and having that operations to
research feedback mechanism as well. So
this week was a pretty slow week severe
weather wise across the most of the country
so we operated in a number of different
regions across the country from the
Florida peninsula down to Melbourne up to
Missoula Montana looking in Montana and
Idaho as well so we're able to evaluate
products across a wide range of
convective weather events, a wide range of
severe weather, a wide range of radar
coverage and other types of it as well
so it's pretty valuable week actually
for feedback on several of the products
that we're testing this year. Alright
thank you for the overview Michael. First
we'll be talking about single radar azimuthal shear, or AzShear. The forecasters
who put this together our TJ Turnage
from WFO Grand Rapids Michigan
and David Church from WFO Salt
Lake City Utah, however they had to leave
a little bit early to catch their
flights home so instead we have Brandon
Smith who is a CIMMS researcher with the
National Severe Storms Lab here to
discuss this content for them. Go ahead
Brandon. Thank you Sarah.
so looking at the first slide here kind of
highlight how extremely helpful AzShear
is in detecting boundaries that are
associated with convective lines. In this
example here AzShear really highlights
the portions of the QLCS events here
that have become well orientated with
the 0 to 3 to 6 or 0 to 3 kilometer
shear vector. Using this helps to kind of
draw warning forecasters attention to
locations on the line that might be
favorable for severe weather. It's
especially important when they're
interacting boundaries and mesovortices that develop along the kinks in
these lines like we have in this example.
We're commonly finding that developing
mesovortices the forecasts refined this week that they were more easily
spotted in AzShear approximately two
radar scans earlier than what they would
see in the raw velocity product and this
kind of example here AzShear's on the
left hand side the raw velocity product's on
the bottom right hand corner and another
major advantage of the AzShear product is
having access to the negative values of
AzShear as opposed to the rotation
tracks which are operationally available and
only show the positive values of azimuthal shear. In this example here on the
right hand side of the left hand image
in a circle area you see a bright area
very positive AzShear values with a
blue negative area that's just to the
south. This kind of highlights something
that they would see forecaster would see
frequently with developing rear flank
downdraft or RFDs
they can often be precursors to tornadogenesis. Now kind of drawing attention to
the right-hand image there we see a mesocyclone that's flanked by two blue
areas with the positive area right in
the middle. That helps give forecasters a
quick idea about how well sampled and balanced a mesocyclone
might be and this of course gets
better sampled as it's closer to the
radar. There's more information on the forecasters' thoughts behind this on a
blog post which at the end 
Michael will talk about the blog post later in
this webinar. On this third slide here
it's kind of highlights how AzShear helps
to pinpoint where damage is most likely
to be observed
assuming you're not looking too high
and assuming not too far from the radar
in this case you see a tornado track along
the southern edge of an AzShear maximum
the tornado tracks in the fuchsia line there. It's a little might be a little non-intuitive
at first but it turns out that the
strongest rotational velocity may
actually be edge of this AzShear
maximum here so when you combine this
with translation of the circulation
combined with the inflow it kind of
makes sense that the strongest winds the
greatest damage potential might be located
on the south side but a caveat is
there is to make sure you're not too far
from the radar because might get some
displacement there and then this last
slide here shows forecasters really like
AzShear but they want to kind of
provide a cautionary tale on how to
use it since it is derived from raw
radar velocity data subject to errors from
ground clutter and other radar artifacts
and this is one of the cases that kind of
highlights this is from the Bismarck
North Dakota area where
there is an area of ground clutter that
results in bad velocity data that can
seen in the bottom left hand of this
image as a storm tracked over this area
ground clutter it would be easy to kind
of mistake increased AzShear values for
increasing low-level rotation however
this is not the case and in this event here
the false AzShear texts were ingested
into the probTor algorithm which
causes false alarms with the probTor
values they jump from about three
percent to over fifty percent so this is
kind of good reminder to always stay
connected to your base data and to watch
for different types of artifacts that might causes false
alarms to jump in these downstream algorithms.
Some of the takeaways with this
basically you wanna AzShear's really good
at detecting rotation along boundaries, 
specifically QLCS events. There's
also a lot of potential utility with a
negative AzShear this is the length of
that blog post which will be in the
archived version of this webinar later
it's also very important when looking at
AzShear that it can be can be susceptible to
Radar artifacts noisy data and things
that can mislead so make sure always
look at the base data when looking at
these downstream algorithms
Alright thanks so much for stepping in
there for us Brandon. Next we'll be
talking about the NOAA unique combined
atmospheric processing system or NUCAPS
with Jennifer Shoemake from WFO
Albuquerque New Mexico
Go ahead Jennifer. Great thank you. So on this particular day we were looking in North Dakota
and all signals for that become
more unstable later in the afternoon and
the 12Z Bismarck sounding was wholly unrepresentative of the state of the atmosphere
during the afternoon hours. The dew points that morning were in the low 30s. By this time
around 18-19Z dew points were already climbing
into the upper 40s to around 50 so I
started looking at the modified and
unmodified NUCAPS standings in the area
and these two soundings here from the
same point just northwest of Bismarck
near the peak of the instability and if
you look on the left non-modified NUCAPS
sounding it shows a pretty healthy
amounts of cape over a thousand joules
per kilogram and the same goes for the
right. Now usually the unmodified NUCAPS
soundings have some issues in the
boundary layer so the modified NUCAPS
soundings use the RITMA
to modify that boundary layer but in this
particular case the values of CAPE
and surface dew point and temperature
didn't actually change all that much. Now
if we shift eastward now
about this was about 150 or so miles east of Bismarck
into the much drier air and if you look
on the left the non-modified NUCAPS
sounding was still showing values that
were way too high in terms of dew point
near the low levels which in turn was
returning Cape values on the sounding of
a couple of hundred joules per kilogram where in
actuality the dew points in this area
were still in the low 30s and so the
modified NUCAPS sounding on the right
was modified by the RITMA accurately
showed the boundary layer conditions
which in turn then produced CAPE values
of around zero which was much more
representative of the area that day.
Interestingly though the 19Z Bismarck
sounding special sounding that they
launched did show some cape values that
were around five hundred joules per
kilogram so this closer to the modified NUCAPS sounding in the the unstable
area but the NUCAPS soundings produced values of cape that were just a bit
too high. So the key takeaways for the
NUCAPS soundings were they're very
timely the past is around 18 to
20Z each day and they can serve
as the first guest indication of how
the atmosphere has changed since the 12Z
sounding. The boundary layer data can be
imprecise though as noted in the
unmodified soundings. The soundings that
were modified with RITMA have more
realistic boundary layer information and
can garner more information from those
soundings and these soundings can be
particularly useful to assess gradients
in the atmosphere such as cape. 
Alright thanks Jennifer. Next we'll get
a unique perspective on the GOES
lightning mapper RGB suite, AzShear and
ProbSevere version two with Timothy
Jeter and Thomas Herb who are both from
the US Air Force.
Go ahead Tim and Thomas. Yes thank you
so coming from the air force we took a bit
of a different approach this week we
wanted to use the products and try to
understand how to either supplement or
replace our current products more
specifically the GLM RGB, AzShear
and the ProbSevere as they seem to be
the products that would immediately improve the
quality of product for our customers. So
the RGB specifically the day cloud
base distinction and the day convection
RGB would be good to use to identify the
intense updrafts and rapidly developing
cumulus day cloud specifically helps to
distinguish between ice and water clouds
as well as the GLM would help identify
and quantify a substantial storm growth
as well as it provides ability for us to
see the lightning off the coast and
far out into the ocean where we have
missions going and we usually don't get
very good lightning data there. This is
Tom I'm a trainer for the air force as
well as a forecaster regional forecaster.
This will be very useful in the
classroom to emphasize reinforce
convective concepts of developing
thunderstorms intensity changes also
we also have a large coastline in the
southeast CONUS that we're interested in
keeping an eye on for not just warnings but
also we issue watches with some pretty
healthy lead times on them so for cells
that are outside radar coverage I
believe most of these or a large part
of these products and GLM will help us
improve our situation awareness for the
watch programs that we have for
lightning and then also severe
weather events. So the takeaways for GLM
it enhanced our capability over water and 
currently not available on the DoD platforms
and provides thunderstorm pulse
trends and the RGB suite allows us to
have a higher resolution for cloud temps
and developing thunderstorms and the
temperatures overlaid on the vis
satellite provides a better analysis
parameters than we currently have. So AzShear seems to be very useful for
us as we're responsible for very huge
areas of met watch so AzShear while it has
a lot of other useful uses would help to
quickly ID an area where shear may
aid in development of severe
thunderstorms where reflectivity isn't
showing it quite yet it helps us to
quickly ID an area we may need to
interrogate further. It looks especially
useful in identifying squall line
areas or QLCS's and we would need that
for once again for our lightning watch
and severe watch program and probably
supplement the layered azimuthal shears
with the normalized rotatio that's
available on GR2 site-specific radars.
ProbSevere shows some great
promise. We're looking at
that. It obviously has some drawbacks,
it has some false alarm issues but I
think for warnings and watches
for air force criteria with the lead times we have
we got to get point locations spotted
and the growth in cells and
and also just as importantly when
they're dissipating as well and
specifically for the hail. So the
takeaways for the AzShear
like I said all aid in large-scale
situational awareness, provides a good
first look where we need to interrogate
further and it's currently not
available on DoD platforms. and the ProbSevere just adds additional confidence for
evaluating severe thunderstorms
especially it seems good at hail.
Also once again in the classroom for concepts
reinforcement concepts it's going to be
invaluable as well and those aren't the
only products that we're interested in
the new MBA looks like that's
something we probably get some good mileage
out of if that hits the streets sooner, sooner 
than later would be better for us
Alright thank you both. Lastly we'll be
talking about the GOES lightning mapper
total lightning products with Stephanie
Henry from WFO Boise Idaho
go ahead Stephanie. Thank you. Living up
in Northwest I wanted to take a closer
look at how the GLM was evolving in
storm situations and I took in an
example of Southwest Montana and central
Wyoming and the main takeaways that I
got was at the parallax effect looking
at both goes east and west was still
pretty prominent in both cases. The
lightning was able to be detected by the
ground networks sometimes but not by the
flash extent density product and then
it was also the opposite where the
flash extent density did pick up some
lightning areas where the ground network
might not be as good in most places but
looking at flash extent density and
comparing it to total optical energy I
was able to find more use out of the
total optical energy in these locations
just because it's able to depict maybe
the intensity a little bit better in the
low scale ends and also able to pick out
the average area and give a big
picture representation of a storm course.
Now here's the group centroid density
product. It is more about point product
versus the flash density so but I just
wanted to show how it does evolve really
well with lightening cores that are
developing in larger storms. So here's a
case in southeast Missouri. The parallax
effect is still there so it's important
to note that the GLM might not be the
only product that you would want to look
at with seeing where all of lightning is
located but it's a good product that
complements the ground data. And another
great use of GLM has been over water areas. So this is the Gulf of Mexico where the
radar data drops out rather quickly but
you can still see the ground lightning a
little bit and then you can see the
intensity of the
flash extent density increasing over the
Gulf and especially you get to see the
different storm cell structures and
which one might be more intense than
the other product so I found it very
useful in those lower data
situations. And now here we were introduced to a
minimum flash area product versus the
average flash area and the minimum flash
areas basically identifying smaller
stroke values with the color scale more
easily and so it's able to pick up the
new convective storm cells that might
not have large flash extent density and it
also might the average flash area a
little bit washes out those higher
resolution pixels that you might see in
the minimum flash area. So I found it really
useful if you look over New Mexico it's
really pointing out the area of new
convection a lot more easy to your eye
versus the average flash area and I
found that to be really useful for cases
in the West where maybe the lightning
data is not as frequent or easily
viewable. So main takeaways is to still be
aware of the parallax effect in the
northern and Northwest latitudes. I did
see that it was a little bit better in
the Missouri case but it's still there so
that's definitely something to be aware
of when you're looking at only GLM
data versus other products and I
noticed the TOE the optical energy
product is a little bit better in
the West and in other cases where the
lightning is a little bit lower in
frequency but the TOE is able to
pick up those flashes in a big picture
sense and it's also very useful the GLM
is useful over water where you might have
poor data coverage in other cases and then we
determine that the minimum flash
area was a little bit better to use for
new convective cells. Alright thanks
everybody for those presentations. So
just a general information if you're looking
for more information about the EWP this
year or looking for
or use from previous tales from the
testbed it's located that website there
Also the blog as Brandon
mentioned earlier on if you're
interested in looking at more cases from
this week and previous weeks you can find
a multitude of cases on the blog that we
have from this year so that link is
located there as well if you want to
want to navigate there
to see more details on some of these
things. And with that we'll close for questions.
Thank you all for participating in this presentation. We'll now begin our Q&A session and I do
see that we did have a few come in
during the webinar so I'll go ahead and
start with the first which is from Brian
Motta. He asks to please comment on the
training before during and after your
hwt attendance. Was anything specific
missing in need of revision or desired
but not provided? For DoD folks I would say
don't take that recommendation to get to
your local weather forecast office for
some awips familiarization
proficiency is important it'll slow you
down if you aren't familiar with the interface.
I would say for the weather forecaster aspect I thought that the
training prior to attending that hwt was
very useful in helping introduce each of
the products and then once we got here
they went over in more detail about what
each product means and which ones to
focus on so I felt that the training at
least we knew what exactly to look for
what what items to focus more on each
day and we were able to using the
survey feedback we were able to kind of
have even more ideas of things to look
for so I thought it was really useful. Ok
great.
the next question is also from Brian
Motta, he asks is there a particular
example of AzShear that indicated a
hazard when the reflectivity data did
not. We're talking single radar or multi radar or both. Multi picked up better
than the single for my purposes that was
the Maxwell squall line. I think
on the Fort Rucker mesovortex it did
pick up where maybe you wouldn't get a
definitive signature on reflectivity
the AzShear can focus you in and compel
you start digging a little bit deeper I
think that was good takeaways of that. I
think probably it didn't necessarily
always show or show a signature that
reflectivity didn't but it did draw your
attention to areas we should pay more
attention and so it's kind of a triage
situation.
Alright great thank you guys. I also
now have a comment from Bill Sjoberg he
states as a retired USAF weatherman I
know the challenges. I hope that the USAF
personnel were able to look at the NUCAPS
soundings. There are a lot of remote
areas worldwide that the military
operate in that satellite soundings
would be helpful. We can get them access.
So Bill if you'd like to just maybe
throw your email in a comment I can give
that to them after the webinar as well.
The next question came from Brian Motta
he asks a lightning question. Did you
observe any lightning jumps this week
how useful was that trend information
Yeah actually I did observe a lightning jump just southwest of Bismarck in the supercell in that area.
It was actually super useful because I noticed the jump in the FED flash extent density
prior to when I saw the supercell wrap up and become tornadic.
So the flash extent density actually clued me in that something was going on
in the storm to when I saw
it in the velocity data so it's extremely
helpful. Alright thank you.
And the last question that I see here
right now is from Scott Lindstrom
he asks in the AzShear animation from
the Air Force folks
I saw parallel lines of a shear maxima
was that actually in the data or was I a
victim of bad streaming over my Wi-Fi.
That's actually in the data that's
that's a product of SAILS scans getting
in the merged product it's the way that
with products layered single radar
site and how we saved the individual
tilts the SAILS can come cause that
ghosting artifact downstream. Great thank you.
As for right now I'm not seeing any
additional questions so I think we can
call this webinar complete. Thanks again
to all of the presenters who took their
time out to prepare this presentation
and to Michael Bowlan for co-facilitating.
Thanks and have a great afternoon.
