Week  8  -­‐  Map  Assignment:    Severe  Weather  Forecasting     Here’s  a  chance  to  make  your  first  severe  weather  forecast.    Using  everyday  data,  you  will  be  able  to   make  your  forecast.    But  first:   Severe  Weather  Ingredients  –  A  quick  discussion.   In  order  to  get  severe  weather  in  the  U.S.,  you  need  3  ingredients.   -­‐Moisture   -­‐Instability   -­‐Lift   Let’s  look  at  each  one.   Moisture:    When  we  are  looking  at  moisture  for  severe  weather,  we  are  focused  on  dew  point   temperatures  across  the  country.    Typically,  we  need  a  dew  point  of  55F  or  higher  to  provide  enough   energy  and  moisture  to  sustain  severe  weather.   Instability:    This  is  a  bit  more  complicated.    The  end  of  chapter  8  has  a  discussion  and  shows  examples  of   both  upper  air  troughs  and  ridges.    Troughs  are  what  generate  our  unsettled  weather  (clouds,  rain,   wind,  etc)  and  in  some  cases,  bring  about  severe  weather.    When  forecasting  severe  weather,  we   typically  look  for  areas  across  the  country  where  a  trough  is  approaching.    An  upper  air  trough  increases   instability  in  the  atmosphere.    Most  unsettled  weather  occurs  just  to  the  EAST  of  a  trough.   Lift:    Lift  simply  refers  to  a  boundary  (cold  front,  warm  front,  dry  line)  that  lifts  moisture  at  the  surface,   through  convergence,  higher  into  the  atmosphere.    Remember,  we  can  find  boundaries  by  finding  wind   shifts,  and  tight  gradients  of  both  dew  point  and  temperature.   If  all  three  ingredients  are  present  in  the  same  area  of  the  country,  chances  are  pretty  good  that  there  is   a  severe  weather  threat.   Question  1:    Below  are  three  maps.    An  upper  air  map  (500mb),  a  dew  point  map,  and  a  wind  analysis  all   from  the  same  time.   A.)   B.)   C.)   (2pt)  Using  the  500  mb  map.    Locate  the  trough(s)  and  ridge(s).   (2pt)  Where  across  the  US  is  there  enough  moisture  to  sustain  severe  weather?   (2pt)  Using  the  wind  map,  is  there  a  boundary  in  the  central  part  of  the  U.S.    If  so,  where  is  it  located?  .

1. Week
8
-­‐
Map
Assignment:
Severe
Weather
Forecasting
Here’s
a
chance
to
make
your
first
severe
weather
forecast.
Using
everyday
data,
you
will
be
able
to

2. make
your
forecast.
But
first:
Severe
Weather
Ingredients
–
A
quick
discussion.
In
order
to
get
severe
weather
in
the
U.S.,
you
need
3
ingredients.
-­‐Moisture
-­‐Instability

3. -­‐Lift
Let’s
look
at
each
one.
Moisture:
When
we
are
looking
at
moisture
for
severe
weather,
we
are
focused
on
dew
point
temperatures
across
the
country.
Typically,

4. we
need
a
dew
point
of
55F
or
higher
to
provide
enough
energy
and
moisture
to
sustain
severe
weather.
Instability:
This
is
a
bit
more
complicated.
The
end
of
chapter
8

5. has
a
discussion
and
shows
examples
of
both
upper
air
troughs
and
ridges.
Troughs
are
what
generate
our
unsettled
weather
(clouds,
rain,
wind,
etc)
and
in
some
cases,
bring
about
severe
weather.

6. When
forecasting
severe
weather,
we
typically
look
for
areas
across
the
country
where
a
trough
is
approaching.
An
upper
air
trough
increases
instability
in
the
atmosphere.
Most
unsettled
weather
occurs
just
to

7. the
EAST
of
a
trough.
Lift:
Lift
simply
refers
to
a
boundary
(cold
front,
warm
front,
dry
line)
that
lifts
moisture
at
the
surface,
through
convergence,
higher
into
the
atmosphere.
Remember,

8. we
can
find
boundaries
by
finding
wind
shifts,
and
tight
gradients
of
both
dew
point
and
temperature.
If
all
three
ingredients
are
present
in
the
same
area
of
the
country,
chances
are
pretty

9. good
that
there
is
a
severe
weather
threat.
Question
1:
Below
are
three
maps.
An
upper
air
map
(500mb),
a
dew
point
map,
and
a
wind
analysis
all
from
the

10. same
time.
A.)
B.)

11. C.)
(2pt)
Using
the
500
mb
map.
Locate
the
trough(s)
and
ridge(s).
(2pt)
Where
across

12. the
US
is
there
enough
moisture
to
sustain
severe
weather?
(2pt)
Using
the
wind
map,
is
there
a
boundary
in
the
central
part
of
the
U.S.
If
so,
where
is
it
located?

13. (2pt)
Given
the
answers
from
the
previous
questions,
where
would
you
expect
severe
weather
to
occur?
Be
specific,
include
the
states
and
where
in
the
state
you
would
expect
this
weather.
(2pt)

14. Why
is
wind
shear
important
to
severe
thunderstorms?