The Clouds Outside My Window

The Clou
My W

National We
NO

uds Outside
Window

eather Service
OAA

Updated 10/2017



The Clouds O

Written an
John

With help from

Outside My Window

nd illustrated by
n Jensenius

My window

Owlie Skywarn

1

The Clouds
My Wind

Whether I’m outdoors or just loo
observe the clouds. Each cloud
different story to tell. In this boo
the basic cloud types and show
clouds I’ve observed outside my
National Weather Service Office

I hope this book will encourage
sky. You may want to take pictu
or school and make a book of yo
me know, so I can see the cloud
window.

-- John Jensenius
Meteorologist

2 National Weathe

Outside
dow

oking outside, I like to
d is different and has a
ok, I’ll explain some of
w you some of the
y window at the
e in Gray, Maine.

you to observe the
ures outside your home
our own. If you do, let
ds outside your

s

er Service

A Look Ou

Here’s a look out my
across the street from
Center which you’ll see

(The black silhouette
flying into m

ut My Window

window. My office is located

the Pineland Farms Equestrian

e in many of the cloud pictures.

e of the hawk keeps birds from

my reflective windows) 3

What are c
made o

High in the atmosphere where t
very cold, most clouds are mad
Closer to the ground, the clouds

of tiny water dro

4

clouds
of ?

temperatures are very,
de of tiny ice crystals.
s that we see are made
oplets.

How d
fo

In general, there are
In both cases, thoug
because the air is co

In the atmosphere, r
sinking air warms. I
that you see are cau

do clouds
orm?

e two ways clouds form.
gh, the clouds form
ooling.
rising air cools and
In most cases, the clouds
used by rising air.

5

How do c
form

Clouds can also form whe
colder for other reasons.
overnight when the air is
warm air moves over a co
covered surface.

6

clouds
m?

en the air gets
This can happen
cooling, or when
old lake or a snow-

How a
na

Clouds are classified
on how high they are
sky, whether they are
up of tiny water drople
ice crystals, their gen
appearance, and whet
they are producing
precipitation.

On the next few pages
explain some of the b
terminology used to
classify clouds.

are clouds
amed?

based
in the
made
ets or
neral
ther

s, I’ll
basic

7

How are c
named

Puffy clouds are called cum
prefix “cumulo.”

Clouds that form a layer are
have the prefix “strato.”

Clouds that are made up of
called cirrus or have the pr

Clouds that produce precip
nimbus or have the prefix “

8

clouds
d?

mulus or have the

e called stratus or

f ice crystals are
refix “cirro.”
pitation are called
“nimbo.”

How a
na

We often need to comb
terms to accurately de

For example, puffy clo
however, if the cumulu
are called stratocumul

If those puffy cumulus
clouds grow upward h
into the sky and produ
rain, they are called
cumulonimbus clouds

are clouds
amed?

bine the various cloud
escribe the clouds we see.

ouds are called cumulus;
us clouds form a layer, they
lus.

s
high
uce

s.

9

Types of Low

LOW Stratocumu
Cumulus
Stratus

10

w Clouds

ulus

Types of
St

Stratus clouds often for
the ground. They give th

f Low Clouds
tratus

rm a blanket of low clouds near
he sky a dull, gray appearance.

11

Types of Low
Stratus -

When stratus clouds form a
call it fog. If you’ve ever be
12 been inside a stratu

w Clouds
- Fog

at the ground, we
een in fog, you’ve
us cloud.

Types of
Nimb

These stratus clouds
rain falls from stratu
called nimb

Low Clouds
bostratus

are producing rain. When 13
us clouds, the clouds are
bostratus clouds.

Types of Low
Stratus – Gro

Sometimes on clear nights,
forms in the air just above th
this ground fog. If you can lo
14 the fog, you’re abov

w Clouds
ound Fog

a thin layer of fog
he ground. We call
ook over the top of
ve a cloud.

Types of
Cu

These puffy, low cloud
specifically, they are cal
They have distinct botto

on sunny days as ai

f Low Clouds
umulus

ds are cumulus clouds. More 15
lled cumulus humulus clouds.
oms and edges and often form
ir rises in the atmosphere.

Types of Low
Cumul

These low clouds are also c
this case, they are called cu

have rough edges, look da
16 form on sunny, wi

w Clouds
lus

cumulus clouds. In
umulus fractus and
arker, and usually
indy days.

Types of
Strato

When cumulus clo
them stratocumulu
are breaks between

this is a broken l

f Low Clouds
ocumulus

ouds form a layer, we call 17
us clouds. Because there
n the clouds, we would say
layer of stratocumulus.

Types of Midd

MIDDLE

18

dle Clouds

Altocumulus
Altostratus

Types of M
Altoc

These puffy clouds a
However, because the

sky, we call them

Middle Clouds
cumulus

are also cumulus clouds. 19
ey are at mid-levels in the
m altocumulus clouds.

Types of Midd
Altocumu

Altocumulus clouds early
morning could be a clue that
20 thunderstorms later in

dle Clouds
ulus

on a summer
t there might be
n the day.

Types of M
Alto

These mid-level clouds
sky and are called altos

see the dim sunshine

Middle Clouds
ostratus

s are forming a layer across the
stratus clouds. Often, you can
e through altostratus clouds. 21

Types of High

HIGH C
C
C

22

h Clouds

Cirrus
Cirrostratus
Cirrocumulus

Types of
C

These wispy, high clou
clouds are made up
sometimes resem

f High Clouds
Cirrus

uds are cirrus clouds. Cirrus 23
p of tiny ice crystals. They
mble the tails of horses.