Wal

lClo

ud: R

otat

ing,

lo

wer

ed, r

ain-

free

base

of

thun

ders

torm

in a

rea

ofst

rong

est u

pdra

ft,un

der

whi

ch a

torn

ado

may

form

.

Shel

fClo

ud: F

orm

sin

a

gust

front

from

asq

uall

line

or

thun

ders

torm

.

Mam

mat

us: S

mal

l pou

ch o

r po

cket

-like

clo

uds

sink

ing

into

drie

r air

and

ofte

n se

enne

ar th

unde

rsto

rms.

Virg

a: P

recip

itatio

n th

at

evap

orat

es b

efor

e re

achi

ng

the

surfa

ce.

Aspe

ritas

: Lon

g w

aves

that

rip

ple

thro

ugh

the

base

of t

he

cloud

nea

r the

dry

/moi

st a

ir bo

unda

ry o

f a th

unde

rsto

rm.

Fog:

A c

loud

on

the

grou

nd

whi

ch li

fts fr

om th

e su

rface

an

d be

com

es S

trat

us o

r di

ssip

ates

with

hea

t fro

m

the

sun.

Other Cloud Phenomena

Cum

ulon

imbu

s: V

ery

tall

sum

mits

with

anv

il-sh

aped

up

per p

art.

Cum

ulus

/Str

atoc

umul

us:

Stra

tocu

mul

us n

ot fr

om

spre

adin

g C

umul

us, w

ith

Cum

ulus

bas

e at

a

diffe

rent

leve

l.

Stra

tus-

or C

umul

us-

frac

tus:

Rag

ged

shre

ds

durin

g pr

ecip

itatio

n, u

sual

ly

seen

bel

ow A

ltost

ratu

s or

Nim

bost

ratu

s.

Stra

tus:

In a

con

tinuo

us

laye

r, or

Str

atus

frac

tus:

In

ragg

ed s

hred

s, o

r bot

h,

with

out p

reci

pita

tion.

Stra

tocu

mul

us: O

ne o

r m

ore

laye

rs, n

ot re

sulti

ng

from

spr

eadi

ng C

umul

us.

Stra

tocu

mul

us: S

prea

d ou

t C

umul

us w

hen

verti

cal

deve

lopm

ent s

tabi

lizes

; so

met

imes

can

occ

ur a

long

w

ith C

umul

us.

Cum

ulon

imbu

s: V

ery

tall

sum

mits

, whi

ch la

ck s

harp

ou

tline

s an

d ar

e no

t an

vil-s

hape

d.

Cum

ulus

: Mod

erat

ely

tall

with

roun

ded

puffy

tops

; m

ay o

ccur

with

Cum

ulus

/ St

rato

cum

ulus

(L4)

.

Cum

ulus

: Thi

n an

d ra

gged

w

ith c

ontin

uous

ly c

hang

ing

edge

s; fo

rms

durin

g fa

ir w

eath

er b

y da

ytim

e he

atin

g.

Alto

stra

tus:

Ful

l or n

early

fu

ll sk

y co

ver t

hat i

s gr

ay,

shap

eles

s an

d tra

nslu

cent

; pr

oduc

es n

o ha

lo.

Alto

stra

tus:

Thi

ck o

paqu

e co

vera

ge, n

o pr

ecip

itatio

n,

or N

imbo

stra

tus:

dur

ing

prec

ipita

tion

or v

irga.

Alto

cum

ulus

: Tra

nslu

cent

ba

nds

or p

atch

es in

a

rela

tivel

y co

ntin

uous

laye

r.

Alto

cum

ulus

Len

ticul

aris

: Le

ns o

r alm

ond

shap

ed,

ofte

n fo

rmed

by

air m

ovin

g ov

er h

ills o

r mou

ntai

ns.

Alto

cum

ulus

: One

or m

ore

laye

rs o

f tra

nslu

cent

or

opaq

ue b

ands

.

Alto

cum

ulus

: A re

sult

of th

e sp

read

ing

tops

of C

umul

us

or s

ides

of C

umul

onim

bus.

Alto

cum

ulus

: In

one

or

mor

e op

aque

laye

rs,

som

etim

es w

ith A

ltost

ratu

s or

Nim

bost

ratu

s.

Alto

cum

ulus

: Sm

all t

ower

s,

whi

ch c

an b

e si

mila

r to

smal

l Cum

ulus

with

wis

py

trails

of v

irga.

Alto

cum

ulus

: Cha

otic

sky

w

ith m

ultip

le la

yers

and

ki

nds

of A

ltocu

mul

us a

t se

vera

l alti

tude

s.

Cirr

us: S

traig

ht, n

early

st

raig

ht, o

r cur

ved

filam

ents

, st

rand

s or

hoo

ks.

Cirr

us: D

ense

whi

te p

uffs

w

ith w

ispy

edg

es.

Cirr

us: D

ense

, anv

il-sh

aped

re

mai

ns, w

hich

wer

e or

igin

ally

the

uppe

r par

ts o

f C

umul

onim

bus.

Cirr

ostr

atus

with

or w

ithou

t C

irrus

: Inc

reas

ing

dens

ity

and

cove

rage

, but

cov

erag

e do

es n

ot re

ach

mid

way

ab

ove

the

horiz

on.

Cirr

ostr

atus

: Vei

l cov

erin

g th

e w

hole

sky

, som

etim

es a

ha

lo a

roun

d th

e su

n or

m

oon

is p

rese

nt.

Cirr

us: F

ilam

ents

, stra

nds

or h

ooks

, inc

reas

ing

in

cove

rage

and

gen

eral

ly

thic

keni

ng a

s a

who

le.

Cirr

ostr

atus

: Vei

l not

co

verin

g th

e w

hole

sky

nor

in

crea

sing

in c

over

age.

Cirr

ocum

ulus

: Thi

n w

hite

rip

ples

or s

mal

l puf

fs, w

hich

m

ay b

e ac

com

pani

ed b

y so

me

Cirr

us/C

irros

trat

us.

Cirr

ostr

atus

with

or w

ithou

t C

irrus

: Inc

reas

ing

dens

ity

and

cove

ring

muc

h of

, but

no

t the

ent

ire s

ky.

Alto

stra

tus

Nim

bost

ratu

sAl

tocu

mul

us

Cirr

ostr

atus

Cirr

ocum

ulus

Cirr

us

Cum

ulus

Cum

ulus

/ St

rato

cum

ulus

Stra

tus

Stra

tocu

mul

usCu

mul

onim

bus

Cum

ulon

imbu

s

Hig

h1H

igh1

H2

H2

H3

H3

H4

H4

H5

H5

H6

H6

H7

H7

H8

H8

H9

H9

Mid

1M

id1

M2

M2

M3

M3

M4

M4

M5

M5

M6

M6

M7

M7

M8

M8

M9

M9

Low

1Lo

w1

L2L2L3L3

L4L4L5L5

L6L6L7L7

L8L8L9L9

NO

AA

Clo

udw

iseA

ltocu

mul

usm

ulu

uulul

mmumto

cumum

Alt

uA

ltu

lmm

Alto

A

Alto

strs

Cirr

us

Stra

tus

Stra

tus

Cirr

ocum

ulus

Cirr

ocum

ulus

Cirr

ostr

atus

Cirr

ostr

atus

Cirr

usC

irrus

Stra

tocu

mul

usSt

rato

cum

ulus

Alto

stra

tus

Alto

stra

tus

Nim

bost

ratu

sN

imbo

stra

tus

Cum

ulus

C

umul

us

Cum

ulon

imbu

sC

umul

onim

bus

Low Clouds Low CloudsMiddle Clouds Middle CloudsHigh Clouds High Clouds

Ther

e ar

e te

n ba

sic

clou

d ty

pes

arra

nged

in th

ree

divi

sion

s ba

sed

on th

e al

titud

e at

whi

ch th

ey fo

rm. L

ow

leve

l clo

uds

are

Cum

ulus

, Cum

ulon

imbu

s, S

tratu

s, a

nd S

trato

cum

ulus

. Mid

dle

leve

l clo

uds

are

Alto

cum

ulus

, Al

tost

ratu

s an

d N

imbo

stra

tus.

Hig

h le

vel c

loud

s ar

e C

irrus

, C

irroc

umul

us a

nd C

irros

tratu

s. P

reci

pita

tion

prim

arily

occ

urs

from

Cum

ulus

, Cum

ulon

imbu

s an

d N

imbo

stra

tus.

Thes

e te

n cl

ouds

are

furth

er d

ivid

ed in

to 2

7 cl

assi

ficat

ions

. Man

y of

thes

e cl

assi

ficat

ions

repr

esen

t the

sam

e ba

sic

clou

d ty

pe (o

r com

bina

tions

of c

loud

s) b

ut in

var

ious

sta

ges

of d

evel

opm

ent,

opac

ity, o

r sky

cov

er.

Lear

n m

ore

abou

t clo

uds

at w

ww

.wea

ther

.gov

/jets

tream

ww

w.n

oaa.

gov/

educ

atio

n

ww

w.w

eath

er.g

ov

6,50

0 ft.

20,0

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.

Sky

Cle

ar0%

Few

1 - 2

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atte

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50%

Brok

en51

- 99

%O

verc

ast

100%

Sky

cove

rTh

e pe

rcen

t of s

ky c

over

ed b

y cl

ouds

. Clo

uds

near

the

horiz

on a

ppea

r to

be lo

wer

, m

ore

num

erou

s an

d cl

oser

toge

ther

.

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Mcl

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nt_0

8261

9.ai

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8/2

9/20

19

10:5

6:04

AM

Nat

iona

l Oce

anic

and

Atm

osph

eric

Adm

inis

tratio

nN

OAA

- ht

tps:

//ww

w.no

aa.g

ovN

OAA

Edu

catio

n Po

rtal -

http

s://w

ww.

noaa

.gov

/edu

catio

n

Nat

iona

l Wea

ther

Ser

vice

NW

S Ed

ucat

ion

- http

s://w

ww.

wea

ther

.gov

/ow

lieJe

tStre

am -

An O

nlin

e Sc

hool

for W

eath

er -

http

s://w

ww.

wea

ther

.gov

/jets

tream

NO

AA

Wea

ther

wis

e

War

m fr

ont

War

mer

air

repl

acin

g co

ol (o

r col

d) a

ir

Col

d fro

ntC

old

(or c

oole

r)ai

r rep

laci

ng

war

mer

air

Dry

line

Boun

dary

div

idin

gdr

y de

sert

air

from

moi

st

gulf

air

HHi

gh p

ress

ure

Loca

tion

of

high

est s

urfa

ceai

r pre

ssur

e

Stat

iona

ry fr

ont

Non

-mov

ing

boun

dary

divi

ding

war

m

air f

rom

coo

ler a

ir

Surfa

ce w

ind

Jet

stre

am

LLo

w p

ress

ure

Loca

tion

of

low

est s

urfa

ce

air p

ress

ure

idin

gai

r

HHi

ghpr

essu

reLo

catio

n of

hi

ghes

tsur

face

Surfa

ce w

ind

Jet

LLo

wpr

essu

reLo

catio

n of

lo

wes

tsur

face

HH

LHHHH

LLLLLHH

L

Jet s

tre

am

Equa

tor

Pola

r jet

str

eam Su

btro

pica

l je

t str

eam

Trop

ical

air

Tem

pera

teai

r

Pola

r air

Stro

ng w

inds

from

the

high

-pre

ssur

e sy

stem

car

ry c

olde

r, dr

ier a

ir in

to th

e da

rk b

lue

area

. As

the

cold

fron

t pa

sses

, pre

cipi

tatio

n en

ds a

nd s

kies

cle

ar fa

irly

rapi

dly.

Poss

ible

impa

cts

The

diffe

renc

e in

air

pres

sure

bet

wee

n tw

o po

ints

det

erm

ines

win

d sp

eed

and

dire

ctio

n. L

arge

pre

ssur

e di

ffere

nces

cau

se v

ery

stro

ng w

inds

. The

y ar

e m

ore

likel

y to

occ

ur in

win

ter a

nd c

an le

ad to

bliz

zard

con

ditio

ns

and

dang

erou

s w

ind

chills

. In

mou

ntai

nous

are

as, l

ight

ning

from

thun

ders

torm

s w

ith li

ttle

or n

o ra

infa

ll ca

n ig

nite

wild

fires

. The

se fi

res

may

spr

ead

rapi

dly

whe

n dr

iven

by

stro

ng w

inds

ass

ocia

ted

with

the

thun

ders

torm

.

Wea

ther

saf

ety

Rem

embe

r: Ic

e an

d Sn

ow, T

ake

It Sl

ow! b

oth

on a

nd o

ff th

e ro

ad. W

hile

driv

ing,

slo

w d

own

to re

duce

the

chan

ce o

f an

acci

dent

on

slip

pery

road

s. D

on’t

over

exer

t you

rsel

f whe

n sh

ovel

ing.

Avo

id p

rolo

nged

exp

osur

e to

col

d te

mpe

ratu

res,

whi

ch c

an c

ause

fros

tbite

and

/or h

ypot

herm

ia. P

repa

re fo

r and

be

awar

e of

pot

entia

l fire

ha

zard

s du

ring

dry

perio

ds.

Nor

th o

f the

col

d fr

ont

In th

e lig

ht b

lue

area

, the

air

tend

s to

be

cool

and

dry

. Clo

ser t

o th

e w

arm

fron

t, m

oist

ure

incr

ease

s. A

s a

resu

lt, c

loud

s th

icke

n,

whi

ch c

an le

ad to

rain

or s

now.

Poss

ible

impa

cts

War

m fr

onts

nea

r are

as o

f low

-pre

ssur

e ca

n br

ing

heav

y ra

in,

snow

, or s

leet

. Rai

n ca

n le

ad to

floo

ding

, whi

le s

now

and

sle

et

may

resu

lt in

a v

arie

ty o

f haz

ards

incl

udin

g sl

ick

road

s an

d po

wer

out

ages

.

Wea

ther

saf

ety

Nev

er d

rive

into

floo

ded

road

way

s or

aro

und

a ba

rrica

de. T

urn

Aro

und

Don

’t D

row

n! K

now

the

risks

of f

lood

s an

d pl

an y

our

evac

uatio

n ro

ute.

Hav

e ex

tra fo

od a

nd w

ater

in c

ase

you

lose

po

wer

or a

re tr

appe

d in

you

r hom

e. D

urin

g w

inte

r wea

ther

, driv

e sl

owly

or n

ot a

t all.

Nor

th o

f the

war

m fr

ont

War

m, m

oist

air

from

the

Gul

f of M

exic

o an

d At

lant

ic O

cean

mov

es in

to th

e gr

een

area

, in

crea

sing

tem

pera

ture

s an

d hu

mid

ity. S

how

ers

and

thun

ders

torm

s ca

n de

velo

p al

ong

and

in

adva

nce

of a

col

d fro

nt o

r dry

line

.

Poss

ible

impa

cts

War

m, m

oist

air

can

be fo

rced

upw

ards

as

it re

ache

s an

app

roac

hing

col

d fro

nt a

nd/o

r dry

line

. Th

is c

an c

ause

sev

ere

thun

ders

torm

s, fl

oodi

ng,

and

torn

adoe

s.

Wea

ther

saf

ety

Alw

ays

be W

eath

er-R

eady

— fo

reca

sts

can

prov

ide

seve

ral d

ays

adva

nce

notic

e of

sto

rms.

C

heck

them

regu

larly

. Be

prep

ared

and

W

hen

Thun

der R

oars

, Go

Indo

ors

to s

tay

safe

fro

m li

ghtn

ing.

Kno

w y

our s

afe

plac

e at

hom

e an

d w

ork.

Sou

th o

f the

war

m fr

ont

Sout

h of

the

fron

ts a

nd

wes

t of t

he d

ry li

neIn

the

oran

ge a

rea,

wea

ther

is g

ener

ally

dry

an

d m

ild. A

ppro

achi

ng fr

onts

can

lead

to h

igh

altit

ude

thun

ders

torm

s ov

er m

ount

ain

peak

s,

resu

lting

in s

trong

win

ds a

t the

sur

face

. Ove

r tim

e th

e ef

fect

s of

the

front

s w

ill di

min

ish.

To le

arn

mor

e ab

out t

he c

hara

cter

istic

s of

fron

ts,

expl

ore

the

rest

of t

he m

ap.

Poss

ible

impa

cts

Stro

ng s

urfa

ce w

inds

can

lead

to d

ust s

torm

s an

d w

ildfir

es. I

n So

uthe

rn C

alifo

rnia

, the

war

m,

dry

Sant

a An

a w

inds

blo

w to

war

ds th

e co

ast

from

the

high

des

ert a

reas

. Sea

sona

l hea

vy

rain

, eve

n fro

m d

ista

nt th

unde

rsto

rms,

can

lead

to

flas

h flo

ods

and

debr

is fl

ows

in ty

pica

lly v

ery

dry

area

s.

Wea

ther

saf

ety

Be a

lert

for d

ust s

torm

s, w

hich

can

com

e w

ith

little

war

ning

— P

ull A

side

, Sta

y A

live.

Pul

l far

of

f the

road

and

turn

all

car l

ight

s of

f. Fo

llow

ev

acua

tion

orde

rs d

urin

g fir

es. M

onito

r fo

reca

sts

for f

lash

floo

ds, w

hich

can

be

a ris

k m

any

mile

s fro

m a

sto

rm, e

spec

ially

in d

ry

valle

ys a

nd c

anyo

ns. D

on’t

be c

augh

t off

guar

d;

be p

repa

red

to m

ove

to h

ighe

r gro

und.

Expl

ore

mor

e w

eath

er p

heno

men

a at

ww

w.w

eath

er.g

ov/je

tstr

eam

Dra

win

g C

oncl

usio

ns •

Toas

ty W

ind

A Pr

essi

ng E

ngag

emen

t • G

oing

with

the

Flow

Sugg

este

d le

sson

s:

he w

eath

er w

e ex

perie

nce

ever

y da

y on

the

grou

nd is

a re

sult

of w

hat i

s ha

ppen

ing

far a

bove

our

hea

ds. U

p th

ere,

the

air i

s al

way

s m

ovin

g as

hea

t ene

rgy

is re

dist

ribut

ed a

cros

s th

e Ea

rth.

Met

eoro

logi

sts

stud

y ai

r mov

emen

t to

mak

e w

eath

er fo

reca

sts.

The

Sun

heat

s th

e Ea

rth, w

hich

then

hea

ts th

e ai

r in

the

atm

osph

ere.

Bec

ause

the

Sun

hits

the

equa

tor

mos

t dire

ctly,

the

air a

t the

equ

ator

rece

ives

mor

e he

at e

nerg

y th

an th

e ai

r clo

ser t

o th

e po

les.

Thi

s w

arm

air r

ises

bec

ause

it is

less

den

se th

an c

ool a

ir.

Whe

n th

e w

arm

air

reac

hes

the

uppe

r atm

osph

ere,

it c

an n

o lo

nger

rise

and

is fo

rced

tow

ard

the

pole

s.

As th

e ai

r coo

ls, i

t bec

omes

den

ser a

nd fa

lls b

ack

tow

ard

Earth

. Hig

h-pr

essu

re a

reas

form

whe

re c

oole

r

air i

s fa

lling

tow

ards

the

Earth

. Low

-pre

ssur

e ar

eas

form

whe

re w

arm

air

is ri

sing

. Air

circ

ulat

es fr

om

area

s of

hig

h pr

essu

re to

are

as o

f low

pre

ssur

e.

The

way

the

air m

oves

affe

cts

the

wea

ther

. Bet

wee

n th

e la

rge

area

s of

circ

ulat

ing

air,

jet s

trea

ms

form

.

Jet s

tream

s ar

e tu

be-li

ke p

aths

of s

trong

win

d m

ovin

g fro

m W

est t

o Ea

st a

roun

d th

e gl

obe.

The

pos

ition

and

stre

ngth

of j

et s

tream

s va

ry fr

om N

orth

to S

outh

, as

wel

l as

verti

cally

thro

ugho

ut th

e at

mos

pher

e.

The

loca

tion

of th

e je

t stre

ams

and

thei

r sea

sona

l mov

emen

t driv

e m

ajor

wea

ther

pat

tern

s ar

ound

the

wor

ld. I

n th

e U

nite

d St

ates

, col

d sn

aps

happ

en w

hen

the

pola

r jet

stre

am d

ips

sout

h. H

eat w

aves

can

occu

r whe

n th

e po

lar j

et s

tream

is v

ery

far n

orth

, allo

win

g fo

r war

m s

ub-tr

opic

al a

ir to

mov

e no

rth.

TBe

wea

ther

wis

e w

here

ver y

ou a

reTh

is m

ap s

how

s a

sim

plifi

ed fo

reca

st fo

r a s

ingl

e, h

ypot

hetic

al d

ay.

The

loca

tions

of t

he lo

w- a

nd h

igh-

pres

sure

sys

tem

s, je

t stre

am,

and

front

s sh

ape

the

wea

ther

that

a g

iven

regi

on m

ay e

xper

ienc

e.

Ther

e ca

n be

haz

ardo

us w

eath

er a

nyw

here

, at a

ny ti

me.

Beg

in

each

day

kno

win

g th

e w

eath

er fo

reca

st. I

f sev

ere

or e

xtre

me

wea

ther

is a

pos

sibi

lity,

per

iodi

cally

che

ck fo

r for

ecas

t upd

ates

. Be

pre

pare

d w

ith a

saf

ety

plan

. Hav

e a

“go-

kit”

with

impo

rtant

pr

oper

ty a

nd d

ocum

ents

read

y in

cas

e of

em

erge

ncy.

Hav

e at

leas

t a

thre

e-da

y su

pply

of f

ood

and

wat

er. L

earn

the

spec

ific

reco

mm

enda

tions

for r

egio

nal a

nd s

easo

nal w

eath

er h

azar

ds.

Lear

n m

ore

abou

t sea

sona

l saf

ety

at

http

s://w

ww.

wea

ther

.gov

/saf

etyc

ampa

ign.

C M Y CM MY

CY CMY

K

clou

dcha

rt_b

ack_

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19.a

i 1

8/

29/2

019

10:

57:1

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oudc

hart

_bac

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.ai

1

8/29

/201

9 1

0:57

:14

AM