FLOOD04806

• County: Larimer
• Stream Name: Big Thompson/Cache la Poudre
• Basin: South Platte
• Title: Storm and Flood of July 31-August 1, 1976 in the Big Thompson River and Cache la Poudre River Basins
• Date: 1/1/1979
• Prepared For: Colroado Geological Survey
• Prepared By: USGS/NOAA
• Floodplain - Doc Type: Flood Documentation Report

20

FLOOD. JULY 3I-AUGUST I, 1976. BIG THOMPSON RIVER. COLORADO

115"

110"

\..

~

105"

100"

95'

40'

24
1

\r----"''';
NO ECHOES!

I
I
-.- j
---I
,
1
L

-------1
I <DRW
~I'f!l!!.ii~.,.'"
L~
200
r-------
I

\,.
"-
.........

I
A470 1 L
~ I
;~ \TRW I
o'V~
e .::...~iISOLO I
~ TRW++ :
---0 '
-O----u--!-__
1----'

H

. 0

I 0
00 <>
0
35' I 0
0
I o OTRW-

1100

o
1

100
1

AREA OF RADAR ECHOES. -Usuallv interpreted as an
area with precipitation

COLD FRONT -Dashed where dissipating

STATIONARV FRONT

SnUALlllNE

.

.

.

-

H
L

GEOGRAPHIC CENTER OF HIGH-PRESSURE SYSTEM

GEOGRAPHIC CENTER Of lOW-PRESSURE SYSTEM

DIRECTION (ARROW) AND SPEED (NUMBER) OF
ECHOES -Speed, in knots

-25

\
\---
-r-----~--

r ------,1
: 1
I
I
,
I

H

NO ECHOES

105"

200
1

300
1

~

,
,
\ NO ECHOES
--.---.
~--./
1
,

EXPLANATION

CD
A470
r
TRW
TRW++
TRW-

RW
RW-/+
RWU
IS OLD

-ORWU

.",--,,"

.,
"

\
\

<D RW-j+
~20
, -
L .. ...
----~--

\
''C'''/
-~'-
---- ~- ~-- .~.

40'

-25

\

----

35'

'-,
.,-.\

NO ECHOES

--~
"V--~?',J-^<'-""-./

100"

400 MILES
1

SCATTERED ECHOES IN AREA
lOCATION OF ECHO. -A=estimated; 470=maxirnum
altitude of top of echo, in hundreds of feet.
470~47,OOO feet
MODERATE THUNDERSTORM
VERY HEAVY THUNDERSTORM
THUNDERSTORM,
APPARENTLY WEAKENING
MODERATE RAIN SHOWER
LIGHT RAIN SHOWER, INCREASING IN INTENSITY
RAIN SHOWER, INTENSITY UNKNOWN
ISOLATED

FIGURE 15.-Radar summary for 1135 MDT, with locations of fronts and squall line for 1200 MDT. July 31, 1976.