FLOOD01529

• County: Larimer
• Community: Big Thompson Canyon
• Stream Name: Big Thompson
• Title: Natural Disaster Survey Report 76-1: Big Thompson Canyon Flash Flood of July 31 - August 1, 1976
• Date: 10/1/1976
• Prepared For: Department of Commerce
• Prepared By: NOAA
• Floodplain - Doc Type: Flood Documentation Report

CHJIPlER 2

DATA ACQUISITION

Meteorological data and information from surface, upper air, radar and
satellite observations are available at WSFO Denver. These data arrive
over several communications channels. This chapter will discuss these
data sources and channels of communication as they existed on the day of
the flood.

Surface Observations

WSFO Denver receives four types of surface observations for its forecast
and warning programs: (1) aviation observations from first and second
order stations and supplementary aviation weather reporting stations
(SAWRS); (2) reports from cooperative or paid observers in the hydrologic,
fire weather, and public service networks; (3) reports from automated
reporting equipment; and (4) reports from the public, spotter networks,
and law enforcement agencies.

Communication channels used to deliver data to WSFO Denver are listed in
the following table. Commercial telephone service into the flood area
was disrupted by the flood. The radar remote display from WSMO Limon
was inoperative on July 31, 1976, and there were long-standing problems
with some automated observations. These will be discussed under the section
dealing with the particular type of observation. There were no problems
reported with other channels of communication.

Teletype

Facsimile

Telephone

Service A
Service C
Fire Weather Circuit
RAWARC
NOAA Weather Wire
AlIOS/S
Computer Terminal

Commercial
FTS
Hot-line
NAWAS
AlIOS/T

FOFAX
NAFAX

WBRR

Aviation Observations--Aviation weather observations are taken by NWS or
FAA personnel on a 24-hour basis at 9 Colorado locations. The NWS WSMO at
Limon takes three-hourly surface observations. Surface weather obser-
vations are made at Alamosa from 4:00 a.m. to midnight on weekdays and
from 4:00 a.m. to 7:00 p.m. on weekends. With the exception of Alamosa,
where no provision is made for evening precipitation reports on the week-
ends, all these stations report 6-hourly precipitation amounts. Observers
at second-order (contract) stations and Supplementary Aviation Weather

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