WMOD00389

• Title: Winter Precipitation, Snowpack and Atmospheric Conditions in the Southern Canadian Rockies
• Date: 1/1/1983
• Country: Canada
• Weather Modification - Doc Type: Report

~ ~..;.-..-4t... ..........'....__....~. ......,... "'-4-_..~.. >_3: ,_ ~ ... .~."._...... .__....c..,__..._...._

_4*10-...._,.~-:;.._.._~."....

4'd!!._lc.a..... ......,.;.,,\.l..~J,..,Io~.u....I....~....;.....~.~..""'__..~~--..:..\....'~~.o:.._:t,; . ,,'AJ' \.'Q,....j/,.-4;.~.tA;.(t!.....;!,......,... h

......-~~

Page 2

c~.

1.0 INTRODUCTION

The meltwater from winter snowpack of the southern Canadian Rockies
provides the principal water source for irrigation agriculture in
southern Alberta. Future agricultural expansion and accommodation of
other water-based requirements depends on careful management of this
region's water resources (Environment Council of Alberta, 1982).
Supplementing this water resource by increasing the snowpack storage may
assist in such management.

The Alberta Research Council initiated a preliminary project to
examine the feasibility of supplementing the snowpack through the
controlled use of cloud-seeding techniques. This projects's initial aim
is to measure and analyze precipitation processes of snow-producing
orographic clouds. The project study area straddles the Alberta-British
Columbia border and includes the Oldman River basin (Figure 1).

As part of this analysis, a study of the long-term precipitation
data of the region was initiated. Snowpack and daily precipitation data
selected from climate stations, snow survey stations and upper air
measurements were used. This paper reports on some of the results.

There are three sections to the climatological examination
presented here: a) seasonal snowfall characteristics, b) snowfall/upper
air relationships and c) snowfall/snowpack relationships. Each of these
sections presents highlights and examples of the analysis.

2.0 SEASONAL SNOWFAll CHARACTERISTICS

Analyses discussed in this section were carried out for 24 stations
in the study area (Figure 2 and Table 1). Periods of record for these
stations range from 11 to 33 years, with varying degrees of
completeness. Days with missing data were not included.

2.1 Procedures

For the selected stations, three analysis steps were carried out:

(I) total snowfall measured for each month of record was
detenni ned;

(2) the number of occurrences for each month of daily snowfall
exceeding 0, 2, 4, 8, 16, and 32 centimetres were found;

(3) the number of occurrences for each month were summed over
all years of record.

\
"- .