The Iola register. [volume] (Iola, Allen County, Kansas) 1875-1902, 1896-03-06
U. S. WEATHER BUREAU.
Some Interesting aud Instructive Obser-
Vations About the Objects it Seeks
and the Work it Does
BY CLARENCE ]. NORTON.
PART NJ.

long these papers one or two weeks.
In substance, he wished me to ex-
plain why his state had wet and dry
seasons; why he felt the cold worse in
Kansas than he did i'm Minnesota, the
theory of Auroras and of Electric dis
play.
In reply, can only give the con-
illusions arrived at by the Weather
Bureau, based upon their observation.
The periods of the year in Califor-
MIA are more generally spoken Of as
wet and dry seasons. The term "wet''
does not in this sense mean continuous
wet, nor does the term "dry" mean no
rainfall. They are used in compar-
alive sense and mean: the wet season
that rain is more probable, and the
dry that no rain il more probable,
than the reverse. l only have before
me the rain data of San Francisco,
but it represents very largely the
whole state.
Rain has fallen every month in the
year at San Francisco. August has a
mean of OO1 of an inch; July OO2;
Sept. O.22; June 0.25; May O.73; Oct.
LIS; and the other months have aver
age of from to inches. From May
lst to Oct. 1st, five months have an
average rainfall of 1.23 inches, and
the remaInding seven months have
an average of % 20 inches, making an
annual average of 1893 inches.
The records show that the average
data of first 0.05 of an inch of rainfall
occurs by Sept. II. Considering June
80 as the official end of one season and
July as the commencement of the
next season, we. find that the earliest
date of 0.05 of an inch of rain is July
8, and the latest, Oct. q, that is, from
July TO Oct. q, only 0.O5 of an inch
of rain fell. AS O.05 of an inch of rain
is such a small amount. it has been
deemed best to consider that when
one quarter of an inch of rain has
fallen, that date be considered the
commencement of the rainy season.
Using this, then, as basis, we find
that the rainy season begins on Oct. s.
The earliest of quarter of an inch is
Sept. 8 1884, and the latest Nov. %
1880. AS one quarter of an inch of
rainfall at San Francisco is hardly
sufficient to allow of rainfall over the
southern portion as the commence
ment of the rains there, and this is
found to be Nov. ]. The earliest date
is Sep Is 1883, and the latest, Dec. 8
1890. One inch of rainfall at San
Francisco is not sufficient for the in
terror of the State to allow good plow-
ing and seeding; hence, a total of two
inches at San Francisco was consider
ed, and it is found that . inches of
rainfall at San Francisco up to Nov.
13; hence, that date can be said to be
the date of commencement of good
plOughing. inches is considered as
the rainy season being in full blast,
and it is found that inches has fallen
as early as Oct. p 1889, and as late as
Feb. 1891. Thus:-the first rains are
Sep. Il; rainy season begins Oct. s,
and in the northern part of Stale,
Nov. l; ground mOistened for blowing
Nov. Is, and rainy season in full
effect, Dec. 10.
These facts will be found of value
to many, for it shows the averages of
the past % years.
The amount of rainfall in California
is dependent upon the north or south
detection of the storm areas. The
food of a storm is heat and moisture.
With the approach of the summer
the heat is increased and the
moisture becomer less, hence, the
storm areas retreat northward to OBJ
tain their greater supply of moisture.
AS the storm areas seek their more
path, the rainfall over
becomes less aud less, and
with the passing of the summer heat
the path of the storm areas moves
southerly. and the rainfall then in
creases.
The normal path of storm areas
across the Rocky mountains from
to april is about 80 degrees
north latitude, and when the path is
south of this line the rainfall over
California is increased; when to the
north it is decreased. From April
the path of the storm areas moves
northerly until July and August,
when it is at its farthest point north,
which is about or above the latitude
of Sitka: from August they advance
and the rain then begins
in the north, in British Columbia;
then in Washington aud in Oregon
and finally in California. Rain in
unless it is local shower,
seldom occurs with winds from any
point of the compass except the north