The National tribune., 1891-01-08
THE WEATHER.
Pacific Coast.
BY LIEUT.. ]. P. rryLrY. U. g. SIGNAL SERVICE.

BY LIEUT.. j. p. FINLEY, U. g. SIGNAL SERVICE.
correspondence Invited. suggestions desired.
and information ChreFfIlly furnished. Every ef-
Tort employed 20 make this Bureau Of practical use
communications should be addressed Hsdfter
THE SATIoSAL TRIBUNE Office Washington, u. O.
During the " wet season" on this coast there
is marked increase in the number of storms
tFayersing the North Atlantic Ocean and dur
ing the dry season y there is not only "A
marked diminution IN the number Of storms
passing over the North Pacific but also q SINH
lar decrease in storm frequency over the North
Atlantic. This relation of the storm eondi tious
Of the two great oceans Of the Northern Hemis-
phere has important bearing upon the subject
Of tho weather Of the western coast Of this
continent. North America is only one Of tire
great sections in the pathway Of storms about
the earth. Its geographical location. however,
between the two great breeding grounds or
sources of cyclonic development lthe Japan
Current and the Gulf Streamj will always make
il the region Of the most diverse meteOrologi-
cal changes and therefore the most valuable
field for study.
The so-callcd "dry season" on the Pacific
coast is practically confined TO the region south
of the 4jth parallel and west of the Il2th
meridian. This region embraces CalifOrE Ia
and Nevada and portions Of Arizona Utah aud
Idaho. The rainfall is small or absolutely
nothing over this region in Summer May TO
August inclusivc.) because Of the extreme
noTtherly movement Of all cyclOnic develop
ments from the Pacific. All cyclonic move
mcnts IN the Northern Hemisphere take place
at a higher latitude in Summer than in Wiz
! ter, which may be ascribed to tho apparent
movement Of the sun nOTthward in the former
season aud a consequent increase in the heat
! conditions Of the higher latitude. The storm
| areas are not drawn as far southwark to find
/ the conditions or heat and moisture necessary
for their development
The preparation of storm-tT track charts Of the
| Pacific coast Of North America dsCluses tho
! fact that from Nay TO September inclusive the
| cyelOuc movements from the Pacific Ocean
! pass eastward north OF the northern boundary
/ Of Washington aud appear in the United
] States over Dakota aud Minnesota. Sometimes
/ the storm eenters maintain a high latitude
across the continent aud move eastward north
! Of Lake Superior
Their passage, however, is at a sufficiently low
! latitude TO give rise to light rains in Washing.
ton and northwestern Oregon, thus maintain
ing in this region an equable distribution Of
| precipitation throughout the year. This con-
ditiOn OF things explains the great fertility Of
the North Pacific region Of the United States
! aud the rank growth OF al vegetation there.
! The daily variability Of temperature is less in
/ Oregon and Washington, especially the latter,
than in any other portion Of the United States.
Such a meteorological condition is Of the
utmost importance 10 plant and animal life.
and insure the probability Of the highest de-
veloument in each. Its influence upon the
commercial aud agricultural development OF
the country is very powerful. The tempeTa-
turc is modified by the proximity Of the warm
waters OF the great japan Current, which also
forms the source Of q most bCnefcent and
oquable supply OF moisture.