The National tribune. [volume] (Washington, D.C.) 1877-1917, 1890-12-04
THE WEATHER.
The Hot North Wind, or Cqliroruf


BY LIEUT.. J. T. FINLEY, U. 8 SIGNAL SERVICE
Correspondence invited suggestions desired
and information checrfnlly furnished Every 81
fort employed TO make this Bureau @ practical use
to the readers of THE NATIONAL TKIGUNE- A
communications should be addles-e,!- If'raftsi
TIE NATIoSAL TRIBUNE Oncs. Washington, ID. u
With clOudless atmosphere during Spring
Summer and Autumn, the interior valleys d
California become very warm during the day
and cool off rapidly during the night. The ain
is so clear and dry that there IA little cheek q
radiation, consequently the temperature fall.
rapidly after the sun goes down. This condition
of things avoids the oppressive sultriuess oil
Summer nights in the East, and permits the
enjoyment Of complete rest in sleep. To The
east Of California lie the lava beds and slkaI
plains Of Nevada. They become quickly ard
intensely heated under the direct rays Of the
sun, which beat down upon them from a cloud
less sky. A disposition Of baTOmetTic pressure
which will cause the air 10 move southwark
over Nevada, inclining to the westward, will
carry into California vast quantities Of air from
the heated plains and lava beds Of the former
As the gradient Of pressure Is from southwest
10 northeast, the warm air in the interior val
leys of California will, under the increase oil
barometric pressure in Nevada, start % move
southwark, and RortheTly winds will prevail
IN these two States.
With eonstantly-renewcd installments oil
warm air pushing southwark the temperature
rises steadily, and will maintain n high degree
as long as the source OF heated air is kept up.
These hot winds arc a great boon to the raisiu-
making districts Of California. The best
quality Of Taisins must be cured by the suns
heat and not by artificial heat Cloudy, foggy
or rainy weather is n most serious obstacle to
tho proper curing Of grapes, especially if main
tanned steadily for few days. While the hot
nOrtheTs Of California give rise 10 considerable
physical discomfort during the day, vet their
great value TO the raisin Industry is much APP
pFeciated. As before explained. the heat Of the
day is much modified at night by rapid radia-
ton, which cOols the air quickly and efectu-
ally.
In order to maintain the hot northers the
barometric pressure must be considerably
above the normal in Nevada, Utah, northern
California, Oregon, and southern Idaho; at
least from O.2J inches to 040 inches. This
High" as it is called on the weather map,
may arise from the movement southwark oil
cold dry air from British America. As the
area passes southwark into Montana 10 is usu-
ally attended with freezing temperatures and
light snow. On reaching Nevada the tcmpera-
ture Of the air has greatly increased by contact
with the heated lava beds and alkali plains OF
Wyoming. IL is then subjected TO another and
greater heating in Nevada in a similar manner,
aud thus tho supply Of air for the support OF
the hot nOrtheFs of California is developed.
These desiCating north winds usually occur in
the months Of June TO October inclusive. They
have been quite marked during October 1890.
When prolonged and intense they are destruet-
i've to animal and plant life, although such oc-
currenees are rare, the most notable happening
IN June, 1859, when the temperature rose to
over 100 degrees in the shade at many places
IN both northern and southern California. In
the sun the thermometer rose to I35 degrees at
some places At Santa Barbara, Cal, June IL,
1853, an eyewitness states that " the sun rose
like ball of FIRE, and at 2 p. m. blast Of
heated air from the north swept through the
streets, followed quickly By others, aud soon the
atmosphere became so intensely heated that no
live thing could withstand its burning effect
Calves, rabbits birds and other small animals
were killed trees were blasted, and the fruit
literally roasted on them." similar noTther,
but not quite 50 severe, occurred in the second
week Of September, 15s6. In all eases an area
Of ahnormaliy high harometrie pressure pre-
vailed TO the northward preceding and during
the prevalence Of these hot noFthers as before
explained.