Evening star. [volume] (Washington, D.C.) 1854-1972, 1906-08-24
Frustrating August Heat Waves.

from the new YORK Heralu.
For nearly three weeks New York has
suffered with little intermission from pros
trating heat, aggravated frequently by in
tense humidity, making altogether COM
pound which at times might well be COM
pared to the weather In the equatorial dol
drums.
The cause Of these torrid conditions at
this period Of the season is to be looked for
in the distribution Of barometric pressures
over the country rather than in any abnor-
NAL and direct radiation of solar heat. The
sun has now completed two-thirds of his
jouAley from the northern tropic to the
equator, and very naturally his direct rays
in the latitude Of New York must be de-
cidedly weaker than they We're in June or
July. Why under the weaker solar radia-
ton of late summer the weather becomes
more torrid than 1t was at or near the sum-
mer solstice seems mystery. 1t is ex-
planned, however, by the recent formation
of relatively high barometric pressure over
and around our torrid southern borders and
by the obvious fact that these high pres
sures drive the heated air of the Mexican
gulf and the gulf stream northward until 1t
overspreads the eastern half Of the country.
The great air waves of intense humidity
thus formed are rarely observed as late In
August as they have been this year. In July,
1881, one of these humid waves was devel-
oped rapidly from the gulf states north
ward to the great lakes and the North At
lantic states, causing an immense number
of fatal heat prostrations and sunstrokes in
the Ohio valley and the eastern states.
Again, in August, 1896. similar and most
phenomenal wave of great duration domi-
mated the weather from the first to the
eleventh of the month, and thousands were
fatally stricken In the streets of our sea-
board cities. But this latter spell of killing
humidity, coming in the first half of August
instead of developing in the hotter month
Of July, made record for its appearance
SO late in the season.
Since that record was made ten years
ago 1t has been confidently inferred that
after the middle of August long continued
regime of intense humidity combined with
excessive heat was not to be expected. And
this inference, so far as 1t refers to New
York city, is generally true. For though in
this locality weather records show the fire.
late August and even a maximum tempera-
ture of 100 degrees in early September
such belated heat waves are usually OF
short duration and rarely accompanied by
intense humidity.
But despite the present protracted wave
of sweltering heat there Is good reason to
hope for an early reduction of the torrid
temperatures. AS the sun is now reced:ng
from the northern hemisphere cool anti-cy-
clones begin to advance from the British
Northwest territory eastwardly over the
Dakotas and the lake region, and to send
their reviving air currents into the Middle
and North Atlantic states. At first these
cool waves are feeble and their chief nf1u-
ence In lowering eastern temperatures is
felt in the generation of local thunder
storms from the Appalachian mountains to
the Atlantic coast. The severity of summer
may not at once be terminated, but after
the present week there is every reason to
hope for a prevalence of more moderate
temperatures in the eastern states north of
the Carolinas.