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Barometric Pressure
What Is a High
or Low Reading in Barometric Pressure?
By Michelle Miley
Barometric pressure, an indicator of the
weight of column of air, ranges from an historic high of 32.01 inches to an
all-time low of 25.9 inches.
Electronic barometers now are available
in addition to older-style units that use a needle and dial to track pressure changes.
Changes in barometric pressure
correspond to changes in weather and pressure extremes are often associated
with extreme weather events.
Amount of
Barometric Change
Barometric pressure often is measured in
inches of mercury, or in-Hg.
If barometric pressure rises or falls
more than 0.18 in-Hg in less than three hours, barometric pressure is said to
be changing rapidly.
A change of 0.003 to 0.04 in-Hg in less
than three hours indicates a slow change in barometric pressure.
A change of less than 0.003 in-Hg in
less than three hours is considered to be holding steady.
Time and Pressure
Change
Approaching storms and wind cause
barometric pressure to decrease. Rising pressure indicates fair weather.
The longer it takes barometric pressure
to change, the longer the coming weather pattern can be expected to last.
It is possible that a small weather
event, such as a passing shower, may trigger no change in barometric pressure.
Record Barometer
Readings
The highest barometric pressure ever
recorded was 32.01 inches. This reading was taken in Agata, Siberia, on
December 31, 1968, during clear and extremely cold weather.
The lowest known barometric pressure was
recorded over the Pacific Ocean during a typhoon on October 12, 1979. The
pressure was 25.9 inches.
Writing professionally since
2008, Michelle Miley specializes in home and garden topics but
frequently pens career, style and marketing pieces. Her essays have been used
on college entrance exams and she has more than 4,000 publishing credits. She
holds an Associate of Applied Science in accounting, having graduated summa cum
laude.
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