Meteograms

Observations for the past 24 hours for a single station are plotted on a
meteogram.

Temperature and Dewpoint chart: This shows temperature as the top line and
dewpoint as the bottom line. The maximum and minimum temperature is plotted
below the chart at specific reporting times. Low temperatures are generally
reported at 12Z and 18Z and high temperature are generally reported at 0Z
and 6Z.

WX - present weather: This shows the weather being reported as a weather
symbol.

SNOW - snow cover: This shows the reported snow cover in inches. This
generally is only reported at 12Z unless snow is accumulating.

PREC - precipitation: This shows precipitation totals in inches. The values
are generally 24 hour totals at 12Z, 6 hour totals at 0Z, 6Z, and 18Z, and
3 hour totals at other times.

VIS - visibility: This shows the horizontal visibility in miles.

GUSTS - wind gusts: This shows the wind gusts in knots. This is generally
the maximum wind speed over a several minute period during the observation.
The gusts may be display either above or below the winds.

WINDS - wind and cloud cover: This plots the standard wind barb and cloud
cover symbol. A half barb is 5 knots, a full barb is 10 knots, and a flag
is 50 knots. The shaft of the barb points to the direction the wind is
from.

Cloud chart: This chart gives cloud layer infomation. The vertical axis is
a logarithmic scale of the cloud base height in feet ranging from 100 feet
to 50,000 feet. Each cloud layer base is plotted as horizontal lines. Clear
skes are plotted as 'C'. Scattered layers (1/8th to 3/8th coverage) are
pltted as a single short dash '-'. Broken layers (4/8th to 7/8th coverage)
are plotted as two short dashes '--'. Overcast layers are plotted as a
single long dash. The actual cloud ceiling (first layer with 4/8th coverage
or more) is displayed below the chart in 100s of feet if the ceiling is
below 10,000 feet.

Pressure chart: This chart plots sea level pressure (or altimeter setting
if sea level pressure is not reported) in millibars.


Time: This is the report hour in universal time.
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Department of Atmospheric Science / oolman@grizzly.uwyo.edu

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