Cedarville, Arkansas

... Winter weather awareness in Arkansas...

Governor mike Beebe has proclaimed November 17th through 21st as
winter weather awareness week in Arkansas. People are asked to take
some time and prepare for the upcoming winter season.

Todays topic is winter precipitation types.

Snow. Snow forms in the clouds and remains as snow all the way to
the ground. It most commonly takes the form of snowflakes... which
are the familiar six-sided ice crystals. It may also fall in the
form of snow pellets or snow grains.

Snow flurries are most commonly seen as a few snowflakes
falling... although visibilities can be reduced at times. In
northwestern Arkansas... the term snow flurries is used to indicate
that no accumulation is expected.

In Arkansas... heavier snows most commonly occur when cold air is
already in place over the state and a strong upper level low
pressure system moves out of the southwestern United States. The
low serves to pull moist air northward into the cold air. Light
snow or snow flurries can also occur in the cold air that follows
the passage of an Arctic cold front.

Sleet. Sleet consists of pellets of ice and is often even referred
to as ice pellets. For sleet to form... snow falls into a
relatively warm layer of air that is above freezing a few thousand
feet above the ground and partially melts. This particle then
refreezes into a pellet of ice when it falls into a layer of air
that is below freezing near the ground.

In Arkansas... sleet most commonly occurs in a narrow band between an
area of rain to the south and an area of snow to the north.

Freezing rain is a phenomenon sometimes called glaze because it
results in a glaze of ice on exposed surfaces. For freezing rain
to form... snow falls into a relatively warm layer of air that is
above freezing a few thousand feet above the ground and completely
melts. This rain drop then refreezes on exposed surfaces when it
reaches the ground... where temperatures are below 32 degrees. In
the worst cases... everything becomes coated with a layer of ice.
Widespread power outages tend to occur as heavy glaze breaks tree
limbs that fall on power lines. In addition... Road surfaces become
extremely hazardous.

In Arkansas... freezing rain commonly occurs as an Arctic high
pressure system begins to move away from the state. In this
situation... cold air is still lingering at the ground... but warmer
southerly winds from the Gulf of Mexico begin bringing moisture back
over the top of the cold air. Since the air at the ground has not
warmed above freezing... the rain that falls into it freezes on
exposed surfaces.

For additional information... contact the National Weather Service
office in Tulsa at 918-838-7838 or visit our website at
www.Weather.Gov/Tulsa