Public Information Statement  Statement as of 6:00 am CST on November 19, 2008

... Winter weather watches - warnings - and advisories...

November 17th through 21st is winter weather awareness week in
Arkansas. People are asked to take some time and prepare for
the upcoming winter season.

Todays topic is winter weather watches... warnings... and advisories.

A watch indicates that conditions are favorable for a winter storm
to develop over all or part of a forecast area... but the
occurrence... location... or timing is still uncertain. Watches are
generally issued when there is a 50 percent or greater chance
of a winter storm. In Arkansas... watches are usually issued 12 to
24 hours in advance of the anticipated weather. However... they
can be issued as much as 48 hours in advance. The term Winter
Storm Watch is always used no matter what types of wintry
precipitation are expected.

A warning indicates that winter storm conditions are occurring...
imminent... or have a very high probability of occurring. Warnings
are generally issued when there is an 80 percent or greater chance
of a winter storm. Warnings are issued for conditions posing a
threat to life or property. In Arkansas... warnings are usually
issued for weather that is expected to occur within the next 12
hours. However... they can be issued as much as 36 hours in advance.

An advisory is issued for similar conditions to a warning... except
that conditions are expected to be less serious. In other words...
snow or ice is expected... but amounts will be less than required for
a warning. Still... conditions will cause significant inconvenience...
and if caution is not exercised... could lead to situations that may
threaten life or property. In Arkansas... advisories are usually
issued for weather that is expected to occur within the next 12
hours. However... they can be issued as much as 36 hours in advance.

Heavy snow would require a watch and/or a warning. The general
definition of heavy snow is 4 inches or more in 12 hours... or 6
inches or more in 24 hours. Due to the relative rarity of snow in
Arkansas and elsewhere in the southern United States... a watch or
warning could be issued for somewhat smaller amounts. /See The Table
below for heavy snow criteria in each County./ In areas of the U.S.
Where snow is more common... larger amounts are needed before a watch
or warning becomes necessary.

An advisory would be issued for snow amounts that are less than
warning criteria. For example... if the criteria for a Heavy Snow
Warning is 4 inches... an advisory would be issued when 1 to 3 inches
of snow are expected.

A blizzard would also require a watch and/or a warning. A blizzard
is defined as sustained winds or frequent gusts of 35 mph or
higher... and considerable falling or blowing snow causing visibility
to be frequently less than 1/4 mile. Note that even if a very large
amount of snow falls... this still does not constitute a blizzard
unless the wind criteria are met also. A blizzard is an extremely
rare event in Arkansas.

An ice storm would require a watch and/or a warning. Ice storms occur
when freezing rain deposits significant or damaging amounts of ice...
usually 1/4 inch of ice or more. /See The Table below for ice storm
criteria in each County./ For lesser amounts of ice... an advisory
would be required.

Heavy sleet would require a watch and/or a warning. This is generally
defined as sleet covering the ground to a depth of 1/2 inch or more.
/See The Table below for heavy sleet criteria for each County./
An advisory would be required for lesser amounts of sleet.

Freeze warnings are normally issued for the first few freezes in the
fall and for late season freezes in the Spring.

Frost advisories are issued for the first few frosts in the fall and
for late season frosts in the Spring.

For the coming winter... the National Weather Service has simplified
the types of warnings and advisories. The only event-specific
warnings that will be issued in Arkansas are blizzard warnings...
ice storm warnings... and wind chill warnings. All other warnings will
be issued as winter storm warnings. Likewise... for advisories... the
only event-specific advisories that will be issued are freezing rain
advisories and wind chill advisories. All other advisories will be
issued as winter weather advisories. When each warning and advisory
is issued... the first paragraph of the text will state what types of
winter weather are expected.

Wind chill warnings are relatively new. In the counties for
which the National Weather Service in Little Rock makes the
forecast... warnings will be issued for wind chills of 15 below
zero or lower when winds average 10 mph or more... and conditions
are expected to persist for an hour or more. Different criteria may
be used in other sections of Arkansas for which weather offices
in Tulsa... Memphis... Jackson Mississippi... and Shreveport make
the forecast.

Wind chill advisories... in the counties for which the National
Weather Service in Little Rock makes the forecast... are issued for
wind chills of zero degrees or lower when winds average 10 mph or
more... and conditions are expected to persist for three hours or
more. Different criteria may be used in other sections of
Arkansas for which weather offices in Tulsa... Memphis... Jackson
Mississippi... and Shreveport make the forecast.

Freezing fog advisories are issued when fog is present with
temperatures below freezing... and the fog is expected to cause a
thin layer of ice to develop on bridges... overpasses... and other
elevated roadways. The issuance of freezing fog advisories began
as an Experiment 10 Winters ago at the National Weather Service
in Little Rock. The Experiment was a Success. As a result... these
advisories can now be issued by National Weather Service offices
nationwide.

                   General criteria for warnings

                heavy snow heavy sleet ice storm
County 12 hrs 24 hrs 12 hrs or 24 hrs 12 hrs or 24 hrs

Little Rock NWS office
Arkansas 4 in 6 in 1/2 inch 1/4 inch
Baxter 4 6 1/2 1/4
Boone 4 6 1/2 1/4
Bradley 46 1/2 1/4
Calhoun 4 6 1/2 1/4
Clark 4 6 1/2 1/4
Cleburne 4 6 1/2 1/4
Cleveland 4 6 1/2 1/4
Conway 4 6 1/2 1/4
Dallas 4 6 1/2 1/4
Desha 4 6 1/2 1/4
Drew 4 6 1/2 1/4
Faulkner 4 6 1/2 1/4
Fulton 4 6 1/2 1/4
Garland 4 6 1/2 1/4
Grant 4 6 1/2 1/4
Hot Spring 4 6 1/2 1/4
Independence 4 6 1/2 1/4
Izard 4 6 1/2 1/4
Jackson 4 6 1/2 1/4
Jefferson 4 6 1/2 1/4
Johnson 4 6 1/2 1/4
Lincoln 4 6 1/2 1/4
Logan 4 6 1/2 1/4
Lonoke 4 6 1/2 1/4
Marion 4 6 1/2 1/4
Monroe 4 6 1/2 1/4
Montgomery 4 6 1/2 1/4
Newton 4 6 1/2 1/4
Ouachita 4 6 1/2 1/4
Perry 4 6 1/2 1/4
Pike 4 6 1/2 1/4
Polk 4 6 1/2 1/4
Pope 4 6 1/2 1/4
prairie 4 6 1/2 1/4
Pulaski 4 6 1/2 1/4
Saline 4 6 1/2 1/4
Scott 4 6 1/2 1/4
Searcy 4 6 1/2 1/4
sharp 4 6 1/2 1/4
stone 4 6 1/2 1/4
Van Buren 4 6 1/2 1/4
white 4 6 1/2 1/4
Woodruff 4 6 1/2 1/4
Yell 4 6 1/2 1/4

Tulsa NWS office
Benton 4 6 1/2 1/4
Carroll 4 6 1/2 1/4
Crawford 4 6 1/2 1/4
Franklin 4 6 1/2 1/4
Madison 4 6 1/2 1/4
Sebastian 4 6 1/2 1/4
Washington 4 6 1/2 1/4

Shreveport NWS office
Columbia 4 4-6 1/2 1/4
Hempstead 4 4-6 1/2 1/4
Howard 4 4-6 1/2 1/4
Lafayette 4 4-6 1/2 1/4
Little River 4 4-6 1/2 1/4
Miller 4 4-6 1/2 1/4
Nevada 4 4-6 1/2 1/4
Sevier 4 4-6 1/2 1/4
Union 4 4-6 1/2 1/4

Memphis NWS office
Clay 4 6 1/2 1/4
Craighead 3 4 1/2 1/4
Crittenden 3 4 1/2 1/4
cross 3 4 1/2 1/4
Greene 4 6 1/2 1/4
Lawrence 4 6 1/2 1/4
Lee 3 4 1/2 1/4
Mississippi 3 4 1/2 1/4
Phillips 3 4 1/2 1/4
Poinsett 3 4 1/2 1/4
Randolph 4 6 1/2 1/4
St. Francis 3 4 1/2 1/4

Jackson NWS office
Ashley 2-4 4 1/2 1/4
Chicot 2-4 4 1/2 1/4

Important note... the amounts shown above are the amounts generally
used for warning criteria. Warnings may... at times... be issued for
amounts somewhat less than shown above. This is especially true
for early and late season storms and those that will have unusual
impacts on the public. All warnings that are issued will state
specifically the amounts that are expected from that particular
storm.

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