Ticker for February 13, 2004

                
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February 13, 2004  February 13, 2004  February 13, 2004  February 13, 2004



Northern Plains Snowcover Makes for Chilly February

Today's Ticker comes from OCS climatologist and Director of Climate
Information Mark Shafer.  Thanks Mark!  Also, note that Mark points
out that today is the 99th birthday of the lowest temperature ever
observed in Oklahoma, a nippy -27F at Vinita (a record tied 25 years
later at Watts).

Nebraska's Snows and Oklahoma's Woes

After the winter season started out on such a balmy note, Oklahoma's
fortunes have sure changed. December and January, each 3 degrees or
more above normal for the state, have yielded to a consistent cold
pattern in February. Part of the explanation is snow cover. While
the recent snows in Oklahoma have melted away, locations further
to our north have some of the greatest snow depths for this time
of year on record:

The snow cover shows up nicely on the following map from the
NWS Operational Hydrologic Remote Sensing Center (currently an
experimental product):


So how can snow cover in Nebraska affect temperatures in Oklahoma?
Snow acts like a layer of insulation, keeping the warmth of the ground
from heating air near the surface. Consequently, air that starts out
in the polar region gets very little heat added to it on its southward
journey. Even the typically warm, southerly winds contribute to
February's cold. The southerly winds bring moisture across the region,
which falls in the form of - yes, more snow - in Kansas, Nebraska
and northern Oklahoma.

February 2004 is shaping up to be one of the coldest in the past
century. The statewide-averaged temperature through the first twelve
days of the month stands at 32.9 degrees. If the cold continues for
the duration of the month - not by any means likely - February 2004
would end up among the ten coldest for the state since 1892. However,
this is a long way from some of the record-cold Februaries of the past.
With the exception of a few places, like north-central Oklahoma that
have had substantial snow cover for a few nights, overnight low
temperatures have not been near records. In fact, the state's record
cold temperature, -27 degrees at Vinita, occurred on February 13, 1905.
Even the high temperatures holding to the 20s are no match for some of
the years gone by.

The good news is this can't last much longer. As the days get longer
and more sunshine fills the skies, the sun's heat will begin to melt
this layer of snow.