Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
335 AM EST Sat Jan 24 2015
Valid 12Z Sat Jan 24 2015 - 12Z Mon Jan 26 2015
...A winter storm lifting up the Eastern Seaboard will bring snow and
freezing rain to sections of the northeastern U.S...
...An Alberta clipper should spread snow from the Upper Midwest to the
Mid-Atlantic from Saturday to Monday...
...Well above normal temperatures expected over the central U.S...
The pattern across the nation will be rather amplified in nature with a
deep upper trough anchoring the eastern half of the country. Meanwhile,
across the western states, a broad ridge will remain a mainstay feature
while a closed low is expected to undercut it across the subtropical
Eastern Pacific. This particular setup is also known as a rex block.
At the start of the period, a coastal storm is in the process of
strengthening in the vicinity of the Virginia Capes. This system has
access to abundant moisture as evident by the widespread heavy
precipitation lifting up the East Coast. A mixture of precipitation types
have been noted across the Mid-Atlantic given the intrusion of milder
maritime air into the region. Over the course of the next 24 hours, expect
the heaviest snowfall and ice accumulations across coastal New England
where the WPC winter weather desk forecasts 6 to 10 inches of snow. The
rapidly deepening surface low will also enhance the pressure gradient
across the Northeast which will bring windy conditions to the region on
The next round of wintry precipitation will come from an Alberta Clipper
which should reach the Upper Midwest by Saturday evening. In general, such
systems are quick moving and do not contain a whole lot of moisture. With
that said, this feature is forecast to race from the northern tier of the
country to the Mid-Atlantic over the course of the next 60 hours. This
will spread snow from the northern tier through the Ohio Valley and into
the Mid-Atlantic states. The corridor of heaviest snow appears to be
across northern Indiana into Central Ohio where 4 to 8 inches are possible.
Well above normal temperatures are in the forecast over the Northern
Rockies into the Northern/Central Plains. Downsloping winds will aid in
abundant warmth for late January with temperature anomalies of 20 to 30
degrees above climatology. In fact, high temperatures this weekend may
reach the 60 degree mark over the Central Plains while 40s and 50s will be
more commonplace over the Northern High Plains.
Elsewhere, above the western U.S. ridge will be persistent onshore flow
accompanied by a series of mid-level disturbances crossing Washington and
British Columbia. Areas of upslope terrain can expect the heaviest
precipitation with snow levels being rather high given the Pacific origin
of the advancing air masses.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php