Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
437 AM EDT Sat May 25 2013

Valid 12Z Sat May 25 2013 - 12Z Mon May 27 2013

...Wet and unseasonably cold weekend for the Northeast...

...Showers and thunderstorms with locally heavy rains for portions of the
plains and Mississippi valley...

...Unsettled weather continues in the Pacific Northwest...

A strong area of low pressure will churn slowly north along the New
England coast over the next couple of days, delivering a prolonged period
of wet weather and anomalously cold temperatures to the Northeast this
holiday weekend.  This area of low pressure, centered currently along the
southern New England coast, will track slowly to the north, not reaching
the Canadian maritime provinces until late Sunday.  Atlantic moisture
thrown around the backside of the system will fuel heavy precipitation
accumulations across portions of northern New England and New York.  Some
of this precipitation is expected to fall in the form of snow as cold air
pours down out of Canada, possibly resulting in significant accumulations
across some of the higher peaks of the Adirondacks, Green and White
mountains.  Further to the south, unseasonably cool, but dry conditions
are expected to highlight the weekend across the mid Atlantic and
Southeast.

Across the central U.S., broad moist southerly winds out of the western
Gulf of Mexico are expected to encourage at least scattered showers and
thunderstorms, with isolated heavy heavy rains, across portions of Texas
and Oklahoma both days.  A better chance for more organized storms is
expected further to the north along a slow moving front stretching from
the northern high plains through the mid Mississippi valley.  In addition
to the storms already firing across Nebraska into Iowa and Illinois, Gulf
moisture pooling along the boundary interacting with a string of upper
level disturbances emanating from the West may produce additional
organized showers and thunderstorms with heavy rains later today across
portions of the northern high plains to the mid Missouri and Mississippi
valleys.

Cool and unsettled weather will continue across portions of the Pacific
Northwest and the northern Rockies as a series of upper disturbances move
through a broad upper trough that is forecast to remain centered over the
western U.S. through the early part of next week.  Low pressure lifting
into western Canada this morning will be replaced by another system
nearing the Oregon coast later tonight.  This is expected to produce some
light to moderate rains centered across western Oregon before pushing
inland on Sunday while yet another system approaches the coast on Memorial
Day.

Pereira

Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php