Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
306 AM EDT Fri Aug 29 2014
Valid 12Z Fri Aug 29 2014 - 12Z Sun Aug 31 2014
...Heavy rain possible for portions of the Central Plains, Middle and
Upper Mississippi Valley into the Upper Great Lakes...
...Heavy showers and thundershowers possible over portions of the Gulf
...After a dry and comfortable start, warmer and more humid air returns to
the Northeast while cooler air floods the Northwest...
A slow moving upper trough accompanied by a weak area of low pressure will
lift slowly northeastward from the Central US toward the Great Lakes. This
system will likely produce an area of heavy rainfall in the form of
showers and thunderstorms especially from the Upper Mississippi Valley
across the Great Lakes where rainfall totals could exceed 1 to 2 inches
over the next few days. This system will weaken as it moves into Canada
after crossing the Upper Lakes.
A series of weak upper disturbances will be found over the Western Gulf of
Mexico and help drive numerous showers and thundershowers especially over
the Western and Central Gulf Coast. Here too, rainfall totals could be
locally excessive with even the potential for some local flash flooding.
Along the East Coast, high pressure and comfortably dry weather will give
way to increasing humidity as the high pressure area moves off the New
England coast. Another mass of cooler air will move into the North Central
States but does not appear to drive appreciably southward beyond the
northern tier of the Midwest as much of the cooler air remains north of
the US Canadian border.
Farther west...a significant push of cooler air will invade the
northwestern quarter of the country through the weekend with showers
especially likely across the higher terrain of the Pacific Northwest, the
Great Basin and the northern Rockies.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php