Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 448 AM EDT Sun Jun 16 2013 Valid 12Z Sun Jun 16 2013 - 12Z Tue Jun 18 2013 ...A threat for severe weather exists across the Central Plains on Sunday... ...Below normal temperatures are expected over much of the northeastern states early next week... The upper pattern featured across the nation for the middle of June consists of a quasi-stationary closed low lingering off the Pacific Northwest coast. Further downstream, an area of ridging will be confined to the Intermountain West while a broad trof holds strong across the northeastern U.S. Numerous impulses tracking from the middle of the country eastward are forecast to be the primary focus for convection this period. On Sunday, storms are expected to develop in response to diurnal heating along the Front Range of the Rockies. Thunderstorms which stay more discrete in nature may pose a threat for severe weather across a large section of the Central Plains. Eventually more expansive complexes of storms should evolve while propagating eastward toward the Mississippi River valley. Looking into early next week, it appears the severe weather threat will linger along the Southern/Central High Plains based on the latest Storm Prediction Center outlooks. After a quiet start to the weekend, showers and thunderstorms will return to the forecast for Sunday and into early next week. This is in response to the multitude of mid-level impulses ejecting from the Central U.S. toward the Ohio River valley. In general, much of the activity should be rather scattered in nature although better coverage may exist along any frontal zone. One notable boundary on the map is a cold front surging south and east from Canada. The cooler air accompanying this air mass will support below normal readings across much of the northeast as highs only reach the upper 60s to mid 70s on Tuesday. This is in response to a well defined upper trof swinging across Southern Quebec on Monday/Tuesday. Rubin-Oster Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php