Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 454 AM EDT Fri Apr 17 2015 Valid 12Z Fri Apr 17 2015 - 12Z Sun Apr 19 2015 ...Heavy snow expected across the Central Rockies... ...A continued threat for flash flooding exists along the Western/Central Gulf Coast... ...Severe weather is possible across the Southern/Central Plains through the weekend... The upper pattern across the country will continue to feature a nearly stalled closed low spinning across the Four Corners region. Meanwhile, the northern stream is expected to be much more progressive carrying a series of upper troughs through southern Canada. The aforementioned cut-off low will remain a key player for the weather from the Rockies eastward to the Great Plains, Gulf Coast, and Mississippi River Valley. Underneath the circulation itself, well below normal temperatures are forecast to prevail with highs generally 15 to 20 degrees below climatology. This generally equates to highs in the 20s and 30s across the higher terrain while 40s and 50s will be more commonplace toward the foothills. In addition to the cold weather, this system will also be quite the snow producer across the Central Rockies. Strong vertical lift underneath the low center will continue to drive moderate to heavy snowfall across the mountains. The WPC winter weather desk suggests 1 to 2 feet is possible with isolated higher amounts in some of the heavier banding. In advance of this broad cyclonic circulation, there will be a strong northward surge of moisture from the Gulf of Mexico. It should be quite active along the Western/Central Gulf Coasts where a meandering frontal boundary will provide a focus for persistent convection. The high-end moisture content over the region is expected to aid in fairly hefty rainfall rates. Given much of this area has already dealt with heavy precipitation in recent days, the saturated soils will make the region more susceptible to flash flooding through the weekend. At this point in time, the WPC precipitation desks are expecting a broad area of 2 to 3 inches of rain through Sunday morning but isolated areas of higher amounts are definitely possible. Across the Southern/Central Plains, daily rounds of convection are expected to fire in advance of a nearly stalled Pacific front/dryline. Moist and unstable air will be present from Texas northward to Kansas with many of these storms taking shape during the peak heating of the day. The Storm Prediction Center has the Southern/Central Plains highlighted in their outlooks through the weekend. To the north of this region, the atmosphere should be much more stable as they will reside north of the warm front generally extending from Southern Nebraska into Central Iowa. Cool easterly flow will keep temperatures a bit below average while overrunning rains are expected to affect areas of the upper Central Plains into the Middle Mississippi Valley and northern tier states. Elsewhere, ridging across the West Coast will ensure tranquil weather through Sunday. Across New England, a series of systems in the northern stream will bring a couple of threats of the precipitation to the region. The most defined upper trough should cross New England on Saturday which will bring the best chance of rain to the region. Enough cold air may be present in Northwestern Maine to support a light accumulation of snow. Rubin-Oster Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php