Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 412 AM EDT Thu Apr 16 2015 Valid 12Z Thu Apr 16 2015 - 12Z Sat Apr 18 2015 ...Heavy snow is likely across the Central Rockies... ...A threat for flash flooding exists along the Western/Central Gulf Coast... ...Severe weather is possible each day across the Southern/Central Plains and into the Central Gulf Coast... A robust upper low currently spinning over the Four Corners region will be the focus for multiple threats including heavy snow, possible flash flooding, and severe thunderstorm activity. This broad circulation is expected to remain cut-off from the prevailing westerlies which will lead to very little forward motion during the next few days. In fact, it appears this system should only make it to the Central High Plains by Saturday morning. Overall, a fairly significant snowstorm is underway across the Central Rockies with already multiple reports in the 12 to 18 inch range across Wyoming. Strong vertical motions underneath this upper low combined with sufficient cold air in place will lead to fairly significant snowfall accumulations during the next couple of days. The WPC winter weather desk is currently forecasting a widespread area of 1 to 2 feet of snow through early Saturday across the Central Rockies. It appears snow levels will drop sufficiently enough to spread snow into some of the major cities like Denver and Cheyenne as well. For more information on the winter weather threats on the map, please check out the WPC heavy snowfall discussion under the header qpfhsd. In advance of this anomalous closed low, ample moisture will continue to surge northward out of the Gulf of Mexico. This is expected to interact with a meandering warm front which will be the site for enhanced lift. Pinpointing the exact area of heavy rainfall is difficult at this time but the threat appears largest along the Western/Central Gulf Coast. A widespread area of 2 to 4 inches of rain is expected through Saturday morning with higher amounts possible within areas receiving multiple rounds of convection. Given some of this region has already seen heavy rainfall in recent days, flash flooding is more of a threat as the soils will be quite saturated and susceptible to rapid run-off. An additional area of enhanced convection is expected across the Southern/Central Plains. A very slow moving Pacific cold front/dry line will help initiate numerous showers and thunderstorms along and ahead of it each day. As usual, these storms should generally increase in number by the late afternoon as the surface begins to warm. The Storm Prediction Center suggests favorable profiles for severe thunderstorm development throughout the next couple of days across much of the Southern and Central Plains and extending into the Central Gulf Coast. The most anomalous temperatures on the map will be underneath the closed low where readings may be about 10 to 15 degrees below normal. Meanwhile, quite the contrary will occur across much of the northern tier of the country given southerly flow pumping milder air northward. Temperatures should generally be about 10 degrees above normal from the Northern Plains and Upper Midwest down to the Middle Mississippi Valley. Rubin-Oster Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php