Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 411 PM EDT Tue Oct 20 2015 Valid 00Z Wed Oct 21 2015 - 00Z Fri Oct 23 2015 ...Flash flooding possible through Thursday for portions of the Southwest and Southern High Plains... ...Severe thunderstorms possible today and Wednesday across portions of the Southwest... The strongest feature over the next few days is the upper-level low that is lifting from the Southwest into portions of the Southern/Central Rockies. A stationary frontal boundary is draped across the higher terrain of Utah and Colorado will combine with a moist and unstable air mass to produce scattered to numerous showers and thunderstorms through Wednesday across much of the Four Corners region. Precipitation will spread across portions of the Southern and Central Plains throughout the day on Wednesday, where most amounts will range from 0.50 up to 2 inches. The best focus for the highest precipitation amounts will likely be north Texas and west Oklahoma where 2 to 5+ inches are forecast. Periods of heavy rain may raise the risk for flash flooding for some areas. Additionally, the Storm Prediction Center has highlighted a marginal to slight risk of severe thunderstorms for portions of the southwestern U.S through Thursday morning. Scattered showers and thunderstorms will be possible across the Central and Northern Plains through Wednesday as a low pressure system moves through the region. Precipitation amounts are forecast to remain mostly below 1 inch. The surface low will track across Ontario on Wednesday, reaching eastern Quebec by Thursday evening. Showers are expected to develop along the warm front as it lifts through New England. Across northern Maine, the air mass may be cold enough north of the warm front to support a mix of rain and snow Wednesday night into Thursday morning. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php