Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 317 PM EDT Tue Oct 29 2019 Valid 00Z Wed Oct 30 2019 - 00Z Fri Nov 01 2019 ...Extremely critical and life threatening fire weather conditions will continue for portions of northern and southern California... ...Huge temperatures contrasts expected across the nation with numerous record cold and warmth likely... ..Heavy snow likely from the Central Rockies, across the Central Plains into the Upper Mississippi Valley... ...Potential major disruptions to trick or treating on Halloween... An anomalously amplified upper level pattern across the nation will support very active and impactful weather for much of the nation over the next two day. A strong cold front sinking south through the Great Basin Tuesday will re-strengthen winds across much of California. These high winds, gusting as high as 80 mph, combined with extremely low relative humidities, will produce extremely critical and life threatening fire weather conditions through Wednesday across Northern California and through Thursday across Southern California. Much below average temperatures will continue to encompass much of the western and central U.S. Wednesday and Thursday. Widespread regions of high temperatures 20 to 40 degrees below average likely across the Great Basin, Rockies and Plains on Wednesday and through much of the Plains and Mississippi Valley on Thursday. In contrast to this, much above average high temperatures expected Wednesday from southeast Texas, across the Gulf coast, Southeast, Mid Atlantic and Northeast, and along the entire eastern seaboard from Florida to Maine on Thursday. These huge temperature differences will support the potential for numerous record low minimum and maximum temperatures across the western and central U.S. and numerous record high minimum temperatures across the eastern U.S. over the next 2 days. The clash of the seasons across the nation will support widespread heavy snows spreading east northeast from the Central Rockies, Central High Plains this evening, into the Central Plains tonight/Wednesday and into the Upper Mississippi Valley and Great Lakes on Thursday. Meanwhile, heavy rains will spread through much of the Mississippi, Tennessee and Ohio Valleys tonight into Wednesday and from the central Gulf Coast into the Appalachians, Mid-Atlantic and Northeast on Thursday. Overall, the atmosphere will be giving tricks to large portions of the nation over the next two days, with calmer weather likely by the weekend. Oravec Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php