Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 358 PM EDT Tue Oct 01 2019 Valid 00Z Wed Oct 02 2019 - 00Z Fri Oct 04 2019 ...Heavy rain and flash flooding, as well as severe thunderstorms are possible from the southern High Plains to the Great Lakes through Wednesday morning... ...Widespread record-breaking heat expected across the Ohio Valley, Mid-Atlantic, and Northeast... ...Much below average temperatures continue in the Northwest and Northern Plains... A slow-moving cold front extending from southern Ontario, Canada into the Great Lakes and across the southern High Plains will move very slowly southeastward through Thursday evening. By late Wednesday, a wave of low pressure will develop along this front over the Middle Mississippi Valley and will move northeast toward western New York by Thursday evening. Moisture from the western Gulf of Mexico and the eastern Pacific Ocean will pool along the boundary. This will result in showers and thunderstorms along the front over parts of the Central/Southern Plains into parts of the Great Lakes, particularly through Wednesday morning. There is a Slight Risk of severe thunderstorms from parts of the Central Plains to parts of the Great Lakes, with the main hazards being frequent lightning, damaging wind, and hail. Heavy rain associated with slow moving showers and thunderstorms will likely lead to flash flooding from north-central Kansas to southern Wisconsin. Addition rainfall amounts of 1 to 4 inches are possible across areas that have been extremely wet over the last month. Therefore, a Moderate Risk of flash flooding has been issued by WPC for the aforementioned areas though Wednesday morning. Showers will linger across the Central and Plains and Middle Mississippi Valley through Thursday morning before the cold front finally pushes through. Meanwhile, gusty winds and low humidity has lead to critical fire weather across western Colorado and eastern Utah today. This fire weather threat will diminish on Wednesday as winds calm. By Wednesday and Thursday, isolated showers and thunderstorms will continue across the Great Lakes and enter the Northeast. Rain and snow showers will be possible behind the system across the Northern Rockies and Northern Plains. Winter Weather Advisories are in effect across portions of southeast Montana and southwest South Dakota, where a general 1 to 3 inches of snow is expected. A large temperature range can be found across the lower 48 into Thursday as an upper-level trough remains over the West and an upper-level ridge is anchored over the Southeast. Underneath the trough, daytime highs could be 20 to 30 degrees below average across much of the Northern Rockies and Northern Plains on Wednesday, with low temperatures dipping into the 20s and 30s. Temperatures will moderate a bit on Thursday, but will still remain around 10 degrees below average. Meanwhile across the southern and eastern U.S., record-breaking temperatures will continue. The core of the heat on Wednesday will stretch from the Southeast/Central Gulf Coast States to the Ohio Valley and Mid-Atlantic, where widespread daytime highs in the upper 80s to near 90 (north) and mid to upper 90s (south) are expected. These high temperatures are around 20 to 30 degrees above average and could break several daily, as well as monthly records. For the Southeast, this stretch of record warmth will continue once again on Thursday. Snell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php