Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 AM EDT Mon Sep 24 2018 Valid 12Z Mon Sep 24 2018 - 12Z Wed Sep 26 2018 ...Heavy to excessive rainfall possible for parts of the Tennessee and Ohio Valleys and the Northeast... ...Elevated to critical fire weather threat continues on Monday across portions of the Central Great Basin, Central Rockies, and northern California... ...Severe thunderstorms possible on Tuesday across the Ohio Valley... The heavy rainfall threat continues as we begin the work week from portions of the Tennessee Valley into the Ohio Valley as plenty of moisture overrides a remnant surface boundary draped across the mid-South and a cold front approaches from the west. The latest WPC excessive rainfall/flash flood outlooks place much of this region within a slight to moderate risk for Monday, and a slight risk on Tuesday. Heavy rainfall is also possible across portions of the Mid-Atlantic/Northeast Monday and into Tuesday as a wedge of surface high pressure erodes and allows for warm and moist air from the south to seep into the region. Expect scattered showers and thunderstorms to also continue this week across the Southeast within an already warm and humid airmass. An elevated to critical fire weather threat will continue today (Monday) across portions of the Central Great Basin, the Central Rockies, and northern California where temperatures are above normal and humidity levels remain low. Red flag warnings are in effect for parts of northeast Utah, southern Wyoming, and northwest Colorado, as well as inland northern California. Conditions across the Great Basin/Rockies should improve by Tuesday, but an elevated risk remains for Tuesday in northern California. Expect showers and thunderstorms to develop along a cold front as it pushes east from the Plains into the Upper Midwest today. Locally heavy rain is possible, particularly across the upper Mississippi Valley as a surface low drifts northeastward along the boundary. Severe thunderstorms are also possible across the Ohio Valley on Tuesday ahead of this front, and the Storm Prediction Center has highlighted much of this region within a slight risk. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php