Flood watch remains active as multi-day storm brings heavy rain

IDAHO FALLS, Idaho (KIFI)- A Flood Watch remains active across much of eastern Idaho tonight through Sunday as a multi-day storm system brings widespread rain to the region.

Temperatures will take another 10 to 15-degree drop on Sunday, capping daytime highs in the upper 40s to upper 50s.

The storm system is drawing tropical moisture from Tropical Storm Rachel into California and the Great Basin, where it will interact with an incoming upper-level trough. Main rainfall amounts will range from 1.0 to 2.0 inches across the Magic Valley, Snake Plain and eastern highlands, with localized totals topping 3.0 inches in higher terrain.

Rain and isolated thunderstorms are expected tonight across eastern Idaho, with precipitation chances at 80%. Temperatures will drop to a low near 42 degrees as south winds from five to 11 mph shift east during the evening, bringing gusts as high as 21 mph.

Rain will continue throughout Sunday, with precipitation chances reaching 100%. Daytime highs will peak near 53 degrees while winds shift from south-southwest at five to nine mph to light and variable, with gusts up to 18 mph. Despite cooler surface temperatures, snow levels will remain high, keeping any frozen precipitation limited strictly to the highest mountain peaks.

Rain will persist into Sunday night with lows near 39 degrees and wind gusts reaching 23 mph. Wet weather carries into Columbus Day on Monday, featuring a 70% chance of rain primarily before noon and high temperatures hovering near 53 degrees.

The cool pattern will linger into the early part of the workweek as the low-pressure system slowly moves across the Intermountain West. Monday night brings a 50% chance of rain with lows near 35 degrees, followed by a 40% chance of rain on Tuesday and high temperatures remaining in the 50s.

Weather conditions will begin to moderate by Thursday as high pressure ridging builds over the region. Forecasts call for sunny skies with high temperatures reaching near 58 degrees on Thursday and climbing to 62 degrees on Friday.