As of Thursday, February 1, 2018
A very moist and slowly warming weather pattern is expected late this week and likely to continue into at least the beginning of next week, according to the National Weather Service (NWS) Missoula office, with possible lowland, overland flooding expected.
standing water, ponding on roads/property
potential flooding of basements, outdoor buildings
poor drainage, clogged culverts
check sump pumps, downspouts
The NWS anticipates snow observed on Thursday (Feb. 1) will transition to rain on Friday (Feb. 2) as the snow level across North Central Idaho rises to near 6,000 feet.
Periods of moderate rainfall are expected on Friday. However, the greatest precipitation appears likely from Saturday night through Sunday night, resulting in 1.00 to 1.50 inches of rain over the course of 24 hours. Rain is likely to continue thereafter, though perhaps at a lesser rate. But by Monday night, the region could see totals upwards of between 2.00 and 3.00 inches over the course of three days.
Lower level weather observations indicate the snow pack below 4,000 feet throughout Clearwater and Idaho counties (Pierce, Weippe, etc.) is highly saturated with moisture and perhaps ripe enough to begin releasing an abundance of melt water. Meanwhile, satellite analysis would suggest that low elevation soil moisture is at present anomalously high.
These factors when combined with an abundance of additional rainfall and lack of additional snowfall could support low land or overland flooding, particularly in places of poor drainage. Land or rock slides may also become increasingly possible during and after this precipitation under these conditions.