Day 6 of Medford, OR (KMFR)

Good radiational cooling with just a few high clouds led to a cooldown to 34F last night, with some mid to high-level clouds perhaps slowing the warmup a bit this afternoon, but still warming up quickly to 61F and still rising. So far, the maximum wind is 6 kt but will very likely get stronger this evening with the sea breeze.

Clouds will thicken tonight leading to little radiational cooling after the initial cooldown this evening with the sea breeze and storm approaching. As such, it will likely not get colder than model guidance like the past few nights. Overcast skies and rain will prevent much warming tomorrow, though some breaks in the rain and periods of less thick clouds could enable a slow warmup. The low will occur at the end (Thursday 06z) as colder air moves in and at least intermittent rain persists, perhaps even mixing with snow! Any mixing with snow will enhance the cool down at the end, as the melting of snowflakes absorbs heat from the atmosphere, causing the temperature to fall further, hence some models dropping it down to ~37F by then, which seems believable. 

 

Despite the pressure gradient with the system, models indicate only weak winds, perhaps due to the terrain blocking the winds and little sunshine to mix any winds down to the surface or trigger sea breezes. The relatively weak winds also mean that the rain shadow effect from the Cascades will not be prominent, with substantial rain expected.

 

Source: PivotalWeather

Source: PivotalWeather