Southwesterly flow will keep things warm for your Sunday with high temperatures in the low to mid 70's, even some upper 70's possible for areas like Fort Benton. As the high pressure to our southeast moves further away, this allows a storm system to work its way into the area by Monday afternoon and evening.
As we have seen time and time again this fall, the majority of the precipitation misses us to the south. Helena could see a stray shower or flurry overnight Monday or Tuesday morning. Overall, the system just brings increased cloud cover Monday night and Tuesday morning.
Temperatures will reach the upper 50's and low 60's on Monday before the frontal passage with much cooler air in the 30's and 40's by Tuesday. A steady warm-up begins on Wednesday with highs back into the mid 60's by Friday and into next weekend. Wednesday through Friday looks to have sunny to mostly sunny skies.