Plenty of active weather is expected across the country through the weekend with the focal points being around troughs in the west and fronts in the eastern two-thirds of the country.
First, in the west troughs will meander around producing scattered showers and storms in much of this region as instability will be present or develop at times across much of AZ, NV, NM, ID, and as far north into parts of OR and WA, and as far east as western CO. Heavy downpours with flash flooding potential will accompany these storms given the fairly slow movement of this activity.
Next, a slow-moving front will be situated from the CO/WY border to the NE/KS border to off the east coast early today and will not move too much through the weekend or slowly south. Much of this activity will be isolated to scattered south and around the front, but an area of showers and storms early today is expected to track east-southeast all the way to the east coast through the weekend making it to the Mid-Mississippi River Valley by Saturday evening, to the Mid-Atlantic states by Sunday afternoon, then offshore sometime Sunday evening. Some isolated severe storms are possible within this area of storms at times with the better chances coming tonight in northeast NE, southwest IA, and north-central MO.
Finally, another front moves into the Upper Midwest and Northeast over the weekend producing showers and storms in these regions with a more organized chance of developing in the eastern Great Lakes and Northeast Sunday and Sunday night.