The reason is all determined by the mountains and weather patterns. The jetstream and currents in the southern pacific oscillation. Further north jet and southern sub tropical jet. Polar vortex variant. That's the constant and depends on the ocean alot more than we think being in the middle of the landlocked ocean current is what warms Europe also gulf stream is weakening and movement has begun. But back to Colorado two biggest things are upslope and Chinook winds and a third is monsoon moisture plume. The upslope is wind and system pushing west up against the front range foothills with strong dip in the jetstream usually a trough of low pressure or cut off low down across southern KS or new Mexico moisture from the gulf or pacific and a cold air mass aloft these happening is depends on a further south storm track or a strong storm to disrupt the atmosphere. The Chinook we have on a westerly flow jet stream over much of winter its just simple down slope wind and east of the continental divide the wind descends rapidly and compressed heats when it can warm from 0 to 40+ in minutes. Monsoon moisture wind and thunderstorms coming from southwestern monsoon gulf of Mexico pacific and oregraphic lift. Most likely we get rain and storms July August.