An amplified Pacific North America (PNA) pattern in the mid levels of the atmosphere will result in a deep trough and unseasonably cool temperatures over the Eastern US and warm and dry conditions over the Rockies. The axis of a large ridge over the Western US will slowly shift to the east of Colorado over the next few days in response to a trough of low pressure digging south across the Pacific Northwest. As this ridge moves east, winds will be predominantly from the southwest on Sunday into the first half of next week. Pacific moisture will make its way across the state and into the Front Range, resulting in more cloudiness and isolated showers, especially in the mountains and west of the Divide on Monday and Tuesday. The latest GFS model run shows a deep cut-off low forming over the southern Great Basin on Tuesday with this system eventually weakening and passing over the Four Corners by Thursday. The ECMWF is similar. Moisture will become more widespread over Colorado as the winds back to the south and south east, and precipitation will be possible, especially on Wednesday. This could be the beginning of a more active weather pattern over the Western US in the second half of October.
Tonight: Partly Cloudy, Low 38 F
Saturday: A mixture of sun and high clouds, warm, High 64 F
Saturday Night: Partly Cloudy, Low 41 F
Sunday: Partly Sunny, High 63 F
Sunday Night: Some Clouds, Low 40 F
Monday: A mixture of clouds and sun with an afternoon shower possible, High 62 F, chance of rain 20 %.