Our forecast area is still sandwiched between broad upper high to our south and upper trough to north, leaving our area in a relatively dry west to south west flow aloft. Upper trough will be moving east, allowing upper high to bulge northward a little on Sunday and Monday with slightly warmer air mass. This should also allow gradual trickle of subtropical moisture to spread into the southwest and west central Colorado where isolated diurnal thunderstorms possible on Sunday and a few more on Monday.
Broad high pressure continues to stretch across the southern tier with a swath of westerlies over the northern tier. A series of shortwaves embedded in the westerlies will brush the forecast area with the strongest one scheduled for the Wednesday-Thursday time period.
A little moisture twill creep into the area from the south bringing a slight chance of rain over the southern mountains through Tuesday. By Wednesday a stronger shortwave will come onshore over the northwest resulting in a southwest flow over the forecast area. The trough is expected to pass across our forecast area in the Wednesday-Thursday time period. The broad southern ridge will get pushed to the east ahead of this wave allowing sub tropical moisture to again increase over the region. Therefore, expect shower and thunderstorm development, especially over the southern mountains.
Models agree that a drier flow will follow for Friday and Saturday with a decreasing chance of rain on Friday. A slight chance of rain over the Mountains and for most valleys is expected for Friday with the drying trend continuing into Saturday.