Monday, August 1, 2016
A Pacific Northwest storm will cross the coast Tuesday morning and travel well north of the Steamboat Springs area along the US-Canadian border on Wednesday. Drier air ahead of this storm has spread through northern Colorado in westerly flow and will reduce, but not eliminate the threat of afternoon storms for Tuesday.
As the northern storm swings north of our area on Wednesday, winds will increase ahead of a weak cool front forecast to move through northern Colorado late Wednesday or early Thursday. The storm will be drier than I thought in the last forecast, so the meteorological concern will be wind rather than rain for Wednesday and Wednesday night.
Though Thursday will start cool and dry, a relatively well-defined wave from the southwest will travel across the Four Corners later Thursday and western Colorado by Thursday night into Friday. Moisture will rapidly increase ahead of this wave, increasing the chance of locally heavy rainfall by Thursday afternoon and possibly extending into the night.
By Friday, another Pacific Northwest storm carves out a trough of low pressure off the West Coast, keeping the moist southwest monsoonal flow going for the weekend. A currently ill-defined wave may move over our area on Friday, again increasing the threat of locally heavy rainfall that may last into the evening.
Earlier forecasts had dry air overspreading our area for most of the weekend, but current forecasts have the West Coast trough deeper and more persistent, keeping the still moist, but drying, monsoonal moisture plume over our area through Monday. This will continue the threat of afternoon storms through Monday before the Pacific Northwest storm moves inland, bringing dry air and likely eliminating the chance of afternoon storms for the rest of the next work week.