Sunday, June 27, 2021
Rain showers have again overspread the Steamboat Springs area this Sunday mid-afternoon along with chilly temperatures in the mid-fifties, though the thermometer did reach 65 F around 2 pm when we had some clearing before the first round of showers arrived. Showers will continue today before their chances diminish on a warmer Monday that should see temperatures in the seventies. These temperatures will persist for most of the rest of the work week along with increased shower chances that will last through the Independence Day weekend.
The wetter weather that arrived last Thursday and the cooler weather that followed on Friday and hung around this weekend is a welcome change from the record-breaking hot and dry weather of last week. My weather station recorded over eight tenths of an inch in the last three days, and I have already received another tenth of an inch so far today, with more expected this afternoon and evening.
Currently a strong ridge of high pressure centered over the Pacific Northwest is flanked by cold areas of low pressure, with the one to our east extending from Hudson Bay all the way to the Desert Southwest. The low pressure area is forecast to split on Monday, with some of the southern part of the split forming an eddy that is forecast to spin in the Great Basin starting on Tuesday. While we will see only the slightest chance of showers on a warmer Monday with high temperatures near our average of 78 F, shower chances increase again on Tuesday as the counter-clockwise rotation of air around the eddy to our west brings moist air from the south overhead.
The location of the eddy south of the area of high pressure over the Pacific Northwest makes forecasting its location through the work week difficult since there is really nothing to force the storm to move. Additionally, more cold air flowing into the low pressure area to our east may be incorporated into the eddy and keep it in our proximity. The eddy is currently forecast to move overhead around Thursday or Friday as incoming Pacific energy weakens and moves pieces of the Pacific Northwest high pressure eastward, so expect good shower chances to continue on Wednesday ahead of the storm and increase later in the work week as the storm eventually moves overhead.
Weather forecast models have the moisture sticking around after the eddy eventually departs as light southerly winds reinforce the existing moisture and warm temperatures into the eighties for the weekend. These southerly winds may indicate the beginning of the North American monsoon, though it is not clear if the southerly flow is from an area of high pressure off the East Coast near Bermuda expanding westward or an approaching area of low pressure traveling across the Pacific.
Enjoy the coming week, which will seem like the ‘old days’, with around average temperatures and mostly sunny mornings giving way to chances for afternoon showers. And I’ll have more details on the evolution of that Great Basin eddy and the weather for the upcoming Independence Day holiday weekend on my next regularly scheduled weather narrative on Thursday afternoon.