Sunday, May 10, 2020
Sunny skies and early afternoon temperatures in the low sixties are observed this Mother’s Day in Steamboat Springs. A rainy day starts the work week tomorrow, with nicer weather returning for a couple of days. But unsettled weather returns around late Wednesday and lasts through Saturday, with at least one period of good rainfall expected sometime between Thursday night and Saturday.
Currently, a ridge of high pressure extending along the Rockies and through Alaska has brought the beautiful weekend weather, and high temperatures today should reach five degrees or so above our average of 61 F. But the ridge of high pressure is under attack by incoming Pacific storms from the west and cold air from the east.
Only a high latitude piece of the ridge forecast to be near the North Pole will survive the attack as a complicated weather pattern sets up over the Northwest through the week. A large and elongated area of storminess currently extending form the Gulf of Alaska southward will move eastward today, with the very southern warm piece moving across the Great Basin tonight and over our area on Monday.
Shower chances will be increasing starting very early Monday as the wave approaches, with the heaviest showers associated with possibly strong storms in the afternoon and evening in the unstable atmosphere behind the wave. Localized strong winds and periods of moderate to heavy rain, along with thunder and lightning are likely to be associated with these storms.
After an active Monday, the weather quiets for a few days as the Gulf of Alaska storm consolidates and moves eastward, mixing with the westward moving cold continental air mass over the Pacific Northwest by Tuesday night.
There is rather large uncertainty in the weather forecast models as to how this mixing occurs, as first discussed in my last weather narrative on Thursday. Though the European ECMWF has come around to the solution offered first by the American GFS, with unsettled weather lasting from Thursday through Saturday, the periods of heaviest rainfall vary between Thursday night and Saturday between the models, depending on when the most organized waves move over our area.
Nonetheless, after a wet start to the weekend, the weather models agree another storm develops in the Gulf of Alaska early in the weekend and approaches the middle of the West Coast by early in the work week. The southwesterly flow ahead of the storm will allow our weather to dry and warm starting on Sunday and lasting several days into the following work week. After that our weather will depend upon the fate of this storm, and I hope to have some clarity on that by my next regularly scheduled weather narrative on Thursday afternoon.