Thursday, September 1, 2016
A persistent and large Pacific Northwest trough will affect our weather for the next week as it is reinforced by cool air traveling southward from the North Pole. Southwest flow ahead of the trough has picked up a shortwave currently producing showers in northern Arizona, and the short range HRRR model has rain reaching our area before sunrise Friday.
There will be a break in the rain after it ends Friday morning, but the wetter AVN model has another round of afternoon storms as another ill-defined wave moves near the Steamboat Springs area. Curiously, the NAM is dry so that discrepancy lowers forecast confidence.
Though some drier air works into the area on Saturday, there will be enough moisture for another round of afternoon storms, some possibly strong.
By Sunday, much drier air ahead of the advancing trough, forecast to take up residence in the Great Basin for the week, will move overhead and likely produce some spectacularly nice weather for the remainder of the long Labor Day weekend.
Though dry, some cool air from the Great Basin trough will be dragged over our early by Monday by ejecting energy traveling west and then north of our area. The combination of seasonably cool temperatures and a very dry atmosphere will keep morning lows chilly and tender plants in low-lying areas may require some protection.
Cool air continues to pour into the Great Basin trough through the week keeping it quasi-stationary. It appears we will be on the boundary between dry and moist air, with some moisture possibly returning for a brief spell on Tuesday to fuel a slight chance of afternoon storms. Otherwise, seasonably cool temperatures with cool mornings look to persist for the rest of the work week before the Great Basin trough is kicked eastward by another Pacific storm that may threaten next weekend’s weather.