Thursday, September 25, 2014
The storm advertised last week will begin affecting our weather by Saturday afternoon as it moves from its current location in the Gulf of Alaska southeastward towards the Great Basin over the weekend. Moisture drawn from the southwest ahead of the storm will move over our area during the day Saturday and will create the threat of some wetting rains, especially in the afternoon and evening.
The low is forecast to become cutoff from the main westerlies by mid-weekend, and waves rotating around this cutoff will eventually bring moderate to heavy rain to our area during the day Sunday. There may be breaks in the precipitation, but rain will continue for most of Monday as the upper cutoff low approaches and eventually moves over us by Monday night. As that happens, the cool flow will turn to the Steamboat’s favored northwest location and keep the chance of rain showers for the valleys and possible snow showers for the higher elevations going through Tuesday until early Wednesday morning.
There is considerable inter-model and intra-model uncertainty with the eastward speed of the cutoff low that may slow its eastward progression by a half day or so. Additionally, there are another two waves upstream, with the first bringing a reinforcing surge of cool air by Wednesday.
The second storm looks to be quite strong as it travels southeastward from the Pacific northwest by Friday. The southwest flow ahead of that storm looks to bring some brief warming and drying ahead of the storm by late in the workweek, but some models have it finally moving over our area sometime next weekend. This storm is currently advertised to bring a stronger push of cold air over our region and may threaten snow near the valley bottom.