Monday, November 11, 2013
It appears model differences have largely been resolved for the pattern change beginning on Thursday, with the American ‘GFS’ (Global Forecast System) model coming into line with the European ‘ECMWF’ (European Center for Medium Range Weather Forecasting) model. As a side note, I publish these models in the numerical weather prediction section found under the ‘Models’ menu item.
A wave over northwestern Canada will progress southward bringing some cold air along the Front Range around Tuesday as it travels over the western ridge. Additionally, some energy from the eastern Pacific trough will move through the ridge late Wednesday bringing light showers and seasonably cool air to our area. While moisture is not plentiful, the favorable wind direction from the northwest and cooling atmosphere should be enough to produce 2-4” on the mountain by Thursday morning.
Another wave quickly follows allowing little break between systems. This slightly stronger and colder wave should produce an additional 4-8” on the hill by Friday morning.
Temperatures should warm on Friday before additional weak and very dry waves move across by Saturday morning and again Sunday morning. There may be some showers early Sunday morning, though any accumulations should be insignificant.
Another dry wave on Tuesday will mark the end of this pattern where weak waves travel around the dominant western ridge. Models indicate the eastern Pacific trough / western ridge couplet moving eastward by the end of next week signalling another pattern change.