Tag Archives: Jet Stream

WEEKEND WEATHER OUTLOOK

The snow-free winter continues…

A cold front moves through on Thursday and cold high pressure moves over us for Friday and Saturday. The National Blend of Models (NBM) is showing highs of 33° for both Friday and Saturday although some statistical models (ensemble models) show highs to be a bit colder.  Skies will be sunny both Saturday and Sunday.

The pattern is fast moving and progressive; temperatures rebound into the mid 40s on Sunday as winds shift to southerly with the departure of the high.

The Extended Range GFS model attempts forecasts 384 hours (16 days) into the future. No potential snow storms are currently predicted, except a possibility the last day in February.  Don’t change your plans.

This winter has been characterized by a lack of large, dense, cold air masses sinking straight south in the middle of the country.  

There is a  common misunderstanding, perpetuated by TV weather entertainers, that the jet stream determines where the air masses go.  Actually, it’s really the other way around— the size, shape and temperature-density of the cold air masses in winter determine the position, shape and configuration of the jet stream. The ‘valley’ between the polar air mass and the tropical air mass is where the jet stream is positioned and where major low pressure systems develop and track.

The current pattern has been with us for almost three months. Like bull stock markets, weather patterns don’t last indefinitely. Weather patterns tend to change as the seasons change.