Big changes in jet stream bring big weather changes to low-48 this week


The weather has been relatively calm for much of the low-48 recently, especially for the southern half of the country. The blame for the calm weather and milder temperatures was the jet stream located quite far north. Along with the northern placement of the jet stream, it was also relatively flat. It’s called zonal flow, which keeps the weather fairly inactive, leading to milder temperatures and less wintery and severe threat in most of the lower 48s. Join the group of first-hand weather supporters!

Example of a zonal flow jet stream (courtesy NOAA)

This flat, or zonal, flow will begin to collapse next week. The jet stream will start to get ‘frizzy’ which will lead to a more active weather pattern. This active weather pattern means more rain and storms, more winter precipitation, and colder temperatures for parts of the country that have been relatively calm in recent times. Join the group of first-hand weather supporters!

Note that the animated graph below shows a few different storm systems offering a plethora of low-48 weather conditions over the next few days and most areas will kick in. Showers and storms in the southern, southern and southeastern plains (some of which could be severe from Sunday to Tuesday) as well as snow in much of the west, plains, Great Lakes, from the Ohio Valley and the northeast.

Simulated radar for the coming week (courtesy WeatherModels.com)

Areas of heavy precipitation are expected for the Pacific Northwest, the Central Rockies and the eastern half of the country. The graph below shows the precipitation totals for the coming week. Note that the Pacific Northwest will see 2-8 inches of precipitation. The valleys and lowlands will see this fall as rain while the mountains will receive feet of snow. Even California, Arizona, Utah, Nevada, and New Mexico will be in the rain with snow from the mountains. And yes, Colorado and Denver, you have snow too! Further east, good rainfall is expected for the south, southeast, the Carolinas and the Tennessee Valley. This is great news given the recent fires in the Southeast and the Carolinas. Further north, winter precipitation is expected.

Precipitation Accumulation Forecast (courtesy WeatherModels.com)

Areas of heavy snow are expected for all mountains to the west. This is great news for snowpack and ski lovers. Feet of snow are expected. Even the mountains of southern California, southern Arizona, and New Mexico will see inches of snow. The Great Lakes will also be getting into the action with heavy snowfall. Some of the heavy snow may extend across the Midwest and Plains with a winter storm developing later in the week, but those details will be worked out over the next few days.

Snowfall forecast for this week (courtesy WeatherModels.com)

Each system will have a boost of colder air with a potentially very strong cold front towards the end of the coming week into the weekend!

See the latest winter outlook below.

Read NOAA’s winter outlook here.

Read AccuWeather’s winter outlook here.

Read the Farmers Almanac here.

Read the Old Farmer’s Almanac here.

About Jefferey G. Cannon

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