The northern polar jet stream is shifted northward across the United States, reducing the number of cold outbreaks across the central United States. During La Niña conditions, the jet streams are much …

General weather patterns (hot/cold, wet/dry) are related closely to the position, strength and orientation of the jet stream (or jet streams). A jet stream at low levels is known as a low-level jet.

THE 300 / 200 MB CHART

Many times during winter in the northern hemisphere, the polar vortex will expand, sending cold air southward with the jet stream (see graphic above). This occurs fairly regularly during wintertime and …

As shown in the image below, La Nina episodes in the winter months feature a wave-like jet stream flow across the United States and Canada, which causes colder and stormier than average conditions …

Entrance Regions of Jet Streaks A "jet streak" refers to a portion of the overall jet stream where winds along the jet core flow are stronger than in other areas along the jet stream. The entrance (exit) …

Aug 18, 2025 · User Training Jet Stream - An Online School for Weather OPC Presentation - "Weather Awareness"

The jet stream is a high velocity river of air that flows completely around the Earth at the mid-latitudes. During winter, the jet core is located generally closer to 300 millibars since the air is more cold and …

Conversely, during La Niña's, this dip in the jet stream shifts west of its normal position toward the Central Pacific. The position of this dip in the jet stream, called a trough, can have a huge effect on …

During El Niño, a strong and amplified Pacific jet stream extending across the southern US in association with a polar jet stream shifted further north into Canada favors above normal precipitation …