US Dept of Commerce National Oceanic and Atmospheric Administration National Weather Service NWS Education 1325 East West Highway Silver Spring, MD 20910 Comments? …

Dec 18, 2025 · Within the entrance region of a jet streak, divergence (of the ageostrophic wind) usually occurs along and to the right of the jet core (i.e., right entrance region).

THE 300 / 200 MB CHART

The position and orientation of jet streams vary from day to day. General weather patterns (hot/cold, wet/dry) are related closely to the position, strength and orientation of the jet stream …

What this can mean: • An active jet stream pattern across the northern/eastern tier of the US that directs storm systems across the local area. More often than not, La Niña winters are wetter …

The maps (right) show the regions where the greatest impacts due to the shift in the jet stream as a result of ENSO. The highlighted areas indicate significant changes from normal weather occur.

The pocket of pressure falls causes low-level southerly winds to accelerate, which often paves the way for a low-level jet stream. Such a low-level jet stream rapidly transports moisture …

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 …

The Jet stream’s vertical motion therefore determines the locations of fair or fowl weather. This explains why the majority of inclement weather occurs between the trough and …

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 …