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This is a compilation of official resources produced by Climate Prediction Center and National Weather Service office in Flagstaff, AZ. The graphics are intended to provide a broad awareness of current and forecast conditions.

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El Niño-Southern Oscillation (ENSO)

    

Want to learn more about ENSO and its impact on northern Arizona's weather?

 

Sea Surface Temperatures (SSTs)

 

 

 

Observed Regions Anomalies

 

 

Sea Surface Temperature Anomalies

 

850 mb Wind Anomalies

 

Latest ENSO Forecasts

 

Madden-Julian Oscillation (MJO)

 

MJO 1-Page Fact Sheet

How does the MJO Phase affect temperature and precipitation in the United States?

 

Hires GFS Phase Diagram

 

OLR Anomalies

 

Ensemble GFS Phase Diagram

 

OLR Anomalies

 

Statistical Phase Diagram for Arizona

 

200 mb Velocity Potential Forecast

 

 

Arctic Oscillation (AO)

 

The Arctic Oscillation (AO) refers to an atmospheric circulation pattern over the mid-to-high latitudes of the Northern Hemisphere: the most obvious reflection of the phase of this oscillation is the north-to-south location of the storm-steering, mid-latitude jet stream.

Impacts on temperature and precipitation patterns across the US based on the AO Phase

 

Observed and Forecast Values

 

Example of 500 mb Height Anomalies in a Positive AO

Image Courtesy of the North Carolina Climate Office

 

Example of 500 mb Height Anomalies in a Negative AO

Image Courtesy of the North Carolina Climate Office

 

North Atlantic Oscillation (NAO)

 

The North Atlantic Oscillation (NAO) index is based on the surface sea-level pressure difference between the Subtropical (Azores) High and the Subpolar Low. The positive phase of the NAO reflects below-normal heights and pressure across the high latitudes of the North Atlantic and above-normal heights and pressure over the central North Atlantic and the eastern United States. The negative phase reflects an opposite pattern of height and pressure anomalies over these regions. Both phases of the NAO are associated with basin-wide changes in the intensity and location of the North Atlantic jet stream and storm track, and in large-scale modulations of the normal patterns of zonal and meridional heat and moisture transport, which in turn results in changes in temperature and precipitation patterns especially in eastern North America.

 

Observed and Forecast Values

 

500 mb Height Anomalies During a Positive NAO

Image Courtesy of the North Carolina Climate Office

 

500 mb Height Anomalies During a Negative NAO

Image Courtesy of the North Carolina Climate Office

 

Pacific/North American Pattern (PNA)

 

The Pacific-North America (PNA) pattern is one of the most prominent modes of low-frequency variability in the Northern Hemisphere extratropics, appearing in all months except June and July. The PNA index is measured by the height anomalies (generally at 500 and 700 mb) over the western and eastern United States. Research has shown the PNA is strongly influenced by ENSO. Positive PNA patterns are most commonly associated with El Niño while the negative phase tends to occur during La Niñas. Here are the typical temperature and precipitation patterns across the United States.

 

Observed and Forecast Values

 

500 mb Height Anomalies During a Positive PNA

Image Courtesy of the North Carolina Climate Office

 

500 mb Height Anomalies During a Negative PNA

Image Courtesy of the North Carolina Climate Office