North American monsoon (IMAGE) Università di Bologna Caption Deflection of the eastward jet stream (orange contours) from the midlatitudes toward the equator, where it produces precipitation (blue shading, units of mm/day) as it then ascends over the Sierra Madre mountain range (outlined by magenta contour). Credit Boos, W. R., and S. Pascale Usage Restrictions Credit must be given to the creator. License CC BY Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.