The North American Monsoon System: Recent Evolution and Current Status Update prepared by Climate Prediction Center / NCEP 24 September 2012.

The North American Monsoon System: Recent Evolution and

Current Status

Update prepared byClimate Prediction Center / NCEP

24 September 2012

Outline

• Recent Evolution and Current Conditions

• Summary

• Climatology

Rainfall Patterns: Last 7 Days

During the past week, below-average rainfall was observed over much of the western Mexico.

Rainfall Patterns: Last 30 Days

Much of the NAM core areas have received overall near-average rainfall during the past 30 days.

Recent Evolution: Rainfall

NCEP/GFS Forecast

Near-average precipitations are predicted over southwest U.S. during 24 September – 07 October, 2012. Meanwhile, above-average rainfall during the next week is forecasted over northwestern Mexico and Baja.

Summary

• During the past week, below-average rainfall was observed over much of the western Mexico.

• Most of the NAM core areas have received overall near-average rainfall during the past 30 days.

• The GFS bias-corrected forecasts show near-average precipitations over southwest U.S. during 24 September – 07 October, 2012. Meanwhile, above-average rainfall for the next week is predicted over northwestern Mexico and Baja.

ClimatologyMONSOON ONSET

June 5

June 6June 6

June 8June 7

June 14June 14

June 17June 16

June 23

June 27June 25June 29

July 3July 6July 11

July 7July 8July 13

July 9July 13July 14

June 10June 11

June 22June 21

Higgins, R. W., Y. Chen and A. V. Douglas, 1999: Interannual Variability of the North American Warm Season Precipitation Regime. J. Clim, 17, 653-680

Precipitation ClimatologyPrecipitation Climatology