Educating the Public on the North American Monsoon System (NAMS)

1
Educating the Public on the North American
Monsoon System (NAMS)

• January 12, 2009
• Glen Sampson and Erik Pytlak
• National Weather Service
• Tucson, Arizona

2
Historical Perspective

• Traditionally the NAMS in Arizona was tracked
  with surface-based techniques
• Precipitation (raininess) Index
• Three consecutive days of 55oF average dew point
  at the Phoenix airport (54oF in Tucson)
• These techniques originated in the 1960s and 70s.
• A monsoon start and end could be declared

3
Historical Problems

• Surface-based techniques did not take into
  account remote sensing or modeling advances, nor
  the large scale circulation processes associated
  with NAMS.
• Severe weather would occur before the monsoon
  started.

4
Educating the Public

• Changed the definition of the monsoon in Arizona
  based on climatological data
• Now June 15 through September 30
• Worked closely with the media on these changes.
• Provided new real-time tracking methods for the
  NAMS on the web.
• Documented our increased understanding of NAMS on
  the web.

5
Tracking the Monsoon

• Dew point graphs
• Winds for 700, 500 and 300 mb
• Heights for 500 mb
• Satellite-derived vegetation index
• Satellite water vapor imagery
• Radar precipitation estimates for 1, 3, 6, 12 and
  24 hours
• Upper air plots
• Links to Maricopa and Pima county rainfall data

http//www.wrh.noaa.gov/twc/monsoon/monsoon_tracke
r.php
6
Tracking the Monsoon
http//www.wrh.noaa.gov/twc/monsoon/monsoon_tracke
r.php
7
Comprehensive Climatological Data
http//www.wrh.noaa.gov/twc/monsoon/monsoon.php
8
Monsoon Science
http//www.wrh.noaa.gov/twc/monsoon/monsoon_info.p
hp
9
Questions?
weather.gov/Tucson