- About Us
- SW Climate
Published June 26, 2013
Temperature Outlook(July–December 2013)
Data Source(s): NOAA-Climate Prediction Center (CPC)
The seasonal temperature outlooks issued by the NOAA-Climate Prediction Center (CPC) in June call for increased chances that temperatures will be similar to the warmest 10 years in the 1981–2010 period for the three-month seasons spanning July through December (Figures 10a–d). The seasonal forecasts presented here are based on statistical and dynamical models and are largely consistent with decadal warming trends. The CPC also notes that initial soil moisture conditions played a role in the July–September and August–October outlooks; dry soil moisture conditions favor increased temperatures because there is reduced evaporative cooling. The amount and character of precipitation during monsoon months will also feedback on temperature. For example, evaporation and cloud cover are greater when precipitation is consistent and frequent and both help lower daytime temperatures. Precipitation forecasts call for equal chances for above-, below-, or near-average conditions in the Southwest for the monsoon (see page 13). The highest temperature probabilities in the U.S. for both July–September and August–October are across the central Rockies, Great Basin, and Southwest (Figures 10a–b). The September–November and October–December forecasts are predominantly based on the average conditions in the last 10 years because there is high uncertainty in the evolution of the El Niño-Southern Oscillation (ENSO; Figures 10c–d). ENSO usually develops in early winter and can have a substantial influence on temperature and precipitation in the Southwest.
These outlooks predict the likelihood (chance) of above-average, average, and below-average temperature, but not the magnitude of such variation. The numbers on the maps do not refer to degrees of temperature.
The NOAA-CPC outlooks are a 3-category forecast. As a starting point, the 1981–2010 climate record is divided into 3 categories, each with a 33.3 percent chance of occurring (i.e., equal chances, EC). The forecast indicates the likelihood of one of the extremes—above-average (A) or below-average (B)—with a corresponding adjustment to the other extreme category; the “average” category is preserved at 33.3 likelihood, unless the forecast is very strong.
Thus, using the NOAA-CPC temperature outlook, areas with light brown shading display a 33.3–39.9 percent chance of above-average, a 33.3 percent chance of average, and a 26.7–33.3 percent chance of below-average temperature. A shade darker brown indicates a 40.0–50.0 percent chance of above-average, a 33.3 percent chance of average, and a 16.7–26.6 percent chance of below-average temperature, and so on.
Equal Chances (EC) indicates areas where no forecast skill has been demonstrated or there is no clear climate signal; areas labeled EC suggest an equal likelihood of above-average, average, and below-average conditions, as a “default option” when forecast skill is poor.
For more information on CPC forecasts, visit:
For seasonal temperature forecast downscaled to the local scale, visit:
For IRI forecasts, visit:
Southwest Climate Outlook Staff
- Michael Crimmins, UA Extension Specialist
- Stephanie Doster, Institute of the Environment Editor
- Gregg Garfin, Founding Editor, Institute of the Environment
- Zack Guido, Managing Editor, CLIMAS Associate Staff Scientist
- Nancy J. Selover, Arizona State Climatologist
- Jessica Dollin, CLIMAS Publications Assistant
- Dave Dubois, New Mexico State Climatologist
Please direct your Southwest Climate Outlook comments and suggestions to Zack Guido.
The CLIMAS Web site contains official and non-official forecasts, as well as other information. While we make every effort to verify this information, please understand that we do not warrant the accuracy of any of these materials.... Read full disclaimer