Skip Navigation Links www.nws.noaa.gov 
NOAA logo - Click to go to the NOAA home page National Weather Service   NWS logo - Click to go to the NWS home page
Climate Prediction Center
 
 

 
About Us
   Our Mission
   Who We Are

Contact Us
   CPC Information
   CPC Web Team

 
HOME > Monitoring_and_Data > Oceanic and Atmospheric Data > Reanalysis: Atmospheric Data > CFSR plant hardiness zones
 

CFSR: plant hardiness zones

Introduction

The Climate Forecast System Reanalysis (CFSR) creates analyses of many fields including the 2 meter temperature. The CFSR analyses were used to create a plant hardiness zone map using the same formula as used by the USDA. See https://en.wikipedia.org/wiki/Hardiness_zone. For practical use, you should use the USDA product. The CFSR based product is for reasearch on performance of the reanalysis.

For the plots, a value between 7,0 and 7.5 corresponds to zone 7a and value between 7.5 and 8.0 corresponds to a zone 7b.

Calculation

  1. Find the minimum 2m temperature (6 hour forecast) for 1979 from the CFSR.
  2. Repeat the above for the years 1980 to 2008 (30 years in total).
  3. Average the 30 years to produce a 30-year average annual minimum temperature
  4. Convert the data from Kelvin to Fahrenheit.
  5. To the temperature data, add 70, divide by 10 and set the negative values to zero.

Details and Caveats

The CFSR uses a system very similar to those run by the National Weather Service to produce the 1-6 day weather forecasts that you see on TV. (Other countries run similar systems for their 1-6 day forecasts.) As part of producing a weather forecast, an analysis of the current atmospheric state is created. This analysis is made using data from satellites, aircraft, weather ballons and other sources but surprising no 2-meter temperature observations. The 2-m temperature is model derived product which depends on the land-surface model, the model physics, the model parameterizations and the analyses of the winds, temperatures and humidity at the model levels. There are many reasons why the analyses will differ from observations. For example, you make your temperature observation on a patch of grass and the model is using a forest. (The land surface is suppose to be representative of the average conditions in a 35x35 km grid box.) Yes, grass vs. forest can be a big difference. Another problem is model uses the average height of the grid box. Your measurement will be at a different elevation. An other problem is the model doesn't know the local orography. You could be on an exposed peak or in a sheltered valley. These features are not resolved within a 35-km grid used by the CFSR model.

One way to view the CFSR temperature is they are a model estimate of average temperature of a 35km x 35km grid box. It will not give you the same number as an observation.

Links

https://en.wikipedia.org/wiki/Hardiness_zone
CFSR based plots

Comments

Please send comments to: Wesley.Ebisuzaki@noaa.gov

NOAA/ National Weather Service
National Centers for Environmental Prediction
Climate Prediction Center
5830 University Research Court
College Park, Maryland 20740
Climate Prediction Center Web Team
Page last modified: Aug 13, 2010
Disclaimer Privacy Policy