Winter 2014/15 Forecast Final Grade

Jan Null, meteorologist in the San Francisco area, each year grades the winter outlook issued by the Climate Prediction Center.  It covers the 3 winter months of December, January and February.  Jan's final report for this winter is now available.  Here in Star Valley the forecast was for a slightly warmer than normal winter and equal chances of above/below normal precipitation.  Both forecasts were OK.  The forecast failed in the northeast which has suffered through one of their coldest winters in a while, which was not forecast!

Following is the summary of the winter by month with a discussion by Jan of the forecasts.

Winter 2014/15 Forecast Performance for Temperatures

Winter 2014/15 Performance for Precipitation

ABSTRACT This review compares last year's NOAA Climate Prediction Center (CPC) 30-day and 90-day precipitation and temperature forecasts for the winter period of December-February (DJF) 2014-2015 with the actual observed conditons. ANALYSIS Winter Precipitation:  The CPC Winter precipitation forecast for DJF 2014-15 did poorly at capturing the negative precipitation anomalies for California and Oregon. It did capture the negative anomalies in Washington and the Midwest.  The above normal precipitation forecast along the southern tier of states only verified in a few places and was out of phase along much of the Gulf Coast and southern Florida. Winter Temperature: For the second year in a row the winter temperature outlook for most of New England was a complete fail.  Above normal temperarures were forecast for most of West and verified well west of the Rockies but not in the Rockies and the western Plains.   The below normal forecast for most of the Southeast verified, but the remainder of the eastern half of the country was not well captured. Monthly Precipitation and Temperature Analyses:  Forecast and observed conditons are graphically also depicted below. Winter 2014-2015 Precipitation NOAA CPC 90-Day Precipitation Outlook DJF 2014-2015 Observed DJF 2014-2015 Precipitation Anomalies Winter 2014-2015 Temperature NOAA CPC 90-Day Temperature Outlook DJF 2014-2015 Observed DJF 2014-2015 Temperature Anomalies December 2014 Precipitation NOAA CPC Precipitation Outlook December 2014 Observed December 2014 Precipitation % Normal December 2014 Temperature NOAA CPC Temperature Outlook December 2014 Observed December 2014 Temperature Anomalies January 2015 Precipitation NOAA CPC Precipitation Outlook January 2015 Observed January 2015 Precipitation % Normal January 2015 Temperature NOAA CPC Temperature Outlook January 2015 Observed January 2015 Temperature Anomalies February 2015 Precipitation NOAA CPC Precipitation Outlook February 2015 Observed February 2015 Precipitation % Normal February 2015 Temperature NOAA CPC Temperature Outlook February 2015 Observed February 2015 Temperature Anomalies DATA SOURCESThe 30-day and 90-day outlooks were retreived from the NOAA Climate Prediction Center (CPC) archives and the corresponding observed temperature and precipitation data were downloaded from the High Plains Regional Climate Center's Climate Summary Maps. CPC Gridded Seasonal Verifications can be found athttp://www.cpc.ncep.noaa.gov/products/predictions/long_range/tools/briefing/seas_veri.grid.php