Mini Review of Last year's CPC Winder (DJF) Outlook

Comparison of last year's NOAA Climate Prediction Center (CPC) 90-day precipitation and temperature forecasts for the winter period of December-February (DJF) 2021-2022 with the actual observed conditions.

The 90-day (DJF) outlooks were retrieved from the NOAA Climate Prediction Center (CPC) archives and the corresponding observed temperature and precipitation data were downloaded from NOAA ESRL Climate Division Data.

The CPC Winter Outlook DJF 2021-2022 did better than in several of the recent winters, partly because the overall pattern ended up close to a "typical" La Niña.  However, it must be noted that the CPC outlooks are probabilistic versus deterministic, which makes them harder to judge as right or wrong.

Here is t subjective graphical grading used below. Overall if a forecast was in the right category (i.e., above normal was forecast and above normal was observed) it was graded as "good" and marked with a "+". Conversely, if it was the wrong category (i.e., above normal was forecast and below normal was observed then it was graded as "not good" with a "-". And if the forecast was off by a single category (i.e, above normal was predicted and it was normal) or there was a mixture of above and below in close proximity to one another then graded it as "mixed" and marked with a "0".  

Of the 41 precipitation regions compared, 14 (34%) regions rated as "good", 10 (24%) as "not good" and 17 (41%) as "mixed".
Of the 39 temperature regions compared, 20 (51%) regions were rated as "good", only 1 (3%) as "not good" and 18 (46%) as "mixed".

However, it is left to the individual reader to do their own comparisons and evaluate the relative usefulness of the forecasts to their particular activity.

Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Twitter: @ggweather