August 2012 in Review

Before reviewing August 2012, let’s look back at the monthly temperature outlook from the Climate Prediction Center:

CPC Temperature Outlook for the month of August 2012.

As you can see, the CPC projected below normal temperatures in the extreme northwest of the lower 48 while nearly 90% of the nation had at least a 33% chance to be above normal in the temperature department.  The best chance for above normal temperatures centered on the middle of the country.  So, how accurate was this outlook?  We’ll look at two different maps to address this question.  First, we’ll begin with the High Plains Regional Climate Center‘s shaded map of temperature anomalies for the month of August:

In this map, the shading changes for every 2 degrees above or below normal for the month.  We can see the middle of country oscillates between above and below normal temperatures as you go from one station (or group of stations) to the next.  Overall, it appears the southeast was cooler than normal while the west and extreme northeast were warmer than normal.  Unfortunately, we lose some detail in this map.  For example, in areas shaded light yellow, we don’t know if the temperature was 0.1 or 1.9 degrees above normal for the month.  Also, there’s no historical perspective other than the temperature relative to normal.  To smooth out the data and bring in some historical perspective, we look at a map from the National Climatic Data Center:

In this map, we learn that temperatures in the middle of the country were near normal to below normal.  The yellow colors seen in the previous map don’t show up as above normal temperatures when averaged out over the divisions designated by the NCDC.  The overall picture of below normal temperatures in the southeast and above normal temperatures in the west and extreme northeast is confirmed.  However, we’re able to see that some divisions experienced record-setting warmth for the month of August.  (In fact, it was the warmest month of August on record in Nevada.)

Now, when comparing the last two maps to the CPC outlook at the top of the post, I feel comfortable saying the August outlook from the CPC was terrible.  The middle of the nation was near normal to below normal despite the 60% chance of being above normal for the month.  The Pacific Northwest was near normal to above normal.  Maine was above normal including record-setting warmth along the coast.  And while some of the warmth out west falls under the umbrella of above normal projection from the CPC, there is still a fair amount not covered by the CPC outlook.

FINAL VERDICT: On a scale of 1 to 10, with 1 being “Laughably Wrong” and 10 being “Frighteningly Accurate,” I will generously assign a 2 to the CPC August outlook.  They did manage to cover some of the above normal temperatures out west.  Of course, when you cake 90% of the nation in orange and red, you’ll manage to get something right.  The bottom line is that the outlook was in no way skillfully accurate.

Up Next: The CPC outlook for September (which I acknowledge is nearly 2/3 gone) as well as the outlook for meteorological Fall (September through November).

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