Thursday, March 20, 2008

What's Normal?


NOAA [National Oceanographic and Atmospheric Administration] published two charts for February both showing variances from normal:


My own sampling of various cities and towns in the Northeast showed similar variances to the Departure from Normal chart because they were based on the same "normal" baseline ... 1971 to 2000.

Based on my sampling, I'd guess that NOAA uses some sort of smoothing technique? when drawing the Departure from Normal map [middle] because our suburban Detroit area had over a -4°F average variance from normal [click on map immediately above], but on the Departure from Normal it is shown in the 0 to -2 range.
What caught my eye was the difference between the Climate at a Glance and the Departure from Normal maps. Here in Michigan, most people will say that this February was very similar to those in the early 70s when temperatures seemed colder than "normal." Yet the Climate at a Glance shows Michigan as "near normal'. What is different is that NOAA uses temperature records going back to 1895 for their climate analysis and records going back to 1971 for their normal baseline.
NOAA also states that they use adjustment techniques for the temperatures used in the normal calculation, but I'm not sure if those same techniques go back to the 1895 data used in the calculation of the other normal.
Regardless, I was curious about what constituted normal for the Climate at a Glance maps, so I did a quick sampling of February temperatures for Michigan at the decade breaks and came up with this:
1900 ____16.3
1910 ____17.9 <---
1920 ____16.5
1930 ____26.9
1940 ____21.7
1950 ____20.0
1960 ____21.3
1970 ____18.3 <---
1980 ____17.6
1990 ____24.0
2000 ____26.8
2008 ____18.4 <--- [ranked 41st coldest out of 114 Februarys]

Average ____20.5
While the sampling average of 20.5° F may not be Michigan's actual overall average for 1895-2008, there is an interesting pattern that shows an oscillation more than a trend. I have argued this point before when looking at the pattern of the number of statewide high temperature records for the nation. I acknowledge that this is a small sampling, but it seems to be in agreement with other looks at U.S. climate reporting.
Furthermore, what is the criteria for NOAA stating that a particular month's average temperature is near normal versus above normal or below normal? ......What's Normal?

How, for example, can a month that is barely out of the lower third of recorded averages [Feb. 2008 - 41 of 114 is 36th percentile] be "near normal" on a scale that includes 7 categories?

  • If we start the temperature series in 1930 instead of 1895 or 1971 [cold points] would our perception of normal and trend be different? The obvious retort is that we use the earlier starting point because we happen to have data going back to the 1890s and it just happens to be a colder period.

    Then why have two starting points and why 1971... also a colder period? Why not 1951... a more normal time?

  • If we use raw data instead of adjusted data would the results be markedly different?
  • If we insist on the same weather stations for the entire period used in the calculation of normal, would the results be different?
  • If all weather stations had to be maintained to official specifications, would the results be different?
Other thoughts...

One might ask if the increasing impact of Urban Heat Island [UHI] effect has caused an overstatement... over 113 years... in the average temperatures being reported. There are a lot of sources who say that it has.
Even a 1° increase in reported temperatures due to small towns becoming suburbs and suburbs becoming part of large cities may have a significant impact in the analysis of what is normal. Remember... temperatures will be cooler in the outlying areas, in case you haven't heard that lately on your local weather forecasts.

Meanwhile, today's forecasted high around here is 38°F ... about 12° below the normal high temperature... but we might have some above normal temperatures by the end of the month. Oh, and after years of high sunspot activity, the sunspots are virtually absent... and el Nino's warmth has turned into la Nina's cold. Just more of the same changes that happened before.

But that's normal.
What doesn't seem normal is panic about a possible [but questionable] trend change of 1° over 100 or so years... or spending trillions of dollars to prevent a possible cause of a possible change.

Can"t Find It?

Use the SEARCH BLOG feature at the upper left. For example, try "Global Warming".

You can also use the "LABELS" below or at the end of each post to find related posts.

Blog Archive

Cost of Gasoline - Enter Your Zipcode or Click on Map

CO2 Cap and Trade

There is always an easy solution to every human problem—neat, plausible, and wrong.
Henry Louis Mencken (1880–1956)
“The Divine Afflatus,” A Mencken Chrestomathy, chapter 25, p. 443 (1949)
... and one could add "not all human problems really are."
It was beautiful and simple, as truly great swindles are.
- O. Henry
... The Government is on course for an embarrassing showdown with the European Union, business groups and environmental charities after refusing to guarantee that billions of pounds of revenue it stands to earn from carbon-permit trading will be spent on combating climate change.
The Independent (UK)

Tracking Interest Rates

Tracking Interest Rates


SEARCH BLOG: FEDERAL RESERVE for full versions... or use the Blog Archive pulldown menu.

February 3, 2006
Go back to 1999-2000 and see what the Fed did. They are following the same pattern for 2005-06. If it ain't broke, the Fed will fix it... and good!
August 29, 2006 The Federal Reserve always acts on old information... and is the only cause of U.S. recessions.
December 5, 2006 Last spring I wrote about what I saw to be a sharp downturn in the economy in the "rustbelt" states, particularly Michigan.
March 28, 2007
The Federal Reserve sees no need to cut interest rates in the light of adverse recent economic data, Ben Bernanke said on Wednesday.
The Fed chairman said ”to date, the incoming data have supported the view that the current stance of policy is likely to foster sustainable economic growth and a gradual ebbing in core inflation”.

July 21, 2007 My guess is that if there is an interest rate change, a cut is more likely than an increase. The key variables to be watching at this point are real estate prices and the inventory of unsold homes.
August 11, 2007 I suspect that within 6 months the Federal Reserve will be forced to lower interest rates before housing becomes a black hole.
September 11, 2007 It only means that the overall process has flaws guaranteeing it will be slow in responding to changes in the economy... and tend to over-react as a result.
September 18, 2007 I think a 4% rate is really what is needed to turn the economy back on the right course. The rate may not get there, but more cuts will be needed with employment rates down and foreclosure rates up.
October 25, 2007 How long will it be before I will be able to write: "The Federal Reserve lowered its lending rate to 4% in response to the collapse of the U.S. housing market and massive numbers of foreclosures that threaten the banking and mortgage sectors."
"Should the elevated turbulence persist, it would increase the possibility of further tightening in financial conditions for households and businesses," he said.

"Uncertainties about the economic outlook are unusually high right now," he said. "These uncertainties require flexible and pragmatic policymaking -- nimble is the adjective I used a few weeks ago."

December 11, 2007 Somehow the Fed misses the obvious.
[Image from:]
December 13, 2007 [from The Christian Science Monitor]
"The odds of a recession are now above 50 percent," says Mark Zandi, chief economist at Moody's "We are right on the edge of a recession in part because of the Fed's reluctance to reduce interest rates more aggressively." [see my comments of September 11]
January 7, 2008 The real problem now is that consumers can't rescue the economy and manufacturing, which is already weakening, will continue to weaken. We've gutted the forces that could avoid a downturn. The question is not whether there will be a recession, but can it be dampened sufficiently so that it is very short.
January 11, 2008 This is death by a thousand cuts.
January 13, 2008 [N.Y. Times]
“The question is not whether we will have a recession, but how deep and prolonged it will be,” said David Rosenberg, the chief North American economist at Merrill Lynch. “Even if the Fed’s moves are going to work, it will not show up until the later part of 2008 or 2009.
January 17, 2008 A few days ago, Anna Schwartz, nonagenarian economist, implicated the Federal Reserve as the cause of the present lending crisis [from the Telegraph - UK]:
The high priestess of US monetarism - a revered figure at the Fed - says the central bank is itself the chief cause of the credit bubble, and now seems stunned as the consequences of its own actions engulf the financial system. "The new group at the Fed is not equal to the problem that faces it," she says, daring to utter a thought that fellow critics mostly utter sotto voce.
January 22, 2008 The cut has become infected and a limb is in danger. Ben Bernanke is panicking and the Fed has its emergency triage team cutting rates... this time by 3/4%. ...

What should the Federal Reserve do now? Step back... and don't be so anxious to raise rates at the first sign of economic improvement.
Individuals and businesses need stability in their financial cost structures so that they can plan effectively and keep their ships afloat. Wildly fluctuating rates... regardless of what the absolute levels are... create problems. Either too much spending or too much fear. It's just not that difficult to comprehend. Why has it been so difficult for the Fed?

About Me

My photo
Michigan, United States
Air Force (SAC) captain 1968-72. Retired after 35 years of business and logistical planning, including running a small business. Two sons with advanced degrees; one with a business and pre-law degree. Beautiful wife who has put up with me for 4 decades. Education: B.A. (Sociology major; minors in philosopy, English literature, and German) M.S. Operations Management (like a mixture of an MBA with logistical planning)