The National Weather Service tweeted yesterday that March was coldest on record at many locations in Upper Michigan. I responded by pointing out that NCDC said March was only fifth coldest in Michigan.
NWS responded by saying that the temperatures in lower Michigan must have been warmer, and I pointed out that record ice on Lake Erie made that implausible. NWS didn’t have an explanation and left it up to NCDC to explain the discrepancy – which of course they didn’t.
HCN data shows no trend in Michigan March temperatures since 1895, but NCDC reports a 3.8 degrees/century warming trend.
The USHCN adjustments are astonishing – almost five degrees between 1895 and 2014. Apparently the freezing point of water must have changed and the record ice on Lake Erie at the end of March is meaningless. The adjustments are peer-reviewed, which trumps reality.
The next graph shows the total difference between NCDC reported temperatures and GHCN HCN raw temperatures
Environment Canada shows Great Lakes ice coverage as being completely unprecedented. Perhaps the freezing point of water has changed, due to an increase of 0.0001 mole fraction CO2?