Thursday, May 3, 2018

April NCEP/NCAR global surface anomaly up by 0.046°C from March

In the Moyhu NCEP/NCAR index, the monthly reanalysis anomaly average rose from 0.331°C in March to 0.377°C in April, 2018, mainly due to a spike at the end of the month. It's the same rise and pattern as last month. The rises are not huge, but have been consistent since the low point in January, so that now April is the warmest month since May last year. This seems consistent with the fading of a marginal La Niña.

The big feature was cold in North America, except for the Pacific coast and Rockies. Much of Europe was warm, as was Australia. There was a lot of (relative) warmth in Antarctica, but the Arctic was patchy. Interactive map here.

The BoM says that ENSO is neutral, and likely to stay so for a few months.

This post is part of a series that has now run for some years. The NCEP/NCAR integrated average is posted daily here, along with monthly averages, including current month, and graph. When the last day of the month has data (usually about the 3rd) I write this post.
The TempLS mesh data is reported here, and the recent history of monthly readings is here. Unadjusted GHCN is normally used, but if you click the TempLS button there, it will show data with adjusted, and also with different integration methods. There is an interactive graph using 1981-2010 base period here which you can use to show different periods, or compare with other indices. There is a general guide to TempLS here.

The reporting cycle starts with a report of the daily reanalysis index on about the 4th of the month. The next post is this, the TempLS report, usually about the 8th. Then when the GISS result comes out, usually about the 15th, I discuss it and compare with TempLS. The TempLS graph uses a spherical harmonics to the TempLS mesh residuals; the residuals are displayed more directly using a triangular grid in a better resolved WebGL plot here.

A list of earlier monthly reports of each series in date order is here:
  1. NCEP/NCAR Reanalysis report
  2. TempLS report
  3. GISS report and comparison with TempLS


Post a Comment