A brief update for GISTEMP, whilst I try to get some more interesting posts completed.
I'm only updating a few data sets a month for now, as they are mostly pretty similar.
GISS Surface Temperature Analysis (GISTEMP) has March 2018, at 0.89°C above the base period of 1951 - 1980.
This is 0.1°C warmer than the anomaly for February.
It makes 2018 the 6th warmest March, with the last 4 Marches being 4 of the 6 warmest on record.
As is something of a theme so far for 2018 across all the data sets, March was close to the trend since 1970.
The average anomaly for the first 3 months of 2018 is 0.817°C.
My forecast for 2018 is 0.802 ±0.166°C, which is almost identical to the forecast from February.
This would put 2018 between the big gap between 2014 and 2015.
There is around a 74% chance of 2018 being the 4th warmest, and a greater than 99% likelihood of being between 7th and 2nd warmest.
Apologies for not updating this blog much recently.
I've been having more fun commenting on Watts Up With That, which I expect is a better use of my time as people actually read that blog.
I want to write some posts about some of the discussions there, but for the time being lets get back to charting global temperatures.
Note, I've skipped February's updates - none where particularly interesting being mostly slightly cooler than January, and this early in the year making little difference to the annual predictions.
UAH Temperatures
The global temperature anomaly according to The University of Alabama in Huntsville was 0.24°C, compared with the 1981-2010 base period.
This is the equal 6th warmest March in the data set.
This is a slightly higher anomaly than February, which was 0.2°C.
The start of 2018 continues to be slightly below the trend since 1979.
There's still little sign of a big La Niña drop, as happened after the 1998 El Niño.
Prediction
My statistical prediction based on the 3 months so far, and the trend is that 2018 will have an average anomaly of 0.243 ± 0.136°C.
This is up 0.01°C since last month.
An anomaly of 0.243°C would make this the 6th warmest year on record.
The probability spread suggests there is about a 28% chance of finishing in 6th place (ahead of 2002), and a similar chance of finishing 5th, ahead of 2015.
However, there is only a slim chance (less than 10%) of finishing 3rd or 4th, and virtually no chance of 2018 being the 2nd or 1st warmest.
There's about a 35% chance of finishing cooler than 2002, in which case it could finish just about anywhere as there are so many years with similar temperatures.
How much credence do I attach to these predictions?
If I'd posted last month I'd have said not much.
The predictions at this stage are heavily dominated by the trend and it seems likely that we are overdue a below the trend year, especially given the possibility of a La Niña.
However the small rise this month and the fact during the first quarter of the year anomalies have remained close to the trend, makes me slightly more confident that this prediction method might not be too far of this year.
I still expect it's more likely that we will finish below the mid-point prediction, but maybe not so far off.
All this will be bad news to those yearning for a return of the so-called pause.
At present even the lowest trend using Christopher Monckton's cherry picking exercise is for a trend of 0.72°C / century starting in July 1997.
