Top of the League

Rio de Janeiro has been the warmest of my Ten Stations for all but two of the last 22 weeks. Its mean daily temperature above Pre-Industrial (my version) has dipped below the dreaded 2 degrees C and seems unlikely to rise again this meteorological year. Rio and the southern hemisphere are running cooler than the trendlines indicated at the end of August.

Wk46_RioSouthTREND

Below are a couple of graphs that present the Week 46 Mean Temperature in a different way. I have ranked the table from highest to the lowest temperature and added Durham Tees to the Ten Stations to put north-east England into what passes for a global context. I’ve given the ten stations “hemisphere colours” and Durham Tees the indicator colour for the goldilocks zone – not too hot and not too cold (between zero and 1.49°C above Pre-Industrial). You can clearly see the four stations “over the limit” in Week 46. (Mumbai is the week’s elephant in the room.)

Week46_wkplusYTDinsets

Don’t be too complacent that the running average is below two degrees for all my stations as we near the end of the year. Robin at Seemorerocks offers an article by Anton Troianovski from The Independent about the melting permafrost in Siberia. Koltsovo is a long way from Siberia but is catching some of the heat. Climate Reanalyzer shows much of the Arctic Ocean to be over 4°C above average for much of the coming week, though mainland Siberia appears to be cooler.

Should one of my ten stations rise above two degrees next week, I think it will be Sydney. If I had a house, I’d put it on Buenos Aires being coolest. Again.

More Errant Forecasts

The southern hemisphere was warmer than I expected last week with Buenos Aires and Rio taking two of the top three places in the Table. This took the gloss off correctly nominating Koltsovo for Week 45 top spot.

45_FullTable

Roughly in the centre of the Russian Federation, Koltsovo might be expected to descend rapidly into sub-zero winter. Last week seemed to be the beginning – after the last burst (perhaps) of heat.

wk45_KoltsovoCombo

The first-day figure of almost ten degrees centigrade above P-I is the highest I can recall being recorded in my ten stations this year. A fall from a daily mean of 13.4°C on Saturday to 1.8 the following Friday is not something I’d care to experience. Having said that, Durham Tees was colder every day of Week 45 than Koltsovo’s warmest day. (Range 10.7°C on Wednesday to 12.2 on Friday.)

Wk45_KoltsovoNorthTREND

A warm Koltsovo has been the main reason for the northern hemisphere reversing the trendline forecast of cooling to the end of the meteorological year.

A quick look at the GFS model for this week points to Koltsovo turning warm again for several days. Three southern hemisphere stations might make it into the top four (Cape Town, Rio and Wellington. I’m putting pretend money on Washington and Buenos Aires propping up the Table at the end of Week 46.

Typhoon Hagibis was the week’s most obvious villain but the Arctic is a continuing cause for concern. For the next ten days, GFS indicates it will run between two and three degrees centigrade above what used to be considered “normal”. For weird weather-with-consequences, keep your eye on California. Let Jane Tande be your guide.

 

Blame Game

I lost my wager on the Hot Three weather Stations in Week 44. Sydney trailed in sixth and an outsider came up fast on the rails to pip Koltsovo for third place. The favourite, Washington DC, romped home but one out of three is poor. I blame my analysis of the GFS Model forecasts on Climate Reanalyzer rather than the model itself. I’ll try to do better this week.

44_FullTable

The aforementioned outsider was Cape Town, which is under the spotlight this week. For the first 36 weeks of the meteorological year, it has been colder than the station’s Ten-Year running average. It is, however, one of three southern hemisphere stations with a warming trendline to the end of November.

wk44_CapeTowncombo

If Cape Town reaches the forecast 1.2°C that will be 0.35°C warmer than the Ten-Year average. After five weeks of the southern spring, it is 0.25°C warmer.

44_CapeTowncf10yr

 

Cape Town is ahead of schedule and the rise seems steady, but the southern hemisphere continues to run cold. (An earlier error in the South’s figures has been corrected.)

44_CapeTownSouthTREND

I don’t think the northern hemisphere will be as warm this week as last and the south will continue to be relatively cool. Australians have been warned of an imminent “scorcher” lasting several months but South America, South Africa and New Zealand may not be similarly cursed.

Week 45 warmest of the Ten – all northern hemisphere: Koltsovo, Shanghai, Washington DC.

 

Temperature Trends

The Ten Stations conspired to push their contribution to global warming to 1.5°C above my Pre-Industrial baseline, breaking through the Paris Limit on the day of the Climate Protests.

Buenos Aires spent the first nine weeks of this meteorological year propping up the Table, moving up a place to 9th for the next fifteen weeks.

wk42_BuenosAiresCombo

A mild southern winter pushed Buenos Aires up to 6th for five weeks. It fell back to 6th three weeks ago but won’t rest there if it follows the Trend Forecast.

Buenos Aires is the station least likely to reach the indicated temperature at the end of the year. Currently, at 0.79°C above P-I, it must warm another 0.9 degrees in ten weeks to reach the target. The GFS model shows a few warmer than average days heading Argentina’s way in the next week or so, perhaps raising the temperature by one or two-tenths of a degree.

I think it is worth monitoring the trends closely though. It is too early to say if the scheme I’ve devised will work but, here goes. Using the mean daily temperatures for each station over a period of ten years I have calculated the annual range in degrees centigrade, from warmest day to coldest, divided the figure by 13 and apportioned the rise or fall to the weeks of the northern autumn and southern spring AS A PERCENTAGE. I am calculating the actual ongoing weekly change as a percentage of the 10-year range. The resulting graphs should show clearly which stations are returning temperatures higher or lower than the trendlines have indicated.

In the first three weeks of spring, Buenos Aires has already fallen behind – and so has the Southern Hemisphere. Their two graphs share a family resemblance.

In the wider world, last week saw Tropical Depression Imelda bringing greater devastation to parts of Texas than the infamous Hurricane Harvey in 2017. Several storms are currently lining up to make names for themselves, so to speak – Kiko, Mario and Lorena in the Pacific; Jerry in the Atlantic. The kids are all right.

Update 28 September

While collecting Week 43 data I realised I had made a couple of significant errors in compiling last week’s Table and the Buenos Aires/SOUTH graph. I have replaced both with revised graphics. The Table gave the Week 41 mean temperature for Durham Tees (-1.11ºC) in error and underestimated the percentage drop in Southern Hemisphere temperature in the second week of Autumn. The correct figure makes the “family resemblance” more obvious!