I’ve recently added some additional products from the NCEP Climate Forecast System version 2 (CFSv2) to my site — namely, forecasts of the weekly-average 500 hPa geopotential height anomalies for the next 4 weeks, and forecasts of the monthly-mean 700 hPa geopotential height anomalies over the next 6 months. These sit alongside the 44 day… Read More CFSv2 ain’t that bad: tips on using long-range forecasts
The atmosphere is a chaotic system with an infinite number of configurations – the weather pattern on any specific day has never before been exactly the same everywhere. Thus, it is extremely difficult to link a specific weather event to climate change. And yet, when significant weather occurs, discussion immediately jumps toward climate change –… Read More Weather and climate records are not mutually exclusive
If I followed up every time Donald Trump opened his mouth on climate change with a blog post pointing out where he was wrong, I’d have no time left to do anything else – but this one is a bit more special. This week, Trump visited the U.K., and part of that visit involved a… Read More Trump on climate change: what he should have said
The final week of February 2019 has been characterised by anomalously warm, record-setting conditions over NW Europe. The United Kingdom broke its all-time maximum record temperature for February on several occasions and at several stations – the previous record of 19.7C from 1998 was obliterated, replaced with a new record of 21.2C (a huge difference… Read More A “winter heatwave” in a warming world
Non-downward propagating SSWs? Major stratospheric sudden warming events (SSWs) attract widespread attention because they are now known to have significant impacts on the tropospheric circulation (e.g. Baldwin and Dunkerton 2001, hereafter BD01). Anomalies in the stratospheric circulation (often expressed as the Northern Annual Mode (NAM) index, or polar cap geopotential height anomalies) propagate downwards through… Read More Not all SSWs were created equal
I study the stratosphere, the layer of atmosphere that extends above the troposphere from about 10-50 km. Friends and colleagues of mine often joke (I hope…) that “nobody cares about the stratosphere” *, primarily because it contains no real ‘weather’ – such as what happens in the troposphere. With little to no water vapour, it… Read More The Stratosphere – why do we care?
I was on a long train journey a few days ago, and ended up in conversation with the person next to me. When I explained what I’m doing (a PhD project looking to improve sub-seasonal forecasting), I was greeted with the all-too-familiar response of “oh, that’s good because they get it wrong 90% of the… Read More “They get it wrong 90% of the time”