Stratosphere-troposphere coupling, climate variability & subseasonal-to-seasonal prediction
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 …
Continue reading "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 - …
Continue reading "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 …
Continue reading "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 …
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 …
I study the stratosphere, the layer of atmosphere above the troposphere that extends from about 10-50 km above the surface. Some people might joke (I hope) that "nobody cares about the stratosphere", primarily because, unlike the troposphere, it contains no 'weather' in the traditional sense. Being very dry (...literally), it can't be seen on visible …
Sunday, July 22, 2018, 9:31 PM BST. I put out a relatively simple tweet comprising of two NASA GISS global temperature anomaly graphics - one for June 1976, and one for June 2018. After listening to the media and meteorologists alike comparing and contrasting the current UK heatwave with that of 1976 (something which I …
Continue reading "Going Viral: Some thoughts one week later"
This year's Reading Half Marathon was cancelled at ~6:40 AM on the day of the race (Sunday March 18) due to substantial snow in Reading and the surrounding area (indeed, across most of England...). The cancellation of the event only ~4 hours before runners would be taking to the course was far from ideal, with …
Continue reading "Reading Half Cancellation: Do people believe forecasts?"
MODIS imagery of Ophelia at landfall on Monday October 16, 2017. It can't have escaped the attention of most people that a storm by the name of Ophelia smashed into Ireland on Monday killing three. Met Eireann issued a RED warning 48 hours in advance of Ophelia's arrival, which is unprecedented forewarning. However, this post …
This summer I have been working as a gardener in my hometown of Harrogate, North Yorkshire. Being outside and directly affected by the weather means it's an obvious topic of conversation with customers, other tradespeople and my colleagues. I'm aware that British people apparently always talk about the weather, but when you're outside cutting a …
Simon H. Lee 