CFSv2 ain’t that bad: tips on using long-range forecasts

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

Weather and climate records are not mutually exclusive

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

The link between climate change and Britain’s winter storms

This article originally appeared in the February 16th 2020 edition of The Sunday Times, and was co-written with Shingi Mararike. Every winter Britain gets hit by a series of storms. Ciara and Dennis are just the latest — but with two key differences. The first is their strength. Our storms get their energy from temperature… Read More The link between climate change and Britain’s winter storms

There’s more to the UK winter than the stratosphere

The title might seem rather obvious – or a surprising statement coming from me! But what I seek to achieve in this short blog post is provide a simple reminder that historically cold weather has indeed happened without a sudden stratospheric warming (or significant stratospheric polar vortex disruption). The role of the stratosphere can sometimes… Read More There’s more to the UK winter than the stratosphere

10 FAQs on “Increased shear in the North Atlantic upper-level jet stream over the past four decades”

Lee, S. H., P. D. Williams, and T. H. A. Frame, 2019: Increased shear in the North Atlantic upper-level jet stream over the past four decades. Nature, https://doi.org/10.1038/s41586-019-1465-z. What is the key result of the study? Our study shows that the annual-mean vertical west-to-east (zonal) wind shear over the North Atlantic at aircraft cruising altitudes (within the… Read More 10 FAQs on “Increased shear in the North Atlantic upper-level jet stream over the past four decades”