Some reflections of a weather forecaster

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  • An example of a Stevenson screen, open to show the thermometers. Photo: Ian Crawford/EMPICS Sport

    People cool off by the River Thames in Gravesend, where record breaking high temperatures were recorded on 10th August 2003. Photo: Gareth Fuller/PA Archive

    The cliffs at Boscastle, where heavy rainfall lead to flash floods on 16th August 2004. Photo: PA/PA Archive

    An RAF Sea King helicopter pulls people from their waterlogged homes in the flood-raveged coastal community. Photo: PA/PA Archive

  • Some reflections of a weather forecaster
    08.08.2013 14:18

     

    Having been a weather forecaster for 13 years now, I have witnessed some of the recent extreme weather events from the comforts of the MeteoGroup UK office. Two that particularly stick in my mind occurred in the month of August; the highest temperature ever recorded in the UK on 10th August 2003 and the Boscastle flooding on 16th August 2004.

    Faversham in Kent recorded the highest temperature on 10th August 2003 with the thermometer reading a maximum for the day of 38.5C (101.3F). However, some meteorologists and climatologists question the validity of the exposure of the site (at Brogdale).

    Gravesend’s 38.1C (100.6F) recorded on that day is certainly accepted, though. These high temperatures came towards the end of a very warm couple of weeks in the UK, with temperatures above 30C everyday somewhere in the country from the 3rd to the 12th.

    With high pressure sitting just to the east of the British Isles, a very warm plume of air came up from the south and sat over the UK. Even at a height of 1.5km above the surface, temperatures were in the low 20s Celsius over the south-east of England on the 10th August, so it was not really surprising that on the ground, temperatures reached the high 30s Celsius.

    I remember this day very well as I was working the nightshift that week, so trying to sleep through the day with the high temperatures. Thankfully, being a weather forecaster, I had a bit of a heads up that the hot weather was on the way and so had managed to buy a fan before all the shops sold out. As I arrived at the office on the evening of the 10th, after a very unpleasant train journey into central London, the phone was ringing red hot with journalists wanting quotes on the record breaking temperatures. 

    The following August, it was the wet weather making the headlines. Very localised heavy rain and thunderstorms over the moors of north Cornwall on the afternoon of the 16th August 2004 lead to flash floods in village of Boscastle on the coast. Otterham, on the moors, recorded 200.2mm (7.9in) of rainfall on the 16th, with the majority of that falling in just four hours in the afternoon.

    Nearby, Lesnewth had 64.8mm in an hour. This amount of rain led to a lot of water flowing into the River Valency, which flows through Boscastle, causing a 2m (7 ft) rise in the river levels. This water temporarily got damned behind a bridge by debris, before the bridge collapsed, causing a 3m (10 ft) wave of water to surge down the streets to the harbour. Although over 100 people had to be rescued by helicopter from the village, thankfully no one was killed.

    The torrential rain that led to these devastating floods was caused by a low pressure system to the west of the British Isles, leading to an unstable warm and moist south-westerly flow across the south-west of England. An onshore wind developed in north-west Cornwall through the afternoon, leading to a line of convergence down the spine of the county.

    As this interacted with the local topography of the moors, thunderstorms and towering cumulus clouds developed, bringing the heavy rain. As the upper winds were from the south-west, these storms propagated north-eastwards, with more developing, to form a line that persisted over the same area for several hours. Working the dayshift that day, I remember watching these storms on the rainfall radar before hearing the breaking news of the flooding on the TV later in the day. 

    With the ever changing weather here in the UK, more extreme events are likely to happen, so who knows what else I will witness from my desk here in the MeteoGroup UK office. 

    By: Rachel Vince