• New portal improves forecasts of devasta

    From ScienceDaily@1:317/3 to All on Tue May 3 22:30:40 2022
    New portal improves forecasts of devastating storms in West Africa
    Online tool will enable forecasters to provide communities with more
    reliable warnings

    Date:
    May 3, 2022
    Source:
    UK Centre for Ecology & Hydrology
    Summary:
    Storms in the Sahel region, which can reach over 100km in size,
    have become more extreme since the 1980s due to global warming, with
    more intense rainfall. An online portal will enable forecasters in
    West Africa to provide communities with earlier and more reliable
    warnings about large storms.



    FULL STORY ==========================================================================
    An online portal developed by the UK Centre for Ecology & Hydrology
    (UKCEH) will enable forecasters in West Africa to provide communities
    with earlier and more reliable warnings about large storms.


    ========================================================================== Storms in the Sahel region, which can reach over 100km in size, have
    become more extreme since the 1980s due to global warming, with more
    intense rainfall.* Severe flooding during the monsoon from June to
    September causes human and livestock deaths, plus damages property and infrastructure, leaving thousands of people without homes and livelihoods.

    State-of-the-art weather forecast models struggle to predict where new
    storms will hit and how strong they will be, which makes it difficult to provide warnings to people in affected areas so they can protect their
    property and livestock or get out of harm's way.

    National forecasting agencies in Africa can already make predictions of
    how storms will behave in the next couple of hours by observing current atmospheric conditions, and analysing hundreds of historical storms.

    Now, thanks to a recent breakthrough by UKCEH scientists, they can make
    these short-term forecasts, known as 'nowcasts', for six hours ahead
    and with a higher degree of accuracy. The new research found drier
    soils can increase the intensity of storms when they are on the move,
    affecting where they travel and the amount of rainfall they produce.

    These novel nowcasting predictions and related satellite observations
    for West Africa are available via UKCEH's new free portal, which has
    been funded by the Natural Environment Research Council (NERC).



    ========================================================================== National forecasters can interpret the data and make localised forecasts, sending out warnings to people in areas that are expected to be hit by
    a storm.

    Last year, as part of a trial of the nowcasting tool, forecasters in
    Senegal used it to issue a severe weather warning to the public via
    text message.

    Dr Steven Cole of UKCEH says: "The portal is a great example of how new scientific understanding can be translated into useable real-time tools
    by working with forecasters. Importantly, this will support communities in
    West Africa to better manage flood risk from intense rainfall." A recent
    study found that using data about land surface temperatures improves predictions about the path and strength of an approaching mesoscale
    convective system (MCS) up to 12 hours ahead. These 'megastorms' can be
    bigger than the size of England and unleash over 100mm of rainfall in
    just an hour.

    "We found a surprising level of predictability of storms from land
    surface temperatures when testing our methodology on historical data,
    and West African forecasters are finding our approach very useful for
    their work," says Professor Chris Taylor of UKCEH.

    "We would expect mesoscale convective systems elsewhere in the world
    to also be influenced by drier soils. Therefore, our methodology could potentially be used to improve storm and flood warning systems in
    tropical regions such as South Asia and Australia, as well as parts of
    USA and South America." The new nowcasting portal allows forecasters
    to observe storm clouds in near real-time via satellite and compare
    them with historical storm behaviour, plus view data on current land
    surface conditions. The online tool then uses these data, updated every
    15 minutes, to calculate the probability of a mesoscale convective system reaching different areas of the Sahel between the current time and six
    hours ahead.

    UKCEH scientists are continuing to work with forecasting services in
    West Africa to increase the advance warning time and its reliability by combining more factors influencing storm behaviour within their nowcast modelling, in addition to land surface temperature. These include soil moisture, atmospheric humidity, wind conditions and the amount of rainfall there has been in preceding days.

    As part of a collaboration with ANACIM, the national meteorological
    service in Senegal, UKCEH has also developed short-term forecasts of
    potential flood impacts and risk in Dakar which are available on the
    portal. It also hopes to work with other forecasting services to provide
    this service for other areas.


    ========================================================================== Story Source: Materials provided by
    UK_Centre_for_Ecology_&_Hydrology. Note: Content may be edited for style
    and length.


    ========================================================================== Journal Reference:
    1. Christopher M Taylor, Cornelia Klein, Cheikh Dione, Douglas
    J Parker,
    John Marsham, Cheikh Abdoulahat Diop, Jennifer Fletcher, Abdoul Aziz
    Saidou Chaibou, Dignon Bertin Nafissa, Valiyaveetil Shamsudheen
    Semeena, Steven J Cole, Seonaid R Anderson. Nowcasting tracks of
    severe convective storms in West Africa from observations of land
    surface state.

    Environmental Research Letters, 2022; 17 (3): 034016 DOI:
    10.1088/1748- 9326/ac536d ==========================================================================

    Link to news story: https://www.sciencedaily.com/releases/2022/05/220503190227.htm

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