THE WEATHER
15
|
07-2015
www.free.aero
@FreeAeroMag
WIND DIRECTION
WIND SPEED
The national services in Europe are
also used. Since 2008, the AROME
(Application de la recherche à
l'opérationnel à méso-échelle) model by
Météo France has been calculated using
a 2.5 km grid and since April 2015, it has
been based on a 1.3 km grid. At the same
time, the data thus calculated has become
more accessible to other parties. Nicolas
Baldeck from Météo Parapente can now
use the AROME model for free for his own
forecasts adapted to paraglider pilots.
The advantage: it is more precise at a
local level. The disadvantage: no service
can calculate a similar model on a Europe
wide scale. We don’t (yet) have sufficient
power to calculate it. The model therefore
stops near the borders and still doesn’t
cover the east of the Alps.
FINER MORE CONVECTIVE MODELS
When models like AROME are based on
smaller and smaller grids, they can better
take into account small scale vertical
movements such as convection systems,
and that’s exactly what we need.
It isn’t just interesting for us pilots, but for
the forecast for a whole region. A building
storm influences the development around
it, and thus the whole model on a bigger
scale. Better forecasting of vertical
movements greatly increases the quality
of the forecast when the precipitation is
convective.
WHICH MODEL?
Most weather forecasting services offer
‘unique’ forecasts: the meteorologists
have deduced from the models,
according to their own methods, a
probable evolution which they publish.
One of the big advantages of the Swiss
Meteoblue service is the ‘Multimodel’
forecast. This shows different forecasts
depending on the different models
used. When all the models converge,
the pilot can theoretically rely more
on the forecast than if several models
forecast over development, whilst
others show only blue skies.
It should be noted that Météo France
now has an Arome 2 km model.
This service is a great initiative:
publish different probabilities rather
than one single forecast.
www.meteoblue.com/fr/weather/
forecast/multimodel/
