<s>
The	O
Integrated	O
Forecasting	O
System	O
(	O
IFS	O
)	O
is	O
a	O
global	O
numerical	B-General_Concept
weather	I-General_Concept
prediction	I-General_Concept
system	O
jointly	O
developed	O
and	O
maintained	O
by	O
the	O
European	O
Centre	O
for	O
Medium-Range	O
Weather	O
Forecasts	O
(	O
ECMWF	O
)	O
based	O
in	O
Reading	O
,	O
England	O
,	O
and	O
Météo-France	O
based	O
in	O
Toulouse	O
.	O
</s>
<s>
It	O
comprises	O
a	O
spectral	B-Algorithm
atmospheric	I-Algorithm
model	I-Algorithm
with	O
a	O
terrain-following	O
vertical	O
coordinate	O
system	O
coupled	O
to	O
a	O
4D-Var	O
data	O
assimilation	O
system	O
.	O
</s>
<s>
It	O
is	O
one	O
of	O
the	O
predominant	O
global	O
medium-range	O
models	O
in	O
general	O
use	O
worldwide	O
;	O
its	O
most	O
prominent	O
rivals	O
in	O
the	O
6	O
–	O
10	O
day	O
medium	O
range	O
include	O
the	O
American	O
Global	O
Forecast	O
System	O
(	O
GFS	O
)	O
,	O
the	O
Canadian	O
Global	B-Application
Environmental	I-Application
Multiscale	I-Application
Model	I-Application
(	O
GEM	O
and	O
GDPS	O
)	O
and	O
the	O
UK	O
Met	O
Office	O
Unified	B-Application
Model	I-Application
.	O
</s>
<s>
All	O
model	O
versions	O
except	O
HRES	O
are	O
coupled	O
to	O
the	O
ocean	B-Application
model	I-Application
NEMO	O
.	O
</s>
<s>
The	O
EC-Earth	O
climate	B-Application
model	I-Application
is	O
based	O
on	O
the	O
IFS	O
.	O
</s>
