<s>
The	O
Weather	B-Application
Research	I-Application
and	I-Application
Forecasting	I-Application
(	O
WRF	O
)	O
Model	O
(	O
)	O
is	O
a	O
numerical	B-General_Concept
weather	I-General_Concept
prediction	I-General_Concept
(	O
NWP	O
)	O
system	O
designed	O
to	O
serve	O
both	O
atmospheric	O
research	O
and	O
operational	O
forecasting	O
needs	O
.	O
</s>
<s>
WRF	O
offers	O
two	O
dynamical	O
solvers	O
for	O
its	O
computation	O
of	O
the	O
atmospheric	O
governing	O
equations	O
,	O
and	O
the	O
variants	O
of	O
the	O
model	O
are	O
known	O
as	O
WRF-ARW	O
(	O
Advanced	O
Research	O
WRF	O
)	O
and	O
WRF-NMM	B-Application
(	O
nonhydrostatic	O
mesoscale	O
model	O
)	O
.	O
</s>
<s>
The	O
WRF-NMM	B-Application
solver	O
variant	O
was	O
based	O
on	O
the	O
Eta	O
model	O
,	O
and	O
later	O
nonhydrostatic	O
mesoscale	O
model	O
,	O
developed	O
at	O
NCEP	O
.	O
</s>
<s>
The	O
WRF-NMM	B-Application
(	O
NMM	O
)	O
is	O
supported	O
to	O
the	O
community	O
by	O
the	O
Developmental	O
Testbed	O
Center	O
(	O
DTC	O
)	O
.	O
</s>
<s>
The	O
WRF	O
serves	O
as	O
the	O
basis	O
for	O
the	O
RAP	B-Application
and	I-Application
HRRR	I-Application
models	I-Application
:	O
high-resolution	O
operational	O
forecast	O
models	O
run	O
regularly	O
at	O
NCEP	O
.	O
</s>
<s>
A	O
version	O
of	O
WRF-NMM	B-Application
tailored	O
for	O
hurricane	O
forecasting	O
,	O
HWRF	B-Application
(	O
hurricane	O
weather	B-Application
research	I-Application
and	I-Application
forecasting	I-Application
)	O
,	O
became	O
operational	O
in	O
2007	O
.	O
</s>
