RTMA and URMA analyze the wind in two different ways simultaneously and combine the results together in the end.  The first method uses streamfunction and velocity potential as control variables to analyze wind as a vector quantity.  The final streamfunction and velocity potential are converted to wind speed and wind direction.  The second method is the direct analysis of wind speed only.  Because wind speed is a scalar quantity, the resulting analysis is generally more accurate than the wind speed obtained from the first method.  The final RTMA and URMA wind (vector) analysis comprises the wind speed from the second method and the wind direction from the first method.  Note that the direct analysis of wind direction is not a trivial matter due to the cyclical nature of this quantity.  Also note that wind gust is only analyzed as a scalar quantity.

For questions regarding how this information is used in the NBM, I'd suggest reaching out to the NBM team.