Question

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Our current method for finding surface wind values is to find the 500 mb geostrophic winds using 
the equation from the beginning of our kinematics/dynamics packet, then the thermal wind vector 
and finally using the difference as our surface winds. We're getting some unreasonable values using 
this method - is there a simpler, alternative way? If so, please elaborate.



Answer

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The error associated with each of the steps needed in this method is undoubtedly leading to an
accumulation that masks the true 'signal' of the near surface (10 m AGL level) winds. It is probably 
simplest to keep the wind estimate methodology to the single near-surface (1000 hPa) level, although 
no method will be entirely without error. There are several options for this and all require a
method for relating the change in surface central cyclone pressure (geopotential height) to the 
changing horizontal pressure gradient. All methods for doing this require some assumptions, but one
method uses information directly from one of the sets of GARP maps given for the final project. Be
clear in your project description of the methodology and assumptions used in implementing the
methodology. I'm sorry I can't be more specific than this.