real function xmytw	(	real	t,
		real	td,
		real	p
	)

GFS calpreciptype General Algorithm

• Compute wet bulb temperature and relative humidity.
• Call calwxt() to calculte instantaneous precipitation type component 1.
• Call calwxt_ramer() to calculate instantaneous precipitation type component 2.
• Call calwxt_bourg() to calculate instantaneous precipitation type component 3.
• Call calwxt_revised() to calculate instantateous precipitation type component 4.