calc_sow_daily.ncl

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2018, Copyright University Corporation for Atmospheric Research
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/;
 rad is solar radiation
 ppt is hourly precipitation amount in inches/hr (sum of all precip over 24 hrs) / (24 hrs)
 maxrad is clear sky radiation
 sow are State of Weather Codes
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function calc_sow_daily(rad, ppt, maxrad)
local sow, percent_cloud
begin

	;maxrad1 = conform(rad, maxrad, 0)
	percent_cloud = rad / maxrad	;percentage of cloud cover estimated through solar radiation

	sow = ppt
	sow = -1

	sow = where(percent_cloud .ge. 0.91, 0, sow)
	sow = where(percent_cloud .lt. 0.91 .and. percent_cloud .ge. 0.73, 1, sow)
	sow = where(percent_cloud .lt. 0.73 .and. percent_cloud .ge. 0.5, 2, sow)
	sow = where(percent_cloud .lt. 0.5, 3, sow)
	sow = where(ppt .ge. .01, 5, sow)       ; to indicate recent precipitation
	sow = where(ppt .ge. .05, 6, sow)	; to indicate heavy recent precipitation

	return(sow)

end