NSS Known Issues as of 2017/01/10

TABLE OF CONTENTS

General program issues
Colorado
Georgia
Massachusetts
North Carolina
South Carolina
Texas

General program issues

No known general issues at this time.

Colorado

If input variables include "Percent_above_7500_ft", enter actual percentage (not percentage plus 1 as indicated in the associated report number SIR 2009_5136). The one will be added by NSS during its computations. Also note that prediction errors for Annual Monthly and Mean Streamflows have been corrected for Mountain, Northwest, Rio Grande, and Southwest hydrologic regions as well as Duration flows for Southwest hydrologic region.

Georgia

For Peak_Southeast_US equations in Georgia, North Carolina, or South Carolina, the sum of all percentages entered into NSS by the user must be equal to 100% in order for the equation output to be valid. If all output values report zero, the rounded sum of input values did not equal 100%. Since NSS rounds to 3 significant figures, it is best to enter only 3 significant figures and make sure that all rounded parameters add to 100%. See report number SIR 2009-5043 (GA), SIR 2009-5158 (NC), or SIR 2009-5156 (SC) for further details. Links to these reports can be found on the NSS publications page at: http://water.usgs.gov/osw/programs/nss/pubs.html

Note: NSS results from databases starting with the 2014-03-26 version and ending before the 2014-10-07 version may have produced incorrect results if the above input rule was violated. Results from inputs that added to 100% were unaffected by this error.

Massachusetts

The Massachusetts-Rhode Island Water Science Center strongly recommends contacting a hydrologist from their office before using any peak flow estimates generated by NSS for Massachusetts. New equations are expected in 2017.

North Carolina

For Peak_Southeast_US equations in Georgia, North Carolina, or South Carolina, the sum of all percentages entered into NSS by the user must be equal to 100% in order for the equation output to be valid. If all output values report zero, the rounded sum of input values did not equal 100%. Since NSS rounds to 3 significant figures, it is best to enter only 3 significant figures and make sure that all rounded parameters add to 100%. See report number SIR 2009-5043 (GA), SIR 2009-5158 (NC), or SIR 2009-5156 (SC) for further details. Links to these reports can be found on the NSS publications page at: http://water.usgs.gov/osw/programs/nss/pubs.html

Note: NSS results from databases starting with the 2014-03-26 version and ending before the 2014-10-07 version may have produced incorrect results if the above input rule was violated. Results from inputs that added to 100% were unaffected by this error.

South Carolina

For Peak_Southeast_US equations in Georgia, North Carolina, or South Carolina, the sum of all percentages entered into NSS by the user must be equal to 100% in order for the equation output to be valid. If all output values report zero, the rounded sum of input values did not equal 100%. Since NSS rounds to 3 significant figures, it is best to enter only 3 significant figures and make sure that all rounded parameters add to 100%. See report number SIR 2009-5043 (GA), SIR 2009-5158 (NC), or SIR 2009-5156 (SC) for further details. Links to these reports can be found on the NSS publications page at: http://water.usgs.gov/osw/programs/nss/pubs.html

Note: NSS results from databases starting with the 2014-03-26 version and ending before the 2014-10-07 version may have produced incorrect results if the above input rule was violated. Results from inputs that added to 100% were unaffected by this error.

Texas

Users needing to estimate peak streamflows for Texas should consult report number SIR 2009-5087 before using NSS to solve the regional regression equations. This report provides information needed by the user to determine input values and application limits. Failure to do so may result in improper estimates. This report replaces previous peak-flow equations from WRIR 96-4307.