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<br />. <br /> <br />. <br /> <br />. <br /> <br />Curt's New File and Directory: D:\wpd\proj\gcip\gcip2000-785.rpt.wpd (WOlD ER785) <br />(ER785 = $100k/yr for 3 yrs = $300k total budget) <br /> <br />SECOND ANNUAL REPORT to NOAAlOGP/GCIP <br />April 11, 2000 <br /> <br />Demonstration of Improved Operational Water Resources Management <br />Through Utilization of Better Snow W.ater Equivalent Information <br /> <br />by Dave Matthews, Arlin Super, Curt Hartzell, Ed Holroyd <br />Bureau of Reclamation <br />Denver, CO 8022!;-0007 <br /> <br />Goal: <br /> <br />The goal of this cooperative effort between the Bureau of Reclamation (Reclamation) and the <br />Office of Global Programs, NOAA is to demonstrate improved operational water resources <br />management resulting from better snow water equivalent (SWE) information. This goal will be <br />pursued by helping merge NEXt generation weather RADar (NEXRAD) estimatE~s of SWE into the <br />current National Weather Service (NWS) scheme of SWE and snow cover mapping (which does <br />not use radar), and by demonstrating that the resulting improved streamflow fomcasts are <br />beneficial to Reclamation's ability to prudently managl~ water resources for multi purposes. <br /> <br />Progress Summary: <br /> <br />This report documents an extension of work done on the Snow AGcumulation Algorithm (SAA) <br />development for NEXRAD WSR-88D radars focusing on applications for water resource <br />management. An expansion of operational testing using Level III data shows that the algorithm <br />continues to be robust. For the 1998-1999 season (November - April) a variety of accumulation <br />products were made available on the Internet for five radars across the Dakotas and Minnesota, <br />including a regional mosaic. The 4-S relationship used was 150 R2.o. That network was <br />expanded to 10 radars for the 1999-2000 winter season. <br /> <br />Issues involving the vertical gradient of reflectivity and snowfall continued to bE~ prominent. The <br />vertical gradient of falling snow was used to generate a range correction which boosts integrations <br />by a factor of three at 230 km. The use of this correction scheme appears to be appropriate when <br />compared to surface observations. Experimental work was performed that reduces the effects <br />of virga at far ranges. A visualization routine was created to display the vertical gradient in the <br />lowest 5 km of altitude above the radar. Parts of that routine may be useful in future efforts to <br />reduce virga and bright band effects. <br /> <br />Future work should continue to examine the vertical gradient issue to identify the best style of <br />algorithm. One that can simultaneously adjust for virga, bright band, and range correction would <br />be preferred. In addition, individual radar hybrid scan and occultation files can be adjusted by <br />hand editing to reduce blemishes in the SAA product. <br /> <br />1 <br />