From waterman@enfo.com Mon May 5 12:54:10 2003 Return-Path: Received: from enfo.com ([199.45.135.12]) by bcn.boulder.co.us (8.12.9/8.12.8/ITS-6.0/bcn) with ESMTP id h45Is0Ga013720 for ; Mon, 5 May 2003 12:54:02 -0600 (MDT) Received: (from waterman@localhost) by enfo.com (8.9.0/8.9.0) id MAA09126 for waterman@bcn.boulder.co.us; Mon, 5 May 2003 12:54:13 -0600 (MDT) Received: from culter.Colorado.EDU (root@culter.Colorado.EDU [128.138.77.16]) by enfo.com (8.9.0/8.9.0) with ESMTP id MAA08897 for ; Mon, 5 May 2003 12:09:29 -0600 (MDT) From: Mark.Losleben@Colorado.EDU Received: from culter.Colorado.EDU (markl@localhost [127.0.0.1]) by culter.Colorado.EDU (8.12.9/8.12.8/UnixOps+Hesiod) with ESMTP id h45I8g4a008458; Mon, 5 May 2003 12:08:42 -0600 (MDT) Received: (from markl@localhost) by culter.Colorado.EDU (8.12.9/8.12.8/Submit) id h45I8bnV008457; Mon, 5 May 2003 12:08:37 -0600 (MDT) Date: Mon, 5 May 2003 12:08:37 -0600 (MDT) Message-Id: <200305051808.h45I8bnV008457@culter.Colorado.EDU> To: DJames1717@aol.com, James.H.Butler@noaa.gov, James.Syvitski@Colorado.EDU, James.W.Elkins@noaa.gov, John.A.Ogren@noaa.gov, Scott.Entrekin@noaa.gov, ShelleyJ@ci.boulder.co.us, Stephen.A.Montzka@noaa.gov, Thayne.M.Thompson@noaa.gov, bert@crrel.usace.army.mil, billgage@ix.netcom.com, bradu@cires.colorado.edu, cosper@indra.com, deander@usgs.gov, deborah_luchsinger@nrel.gov, denisec55@yahoo.com, dpinesy@yahoo.com, erin.bissell@Colorado.EDU, gnk@cdc.noaa.gov, jdheiden@aol.com, jean@nednet.net, jhardy@crrel41.crrel.usace.army.mil, johnk@ntsg.umt.edu, kew@cdc.noaa.gov, larrylcnm@juno.com, litaori@telhai.ac.il, matt@nednet.net, mayer@geop.ubc.ca, mokeefe136@aol.com, mph@cdc.noaa.gov, nicholas.pepin@port.ac.uk, nolan@ccc.atmos.colostate.edu, nwtlter@lists.colorado.edu, pedrick@culter.Colorado.EDU, pmb@rmtrr.org, rlax@kryos.Colorado.EDU, sburak@qnet.com, sdossett@uiuc.edu, timbard99@yahoo.com, timothy.kittel@Colorado.EDU, waterman@enfo.com Subject: FYI, comments on last report Sender: waterman@enfo.com X-Spam-Status: No, hits=3.9 required=5.0 tests=NO_REAL_NAME,SORTED_RECIPS version=2.53 X-Spam-Level: *** X-Spam-Checker-Version: SpamAssassin 2.53 (1.174.2.15-2003-03-30-exp) Status: OR Timothy Bardsley, Snow Hydrologist with the NRCS Snow Survey in Salt Lake City, had the follwing comments relating to my last report. These help clarify and add perspective to that report. Cheers! Mark L ----------------------------------------------------------------- A selection of Tims comments: Nearly all of Nevada was significantly below average for nearly the entire winter (the sierra is somewhat of an exception, but still low most of the year). Much of California and Nevada has experienced a good couple of weeks this month, but this has only caught them up to the tail end of the snowpack ablation curve. Absolute numbers for max accumulation are quite bad for all of these areas. While it is helpful that they have seen some more snow and rain during April, and they are holding onto what little pack they had for a bit longer, this in now way negates the very low accumulations during the past winter. One less important note concerning the ground truth measurements. There are many ways that can cause the "ground truth" to vary versus the telemetered reading, but I think bridging is more of a problem early in the winter. When the snowpack ripens it tends to settle onto the pillow destroying any bridges that may have existed early in the season. While under many snowpack conditions it is difficult not to under sample with the federal snow sampler (particularly crusts and depth hoar), the published numbers show a ~ 10% over sampling. I believe this happens only under more ideal snow conditions such as the sierra, or an isothermal snowpack. To make a long story short, I would not put any weight on the small difference you measured between the ground measurements and the telemetered. We are happy if they agree within 10% based on all the variables not the least of which is you are not measuring the exact snow that is on the pillow and some physical variation exists along the edges. ----------------------------------------------------------------