Current Theme: Waterworks
	Snowpack report - Niwot Ridge - December, 2004 Mark Losleben - CU INSTAAR Research Staff

The following snowpack conditions on Niwot Ridge have been reported by Mark Losleben for December 2004. Select here for more information about these snowpack reports

Greetings!

Positive snow pack conditions continue to favor the lower western US, and Colorado as of today. The pattern reported at the start of this month continues in both the western US and Colorado (dry north, wet south-western states), and promises to continue into early 2005 (NOAA CPC Dec 6 report on ENSO conditions).

Here on Niwot Ridge, the snow pack is almost average. The hand measurement shows 4.875" of water (90% of past 23 year average). The Snotel network shows 5.1", or 98% of average, and cumulative winter precipitation of 119% of average. Either way, this years snow pack is much better than last, which was 51% of average at this time.

The State of Colorado is also in good shape, loosely mimicking the western US as a whole, in that the south is generally wetter than the north. The similarity ends there, though, because even the northern Colorado basins are not much below average. The state shows 96% SWE and 97% PPT (snow water equivalent (SWE)/cumulative winter precipitation (PPT)). The South Platte basin shows 92%/94% of average SWE/PPT, respectively. The Gunnison basin is still tops with 120% / 113%, SWE/PPT, respectively. The Yampa/White is still in last place with 87% and 93% of average values, respectively. The southern basins of the Rio Grande, and the San Juan/Dolores/San Miguel/Animas are doing very well with 116%/116% and 109%/107%, for SWE/winter precipitation, respectively. Also noteworthy, most of Colorado basins are showing Snowpack Indicies (SI) of near one, meaning the winter weather is also about normal, so far.

The western US snow pack pattern is also little changed from the start of this month, but is much more extreme compared to Colorado. Washington has only 39% of average snow pack (73% of PPT, however), and Oregon has 48%/67%, respectively. Utah still is tops with 137% SWE and 152% PPT. The California Great Basin sites show 123%/97%, and Arizona shows131%/140%, SWE/PPT, respectively. Colorado, Nevada, New Mexico are about average, and Idaho, Montana and Wyoming are lagging with 72%, 69%, and 81% of average SWE, respectively. Low or high snow pack, however, most all states show SI's of less than one (weather conditions less conducive to snow pack development given the amount of winter precipitation received), with the exception of the California Great Basin sites, and Colorado.

Looking "upstream" for clues for the rest of winter we find no strong indicators. The NOAA CPC predicts continued weak El Nino conditions in the Pacific into early 2005, and although the PDO may be shifting (negative index values the past two months), it is too early to say for sure. So, weather-watching may continue to be interesting this month!

Cheers! Mark

                      Sno Tel Data  Niwot Ridge, C-1
                      Snow Water Content (inches)
                      Values are for the end of given month
                      except as noted for May and June


     Season     Dec      Jan      Feb      Mar      Apr     May            Jun 
      81/82    4.75     10.5     11.75    15.5     14.9    12.0   (17th)
      82/83    3.63              4.75     12.75     17     11.75  (30th)
      83/84    12.6     13.25     15      18.9     20.75   
      84/85    3.75     6.25      8.5     10.25    8.75
      85/86     6.5      7.5      14      15.38    17.5
      86/87    6.25     8.75     11.25    12.75    11.75
      87/88     6.5      9.1     12.4     15.75    14.5
      88/89     5.5      7.6      11      10.25     5.6
      89/90     6.5     9.25     10.75    16.1     16.5
      90/91      3        5       7.1     9.38      10
      91/92    6.65     6.75      8.5     12.25    10.25
      92/93    5.75     6.75     10.75     14      15.875
      93/94    7.125    9.063    12.25    13.25    13.25     2.5  (18th)
      94/95    2.625    3.925     7.0     10.125   16.75    17.0  (22nd) 12.375(13th) 19.75(30th)
      95/96    7.50     12.00    17.5     20.375   18.75     6.125 (15th)
      96/97    8.75     12.625   15.125   14.625   20.375   18.0   (15th)
      97/98    7.0625   10.0     10.125   12.875   17.25    12.875 (15th)
      98/99    3.25     6.625     8.375    9.125   14.125   14.25  (15th)
      99/2000  3.5      7.5      10.625   12.375    7.625   
      00/2001  4.375    5.375     7.125   10.00     9.125
      01/2002  2.625    4.25      6.19     7.563    0.0
      02/2003  4.00     5.25      8.5     16.75    14.375   11.44 (15th)
      03/2004  2.75     4.813     7.75     7.875   10.125    3.69 (14th)
      04/2005  4.875

     Average   5.409    7.824    10.274   12.964   13.266