Water Supply Precipitation Summary

Weekly Divisional Precipitation Summary

Click on date to display a different weekly forecast:

06/30/2009 06/27/2009 06/23/2009 06/16/2009 06/10/2009 05/26/2009 05/19/2009 05/12/2009 04/28/2009 04/22/2009 04/14/2009 03/31/2009 03/24/2009 03/17/2009 03/11/2009 02/24/2009 02/19/2009 02/10/2009 01/27/2009 01/20/2009 01/13/2009 12/31/2008 12/24/2008 12/16/2008 12/09/2008 11/25/2008 11/18/2008 11/12/2008 10/28/2008 10/21/2008 10/14/2008 10/07/2008 09/23/2008 09/16/2008 09/09/2008 08/26/2008 08/19/2008 08/12/2008 07/29/2008 07/22/2008 07/15/2008 06/24/2008 06/17/2008 06/10/2008 05/27/2008 05/20/2008 05/13/2008 04/29/2008 04/22/2008 04/15/2008 04/08/2008 03/25/2008 03/18/2008 03/12/2008 03/11/2008 02/26/2008 02/20/2008 02/19/2008 02/13/2008 02/12/2008 01/30/2008 01/29/2008 01/23/2008 01/22/2008 01/16/2008 01/08/2008 12/26/2007 12/18/2007 12/11/2007 11/27/2007 11/20/2007 11/13/2007 10/23/2007 10/16/2007 10/09/2007 09/25/2007 09/21/2007 09/11/2007 08/28/2007 08/21/2007 08/14/2007 07/24/2007 07/18/2007 07/17/2007 07/10/2007 06/26/2007 06/19/2007 06/12/2007 05/29/2007 05/23/2007 05/15/2007 05/08/2007 04/24/2007 04/17/2007 04/10/2007 03/27/2007 03/20/2007 03/13/2007 02/27/2007 02/20/2007 02/13/2007 01/23/2007 01/16/2007 01/09/2007 12/26/2006 12/19/2006 12/12/2006 11/28/2006 11/21/2006 11/14/2006 11/07/2006 10/24/2006 10/17/2006 10/12/2006 09/26/2006 09/19/2006 09/12/2006 08/29/2006 08/22/2006 08/16/2006 08/09/2006 07/25/2006 07/18/2006 07/11/2006 06/27/2006 06/20/2006 06/13/2006 05/30/2006 05/23/2006 05/16/2006 05/09/2006 04/18/2006 04/11/2006 03/28/2006 03/21/2006 03/14/2006 03/07/2006 02/21/2006 02/14/2006 02/08/2006 01/24/2006 12/13/2005 12/06/2005 11/29/2005 11/28/2005 11/22/2005 11/15/2005 08/09/2005 07/26/2005 07/19/2005 07/12/2005 06/14/2005 06/07/2005 05/24/2005 05/17/2005 05/11/2005 04/26/2005 04/19/2005 04/12/2005 03/29/2005 03/22/2005 03/15/2005 03/09/2005 02/23/2005 02/15/2005 02/08/2005 01/26/2005 01/19/2005 01/12/2005 12/28/2004 12/22/2004 12/16/2004 12/15/2004 12/08/2004 11/24/2004 11/17/2004 11/09/2004 10/27/2004 10/20/2004 10/13/2004 09/28/2004 09/21/2004 09/15/2004 09/08/2004 08/24/2004 08/17/2004 08/10/2004 07/27/2004 07/20/2004 07/15/2004 07/13/2004 06/29/2004 06/22/2004

 Columbia Basin Seasonal Precipitation Division Averages  
 Northwest River Forecast Center 


 (Weekly Summary: 12Z jun 1 - 29, 2009) 

  DIVISION               ..JUN TO DAY 29..   ....OCT - JUN.... 
                          OBSD  DEP  PCT AV    OBSD   DEP  PCT AV 

 COLUMBIA ABOVE COULEE   1.61  -0.70  70.    18.10  -2.34  89. 
 SNAKE RV AB ICE HARBOR  3.24   1.83 229.    17.24   2.19 115. 
 COLUMBIA AB THE DALLES  2.08   0.35 120.    19.41  -0.22  99. 
 COLUMBIA AB CASTLEGAR   1.89  -0.87  69.    23.53  -3.88  86. 
 KOOTENAI                1.51  -0.87  63.    17.50  -3.44  84. 
 CLARK FORK              1.50  -0.37  80.    14.33   0.18 101. 
 FLATHEAD                1.62  -0.93  63.    16.42  -2.33  88. 
 PEND OREILLE/ SPOKANE   1.65  -0.46  78.    25.18  -2.00  93. 
 NORTHEAST WASHINGTON    1.17  -0.66  64.    13.13  -3.20  80. 
 OKANOGAN                1.00  -0.52  66.    10.76  -2.24  83. 
 EAST SLOPES WASH CASC.  0.54  -0.75  42.    32.70  -3.87  89. 
 CENTRAL WASHINGTON      0.32  -0.30  51.     6.70  -1.24  84. 
 UPPER SNAKE             4.71   3.02 280.    22.17   5.16 130. 
 SNAKE RIVER PLAIN       3.12   2.20 337.    11.11   1.55 116. 
 OWYHEE/ MALHEUR         2.76   1.86 307.    11.34   1.66 117. 
 SALMON/ BOISE/ PAYETTE  2.53   1.11 178.    16.69  -0.89  95. 
 BURNT/ GRANDE RONDE     2.00   0.64 147.    14.80   0.80 106. 
 CLEARWATER              2.24  -0.17  93.    28.63   1.93 107. 
 SOUTHEAST WASHINGTON    1.24   0.07 106.    17.57   0.36 102. 
 UPPER JOHN DAY          2.24   1.08 193.    13.13   0.47 104. 
 UMATILLA/ LWR JOHN DAY  1.48   0.42 139.    15.99   1.50 110. 
 UPR DESCHUTES/ CROOKED  1.89   1.09 236.    13.78   0.96 108. 
 HOOD/ LOWER DESCHUTES   0.93  -0.20  83.    31.03   4.61 117. 
 NW SLOPE WASH CASCADES  1.35  -2.21  38.    71.08  -8.90  89. 
 SW WA CASCADES/COWLITZ  1.06  -1.80  37.    58.72  -6.76  90. 
 WILLAMETTE VALLEY       1.83  -0.34  84.    47.98  -7.84  86. 
 ROGUE/ UMPQUA           0.97   0.00 100.    29.20  -4.34  87. 
 KLAMATH BASIN           0.98   0.22 129.    15.59  -1.24  93. 
 LAKE COUNTY-GOOSE LAKE  1.55   0.56 157.     9.61  -1.55  86. 
 HARNEY/ MALHEUR BASIN   1.84   0.96 209.     9.57  -0.37  96. 

 This precipitation summary for the Columbia River Basin is based on an 
 analysis using a limited number of reporting stations. Final values 
 depicted in this narrative are prorated by the number of elapsed days  
 in the month. 

 Precipitation normals are based on 1971-2000 historical data. 

 Please contact NWRFC for further information: (503) 326-7291. 
    

Monthly Divisional Precipitation Summary

Click on date to display forecast:

5/2009 4/2009 3/2009 2/2009 1/2009 12/2008 11/2008 10/2008 9/2008 8/2008 7/2008 6/2008 5/2008 4/2008 3/2008 2/2008 1/2008 12/2007 11/2007 10/2007 9/2007 8/2007 7/2007 6/2007 5/2007 4/2007 3/2007 2/2007 2/2007 1/2007 12/2006 11/2006 10/2006 9/2006 8/2006 7/2006 6/2006 5/2006 4/2006 3/2006 2/2006 1/2006 11/2005 7/2005 6/2005 5/2005 4/2005 3/2005 2/2005 1/2005 12/2004 11/2004 10/2004 9/2004 8/2004 7/2004 6/2004 13/0606

 Columbia Basin Seasonal Precipitation Division Averages  
 Northwest River Forecast Center 


 (Monthly Summary - may 2009) 


  DIVISION               ..MAY TO DAY 31..   ....OCT - MAY.... 
                          OBSD  DEP  PCT AV    OBSD   DEP  PCT AV 

 COLUMBIA ABOVE COULEE   1.83  -0.40  82.    16.48  -1.65  91. 
 SNAKE RV AB ICE HARBOR  1.72  -0.17  91.    14.00   0.36 103. 
 COLUMBIA AB THE DALLES  1.79  -0.18  91.    17.33  -0.57  97. 
 COLUMBIA AB CASTLEGAR   2.04  -0.22  90.    21.63  -3.01  88. 
 KOOTENAI                1.88  -0.34  85.    15.99  -2.57  86. 
 CLARK FORK              1.50  -0.55  73.    12.83   0.55 105. 
 FLATHEAD                1.92  -0.52  79.    14.80  -1.40  91. 
 PEND OREILLE/ SPOKANE   2.65   0.04 101.    23.53  -1.53  94. 
 NORTHEAST WASHINGTON    1.41  -0.74  65.    11.95  -2.54  82. 
 OKANOGAN                1.25  -0.23  84.     9.77  -1.71  85. 
 EAST SLOPES WASH CASC.  2.25   0.70 145.    32.16  -3.12  91. 
 CENTRAL WASHINGTON      0.66  -0.11  85.     6.38  -0.94  87. 
 UPPER SNAKE             2.17  -0.22  91.    17.46   2.13 114. 
 SNAKE RIVER PLAIN       1.17  -0.31  79.     7.99  -0.64  93. 
 OWYHEE/ MALHEUR         1.33   0.07 105.     8.58  -0.20  98. 
 SALMON/ BOISE/ PAYETTE  1.59  -0.20  89.    14.16  -2.00  88. 
 BURNT/ GRANDE RONDE     1.71   0.03 102.    12.80   0.15 101. 
 CLEARWATER              2.61  -0.42  86.    26.40   2.10 109. 
 SOUTHEAST WASHINGTON    1.65  -0.24  87.    16.33   0.29 102. 
 UPPER JOHN DAY          1.60   0.04 103.    10.89  -0.61  95. 
 UMATILLA/ LWR JOHN DAY  1.58   0.01 100.    14.51   1.09 108. 
 UPR DESCHUTES/ CROOKED  1.52   0.44 140.    11.89  -0.12  99. 
 HOOD/ LOWER DESCHUTES   3.05   1.44 190.    30.09   4.81 119. 
 NW SLOPE WASH CASCADES  6.38   1.64 135.    69.73  -6.69  91. 
 SW WA CASCADES/COWLITZ  5.73   1.94 151.    57.66  -4.95  92. 
 WILLAMETTE VALLEY       4.74   1.21 134.    46.15  -7.49  86. 
 ROGUE/ UMPQUA           2.70   0.72 136.    28.23  -4.35  87. 
 KLAMATH BASIN           2.08   0.90 177.    14.61  -1.46  91. 
 LAKE COUNTY-GOOSE LAKE  1.62   0.26 119.     8.06  -2.11  79. 
 HARNEY/ MALHEUR BASIN   1.33   0.00 100.     7.74  -1.32  85. 

 Columbia River Basin division values are computed by utilizing 
 un-weighted precipitation amounts from key stations in each area. 

 Precipitation normals are based on 1971-2000 historical data. 

 Please contact NWRFC for further information: (503) 326-7291. 
    
NORTHWEST RIVER FORECAST CENTER PORTLAND OR
 
PRECIPITATION, TEMPERATURE, SNOW, AND STREAMFLOW SUMMARIES
 
may 09 
 

 

 
WEATHER SUMMARY 
 

 
A LARGE SCALE UPPER LEVEL TROUGH BROUGHT COOL WET CONDITIONS TO THE REGION FOR MUCH OF THE FIRST
 
WEEK OF MAY. THIS TROUGH SHIFTED NORTH OVER THE SECOND WEEK...BRINGING CONTINUED COOL BUT DRIER
 
CONDITIONS TO MUCH OF THE REGION. BY MID MONTH A HIGH PRESSURE RIDGE BUILT OVER THE
 
NORTHWEST...BRING DRY AND WARM CONDITIONS TO THE REGION. HIGH PRESSURE DOMINATED THE WEATHER FOR
 
THE SECOND HALF OF MAY...ONLY INTERUPTED BY A STRONG COLD FRONT THAT MOVED THROUGH THE 19TH
 
THROUGH THE 21ST. BY THE END OF THE MONTH...MONSOONAL MOISTURE TRAINED OVER SOUTHERN
 
IDAHO AND OREGON...BRINGING SHOWERS AND THUNDERSTORMS TO THE REGION.
 

 
PRECIPITATION SUMMARY 
 

 
May precipitation was: 82 percent of normal (1971-2000) at Columbia above
 
Coulee, 91 percent of normal at the Snake River above Ice Harbor, and 91 
 
percent of normal at Columbia above the Dalles.
 

 

 
Seasonal (October through May) precipitation was: 91 percent of normal
 
(1971-2000) at Columbia above Coulee, 103 percent of normal at the Snake River
 
above Ice Harbor, and 97 percent of normal at Columbia above the Dalles.
 

 

 
 
 

 
TEMPERATURE SUMMARY
 
 
 
The 37 station temperature index for the Pacific Northwest departed
 
 +1.4 degrees from normal relative to the 1971-2000 normals.  Mean
 
temperature departures ranged from -1.2 to 5.5 degrees.
 

 
General Summary !
 

 
May was a month of contrasts, cool and wet for half a month and then warm 
 
and dry as the month ended.  May precipitation for areas east of the
 
Cascade Range was slightly above average.  An above average high elevation   
 
snowpack began to melt actively at month's end.  Overall, in most northern
 
portions of the Columbia basin, streamflow forecasts improved slightly
 
while streamflow forecasts for most Snake river area decreased slightly.
 

 
Snow Summary !
 

 
At the end of May only high elevation snow remains-generally above 5000 to  
 
6000 feet.  The high elevation snowpack was at 100 to 130 percent of the
 
June 1st average.  In the Canadian portion of the Colunbia river basin
 
snow water equivqlents (SWE's) continued to acccumulate until the middle
 
of May.  The best June 1st SWE's are on the Clark Fork and Bitterroot
 
rivers at 110 to 140 percent of average.  West of the Cascades an above
 
average high elevation snowpack produced some active snowmelt especially
 
in Western Washington.
 

 
Streamflow Summary !
 

 
May streamflow was above average for most areas of the Columbia basin
 
due to rainfall and snowmelt.  The only areas with below average May 
 
streamflow were the Columbia-Kootenai rivers at 60 to 70 percent, the East 
 
slopes of the Cascade Range at 60 to 80 percent and South Central Idaho
 
and Southeast Oregon at 50 to 80 percent.  The best May streamflow was on
 
the Clark Fork in Montana at 130 percent, the Yakima in Eastern Washington
 
at 120 to 130 percent,the Salmon-Clearwater rivers in Idaho at 110 to 120
 
percent and the Blue Mountain tributaries in Northeast Oregon ar 120 to
 
150 percent.  Active snowmelt at the month's end brought flooding to the
 
Naches River on the Yakima system and on the Bitterroot river in Montana.
 

 
The forecast streamflow for June 1st is near the May 1st forecast levels 
 
for the major forecast locations in the Columbia basin.  Forecast values 
 
improved on the Clark Fork river in Montana, on the Spokane river and the
 
Yakima rivers in Eastern Washington.  In contrast, some Middle Snake
 
tributaries decreased in forecast streamflow.  West of the Cascades 
 
streamflow forecasts improved from May 1st due to rainfall and some 
 
snowmelt runoff.
 

 
http://www.nwrfc.noaa.gov/water_supply/ws_fcst.cgi
 
has detailed water supply forecasts. 
 

 

 

 
 MONTHLY PRECIPITATION AND TEMPERATURE RECORDS 
 

 
  
 
Partial list of record high and low temperatures in degrees (F) are listed below.
 
Precipitation is reported in inches.
 
Please see the complete list of records at the National Weather Service Field
 
Offices Climatology Web pages.
 
  
 

 
5/2 	A RECORD RAINFALL OF 0.63 INCHES WAS SET AT BOISE ID. 
 
	A RECORD RAINFALL OF 0.36 INCHES WAS SET AT BURNS OR.
 

 
5/03	A RECORD RAINFALL OF 0.90 INCH(ES) WAS SET AT MEDFORD OR.
 
	A RECORD RAINFALL OF 0.61 INCHES WAS SET AT BURLEY ID.
 

 
5/04	A RECORD RAINFALL OF 0.78 INCHES WAS SET AT OLYMPIA WA.
 

 
5/05	A RECORD RAINFALL OF 0.59 INCHES WAS SET AT SEATTLE-TACOMA WA.
 

 
5/06	A RECORD RAINFALL OF 1.01 INCHES WAS SET AT OLYMPIA WA.
 
	A RECORD RAINFALL OF 0.89 INCHES WAS SET AT SEATTLE-TACOMA WA.
 
	A RECORD RAINFALL OF 0.98 INCHES WAS SET AT ASTORIA OR.
 
	
 
5/08	A RECORD LOW TEMPERATURE OF 25 DEGREES WAS SET AT POCATELLO ID.
 
	A RECORD LOW TEMPERATURE OF 24 DEGREES WAS SET AT IDAHO FALLS ID.
 

 
5/09	A RECORD LOW TEMPERATURE OF 16 DEGREES WAS REPORTED IN CHALLIS ID.
 
	A RECORD LOW TEMPERATURE OF 16 DEGREES WAS REPORTED IN STANLEY ID.
 

 
5/13	A RECORD LOW TEMPERATURE OF 28 DEGREES WAS SET AT OMAK WA.
 
	A RECORD LOW TEMPERATURE OF 36 DEGREES WAS SET AT THE DALLES OR.
 
	A RECORD LOW TEMPERATURE OF 25 DEGREES WAS REPORTED IN IDAHO FALLS ID.
 
	A RECORD LOW TEMPERATURE OF 18 DEGREES WAS SET AT MCCALL ID.
 
	A RECORD RAINFALL OF 0.44 INCHES WAS SET AT SEATTLE-TACOMA WA
 
	A RECORD RAINFALL OF 0.83 INCHES WAS SET AT OLYMPIA WA.
 
	
 
5/18	A RECORD HIGH TEMPERATURE OF 91 DEGREES WAS SET AT POCATELLO ID.
 
	A RECORD HIGH TEMPERATURE OF 88 DEGREES WAS SET AT MISSOULA MT.
 
	A RECORD HIGH TEMPERATURE OF 95 DEGREES WAS SET AT BOISE ID.
 

 
5/20	A RECORD LOW TEMPERATURE OF 25 DEGREES WAS SET AT BURNS OR.
 

 
5/21	A RECORD LOW TEMPERATURE OF 28 DEGREES WAS SET AT MISSOULA MT.
 

 
5/24	A RECORD RAINFALL OF 0.60 INCHES WAS SET AT POCATELLO ID.
 

 
5/29 	A RECORD HIGH TEMPERATURE OF 92 DEGREES WAS SET AT OMAK WA.
 

 
5/30 	A RECORD RAINFALL OF 1.01 INCHES WAS SET AT BURNS OR.
 

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US Dept of Commerce National Oceanic and Atmospheric Administration National Weather Service Northwest River Forecast Center (NWRFC) 5241 NE 122nd Avenue Portland, Oregon 97230-1089 Telephone: 503-326-7401 Last Modified: June 5, 2009

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