Weather

Montana Water Supply Outlook

Posted: Feb 14, 2013 3:39 PM by Meteorologist Mike Heard

Montana Water Supply Outlook as of February 2013

The Montana Water Supply Forecast is issued by the National Weather
Service Office in Great Falls in cooperation and coordination with
the National Weather Service Office in Missoula.

The outlook for the 2013 summer season projects water supply east and
west of the continental divide to be near to below average. These
forecasts assume near normal moisture and runoff conditions for
February through July and do not account for much below average - 70%
or less - or above average - 100% or more - snowmelt or spring
rains.
* Detailed summary of January weather conditions for Montana
www.wrh.noaa.gov/tfx/climate/droughtsum/droughtsum.php?wfo=tfx
* Streamflow forecasts for rivers and sites west of the
Continental Divide provided by the Northwest River Forecast
Center - NWRFC - in Portland, Oregon.
www.nwrfc.noaa.gov/water_supply/ws_report.cgi?type=state&
source=montana&wyr=2013
* Streamflow forecasts for rivers and sites east of the
Continental Divide provided by the Missouri Basin River Forecast
Center - MBRFC - in Pleasant Hill, Missouri.
www.crh.noaa.gov/mbrfc/?n=water

SNOWPACK INFORMATION...
* Current day snow water equivalent information from the National
Operational Hydrologic Remote Sensing Center - NOHRSC.
www.nohrsc.noaa.gov/interactive/html/map.html?var=ssm_swe&
min_x=-116.29&min_y=43.16&max_x=-103.66&max_y=50.27&bgvar=dem&
shdvar=shading&width=800&height=450&lbl=m&palette=1&
snap=1&o9=1&012=1&o13=1
* Current day percent of normal snow water equivalent by basin.
www.wcc.nrcs.usda.gov/gis/images/mt_swepctnormal_update.png

PRECIPITATION INFORMATION...
* January 2013 percent of normal precipitation
www.wrh.noaa.gov/tfx/climate/monthlysum/images/
201301pcntnorm.png
* Calendar Year 2013 percent of normal precipitation
www.wrh.noaa.gov/tfx/climate/monthlysum/images/
201301pcntnorm.png
* Water Year 2013 percent of normal precipitation
www.wrh.noaa.gov/tfx/climate/monthlysum/images/
201210-201301pcntnorm.png
* Preliminary map of percent of normal precipitation for the
current month provided by the Western Region Climate Center
www.wrcc.dri.edu/cgi-bin/anomimage.pl?mon1mppct.gif

RESERVOIR INFORMATION...
* Reservoir storage provided by NRCS - percent of capacity,
percent of average and percent of last year
www.wcc.nrcs.usda.gov/cgibin/resv-graph.pl?state=mt

SURFACE WATER SUPPLY INDEX...
The Surface Water Supply Index - SWSI - is a measure of available
surface water availability for the spring and summer months. The
SWSI accounts for mountain snowpack, mountain precipitation,
streamflow, reservoir storage and soil moisture. SWSI values are
provided by the Natural Resources Conservation Service - NRCS - with
the US Dept of Agriculture.

* SWSI for February 2013 provided by NRCS
nris.mt.fov/nrcs/swsi/pdf/swsi201302

CLIMATE OUTLOOK...
* Current climate outlook issued by the Climate Prediction
Center - CPC
www.cpc.ncep.noaa.gov/products/predictions/multi_season/
13_seasonal_outlooks/color/page2.gif

The next Water Supply Outlook for 2013 will be issued by March 15.

WEATHER.GOV/GREATFALLS