Drought Information Statement
Issued by NWS Great Falls, MT
AXUS75 KTFX 202036
DROUGHT INFORMATION STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
236 PM MDT MON MAY 20 2013
...Lack of Early Spring Precipitation Causes Drought Conditions to
Worsen in West, Southwest and Central Montana...
The monthly accumulated precipitation across Montana for April was
below normal. Scattered areas of the state did see above normal
precipitation, with the wettest area along the Idaho border in
northwest Montana. This was the 4th consecutive month with below
normal precipitation and the ninth of the past 12 months with below
normal precipitation. Snowfall for April averaged below normal for
the state as a whole - the average of 7.5 inches was 0.8 inches
below average. For the water year, statewide snowfall averaged 52.1
inches...about 6 inches below normal.
For the state as a whole, winds were above average in April.
As of May 14, the portion of Montana in some stage of drought on the
National Drought Monitor was just under 35 percent /34.84/, up
slightly from April 16. The portion of Montana in the D3 Extreme
Drought category has increase and is now nearly 5 percent /4.77/.
Nearly 11 percent /10.65/ is in the D2 Severe Drought category. That
portion of the state in the D1 Moderate Drought category remains at
nearly 20 percent /19.42/. Just under 14 percent /13.78/ of Montana
is in the D0 Abnormally Dry category.
The Drought Outlook released May 16 shows Drought Persistence through
the end of August from southwest through south central Montana. The
Outlook also indicates Drought Development is expected slightly
north of this area. The far southeast corner of the state is
expected to see at least some improvement through the end of August.
This assessment is based on current near to slightly below normal
snowpack in the mountains, good reservoir storage and a climate
outlook that is indicating better chances for drier than normal
precipitation amounts for the June through August period.
SUMMARY OF IMPACTS...
STATE AND LOCAL ACTIONS...
The Montana Governor`s Drought and Water Supply Advisory Committee
had its mandatory April meeting Thursday, April 18, and will
continue to meet monthly through the spring, summer and early
SOIL MOISTURE CONDITIONS...
At mid-May, soil moisture over Montana west of the Continental Divide
was noted to be above normal while areas in central, south central
and southeast Montana were noted to be below normal.
As of May 12, topsoil moisture ranked as short to very short was 50
percent /26 percent last year/. Subsoil moisture short to very short
was 49 percent /27 percent last year/. Winter wheat condition was
slightly below that of last year with 52 percent good to
excellent /59 percent last year/.
April across Montana was generally cooler than normal with near
normal precipitation. Temperatures for April 2013 were the 11th
coldest of 119 years of record. Precipitation for the state ranked
as the 67th driest of 119 years. For the first half of May 2013, a
composite of 22 stations across Montana averaged only 0.12 inches of
precipitation - the average is 0.98 inches. This is the driest first
half of May on record for Montana.
The June outlook for Montana released May 16 indicates a 33 to 40
percent chance temperatures will be above normal across west,
southwest, and south central Montana as well as portions of central
and southeast Montana. For the remainder of the state, there are
equal chances temperatures will be above, below or near normal. For
precipitation for June, there is a 33 to 40 percent chance
precipitation will be below normal in a band from northwest to
southeast Montana. There is a 40 to 50 percent chance precipitation
will be below normal over southwest Montana.
For our remaining summer months of July through September, the
outlook indicates better chances for above normal temperatures
statewide - 40 to 50 percent chance for above normal temperatures
across extreme southwest and south central with 33 to 40 percent
chances over the remainder of the state. The precipitation outlook
for July through September shows a 40 to 50 percent chance for below
normal precipitation west of the Continental Divide and over
portions of north central and central Montana. The remainder of the
state shows a 33 to 40 percent chance for below normal
In an update released May 9, the National Weather Service Climate
Prediction Center with the International Research Institute for
Climate and Society stated that El Nino Southern Oscillation /ENSO/
neutral conditions are favored into late summer 2013.
HYDROLOGIC SUMMARY AND OUTLOOK...
With recent warm temperatures causing mountain snowmelt, streamflows
for most sites are in the normal to above normal percentiles.
The SWSI /Surface Water Supply Index/ issued by the Natural Resources
Conservation Service indicates streams across the northern portion
of Montana are mostly Near Average to Slightly Wet. Streams across
central and southern portions of Montana are mostly Slightly Dry to
Reservoirs across Montana are mostly near to slightly above
historical averages for the date. Recent snowmelt runoff and the
beginning of irrigation demands are increasing reservoir releases.
Continued drier than average conditions across much of west and
southwest Montana in April resulted in the snowpack in several
basins continuing to drop below their median for the date. Well
above normal temperatures in early May cause rapid snowmelt in some
basins. As of mid-May, only basins along the Rocky Mountain Front
maintained near average snowpack for the date. All other basins were
below to well below average.
NEXT ISSUANCE DATE...
Through the spring, updates to this product will be made on a monthly
basis, typically between the 15th and 25th. The next issuance of the
drought information statement for Montana should be no later than
Friday June 21 2013.
RELATED WEB SITES...
Additional information on current drought conditions may be found at
the following web addresses...
U.S. Drought Monitor...www.droughtmonitor.unl.edu/
NOAA Drought Information Center...www.drought.noaa.gov/
National Integrated Drought Information System /NIDIS/Drought
Montana Drought and Water Information...drought.mt.gov
NWS Great Falls Drought Information...
Western Regional Climate Center...wrcc.dri.edu
Climate Prediction Center /CPC/...www.cpc.ncep.noaa.gov/
NWS River Information...water.weather.gov/ahps/
USGS Water Resources of Montana...mt.water.usgs.gov/
US Bureau of Reclamation Great Plains Region...www.usbr.gov/gp/
US Bureau of Reclamation Pacific Northwest Region...www.usbr.gov/pn/
US Army Corps of Engineers Omaha District...
Natural Resources Conservation Service Water Supply...
National Interagency Fire Center Predictive Services...
The Drought Monitor is a multi-agency effort involving NOAA`s
National Weather Service and National Climatic Data Center...the US
Department of Agriculture...state and regional centers,
climatologists, and the National Drought Mitigation Center.
Information for this statement has been gathered from NWS and FAA
observation sites, Montana Department of Natural Resources, State
Cooperative Extension Services, USDA, NRCS, USACE and USGS.
QUESTIONS OR COMMENTS...
If you have any questions or comments about this Drought Information
Statement, please contact...
National Weather Service
5324 Tri-Hill Frontage Road
Great Falls MT 59404