HydroClim Minnesota - July 2007
A monthly electronic newsletter summarizing Minnesota climate conditions and the resulting impact on water resources.
Distributed on the Wednesday following the first Monday of each month.
State Climatology Office - DNR Waters
compiled 7/3/2007 (released one day early because of holiday)
WHAT HAPPENED IN JUNE
- June 2007 precipitation
totals were quite variable across Minnesota. Many west central, northwest,
and northeastern Minnesota locations reported above-average precipitation
for the month. In some communities in these areas, rainfall totals topped
six inches for the month. Elsewhere in Minnesota, June rainfall totals were
very light. Some central, east central, south central, and southwestern
Minnesota communities reported monthly rainfall totals of less than two
inches. This is two or more inches less than the historical average for the
month. In many of these areas, the dry weather marked the second consecutive
month of below-average rainfall. The dryness has raised concerns about
deteriorating soil moisture supplies and lower than average surface water
- torrential rains in early June
in west central and northwestern Minnesota, falling upon an already
saturated landscape, led to rural flooding. Some roadways were inundated and
crop replanting was necessary in some spots. The heavy rain also led to
flooding along the Red River and some of its tributaries throughout the
month of June.
- the heaviest rain event of the month occurred on June 13
and 14 in eastern Polk and northern Clearwater counties. A sequence of
thunderstorms dropped a narrow band of over six inches of rain in a 36 hour
period in this area.
- monthly mean temperatures
for June 2007 were warm across Minnesota. Temperatures for the month were
generally two to four degrees above the historical average. Extreme values
for June ranged from 94 degrees at Moorhead on the 11th, to 30 degrees at
Hibbing on the 6th and at Embarrass (St. Louis County) on the 29th.(see: http://climate.umn.edu/cawap/monsum/monsum.asp )
WHERE WE STAND NOW
- growing season precipitation
totals to date (April 1 through early July) demonstrate the striking spatial
variation that is often observed in a state of Minnesota's size and
continental position Portions of west central and northwestern
Minnesota are near all-time record high precipitation values for the period.
By contract, some sections of central, east central, and southwestern
Minnesota have received less than 75% of their normal growing season
rainfall. In these drier areas, precipitation has fallen short of historical
averages by three or more inches since April 1. Growing season rainfall
deficits in the metropolitan area have topped five inches.(see: http://climate.umn.edu/doc/weekmap.asp
- the U. S. Drought Monitor
released on June 28 indicates that portions of north central and
northeastern Minnesota are in a "Moderate Drought". This categorization is
the result of lingering moisture deficits established during the very dry
2006 growing season and a snow-sparse winter. Fortunately, conditions
throughout northern Minnesota have improved greatly from the "Extreme
Drought" situation that existed only a few months ago. Other areas of
Minnesota are drifting in a different direction. Much of central and eastern
Minnesota (including the metropolitan area) is placed in the "Moderate
Drought" category. In these counties, below-average rainfall in May and June
combined with warm June temperatures to create deficits in topsoil moisture
and lower-than-average levels in surface water systems. Much of the
remainder of the eastern two thirds of Minnesota is considered to be
"Abnormally Dry". The NDMC index is a blend of science and subjectivity
where intensity categories are based on several indicators.
- the U.S. Geological Survey
reports that stream discharge values in many north central, northeastern,
central, east central, and south central Minnesota watersheds are below the
20th percentile for the date. Stream flow in some northeastern and east
central Minnesota basins has dropped below the 10th percentile for the date.
Conversely, many locations along the Red River report stream discharge
values that exceed the 90th percentile for the date.
- water levels on Lake
Superior remain just above the all-time record minimum for the date. Water
levels on many lakes in the metropolitan area and northward to the Duluth
area are below historical averages. Water levels on lakes in northern
Minnesota have rebounded from last year's precipitation deficits and are
approaching average values.
- the Minnesota Agricultural
Statistics Service reports that as of July 1, the state's topsoil moisture
was 10% very short, 34% short, 51% adequate, and 5% surplus. A decline in
crop conditions from the previous week was noted.
- the potential for wildfires
is rated by DNR Forestry as "moderate" in most Minnesota counties. Wildfire
potential is depicted as "low" in southeastern Minnesota and some far
northwestern and north central counties.
(see: http://www.dnr.state.mn.us/forestry/fire/ )
- the July precipitation
outlook from the Climate Prediction Center indicates no significant
tendencies away from climatological probabilities across Minnesota. July
precipitation normals range from just over three inches in far northwestern
Minnesota to over four inches in eastern sections of the state.
- the July temperature
outlook indicates no significant tendencies away from climatological
probabilities across Minnesota. Normal July high temperatures are in the low
to mid 80's. Normal July lows are around 60 degrees. July is the warmest
month of the year in Minnesota.
- the 90-day precipitation
outlook for July through September indicates no significant tendencies away
from climatological probabilities across Minnesota. The July through
September temperature projection tilts towards above-normal conditions
across the northern one half of Minnesota, with no significant tendencies
away from climatological probabilities in southern Minnesota.
- the National Weather
Service produces long-range probabilistic river stage and discharge outlooks
for the Red River, Minnesota River, and Mississippi River basins. These
products are part of the National Weather Service's Advanced Hydrologic
Prediction Service (AHPS).
NOTES FROM THE AUTHOR
NOTES FROM AROUND THE STATE
UPCOMING DATES OF NOTE
- July 19: National Weather Service releases 30/90 day temperature and precipitation outlooks
WEB SITES FEATURED IN THIS EDITION
http://climate.umn.edu - Minnesota
Climatology Working Group, Minnesota DNR Waters and University of Minnesota
Department of Soil, Water, and Climate
http://www.drought.unl.edu - National
Drought Mitigation Center
- U.S. Geological Survey
- Minnesota DNR Waters
Detroit District, US Army Corps of Engineers
http://www.nass.usda.gov - USDA,
National Agricultural Statistics Service
- Minnesota DNR Forestry
Climate Prediction Center, National Weather Service
North Central River Forecast Center - Chanhassen, National Weather Service
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