HydroClim Minnesota
HydroClim Minnesota for Early May 2014
A monthly electronic newsletter summarizing Minnesota's climate conditions and the resulting impact on water resources. Distributed on the first Thursday of the month.
State Climatology Office - DNR Division of Ecological and Water Resources, St. Paul
distributed: May 2, 2014 (delayed distribution by one day)
What happened in April 2014:
April precipitation totals were highly variable across Minnesota, ranging from less than two inches in southwest and north central Minnesota counties, to over six inches in many east central, south central and southeast Minnesota locales. In the wetter areas, monthly precipitation totals topped the historical average by three or more inches and approached or exceeded all-time record highs for the month of April. One to two feet of snow fell during April in the northern two-thirds of the state.
A number of spring storms dropped snow and/or rain on Minnesota during the month of April. The most significant event of the month was a multi-day, late-April rain and snow episode that produced precipitation totals of three to five inches in central, east central, and southeast Minnesota, swelling rivers to bankfull and delaying agricultural field work.
Average monthly temperatures for April in Minnesota were below historical averages, finishing three to six degrees below normal. It was the sixth consecutive month of below-average temperatures. Extremes for April ranged from a high of 81 degrees F at Milan and Wheaton on the 9th, to a low of -6 degrees F at a number of northern Minnesota locations on the 2nd. Daily low temperature records were set at a number of locations on April 15.
Where we stand now:
A snow cover remains in far northeast Minnesota. Current snow depths are greater than eight inches in wooded areas of northeast St. Louis, Lake, and Cook counties.
The U. S. Drought Monitor, released on May 1, places portions of southwest Minnesota in the Moderate Drought category. Less than 10 percent of the state is designated as undergoing Moderate Drought. The drought areas are the lingering result of late-summer and early-autumn rainfall shortfalls in 2013. Heavy late-April precipitation substantially mitigated drought conditions in central, east central, and south central Minnesota. The U. S. Drought Monitor index is a blend of science and subjectivity where drought categories (Moderate, Severe, etc.) are based on several indicators.
The U.S. Geological Survey reports that stream discharge values are high to very high at most Minnesota monitoring locations. Minor flooding is occurring in some areas. Moderate flooding is underway or projected at a few locales along the Red River of the North.
In their April 28 report, the Minnesota Agricultural Statistics Service reported that topsoil moisture was 98% Adequate to Surplus across Minnesota. Subsoil moisture was said to be 18% Very Short or Short according to this survey completed just before the late-April heavy rainfall. April snows and the recent long-duration, high-volume, medium-intensity event were very efficient at recharging the landscape in many counties.
Soils are frost-free across most of Minnesota. Frost remains in the ground under the snow cover in northeast Minnesota and in some isolated pockets elsewhere.
Most lakes in the northern one-quarter of Minnesota remain ice covered. Some larger, deeper lakes in central Minnesota have yet to lose their ice as well. Thus far this spring, lake ice out dates are approximately eight days later than historical median ice out dates. However, the lakes are losing their ice 10 days earlier than in 2013.
The potential for wildfires is currently rated by DNR Forestry as Low across Minnesota. Historically, 80 percent of all wildfires in Minnesota occur during April and May.
Future prospects:
The May precipitation outlook leans towards above-normal conditions for the west central Minnesota and the southern one-third of the state. For the rest of Minnesota, the outlook offers equal chances of below-normal, near-normal, or above-normal conditions. May precipitation normals range from just over two inches in northwest Minnesota to just less than four inches in southeastern counties. The historical probability of measurable precipitation for any given day in May ranges from 25 percent in the northwest to near 40 percent in the southeast.
The May temperature outlook tilts towards below-normal conditions across Minnesota. Normal May high temperatures are in the low to mid-60s early in the month, rising to the low to mid-70s at month's end. Normal May low temperatures are in the mid-30s to near 40 to start the month and climb to the mid-40s to low 50s as the month ends.
The 90-day precipitation outlook for May through July offers equal chances of below-normal, near-normal, or above-normal conditions across Minnesota. The May through July temperature projection leans towards below-normal conditions in far northwest Minnesota, and equal chances of below-normal, near-normal, or above-normal conditions elsewhere.
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 address both high flow and low flow probabilities. As referenced earlier in this narrative, some spring flooding is currently underway.
From the author:
Upcoming dates of note:
May 15: National Weather Service releases 30/90 day temperature and precipitation outlooks
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Greg Spoden, DNR Climatologist