More temperature records to start AprilFollowing a record-setting month of March, April started with some new high temperature records in the southwestern counties of Minnesota. On April 1st (April Fool's Day) Marshall set a new record with 78 degrees F, Pipestone had a new record 81 degrees F, Sioux Falls, SD set a new record with 89 degrees F, and Luverne set a new state record with a high of 90 degrees F. April 2nd brought more records with highs of 80 degrees F at Lakefield, 84 degrees F at Sioux Falls and Worthington, 86 degrees F at Luverne, and a new statewide record of 88 degrees F at Pipestone. And on April 3rd new temperature records were set with 79 degrees F at Redwood Falls, 81 degrees F at Windom and Pipestone, and 82 degrees F at Lakefield. Temperatures in southern and western portions of the state are averaging 13-18 degrees F warmer than normal for the month of April so far.
April 2nd also brought a round of thunderstorms to the state, some bringing large hail (up to 3/4 inch diameter). A few observers reported 0.30 to 0.50 inches of rainfall, but it was quite spotty.
Soil moisture still short, but improving in some placesUniversity of Minnesota Research and Outreach Centers monitor soil moisture conditions for Minnesota's major crops. Last fall's (2011) measurements made it obvious that soil moisture storage was well below normal going into the winter season. For many areas over winter and early spring precipitation has been inadequate to help fully restore soil moisture to near normal levels for the spring. At Lamberton the final measurements from last fall showed 2.95 inches of stored soil moisture in the top 5 feet of the soil profile. Measurements made earlier this week showed that the profile moisture content had only "improved" to 3.09 inches of stored moisture, still roughly 2.5 inches less than average for this time of year. Further much of this moisture lies well below 3 feet and is out of the reach of crop rooting systems early in the growing season. So additional spring rains in April and early May are needed to recharge the upper layers of the soil for good germination and early development of corn and soybean crops.
For some areas, over winter and early spring recharge has been helpful. For example, at Waseca the final soil moisture measurements from last fall showed 4.67 inches of available moisture in the top 5 feet of the soil profile. The measurements made earlier this week in the same soil showed 7.37 inches of available stored soil moisture, an increase of 2.70 inches. This recharge came primarily from the Leap Day storm (Feb 29) which dropped 1.96 inches of rain, and the mid-March rains (Mar 20-23) which infiltrated the soil as well. Though this measurement is still below normal for stored soil moisture this time of year, this level of moisture is adequate for starting the planting season with optimism in the Waseca area.
Periodic seasonal updates on soil moisture values around the state will be available under the Agricultural Climate Information section of our web site.
Notes on early ice-out dates for Minnesota lakesWe have spoken in recent years about the obvious trend in earlier ice-out dates on Minnesota lakes. This year a number of lakes with lengthy observation records saw their earliest ice-out in history. The list below is compiled by Pete Boulay of the MN-State Climatology Office and available online here.
Lake Name County New Record Old Record Period of Record
White Bear Lake Ramsey/Wash March 19, 2012 March 21, 2000 85 years
Minnewaska Pope March 21, 2012 March 23, 2000 107 years
Green Kandiyohi March 20, 2012 March 22, 1987 83 years
Mille Lacs Mille Lacs March 26, 2012 April 2, 2000 56 years
Big Sandy Aitkin March 26, 2012 March 31, 2000 59 years
Bemidji Beltrami April 2, 2012 April 6, 2010 76 years
Leech St. Louis April 2, 2012 April 6, 2010 77 years
Vermilion St. Louis April 2, 2012 April 6, 2010 93 years
Perhaps the bill in the MN-Legislature to advance the date of the Fishing Opener to May 5th this year will provoke a movement to make a permanent change to an earlier date so there will be no more conflicts with Mother's Day weekend.
Weekly Weather PotpourriWednesday afternoon and evening brought 13 tornadoes to the Dallas-Fort Worth area of Texas, some that were large and destructive. Hundreds of homes and buildings were damaged, but no fatalities were reported thanks in part to timely warnings from the National Weather Service. Hail damaged more than 100 aircraft at the DFW Airport. It was the first outbreak of tornadoes this month, following 223 reports of tornadoes during March nationwide.
A recent paper by the U.K. Met Office scientists which appears in the journal Nature finds a possible link between industrial air pollution, volcanic activity, and the changes in the temperature patterns of the North Atlantic Ocean. Given the importance of North Atlantic sea surface temperatures to precipitation patterns across Africa and South America it is critical to understand how human caused pollution may affect ocean temperature patterns in the future.
For golf fans following the Master's Golf Tournament this week from August, GA, the Southeast Regional Climate Center has created a complete climatology for this event covering the period from 1934 to the present. You can find all the weather records you want. For example, there have been 15 years when no rainfall occurred during the tournament. Conversely it rained 2.67 inches on Saturday, April 7, 1973. More information can be found at the web site.
Despite the prevailing warm temperatures this season across the state of Minnesota, Silver Bay reported one of the coldest mornings in the nation on Friday, April 6th with just 16 degrees F.
MPR listener questionI know that forecasters have warned us that possible freezing temperatures will occur in the Twin Cities yet in April, but what about snowfall. How often does it snow in April or May in the Twin Cities area?
Answer: Indeed, frost may be a possibility on Monday through Wednesday mornings, and yet again even later in the month. At least a trace of snowfall has been observed during the months of April and May in the Twin Cities 95 percent of all years since 1885. This is a remarkably high percent. The most recent years without any snow in April and May were 2010 and 2006.
Twin Cities Almanac for April 6thThe average MSP high temperature for this date is 50 degrees F (plus or minus 12 degrees F standard deviation), while the average low is 32 degrees F (plus or minus 8 degrees F standard deviation).
MSP Local Records for April 6th
MSP weather records for this date include: highest daily maximum temperature of 86 degrees F in 1991; lowest daily maximum temperature of 26 degrees F in 1939; lowest daily minimum temperature of 10 F in 1979; highest daily minimum temperature of 54 F in 1921; record precipitation of 2.58 inches in 2006; and record snowfall of 6.0 inches in 1928. Snow depth was 8 inches on this date in 1975.
Average dew point for April 6th is 28 degrees F, with a maximum of 59 degrees F in 1921 and a minimum of -3 degrees F in 1979.
All-time state records for April 6thThe state record high temperature for this date is 90 degrees F at Madison (Lac Qui Parle County) and Winona (Winona County) in 1991; the state record low temperature for this date is -22 degrees F at Karlstad (Kittson County) in 1979 and at Tower (St Louis County) in 1982. State record precipitation for this date is 2.67 inches at Dawson (Lac Qui Parle County) in 1997; and state record snowfall for this date is 18.0 inches at Fosston (Polk County) in 1947.
Past Weather Features:A heavy fall of snow occurred in the southern part of the state back on April 6, 1928 with many places receiving 6 or more inches. Downtown St Paul reported 7 inches, Zumbrota 8 inches, Maple Plain 9.5 inches, and Fairmont 11.4 inches, still a record snowfall for the date there.
Another heavy snow storm occurred on April 6, 1947 bringing several inches of snow, and record setting snow to some northern Minnesota communities. Moorhead and Babbitt reported 9 inches, 10 inches fell at Blackduck, 14 inches at Red Lake, and 18 inches of snow was reported at Fosston. It was a Sunday and some churches did not hold services.
April 6, 1979 was perhaps the coldest in history across the state as most northern Minnesota communities reported below 0 F readings. For some observers the daytime temperature never rose out of the teens F that day. It was -5 degrees F as far south as Maple Plain.
A remarkable two-day heat wave occurred across Minnesota over April 5-6, 1991. Many observers reported daytime temperatures in the 80s F on consecutive days. Farmers were anxious to get field work done, but thunderstorms prevailed the rest of the month making soil conditions too wet.
An most unwelcome blizzard occurred April 5-6, 1997 across the Red River Valley when most communities were in the middle of a flood fight due to a rapidly rising Red River. Many areas reported 5 to 7 inches of snowfall with near zero visibility at times. A mixture of rain, sleet, and freezing rain fell elsewhere. Ice accumulated on power poles and lines knocking out power to many communities. Interstate 94 was closed for a time between Moorhead and Fergus Falls.
April 6-7, 2006 brought heavy thunderstorms to eastern sections of the state. The Twin Cities reported their heaviest ever April rainfall with 2.58 inches. Albert Lea reported 2.57 inches and Fairmont received 3.35 inches. Many basements were flooded in Martin County, and elsewhere a number of roads were closed due to high water.