Cool temperatures and a boost in rainfall:
For some parts of Minnesota the month of May has brought significant rainfall, the most of any month so far in 2015 for many climate stations. A list of those climate reporting stations clearly benefiting from the wetter trend of weather in May so far includes:
Itasca State Park 2.23", Moorhead 3.57", Park Rapids 2.63", Cass Lake 3.26", Thorhult 2.67", Pokegama Dam 2.58", Grand Portage 3.12", Montevideo 3.18", Browns Valley 2.91", Dawson 2.54", Madison 2.98", New York Mills 2.81", Wheaton 2.78", Elk River 2.77", Kimball 2.91", Melrose 2.45", Pipestone 3.22", Minnesota 2.76", Albert Lea 2.18", Austin 2.69", Grand Meadow 2.75", Chatfield 3.23", and Rochester 3.10". All of these values are above normal for the first half of May. As a result of this wet start to the month of May, the area of severe drought in the northwestern part of the state shrunk by about 6-7 percent in size, as reported by the Minnesota State Climatology Office.
Weekly Weather Potpourri:
NOAA released an El Nino Forecast Update this week which revealed a 90 percent chance that the current episode will continue throughout the northern hemisphere summer, and an 80 percent chance it will persist to the end of the year.
NOAA climate scientists feature this week a detailed article about the lack of snow cover in the Southern Sierra Nevada Range of California and its implications for diminished water supplies this year for that state. April snowpack was only 3% of normal in this mountain range, indicating a dire shortage of meltwater available for the coming growing season in California. You can read more about this in the news section of the climate.gov web site.
MPR Listener Question:
Twin Cities Almanac for May 15th:
The average MSP high temperature for this date is 68 degrees F (plus or minus 11 degrees F standard deviation), while the average low is 48 degrees F (plus or minus 8 degrees F standard deviation).
MSP Local Records for May 15th:
MSP weather records for this date include: highest daily maximum temperature of 94 degrees F in 2001; lowest daily maximum temperature of 39 degrees F in 1907: lowest daily minimum temperature is 31 degrees F in 1907 and 1980; highest daily minimum temperature of 70 F in 2001; record precipitation of 1.95 inches 1911; and record snowfall is 0.8 inches in 1907.
Average dew point for May 15th is 42 degrees F, with a maximum of 70 degrees F in 1998 and a minimum of 20 degrees F in 2011.
All-time state records for May 15th:
Past weather features:
May 14-15, 1907 brought significant snowfall to many parts of the state. Pine River, Leech Lake, Pokegama Dam, and Lake Winnie reported 6 inches of new snow, while Luverne in the southwest corner of the state reported 1.5 inches. The snow was short-lived as temperatures jumped into the 60s and 70s F on May 16th.
May 15-16, 1969 brought heavy thunderstorms to the northern and central counties of the state. Most regions received over 2 inches, while a number of places including Red Lake, Waskish, Hoyt Lakes, Artichoke Lake, and Benson reported over 3 inches with some flash flooding occurring in those communities.
Over 40 Minnesota climate stations reported frost on the morning of May 15, 2000. Frost was observed as far south as Preston (Fillmore County), and Tower reported a record setting morning low of 17 degrees F.
May 15-16, 2001 brought a dramatic mid-May warm spell to Minnesota with over 70 climate observers reporting afternoon high temperatures of 90 degrees F or higher. The day also brought high dew points, and the temperature never dropped below 73F at Winona, setting a warm overnight low temperature record as well.
May 14-15, 2013 brought a dramatic warm-up to Minnesota with over 100 communities reporting a temperature of 90 degrees F or higher. This was a bit of a shock because May of 2013 was overall a colder than normal month.