Moderating Temperatures, Fog, Haze, Freezing Rain, and Poor Air Quality
Temperatures moderated either side of normal this week, with some subzero mornings in northern Minnesota. But there were many daytime high temperatures that were warmer than normal. Much of the moderation in temperature was due to stagnant high pressure across the region, but also fog and haze. In addition, air quality was poor due to inversions keeping the mixing depth of the atmosphere closer to the surface, and therefore building up particulate levels. The poor air quality was the worst since 2005 according to the MPCA.
Small amouts of freezing drizzle and freezing rain were measured on Tuesday and Wednesday. Amounts were generally less than a tenth of an inch, but the build up of ice made conditions dangerous for pedestrians and motor vehicles, especially on Wednesday morning. Hundreds of accidents were reported. Climate studies of Minnesota show that across much of the state freezing rain or freezing drizzle occurs 2-4 times each year.
A notable feature of winter fog and winter rainfall is that it adds significantly to the water content of the snow cover already present on the landscape. Even in the absence of additional snow, the water content of 6 inches of snow cover can continue to increase with a high frequency of winter fog or winter rain and drizzle, as the moisture is absorbed in to the snow pack.
Weather Potpourri:
The AGU EOS Bulletin this week reported on some preliminary success from NOAA’s Modeling, Analysis, Predictions and Projections Program (MAPP) investigations into improving sub-seasonal to seasonal climate outlooks. There are promising results from examining the interactions of surface atmospheric features like the Madden-Julian Oscillation and El Nino Southern Oscillation with stratospheric features like the quasi-biennial oscillation which seem to produce better predictions of colda air outbreaks, heat waves, and tropical cyclones.
NOAA reported this week that the 2022 global average temperature was the 6th warmest since 1880. This factors in all land and ocean areas. It is worth noting that the warm signal prevailed globally despite a La Nina Episode that brought cooler than normal surface waters to the Equatorial Pacific Ocean and the fact that portion of the North American continent experienced a cooler than normal year. The 2022 warm signal was record-setting or near record-setting in many parts of Europe and Asia.
NOAA also reported this week that there were 18 weather-related disasters across the USA in 2022 that produced at least $1 billion dollars in damages. Among these disasters were both of the widespread severe hailstorms that occurred across our region in May, one on May 9th and one on May 19th. NOAA scientists also reported that drought over the western states produced some of the lowest lake and reservoir levels ever measured.
The Weather Underground reports that at least six separate rounds of rain and mountain snow have drenched the Golden State since the day after Christmas. There have been many reports of flooding and mudslides. In addition, the snowpack in the Sierra Nevada mountains has reached record levels for mid-January. Mammoth Mountain near Yosemite National Park reported 190 inches of snowfall between December 26 and January 11th, and 328 inches for the season so far. The series of intense storms is expected to continue through this weekend and may affect the NFL playoff game between the San Francisco Forty-Niners and the Seattle Seahawks this Saturday afternoon.
MPR listener question:
Which months in Minnesota show the highest frequency for freezing rain or freezing drizzle?
Answer:
Studies by the Midwest Climate Center show that the highest frequencies for freezing rain and freezing drizzle in Minnesota are in December and January, typically in the range of 1 or 2 days per year. The frequency in December is statistically slightly higher than in January. The study also shows that freezing rain or drizzle has occurred as early as October, and as late as April, but those are extremely rare cases.
Twin Cities Almanac for January 13th:
The average MSP high temperature for this date is 23 degrees F (plus or minus 14 degrees F standard deviation), while the average low is 9 degrees F (plus or minus 14 degrees F standard deviation).
MSP Local Records for January 13th:
MSP records for this date: highest daily maximum temperature of 48 degrees F in 1987; lowest daily maximum temperature of -14 degrees F in 1916; lowest daily minimum temperature of -30 degrees F in 1916; highest daily minimum temperature of 34 degrees F in 1960; record precipitation of 0.37 inches in 1881. Record snowfall is 6.0 inches in 1967.
Average dew point for January 13th is 9°F; the maximum dew point on this date is 37°F in 1947; and the minimum dew point on this date is -33 degrees F in 1982.
All-time state records for January 13th:
The state record high temperature for this date is 60 degrees F at Lamberton (Redwood County) in 1987. The state record low temperature for this date is -50 degrees F at Bagley (Clearwater County) in 1916. The state record precipitation for this date is 1.41 inches at Grand Marais (Cook County) in 2008. Record snowfall is 15.0 inches also at Grand Marais (Cook County) in 2008.
Past Weather:
A winter storm brought heavy snow to the north shore of Minnesota on January 13, 1874. Areas along Lake Superior from Duluth to Grand Marais reported 14 or more inches.
An Arctic Cold Wave gripped the state on January 13, 1916. All areas of thee state reported subzero temperatures, in many cases record-setting low temperatures. It was -30°F at St Peter and -50°F at Bagley. The high temperature at Campbell (Wilkin County) only reached -28°F.
The warmest January 13th was in 1987. In the absence of snow cover afternoon temperatures soared into the 40s and 60s F most places. Lamberton reached 60°F which is a statewide record high temperature for the date.
A series of storms brought snow to the state over January 11 to 14 in 1999. Many areas reported 5 to 12 inches, along with a good deal of blowing. This produced sizable drifts and took some extra time to clear highways in central Minnesota counties.
Outlook:
Warm and sunny through the weekend, with some melting of snow. There will be increasing chances for rain and perhaps some snow on Monday, then drier for the middle of next week. Temperatures will remain mostly warmer than normal. Another chance for snow later in the week.
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