January Climate Summary: Records Galore

January Climate Summary: Records Galore

What a wild ride in temperature patterns during January. The month will go into the Minnesota record books with most climate stations reporting a mean monthly temperature that is 1 to 4 degrees F colder than normal. What a deceptive statistic that is. It was intimidating to see the unanticipated extremes swings in temperature occur. For the first half of the month (January 1-15) mean temperatures around the state were some of the warmest in history, averaging 11 to 13 degrees F warmer than normal. Embedded in the warm pattern there were over 70 daily records broken or tied in the Minnesota climate observing network with respect to daytime maximum or warm nighttime minimum temperatures.

Then the other shoe dropped and during the second half of the month, when temperatures averaged 12 to 16 degrees F colder than normal. Over 70 daily record minimum temperature values were broken or tied within the climate observing network, and over 70 daily record cold maximum temperature values were tied or broken as well. Further, during the second half of January Minnesota reported the nation’s coldest temperature 11 times (including Alaska). Readings of -56 degrees F at Cotton (St Louis County) on January 27th and January 31st set new all-time statewide low temperature marks for those dates. Over 40 climate stations reported at least one minimum temperature of -40 degrees F or colder, and during the coldest day of the month, January 30th, over 20 communities reported Wind Chill readings of -60 degrees F or colder. The coldest Wind Chill reading came from Hibbing with -65 degrees F.

Extreme temperatures for the month ranged from 49 degrees F at Winona Dam on the 5th to -56 degrees F at Cotton on the 27th and 31st. It is not often that Minnesota reported a 105 degrees F temperature range during one month! Among the scores of record cold temperatures reported some stand out because they occurred for stations with exceptionally long histories. Among these I found six new record cold maximum temperatures reported on the 30th:

-14 degrees F at Duluth
-16 degrees F at Brainerd
-17 degrees F at Hibbing and St Cloud
-19 degrees F at International Falls and Rochester

More detail on the Arctic Cold Outbreak this week can be found at the Minnesota State Climatology Office web site.

One other notable record was that MSP tied the lowest ever dew point reading with -35 degrees F on January 30th. That indeed is very dry air.

January was drier than normal in most places around the state. Caledonia was the wettest spot with 2.76 inches of precipitation (some rain and melted snow), while just northwest of Grand Marais was the snowiest spot in the state with nearly 24 inches.

It was a windy month with 8-10 days producing some winds over 30 mph, and many areas reported wind gusts over 40 mph. On January 8th some observers reported wind gusts over 50 mph.

The exceptional cold of the second half of the month drove frost depths in the ground deeper, now between 2 and 3 feet in places.

Weekly Weather Potpourri:

The BBC Weather Centre reported this week that a serious snow storm was making travel difficult across southwestern England (Devon and Cornwall) as well as Wales on Thursday of this week. Heavy snow was causing very long traffic delays and many schools were closing down for Friday in anticipation of continued cold and snow.

The protracted January Heat Wave continued in Australia this week with temperatures topping 100 degrees F in many places. In Sydney which saw daytime highs up to 104 degrees F, widespread power outages occurred on Thursday of this week. Power usage has been very high for air conditioning.

This week’s AGU-EOS newsletter contains an interesting article about the link between air pollution and the rate of stroke mortality. Regions of the USA with a high level of fine-grained air pollutants have shorter life expectancies and an increased rate of death from a stroke, according to new research.

MPR listener question:

Why are the variations in low temperature for the year greater than the variations in high temperature for the year when we look at the historical record?

Answer:

The simple answer is that the year’s lowest temperature occurs in the winter, the season of long nights and short days. In winter, the low temperature is heavily dictated by the presence or absence of snow, as well as how widespread the snow cover is around the state and region. The presence of snow amplifies the cold readings, producing winters with very low temperatures. Winters with little or no snow cover produce much more modest low temperatures, often only in the single digits below zero.

Conversely, the year’s maximum temperature, usually in summer, is when we have long days and short nights. During the days the atmosphere tends to be well mixed (more wind) and heats up over broad areas, less influenced by the nature of the landscape.

MPR listener question:

Are these periods of extremely cold weather due to polar vortex going to increase in frequency due to climate change? Might they also increase in duration?

Answer:

We don’t know for sure. The upper air pattern, including the position and orientation of the polar jet stream is influenced by a variety of atmospheric and Earth surface features, including the oceans and land surfaces, which are warming. Research already suggests that as climate continues to change, especially in the mid to high latitudes there will be an effect on the polar jet stream that may influence its’ position and orientation. But all of those details we don’t know yet.

In Minnesota history there have been very long and amplified episodes of Arctic Air due to the position of the polar vortex including 1835, 1843, 1857, 1875, 1888, 1899, 1904, 1912, 1916, 1917, 1924, 1933, 1936, 1966, 1972, 1982, 1983, 1985, 1996, and this year.

Twin Cities Almanac for February 1st:

The average MSP high temperature for this date is 25 degrees F (plus or minus 14 degrees F standard deviation), while the average low is 9 degrees F (plus or minus 15 degrees F standard deviation).

MSP Local Records for February 1st:

MSP records for this date include: highest daily maximum temperature of 54 degrees F in 1931; lowest daily maximum temperature of -12 degree F in 1996; lowest daily minimum temperature of -28 degrees F in 1951; highest daily minimum temperature of 33 degrees F in 1892; record precipitation of 0.89 inches in 1922. Record snowfall is 6.7 inches also in 2004.

Average dew point for February 1st is 3°F; the maximum dew point on this date is 35°F in 1931; and the minimum dew point on this date is -35°F in 1951.

All-time state records for February 1st:

The state record high temperature for this date is 60 degrees F at St Peter (Nicollet County) in 1931. The state record low temperature for this date is -58 degrees F at Tower (St Louis County) in 1996. The state record precipitation for this date is 1.85 inches at Fairmont (Martin County) in 1915. Record snowfall for this date is 18.5 inches also at Fairmont (Martin County) in 1915.

Past Weather Features:

A large and complex winter storm brought rain, freezing rain, sleet, and snow to many parts of the state over February 1-3, 1922. In western counties 10-14 inches of snow fell, while in the southeastern counties freezing rain prevailed.

The warmest February 1st in state history was in 1931 when over 30 climate stations reported an afternoon high temperature that ranged from 50 to 60 degrees F. Bright sun, southerly winds, and little snow cover contributed to the warm temperatures.

There have been two severe Arctic Outbreaks on February 1st in Minnesota history. One occurred in 1899, lasting from January 29 to February 13th, and bringing consecutive days of subzero overnight temperatures. It was -38 degrees F at Detroit Lakes on February 1st. The second Arctic Outbreak was over January 29 to February 5th of 1996, again with consecutive subzero nights. On February 1st over 10 Minnesota climate stations reported a minimum of -50 degrees F or colder.

Outlook:

A sharp warming trend will continue throughout the weekend, but with increasing cloudiness and a chance for drizzle, freezing drizzle, or light rain by late Saturday and Sunday. Temperatures will be above normal throughout the weekend. Rain and snow are in the mix for Monday, then snow for Tuesday and Wednesday in places. Cooler by the end of next week, as temperatures fall below normal, but not to record cold values.