Climate Signatures in 2018

Climate Signatures in 2018:

A certain high degree of variability is evident in the Minnesota climate statistics so far this year. Some examples:

-For the January through August period, both average statewide temperature and precipitation are pretty close to the 30-yr averages.

-But for the May-August period this year ranks as the 2nd warmest historically, trailing only the growing season of 1988. And this is mostly thanks to very warm nights.

-Though the statewide May-August rainfall has been near normal, there is great disparity across the state. The southwestern counties have had the 2nd wettest May-August period in history with an average of nearly 23 inches (2nd only to 1993), while the south-central counties have reported the 8th wettest May-August period with an average of nearly 22 inches. Conversely, northwestern counties, which are in a moderate drought, have reported an average of less than 10 inches for the May-August period, ranking as the 12th driest in history back to 1895.

-On a national scale the year 2018 is tracking as the 11th warmest in history back to 1895, but the growing season (May-Aug) is tracking as the warmest in history, slightly ahead of 1934 and 1936 for the 48 contiguous states.

Fortunately some very significant rainfalls occurred across many parts of the state over Friday, August 24, with several climate stations reporting from 1 to 2 inches. This rain was welcome for many areas which had not seen rain since August 3rd.

State Fair Here:

The Great Minnesota Get-Together (our State Fair) begins on August 23 with expectations for dry weather and near normal temperatures. I will be there on Friday (today), August 24th at 11am with the TPT Almanac program at the MPR Booth (corner of Judson and Nelson); and again on Friday, August 31 at 10am with Cathy Wurzer at Carousel Park to do the 23rd Annual Minnesota Weather Quiz broadcast. As usual we will have prizes for audience participants. Hope to see you there.

Weekly Weather Potpourri:

Hurricane Lane, at one time a category 5 storm was bringing heavy rains, strong winds, and high surf to the Hawaiian islands this week. Many areas had received over a foot of rain by midday Thursday (August 23), and some areas were expected to receive over 20 inches of rain. It is the strongest storm to hit Hawaii since Iniki in September of 1992. Friday’s reports suggestion that some parts of the Big Island had received from 20 to 30 inches with widespread flash flooding and downed powerlines.

NOAA reported earlier this week that while much of the country has seen near normal or less than normal rainfall over the May-July period, some of the mid-Atlantic states like Maryland, Pennsylvania, and Virginia have seen enormous amounts of rainfall, in some cases 200 to 300 percent of normal.

For history readers, there is a new paper released by Imperial College in London this week that suggests electrically charged volcanic ash short-circuited Earth's atmosphere in 1815, causing global poor weather and Napoleon's defeat. An interesting review of this work can be found at the Science Daily web site.

MPR listener question:

I have heard you speak many times over the years and make reference to the weather observer networks in Minnesota. I believe you said there are currently over 400 climate that report daily temperature and precipitation to the National Weather Service. But how many were there 100 years ago, or when the state first began weather observations?

Answer:

I think there are currently over 550 daily climate stations in Minnesota. One hundred years ago there were about 100 such stations, but in the 1890s the first decade of the climate station network operated by the Weather Bureau (what the National Weather Service was called back then), there were only about 70 climate stations. Today there are many other weather observing networks operating in the state along with the National Weather Service. One of those is through the Future Farmers of America, represented at the Minnesota State Fair each year.

Twin Cities Almanac for August 24th

The average MSP high temperature for this date is 79 degrees F (plus or minus 8 degrees F standard deviation), while the average low is 61 degrees F (plus or minus 6 degrees F standard deviation).

MSP Local Records for August 24th:

MSP weather records for this date include: highest daily maximum temperature of 98 degrees F in 1948; lowest daily maximum temperature of 56 degrees F in 1915; lowest daily minimum temperature of 43 F in 1887; highest daily minimum temperature of 76 F in 1948; and record precipitation of 4.08 inches in 1893.

Average dew point for August 24th is 58 degrees F, with a maximum of 75 degrees F in 2011 and a minimum of 27 degrees F in 1934.

All-time state records for August 24th:

The state record high temperature for this date is 107 degrees F at Pipestone (Pipestone County) and Worthington (Nobles County) in 1936. The state record low temperature for this date is 22 degrees F at Tower (St Louis County) in 1977. State record precipitation for this date is 5.96 inches at Windom (Cottonwood County) in 1940.

Past Weather Features:

By far the hottest August 24th in state history occurred in 1936 when over 30 communities reported an afternoon high temperature of 90 degrees F or higher. Seven western counties reached 100 degrees F or higher that day.

One of the wettest historical periods in August occurred in 1940 when it rained for 8 consecutive days in many parts of the state over the 23rd to the 30th. Over portions of southern Minnesota 3-7 inches of rain fell, flooding both roads and farm fields near the end of the growing season. Some farmers had to wait until late September to get back into their fields.

Outlook:

Warming trend over the weekend and through Monday, with temperatures a few degrees above average. There will be a chance for widely scattered showers and thunderstorms each evening. Cooler and drier for next Tuesday and Wednesday, then increasing cloudiness and a chance for showers again Thursday.