Record Rainfall in Some Southern Counties

Record Rainfall in Some Southern Counties:

Last Friday I spoke about rapid planting progress across the state by Minnesota farmers, but May 10 through May 14 proved to be one of the wettest 5-day periods for May in history over many agricultural counties in southwestern and south-central Minnesota. Many climate observers in Brown, Watonwan, Redwood, Lyon, Nicollet, and Blue Earth Counties reported from 5 to 9 inches of rainfall over the 5-day period. Some of the long-term daily climate records for rainfall broken during this period included:
2.20 inches at St James and 1.87 inches at Canby on May 11th
3.35 inches at Tracy, 3.04 inches at Lamberton, 2.34 inches at Windom, 2.06 inches at Faribault, and 1.90 inches at Marshall on May 14th.

The heavy rains washed out many freshly planted fields, mostly corn but some were recently planted soybean fields. In addition, the heavy rains flushed out a great deal of starter fertilizer. Ditches, creeks, and streams rose dramatically as the heavy rains ran off the fields carrying large loads of eroded soil. The Cottonwood River rose to its’ 8th highest flood stage in history, 17.59 feet at New Ulm, the highest flow every measured there in the month of May. The Minnesota River at Morton also rose to moderate flood state for the second time this season. A more detailed analysis of these heavy rains can be found on the DNR State Climatology web site.

Agronomists suggest that thousands of acres will need to be replanted as a result of these very heavy rainfalls. But farmers will have to wait for fields to dry out. Those ponded fields where crops survive and continue to develop should be monitored for the appearance of plant diseases. University of Minnesota Extension featured a guide on their web site for farmers to assess potential damage to crops and replant decisions. Some readers will find this to be very valuable information.

In contrast to the southern third of the state, much of central and northern Minnesota shows less than normal rainfall for the month so far, with the largest deficiencies in the northeast, which bore the brunt of an excessively snowy winter season. The balance of May looks to be warmer and wetter than normal, so perhaps those areas lacking rainfall this month will catch up. In addition, replanted fields should germinate and develop fast in warm soil temperatures.

Weekly Weather Potpourri:

This week’s AGU-EOS Bulletin features some research that shows cloud formation are more frequent of cities across the USA. “Eighteen years of daily satellite images capturing the skies above 447 medium and large cities in the United States reveal that clouds form more often above urban areas than surrounding rural landscapes, especially at night and during the summer.” There was a stronger effect in summer than other seasons of the year.

Reuters reported that portions of northern Italy, caught in drought at this time last year, have received record-breaking rainfalls this week which caused at least 14 rivers to overflow their banks. Up to 37 towns were flooded and over 14,000 evacuated from the rising waters. In some areas rainfall amounts from 16 to 20 inches were reported over one and a half days.

The World Meteorological Organization (WMO) has warned that the next five years could be the hottest ever recorded on Earth and that the world might also temporarily hit a key threshold for global warming, driven by the combination of greenhouse gas emissions and an El Niño weather pattern. There is a 66% likelihood that the annual average near-surface global temperature between 2023 and 2027 will be more than 1.5°C above pre-industrial levels for at least one year. There is a 98% likelihood that at least one of the next five years, and the five-year period as a whole, will be the warmest on record.

MPR listener question:

We have had close to 10 inches of rainfall here in Comfrey (Brown County) so far this month. There are many ponded farm fields. We are wondering what is the state record for the most rainfall in the month of May?

Answer:

Two places have reported over 15 inches of rainfall in the month of May: Chatfield (Olmsted County) reported 15.02 inches of rainfall in May 1918; and St Francis (Anoka County) reported 15.79 inches of rainfall in May of 2012.

Twin Cities Almanac for May 19th:

The average MSP high temperature for this date is 70 degrees F (plus or minus 8 degrees F standard deviation), while the average low is 51 degrees F (plus or minus 8 degrees F standard deviation).

MSP Local Records for May 19th:

MSP records for this date: highest daily maximum temperature of 97 degrees F in 2009; lowest daily maximum temperature of 43 degrees F in 1971; lowest daily minimum temperature of 33 degrees F in 1961; highest daily minimum temperature of 66 degrees F in 1877; record precipitation of 2.25 inches in 2014. Record snowfall is 0.2 inches also in 1971.

Average dew point for May 19th is 45°F; the maximum dew point on this date is 66°F in 2004; and the minimum dew point on this date is 11 degrees F in 1926.

All-time state records for May 19th:

The state record high temperature for this date is 104 degrees F at Redwood Falls (Redwood County) in 1934. The state record low temperature for this date is 16 degrees F at Embarrass (St Louis County) in 2002. The state record precipitation for this date is 4.17 inches at St Francis (Anoka County) in 1996. Record snowfall is 8.6 inches at Grand Rapids (Itasca County) in 1971.

Words of the Week: Windrow and Winnow

Since many Minnesota farmers are currently waiting for the first opportunity to cut hay, these verbs are both equally applicable. To windrow a crop is to rake or cut it such that you leave ridges or rows lying along the field in a parallel fashion and oriented perpendicular to the prevailing wind. This facilitates drying before baling, stacking and storing are done. To winnow a crop is to use the wind to help separate the chaff from the grain, or the stems from the leaves. During the harvest season, the person doing this task was called a winnower.

Past Weather:

By far the hottest May 19th in state history was in 1934 when most of the state saw afternoon temperatures between 85°F and 95°F. Temperatures reached 100°F or greater in 10 southern Minnesota Counties. The overnight low at Tracy was 69°F.

Many citizens suffered from “weather shock” when measurable snowfall occurred on May 19, 1971. The snowfall was widespread across portions of central and northern Minnesota, with several climate stations reporting 4 to 8 inches. Grand Rapids had a record 8.6 inches.

A very frosty morning greeted early risers on May 19, 2002, when over two-thirds of the state reported 32° F or less. Some northern Minnesota communities saw lows in the teens with daily high temperatures of just 41°F.

Outlook:

Sunny, with better air quality and cooler temperatures on Saturday. Then, warming to above normal temperatures for Sunday through Tuesday. Chance of showers and thunderstorms returns on Wednesday and Thursday of next week.