May Starts Wet

May Starts Wet:

Most climate stations have reported numerous days with rain already this month. Well over 100 observers have reported over 2 inches so far this month, while observers in 8 counties (mainly SE MN) have reported over 3 inches. Rainfall totals in portions of Freeborn and Wabasha Counties already are close to the average values for the month of May (over 4 inches). Daily rainfalls of an inch or more fell in some places over the first dew days of the month, as well as on May 7th. Some long-term climate stations even reported daily record rainfalls, such as Hallock in Kittson County (still in the grip of Severe Drought) where they reported 1.02 inches of rain on May 3rd. Thanks to widespread significant rains in late April and early May, the area of Minnesota designated to be in Moderate to Extreme Drought has shrunk to just 11 percent, down over 30 percent from earlier in the spring..

Temperatures so far this month are moderate, averaging about 1°F to 2°F above normal around the state. So far, a number of climate stations have reported 70°F days, but just one reading of 80°F or higher this month, coming from Theilman in Wabasha County where they reported 83°F on May 8th. Conversely, there have been morning frosts reported from 8 northern Minnesota counties.

Winds continue to be stronger than normal, but not as extreme as April was. Many days have brought wind gusts over 30 mph, and on May 6th a number of locations reported wind gusts of 40 mph or greater, including:

48 mph at Morris
46 mph at Worthington
45 mph at Detroit Lakes
44 mph at Montevideo, Tracy, and Ortonville
43 mph at Brainerd

The forecasts continue to favor some windy conditions through mid-month with warmer than normal temperatures and more frequent chances for showers.

Weekly Weather Potpourri:

On the Weather Underground web site this week, Jonathan Erdman posted an interesting article about the strongest tornadoes that have occurred in the southern and southeastern states this spring. He points out that one of the EF-4 tornadoes was on the ground for 27 miles. He also mentions that Minnesota has reported 27 EF-4 or stronger tornadoes since 1950 compared with 66 in Oklahoma.

The BBC Weather Center reported on the devastating rains that flooded many portions of Rio uGrande Do Sul in Brazil last weekend. Some observers reported 12 inches to 19 inches of rainfall leading up to the flooding which hit the city of Porto Alegre and displaced thousands of residents, as well as closing the airport. Yet more rainfall was expected this week.

MPR listener question:

We have heard you and Cathy Wurzer talk about the strong winds this spring, with over 50 mph wind gusts. It made us wonder about what is the strongest non-tornadic, straight-line wind ever measured in Minnesota?

Answer:

The official data for wind come from historical anemometer measurements. For Minnesota, the fastest measured straight-line wind gust occurred early in the morning (3am) on September 1 of 2011 at Donaldson in Kittson County (northern Red River Valley) as a squall line associated with a massive thunderstorm complex moved across the countryside. The wind gust was 121 mph. There was widespread damage across the rural landscape to houses, barns, and grain bins, but no loss of life.

Twin Cities Almanac for May 10th:

The average MSP high temperature for this date is 67 degrees F (plus or minus 10 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 10th:

MSP records for this date: highest daily maximum temperature of 90 degrees F in 1987; lowest daily maximum temperature of 43 degrees F in 1902; lowest daily minimum temperature of 28 degrees F in 1907; highest daily minimum temperature of 68 degrees F in 1922, and record precipitation of 1.40 inches in 1986. There was a trace of snow in 1966.

Average dew point for May 10th is 40°F; the maximum dew point on this date is 70°F in 2011; and the minimum dew point on this date is 14 degrees F in 1981.

All-time state records for May 10th:

The state record high temperature for this date is 97 degrees F at Beardsley (Big Stone County) in 1928. The state record low temperature for this date is 11 degrees F at Pine River Dam (Crow Wing County) in 1905 and at Roseau (Roseau County) in 1981. The state record precipitation for this date is 4.27 inches at Wheaton (Traverse County) in 1920. The state snowfall record is 6.0 inches at Pigeon River (Cook County) in 1927.

Past Weather:

May 10 of 1902 saw a fast-moving snowstorm drop several inches of snow across the northern third of the state. In the Duluth area over 5 inches fell, while in Collegeville (Stearns County) they reported 3 inches. The snow was short-lived as the next day temperatures warmed into the upper 40s and low 50s F.

On May 10 of 1979 just as farmers were gearing up to plant corn and soybeans, a series of thunderstorms dropped 1.5 to 3.0 inches of rainfall across southwestern and central Minnesota agricultural counties. These storms brought a halt to field work and farmers had to wait nearly another week to resume planting.

A very cold morning prevailed across Minnesota on May 10 of 1981. Everywhere in the state reported frost, except for Winona where they had a temperature of 34°F. Many northern Minnesota communities reported temperatures in the teens It was as cold as 24°F at Lamberton and Pipestone.

May 10 of 1987 brought mid-summer heat to Minnesota. Climate observers in 45 counties reported afternoon high temperatures of 90°F or greater. Despite starting the morning at 42°F, Crookston warmed to 92°F by mid afternoon.

Outlook:

Generally sunny and warm on Saturday, with increasing clouds by evening in the north and a chance for showers. Increasing clouds statewide on Sunday, with a chance for showers by evening. Continued warmer than normal next week and breezy, but with chances for showers and thunderstorms, especially mid-week.