August 19 and 20 brought coolest temperatures for the month

August 19 and 20 brought coolest temperatures for the month:

Wednesday and Thursday (August 19-20) brought the coolest temperatures of the month so far for many areas of the state. Many observers reported low temperatures in the 40s and 50s F. Extremely low dew points in northern counties helped overnight low temperatures drop even more. Eleven climate stations in Koochiching, Lake, and St Louis Counties reported low temperatures in the 30s F, with Tower reporting just 33°F on August 19th.

This week, scattered thunderstorms brought significant rainfall to parts of Minnesota, especially the north, where several observers reported rainfall totals ranging from 1 to 2 inches. Many other areas in the southern half of the state saw less than a half inch of rain during the week. Drought status in the state remained a big concern with about 30 percent of the landscape still in Moderate Drought, 44 percent in Severe Drought, and 1 percent (parts of Polk, Normand, and Clay Counties in the Red River Valley) now in Extreme Drought. BTW some observers in the Red River Valley area have reported only about half of normal precipitation for the year.

USDA crop condition reports this week for Minnesota showed that 66 percent of the corn crop remains in good to excellent condition ( a decline from the 71 percent reported last week) and 67 percent of the soybean crop remains in good to excellent condition (a decline from the 72 percent reported last week).

Weekly Weather Potpourri:

This week’s AGU-EOS Bulletin features an article by Kimberly Cartier about the U.S. Forest Service rescinding the 2001 Roadless Conservation Area Rule from 45 million acres of federal land. Most of the roadless areas are in western states, with more than 95% located in Alaska, Arizona, California, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming. Some suggest that this move will increase logging production and actually increase the threat of wildfires by making so much federal land more accessible by road.

The BBC Weather Center has posted an interesting article this week about the increased tourism in Scotland this summer that has been provoked by the frequent Heat Waves over the rest of the United Kingdom where many stations have reported their hottest summer. It seems that Scotland provides a respite from the heat much as the north shore area of Minnesota along Lake Superior which for generations has been a highly desired summertime destination.

Wikipedia provided a good synopsis of the destruction that Hurricane Lala caused to the big island of Hawaii last week, mostly on August 16th. Besides wind gusts up to 130 mph, Lala delivered between 25 and 50 inches of rainfall to parts of the island causing devastating flash flooding. Lala has since move into the central Pacific Ocean and returned to hurricane status.

MPR listener question:

Last week you answered a listener question about August temperature trends in Minnesota over the past 20 years, pointing out a strong warming trend. What about any August trends in rainfall? We are very dry this month in Redwood County with less than 1 inch of rainfall so far.

Answer:

Any trend in August rainfall for your area of the state is not evident over the past 20 years as observers there have reported about as many wetter than normal months of August as drier than normal months of August. One disconcerting short term trend is that 5 of the most recent 7 months of August have been drier than normal in your rea of the state, and it appears that this month will fall in that category as well.

Twin Cities Almanac for August 21st:

The average MSP high temperature for this date is 80 degrees F (plus or minus 7 degrees F standard deviation), while the average low is.62 degrees F (plus or minus 6 degrees F standard deviation).

MSP Local Records for August 21st:

MSP records for this date: highest daily maximum temperature of 98 degrees F in 1947; lowest daily maximum temperature of 59 degrees F in 1966; lowest daily minimum temperature of 44 degrees F in 2004; highest daily minimum temperature of 74 degrees F in 1968, and record precipitation of 3.64 inches in 1924. No snowfall has occurred on this date.

Average dew point for August 21st is 58°F; the maximum dew point on this date is 78°F in 1903 and the minimum dew point on this date is 33 degrees F in 2004.

All-time statewide records for August 21st:

The state record high temperature for this date is.103 degrees F at Moorhead (Clay County) in 1947 and at Milan (Chippewa County) in 1976. The state record low temperature for this date is 23 degrees F at Tower (St Louis County) in 2004. The statewide record for precipitation on this date is 6.30 inches at Montevideo (Chippewa County) in 2002. No snow has fallen on this date.

Past Weather:

An F-5 (winds over 260 mph) tornado struck Rochester about 5:30 pm on August 21, 1883, killing 37 people and injuring 200. This tornado also lifted a train off the tracks and tipped it over. Attending to the injured and rebuilding the city resulted in the formation of the Mayo Clinic.

August 21st in 1947 and 1976 brought plenty of heat to Minnesota with widespread readings of 90°F or higher. Many western communities reached 100°F in the afternoon.

Strong thunderstorms brought heavy rainfall to western and southwestern Minnesota over August 20-21, 2002. Portions of Lac Qui Parle, Yellow Medicine, Chippewa, Meeker, and Rock Counties received over 5 inches of rain. Dawson, Madison, Montevideo, Litchfield, Pipestone, and Amboy all reported daily record rainfall amounts.

August 21 in 2004 brought very cold temperatures to the state. Many observers reported a morning low in the 30s F. Observers in Hubbard, Itasca, Cass, and St Louis Counties reported frost with temperature readings in the 20s F. Ground frost was reported as far south as Mower County.

Outlook:

Cooler than normal, but sunny over the weekend. There will be increasing clouds later on Monday with a chance for showers and thunderstorms. Continued cooler than normal Monday and Tuesday with a chance for showers Tuesday into Wednesday. Temperatures will climb back closer to normal for the second half of next week.