Warm May-July Confirmed

Warm May-July Confirmed:

Earlier this month NOAA scientists confirmed that for the 48 contiguous states of the USA the three month period from May through July was the warmest in history, back to 1895, surpassing the previous record year for the 3-month period set way back in 1934.

Specifically for the same time period (May-July) how did Minnesota rank? On a statewide basis the May-July 2018 period was the 6th warmest back to 1895. The only warmer 3-month periods were in 1934, 1977, 1987, 1988, and 2012. However within our state boundaries there was some regional disparity. Here are the rankings by region of the state:

NW-4th warmest

NC-3rd warmest

NE-9th warmest

WC-6th warmest

C-10th warmest

EC-8th warmest

SW-7th warmest

SC-9th warmest

SE-5th warmest

This follows a warming trend which shows that since 2000 the May-July period has warmed by about 1.5 degrees F on a statewide basis. Speaking of warmth, through the first half of August Minnesota reports average temperatures that are 2-3 degrees F warmer than normal, mostly thanks to very warm nights. In addition rainfall has been well short of normal too, showing up in brown lawns and heavy watering of gardens.

State Fair Begins August 23rd:

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, August 24th at 11am with the TPT Almanac program at the MPR Booth (corner of Judson and Nelson); and again on Monday, September 3 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:

In the Western Pacific Ocean Tropical Storm Soulik is gaining strength and heading for southern Japan. It is expected to become a Typhoon over the weekend with winds exceeding 100 mph. It won’t be a threat to Japan until early next week.

According to the Weather Underground Aug. 1-13 was the hottest on record for that period of time in San Diego and the second hottest in Long Beach. The average high temperature for the first 13 days of August 2018 in San Diego is 86.5 degrees, a full 10 degrees above the average high of 76 degrees. Unusually warm sea surface temperatures off the coast of California are at least partially to blame for this. San Diego, often a popular destination for its mild climate has been experiencing a great deal of heat and humidity this summer.


A new study from the Technical University of Munich documents that trees harvested today in Europe for timber are of less density than trees which grew there 150 years ago. This is because the warmer temperatures brought by climate change have provoked more rapid tree growth, but the wood is lighter (not as dense) than it once was.


In the AGU weekly newsletter from EOS there is an interesting article about the increasing damages caused by hail across North America. The trend is significantly upward, and more research is needed on this weather feature.

MPR listener question:

In your book “Minnesota Weather Almanac” you talk about the state record 24-hr rainfall (15.10 inches) that occurred at Hokah, MN (Houston County) on August 19, 2007. But how widespread was that storm, or was it just isolated.

Answer:

It was far from isolated. The storm delivered over a foot of rain to portions of Houston, Winona, and Olmsted Counties, and over 10 inches to portions of Dodge, Wabasha, and Fillmore Counties. Widespread flooding and erosion occurred, as the town of Rushford (Fillmore County) was almost washed away.

Twin Cities Almanac for August 17th

The average MSP high temperature for this date is 81 degrees F (plus or minus 8 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 17th:


MSP weather records for this date include: highest daily maximum temperature of 100 degrees F in 1947; lowest daily maximum temperature of 63 degrees F in 1997; lowest daily minimum temperature of 42 F in 1962; highest daily minimum temperature of 73 F in 1972; and record precipitation of 1.62 inches in 1905.

Average dew point for August 17th is 59 degrees F, with a maximum of 75 degrees F in 1988 and a minimum of 39 degrees F in 2012.

All-time state records for August 17th:

The state record high temperature for this date is 105 degrees F at Campbell (Wilkin County) in 1988. The state record low temperature for this date is 29 degrees F at Tower (St Louis County) in 1981. State record precipitation for this date is 8.12 inches at Redwood Falls (Redwood County) in 2017.

Past Weather Features:

August 17, 1888 brought widespread frost to many parts of northern Minnesota. Fortunately most of the small grain crops (wheat and oats) had already reached maturity, but many garden crops (tomatoes, beans) were killed by the frost.

August 17, 1988 was the hottest in state history, with over 30 communities reporting an afternoon high of 100 degrees F or higher. The temperature at Glenwood, MN never dropped lower than 82 degrees F overnight.

Over August 16-17, 2017 multiple waves of thunderstorms brought very heavy rains to western parts of the state. Rainfall totals ranged from 3 to 7 inches across a 10 county area, with some 6-8 inch amounts concentrated along the Minnesota River Valley near Redwood Falls. It was unusual with these heavy rains that very little lightning was reported.

Outlook:

Warmer than normal temperatures into the weekend, with relatively poor air quality (due to smoke from Canada fires). Increasing cloudiness on Sunday with a chance for showers and thunderstorms, bringing significant rains to some parts of the state. Continued chance for rain on Monday, then cooler and drier for next Tuesday through Thursday.