Storminess Continues:July 5th (Tuesday) brought severe thunderstorms to many parts of the state, with strong winds and large hail. There were reports of short-lived tornadoes in Swift and Wabasha Counties. At least 8 counties reported large hail (1 diameter or greater), and near Artichoke Lake (Big Stone County) hail stones up to 3 in diameter were observed. In addition 17 counties reported strong winds (60-80 mph), and some associated damage.
Rainfall amounts from these storms were highly variable, with the largest amounts reported across a swath from west-central Minnesota through the Twin Cities Metro Area, and southeastern counties. Many observers recorded over 2 inches, and some reported new record daily amounts for July 5th, including: 4.51 at Morris, 2.14 at Artichoke Lake, and 1.77 at Moose Lake. Then on the July 6th Waseca reported a record 3.03 inches of rain,and on July 7th Park Rapids reported a new record daily rainfall of 2.11 inches. In many cases these record or near-record rainfalls were confined to narrow geographic areas by the size of the thunderstorm cells and their speed of movement.
Just before the onset of the storms dew points spiked into the 70s F pushing Heat Index values into the mid-90s F to low 100s F. More periodic high dew point spells are likely for the rest of the month.
Weekly Weather Potpourri:Super Typhoon Nepartak in the Western Pacific Ocean brought high winds, high seas, and heavy rains to Taiwan on Thursday and Friday of this week. It packed winds up to 155 mph, and delivered rainfalls of 6 inches or greater. Eastern China was bracing for heavy rainfall this weekend.
The United Kingdom Meteorological Office will provide rail forecasts for the Eurotunnel train service that connects the UK with France. These forecasts will include storm and flood risk to operations of the trains which average 57,000 passengers daily.
NOAA reports that Alaska just concluded its 9th warmest June in history. This follows a consistent pattern of warmer than normal months during 2016. The first 6 months of 2016 are warmer than any other year in Alaska history, averaging about 9F warmer than normal.
NOAA will host a webinar next week on Thursday, July 14, 2016 at 1:00pm ET to present a discussion of how they are using unmanned aircraft and watercraft to make critical measurements of the atmosphere and oceans. You can find more information and register here.
MPR listener question:I heard you talk about the famous July 1936 Heat Wave earlier this week on Tom Webers program. When was the peak of that Heat Wave? My grandpa said they had a number of cows die that month.
Answer:The peak of the Heat Wave was over July 6-15. There was no respite from the heat. In the Twin Cities alone there were over 175 deaths attributed to heat, and statewide it is estimated between 760-900 people lost their lives. The casualty rate among farm livestock was not formally estimated, but must have been in the hundreds at least.
Twin Cities Almanac for July 8th:The average MSP high temperature for this date is 84 degrees F (plus or minus 7 degrees F standard deviation), while the average low is 64 degrees F (plus or minus 6 degrees F standard deviation).
MSP Local Records for June 24th:
MSP weather records for this date include: highest daily maximum temperature of 101 degrees F in 1936 and again in 1974; lowest daily maximum temperature of 65 degrees F in 1895 and 1997; lowest daily minimum temperature is 51 degrees F in 1958; highest daily minimum temperature of 82 degrees F in 1936; record precipitation of 3.07 inches in 1925; and no snowfall has occurred on this date.
Average dew point for June 24th is 59 degrees F, with a maximum of 74 degrees F in 1983 and a minimum of 42 degrees F in 1953.
All-time state records for June 24th:The state record high temperature for this date is 110 degrees F at Fosston (Polk County) in 1936. The state record low temperature for this date is 25 degrees F at Kelliher (Beltrami County) in 2003. State record precipitation for this date is 6.03 inches at White Rock Dam (Traverse County) in 1950 ; and no measurable snowfall has occurred on this date.
Past Weather Features:July 8, 1936 was the hottest in state history, with over 35 communities reporting record-setting high temperatures above 100F. Little relief from the heat came until July 18th when daytime temperatures cooled into the 80s F.
July 8, 1997 brought cool, dry Canadian air to the state, a respite from the heat of earlier in the month. Many observers reported morning lows in the 30s and 40s F. It was 41F in Wabasha County (Theilman). Afternoon highs remained in the 60s and 70s F.
Repeated thunderstorms brought flash flooding to many parts of the state over July 7-10, 2002. Many areas of western and central Minnesota received 4-5 inches of rain. Rothsay (Wilkin County) reported 7.56 inches an there were many flooded county roads.