Cool, Dry Pattern to Become Hot, Dry Pattern

Cool, Dry Pattern to Become Hot, Dry Pattern:

Through the first three weeks of July, Minnesota is still seeing a cooler than normal temperature trend with less than normal rainfall. Mean July temperature values are running from 1°F to 4°F cooler than normal, and for many climate stations the month so far is the coolest July since 2009. For some long-term climate stations July temperatures are tracking very cool:

Rochester reports its 10th coolest July so far with 12 nights of temperatures below 59°F
Redwood Falls also reports its 10th coolest July so far with 10 nights below 59°F

In the northern areas of the state:
Brainerd reports is 7th coolest July so far with 4 nights of temperatures in the 40s F
International falls reports its 7th coolest July so far with 7 nights below 49°F
Hibbing reports its 3rd coolest July so far with 14 nights below 49°F

Although most climate observers did report some rainfall this past week, the vast majority of the state still has seen less than half of normal rainfall for the month so far. Several climate stations reported some rainfall over July 13-14, but in manyareas it was accompanied by hail. In fact, according to the NOAA Storm Prediction Center, there were over 50 reports of large hail from those storms (mostly over western and central counties). The DNR State Climatology Office provided a more detailed summary of the hail last week.

Then just recently many climate observers reported over half an inch of rainfall on July 19 and some reported over 1 inch. Hibbing reported a record 2.31 inches. Again, with these storms there were many reports of large hail as well (over 30). This rainfall did not diminish the decline in soil moisture around the state. According to reports from the USDA Statistical Reporting Service earlier this week, 54 percent of the state is reporting soil moisture levels that are short or very short of normal. In addition crop condition has declined with 38 percent of the corn crop in poor to fair condition and 35 percent of the soybean crop in poor to fair condition.

According to the U.S. Drought Monitor the drought conditions continued to expand modestly across Minnesota over the past week. Over 70 percent of the state is in at least Moderate Drought, while the first pockets of Extreme Drought (only about 1.5 percent of the landscape) have shown up in eastern sections of the state.

BTW: According to NOAA climate models a massive dome of above normal temperatures is expected to spread from the southwest USA and encompass Minnesota by next Monday (July 24). This Heat Wave will dominate the weather for the last week of the month and will all but negate the cool July temperature anomalies described above. In fact next week may be the hottest week of the summer in Minnesota.

Weekly Weather Potpourri:

The BBC Weather Center reported on the European Heat Wave this week. Many parts of southern Europe have reported high temperatures of 104°F or greater this week, and parts of Italy have seen temperatures climb to 114°F. Rome reported a new record high temperature of 107°F on Tuesday this week. There has been a significant number of people seeking health care for heat related distress because many areas do not have air conditioning.

The Weather Underground reported this week that strong thunderstorms brought heavy rains to western Kentucky on Wednesday of this week and set a new all-time 24-hour rainfall record for the state as Graves County reported 11.28 inches of rain in just 13 hours. Other western Kentucky climate stations reported 6 to 9 inches of rainfall and there was widespread flash flooding.

The Joint Typhoon Warning Center was tracking Typhoon Doksuri in the Western Pacific Ocean this week. It was expected to strengthen, but stay out to sea east of the Philippines and head towards Taiwan later next week.

MPR listener question:

A number of trees were damaged by high wind gusts last night. Do you know how high the winds were gusting around the Twin Cities Metro Area?

Answer:

Preliminary data from the National Weather Service suggest that between 6pm and 7pm wind gusts ranged from 40 mph to 65 mph in the Metro Area, mostly coming from the west or northwest. Some areas further west and north from the Metro Area reported wind gusts over 70 mph (Stearns County)

Twin Cities Almanac for July 21st:

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 66 degrees F (plus or minus 6 degrees F standard deviation).

MSP Local Records for July 21st:

MSP records for this date: highest daily maximum temperature of 105 degrees F in 1934; lowest daily maximum temperature of 69 degrees F in 1947; lowest daily minimum temperature of 49 degrees F in 1947; highest daily minimum temperature of 79 degrees F in 1983; record precipitation of 1.36 inches in 1951. No snowfall on this date.

Average dew point for July 21st is 61°F; the maximum dew point on this date is 78°F in 1983; and the minimum dew point on this date is 40 degrees F in 1947.

All-time state records for July 21st:

The state record high temperature for this date is 113 degrees F at Milan (Chippewa County) in 1934. The state record low temperature for this date is 34 degrees F at Angus (Polk County) in 1947. The state record precipitation for this date is 7.83 inches at Chaska (Carver County) in 1987. No snowfall has been reported on this date.

Words of the Week: Deasil and Withershins

These terms are derived from ancient Gaelic words and though rare are still occasionally used in Wales and Scotland. Deasil, also deiseal or dessil (pronounced dezil or des-hal) means righthanded or clockwise, but climatologically it means sunwise - in the same direction as the sun. When facing south towards the equator the sun moves left to right or clockwise. The Celtics thought this was a natural procession and that moving in this direction was a charm or good omen. Before marriage ceremonies, participants would process around the church three times in a clockwise manner to bring good luck. Similarly, before a battle, people might process or walk the deasil carrying a lighted torch around the soldier(s) before their engagement in combat.

Even today, roundabouts in England run in a clockwise direction and some attribute this to the heritage of the deasil, or the charm of moving with the sun.

Withershins or widdershins is a term of similar age, which means counterclockwise or contrary to the sun's movement. To move widdershins from place to place is considered unlucky or disastrous. In old England, fishermen would not approach a favorite fishing spot by moving withershins (against the sun), but would circle around to approach in a clockwise manner.

Past Weather:

The hottest July 21st came in 1934 when over 30 Minnesota climate stations reported an afternoon high temperature of 100°F or greater. The overnight low temperature at Montevideo and Beardsley was 81°F.

July 21, 1947 brought a very cold morning to northern Minnesota. Temperatures were in the 30s F across the northern third of the state. Daytime high temperatures only reached the low to mid 60s F.

Strong thunderstorms brought 4 to 6 inch rainfalls to many parts of southeastern Minnesota on July 21, 1951. The Zumbro and Root Rivers flooded and some farm fields suffered from tremendous soil erosion.

Outlook:

Near normal temperatures with a chance for showers and thunderstorms on Saturday. Then breezy and sunny on Sunday. Significant warming trend will start on Monday and perhaps next week will be the warmest week of the summer with many days in the 90s F, especially in the southern half of the state. Slight chance for showers and thunderstorms by Friday.