Year-to-Date Precipitation Deficits

Year-to-Date Precipitation Deficits:

After reporting the 14th wettest first four months of the year on a statewide basis (Jan-Apr) and coping with spring flooding on many Minnesota rivers, the climate pattern turned dry starting in May and has maintained that trend to mid-summer. MSP with 12.86 inches so far is about 3.80 inches below normal for the year, but total yearly precipitation deficits at some other climate stations are getting to be even more significant numbers: Some examples:

Mabel (Fillmore County) 12.43 inches, 8.75 inches below normal
Albert Lea (Freeborn (County) 12.22 inches, 7.71 inches below normal
Hallock (Kittson County) 4.37 inches, 7.61 inches below normal
Morris (Stevens County) 7.96 inches, 6.60 inches below normal
Spring Valley (Fillmore County) 13.73 inches, 6.40 inches below normal
Wabasha (Wabasha County) 12.94 inches, 6.35 inches below normal
Crookston (Polk County) 5.42 inches, 6.25 inches below normal
Pipestone (Pipestone County) 9.83 inches, 6.05 inches below normal
Kimball (Stearns County) 10.86 inches, 5.64 inches below normal
Bemidji (Beltrami County) 9.04 inches, 5.61 inches below normal

Precipitation deficiencies of this caliber require about two to three times normal rainfall over the balance of July and August to make it back to normal moisture levels for the summer season. This is highly unlikely to occur. The probabilities actually favor further drought expansion.

Comment on “Comfort Zones”

Comfort zones are used to describe the conditions of temperature, humidity and air movement under which most people function without mental or physical stress (in other words in relative comfort). The limiting conditions vary with the prevailing climate and seasons. For example, in the United States the comfort zone ranges from 63°F to 75°F at 70 percent relative humidity (with adequate ventilation), more typical of late spring-early summer, or mid-autumn indoor conditions in Minnesota. When indoor humidity is less, say 30 percent, the comfort zone rises to 67°F to 80°F. In England the relative comfort zone is centered on about 60°F (because they are generally cooler and wetter year-round), while in the tropics the comfort zone is centered on about 78°F (being very much warmer and less variable than our climate).

Next MCAP Adaptation in Action Webinar Presentation:

The next webinar presented by the Minnesota Climate Adaptation Partnership will be from noon to 1pm on July 18. The speaker is Peter Brickwedde, Assistant Commissioner of Government and External Affairs for the Minnesota Department of Commerce. He will describe the “Strengthen Minnesota Homes” program of the Department of Commerce, an effort to improve climate resiliency at the homeowner level. You can register for this webinar at the MCAP web site.

Weekly Weather Potpourri:

The Associated Press and other news agencies reported on the record flooding in Vermont and New Hampshire this week. Over July 8-11 slow moving thunderstorms dropped 6 to 8 inches of rainfall over portions of Vermont (8.44” at Worchester and 7.19” at Montpelier), as well as 5 to 6 inches of rain over parts of New Hampshire. Many roads were closed and families displaced by the flooding.

NOAA scientists reported this week on the extraordinary warm sea surface temperatures around Florida and the impact this may have on coral bleaching. Sea surface temperatures in some areas are exceeding 90°F and showing no signs of abating. NOAA data show that the high levels of ocean temperatures is unprecedented in the satellite and buoy observations era (since 1979) for this time of year.

The BBC Weather Center reported on a deadly Heat Wave moving across southern Europe this week. Temperatures are expected to surpass 40C (104F) in parts of Spain, France, Greece, Croatia and Turkey. In Italy, temperatures could reach as high as 48.8C (119.8F). A red alert warning has been issued for 10 cities, including Rome, Bologna and Florence. The Heat Wave may moderate a bit over the weekend, but temperatures are expected to remain well above normal into next week.

MPR listener question:

So far in July we have had five nights when the temperatures dipped below 60°F overnight, almost ideal for sleeping (we have no AC). It seems that this is unusual for the Twin Cities, is our perception correct?

Answer:

Yes, you are right. Since the year 2000, we have seen only four Julys bring more than 5 nights with minimum temperatures in the 50s F (2004, 2005, 2009, and 2014). According to the forecast models we will have at least a couple of more nights with temperatures in the 50s F over the rest of this month. BTW in July of 1891 the overnight temperature dipped into the 50s F on 24 nights!

Twin Cities Almanac for July 14th:

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 14th:

MSP records for this date: highest daily maximum temperature of 108 degrees F in 1936; lowest daily maximum temperature of 65 degrees F in 2014; lowest daily minimum temperature of 50 degrees F in 1930; highest daily minimum temperature of 79 degrees F in 1980; record precipitation of 3.17 inches in 1915. No snowfall on this date.

Average dew point for July 14th is 60°F; the maximum dew point on this date is 74°F in 1981; and the minimum dew point on this date is 33 degrees F in 1961.

All-time state records for July 14th:

The state record high temperature for this date is 111 degrees F at New Ulm (Brown County) in 1936. The state record low temperature for this date is 30 degrees F at Alborn (St Louis County) in 1930. The state record precipitation for this date is 5.49 inches at Carlos 3SW (Douglas County) in 2011. No snowfall has been reported on this date.

Past Weather:

On July 14, 1936 over 30 Minnesota communities were reporting afternoon temperatures of 100 degrees F or greater, arguably the hottest day in state history. Minnesota was in the grip of the longest and most intense Heat Wave of record, lasting from July 4th to July 18th. During that interval, Pipestone reported 15 days with temperatures of 100 degrees F or higher, while Moorhead reported a state record tying high of 114 degrees F on the 6th.

Strong thunderstorms delivered heavy rainfall to portions of western and northwestern Minnesota over July 14-15, 1937. Many areas reported 3 to 5 inches of rain, while Baudette reported 6.55 inches. The Roseau River rose to flood levels briefly and many farm fields were flooded.

Campers woke up to a very cold July morning in northern Minnesota on July 14, 1987. Morning frosts were reported at Tower, Brimson, and Cook, and morning temperatures were in the 30s F across most of northern Minnesota. The daytime high at Fergus Falls only reached 57°F.

Outlook:

Cooler than normal temperatures over the weekend with chances for showers and thunderstorms, especially in northern counties. Continued cooler than normal temperatures for portions of next week with chances for showers and thunderstorms from late Tuesday through Thursday. Gradual warming towards the end of next week with temperatures returning to warmer than normal levels.