Change in weather pattern brings relief

Change in weather pattern brings relief:

Since last Sunday, many areas of Minnesota have welcomed below normal temperatures this week, bringing relief from what has been an exceptionally hot summer so far. Many of the temperatures around the state ranged from the upper 60s to low 70s F on July 19th, about 4 to 6 degrees F cooler. In northern areas this week overnight temperatures fell into the low to mid 40s F, with a low of 40 degrees F at Brimson (St Louis County).

Except for far western Minnesota (Browns Valley, Marshall, Pipestone) most of the state experienced a relatively dry week as well, bringing some relief from the heavy rains and flash flooding that occurred in many areas during the first half of July.

It is interesting that the pattern change in the weather noted for this week, cooler and drier, is also the expected pattern for the balance of the month across Minnesota according to many of the NOAA outlook models. Most of the daytime maximum temperatures for the rest of the month are expected to be in the 70s and 80s F.

New Seasonal Climate Outlook:

The new NOAA Climate Prediction Center seasonal outlooks were released on Thursday of this week. For the August-October period they show an equal probability for above or below normal temperature and precipitation. As a result, some of the near record-setting warm and wet growing season will likely be mitigated, and crops may do better than expected.

Weekly Weather Potpourri:

Speaking of seasonal outlooks NOAA announced earlier this month that it would like public comments on its proposal for improving research and deployment of its sub-seasonal and seasonal forecasting products released by the Climate Prediction Center. There is a detailed description of their current products and a narrative about proposed improvements.

Earlier the month the Yale Climate Connections featured a short video piece on how mild production declines in most dairy cows with increasing temperature. This is a factor that is showing up in some geographical areas where daytime temperatures have risen over the past few decades.

Forecast for the British Open Golf Tournament in Carnoustie, Scotland for this weekend does present two challenging days of weather. For Friday’s rounds there is rain in the forecast, and for Sunday’s round some gusty winds. So scores may not be so low by the time the winner is given the Claret Jug on Sunday.

MPR listener question:

Bicyclists tend to notice the wind, especially when it's in your face. My sense is that during this summer, the wind was out of the east an unusual large proportion of the time. Was that the case, or am I just growing old?

Answer:

Indeed, you point out a characteristic that I have observed as well. Predominant wind directions in the summer across Minnesota are SE, SW, and NW. But this summer we have not seen this pattern as much. In fact, across most of the state during June NE, E, or SE winds prevailed on11 to 16 days, while so far this month most climate stations have reported winds with an easterly component on 8 to 10 days. So your perception is correct. BTW I too hate biking into headwinds!

MSP Local Records for July 20th:

MSP weather records for this date include: highest daily maximum temperature of 102 degrees F in 1901; lowest daily maximum temperature of 62 degrees F in 1912; lowest daily minimum temperature of 51 F in 1950; highest daily minimum temperature of 80 F in 2011; and record precipitation of 2.75 inches in 1987.

Average dew point for July 20th is 62 degrees F, with a maximum of 80 degrees F in 2002 and a minimum of 42 degrees F in 1947.

All-time state records for July 20th:

The state record high temperature for this date is 110 degrees F at New London (Kandiyohi County) in 1901. The state record low temperature for this date is 27 degrees F at Kelliher (Beltrami County) in 2009. State record precipitation for this date is 10.75 inches at Beaulieu (Mahnomen County) in 1909; and no snowfall has been reported on this date.

July 20, 1901 was the middle of a 7 day Heat Wave with temperatures in the 90s F all the way into the Iron Range. Over 30 Minnesota communities reported afternoon highs of 100 degrees F or higher. The overnight low at St Cloud never fell below 80 F. The Heat Wave broke on July 26th as temperatures fell into the 70s and 80s F.

One of the heaviest thunderstorms to cross northern Minnesota occurred over July 19-20, 1909. It brought over 11 inches to Bagley and Beaulieu, and nearly 9 inches to Fosston. Walker reported nearly 6 inches, while Park Rapids had 4.33 inches. Some farm fields were underwater for days.

July 17-20, 2011, brought a Historic Heat Wave to Minnesota with Heat Index values ranging from 105 F to 130 F. These were driven by high dew points as the Twin Cities recorded a temperature of 96 degrees F on the 20th with a dew point of 76 degrees F, producing a Heat Index of 110 F. Moorhead, MN reported a Heat Index over 130 degrees F. The Heat Wave broke as temperatures fell off into the 80s on July 21st.

Outlook:

Partly cloudy skies over the weekend with pleasant temperatures a few degrees cooler than normal. Daytime highs will range from the upper 70s F to low 80s F in most places. Continued pleasant on Monday and Tuesday, then a chance for showers on Wednesday, and a return of sunnier weather to end next week.