August Starts Wet for Some

August Starts Wet for Some:

The first five days of the month brought some heavy rains to many parts of the state as many climate stations reported over 1.5 inches. There were strong thunderstorms over portions of central Minnesota over August 3-4 with a weak tornado reported on the ground for 11 miles across portions of Kandiyohi and Meeker Counties (see State Climatology Office Summary).

Some portions of Stearns and Benton Counties reported over 3 inches of rain. Lake Wilson, Moose Lake, Brainerd, and Gull Lake all reported new daily rainfall records on the 4th with amounts ranging from 1.5 to 2.5 inches. Lake Wilson (Murray County) with 30.17 inches, Redwood Falls (Redwood County) with 30.26 inches, and St James (Watonwan County) with 31.63 inches since January 1 are reported some of their wettest values in history for the first 8 months of the year, surpassed only by the wet years of 1979 and 1993.

Conversely portions of Roseau and Lake of the Woods Counties remain in moderate drought entering August. Some climate stations in these areas have received less than 8 inches of rainfall since May 1st.

Guidance from the NOAA Climate Prediction Center suggests that the rest of the month may be warm and dry across Minnesota.

Weekly Weather Potpourri:

NOAA released an interesting article about near record and record warm nights in California during July this summer (following a trend of recent decades) which contributed to the fire danger and the wildfires in the northern part of the state.

According to the Joint Typhoon Warning Center Tropical Storm Yagi in the far Western Pacific Ocean will bring some heavy rains to portions of South Korea early next week. Fortunately this storm is modest in size and intensity.

Speaking of Tropical Storms, this week NOAA scientists released an updated outlook for the Atlantic Hurricane Season which called for below normal storm activity during the balance of the 2018 Hurricane Season. So far there have been only four named storms, two of which were hurricanes.

MPR listener question:

Earlier this week I drove along the St Croix river valley between Wisconsin and Minnesota in very dense fo. It made me wonder if fog is unusual during the month of August. When does fog tend to be most frequent and where is the highest frequency of fog in Minnesota?

Answer:

Fog in August is somewhat unusual, typically occurring on only one or two days. In fact fog is least frequent in the summer months and most frequent during November through March. Around the state the average number of days per year with fog ranges from 8-12 days in southern locations to 25-35 days in some northeastern communities. The highest frequency of fog on a yearly basis can be found along the north shore of Lake Superior where fog may occur on 50 or more days per year.

Twin Cities Almanac for August 10th:

The average MSP high temperature for this date is 82 degrees F (plus or minus 8 degrees F standard deviation), while the average low is 63 degrees F (plus or minus 6 degrees F standard deviation).

MSP Local Records for August 10th:

MSP records for this date include: highest daily maximum temperature of 101 degrees F in 1947; lowest daily maximum temperature of 59 degree F in 2004; lowest daily minimum temperature of 46 degrees F in 1904; highest daily minimum temperature of 80 degrees F in 1944; record precipitation of 2.47 inches in 2010. No snowfall has occurred on this date.

Average dew point for August 10th is 58°F; the maximum dew point on this date is 75°F in 1938; and the minimum dew point on this date is 37°F in 1982.

All-time state records for August 10th:

The all-time state high temperature for today's date is 110 degrees F at Beardsley (Big Stone County) in 1947; the all-time state low for today's date is 27 degrees F at Duluth (St Louis County) in 1923. The all-time state record precipitation for this date is 7.72 inches at Mankato (Blue Earth County) in 1948. No snowfall has occurred on this date.

Past Weather Features:

During the first twelve days of August, 1821 afternoon temperatures reached 90 degrees F or higher on ten days, topping out at 93 F. Overnight lows were warm too as some nights did not cool out of the 70s F. The soldiers at Ft Snelling, relatively new to the Minnesota Territory probably wondered how such a frozen landscape in winter could get so warm in the summer season.

On the morning of August 10, 1967 many vacationing Minnesota citizens in northern counties woke up to frosty temperatures, especially across portions of St Louis County, Koochiching County, and Lake of the Woods County. Some climate stations reported lows in the upper 20s F.

Powerful thunderstorms brought strong winds, hail, and heavy rain to portions of southern and central Minnesota on August 10, 1948. Many areas received 4 to 7 inches of rain causing flash flooding on county roads and state highways. Portions or Rice, Blue Earth, and Sibley Counties received between 7 and 8 inches, daily rainfall records that still stand today.

Outlook:

Lingering smoky skies in western Minnesota (due to wildfires in Canada) early on Saturday will give way to clear sky conditions later in the day. Sunny, but warm weekend coming up with daytime highs in the middle 80s to lower 90s F. Dry. Increasing cloudiness by Tuesday of next week with a chance for showers and thunderstorms, then we will be visited by cooler weather with below normal temperatures for a few days.