Continued Record Dry Spell

Continued Record Dry Spell:

Our record dry spell continues on a statewide basis. The average total precipitation across the state since August 31st is just 0.55 inches, about 3.25 inches below normal. So far this month only a few showers have occurred over northern Minnesota on October 5-6. Observers in Carlton, St Louis, Koochiching, Cook, Lake, Beltrami, Lake of the Woods, Roseau, and Cass Counties reported some measurable amounts of rainfall, but mainly less than a tenth of an inch.

The impact of the dry spell has been exacerbated by temperatures that have averaged 5°Fto 8°F above normal. This combination has produced unusually high evapotranspiration (loss of water vapor from the landscape and area lakes), so consequently Minnesota is showing signs of the dryness in terms of declining lake levels, stream flow, and vegetative stress.

This week’s U.S. Drought Monitor shows that 97 percent of the state is abnormally dry, 69 percent is in at least Moderate Drought, and 20 percent (mostly northeastern counties) are in Severe Drought. All of this has developed over the last six weeks.

After a cool-down period for this Saturday through Tuesday, the NOAA Climate Prediction Center models continue to favor warmer and drier than normal conditions across Minnesota through the end of October, with perhaps a slightly higher chance for showers the last week of the month.

Weekly Weather Potpourri:

The Weather Underground web site reported extensively on the impact of Hurricane Milton this week which made landfall along the central west coast of Florida near Siesta Key. The storm was a category 3 (winds 111-129 mph) at the time of landfall. Preliminary rainfall reports from the climate station network in Florida show that Milton dropped 8 to 18 inches of rain in many areas of the state, producing widespread flash floods. Damages, injuries, and deaths were still being tallied from Milton, but one of the features of this landfall hurricane was that it spawned an unusual number of damaging tornadoes to compound the overall trauma of the storm.

A recent research paper published by the EGU-The Cryosphere documents that in elevated landscapes of the tropics (central Andes Mountains), the snow line is rising and there is measured accelerated loss of ice from glaciers due to episodes of El Nino in the equatorial Pacific. This is pace of ice loss is expected to continue.

The AGU-EOS features a detailed poster suitable for most school classrooms about climate change, symptoms and impacts. It also features links to various adaptation and mitigation strategies and responses. You can find it on their web site.

MPR listener question:

Does our Minnesota weather pattern so far this autumn constitute a flash drought. We know meteorologists have used this term in recent years, but wondered if you could clarify.

Answer:

Yes, Minnesota is experiencing flash drought this autumn, and especially over the most recent six weeks. According to the National Oceanic and Atmospheric Administration a flash drought is produced by rapid intensification of dryness due to changes in precipitation, temperature, wind, or solar radiation, often in combination. These changes in the weather amplify evapotranspiration and lower soil moisture, putting stress on vegetation and water. This rapid onset of drought can cause extensive damage to agriculture, economies, and ecosystems when it is not anticipated or discovered early. In the Minnesota climate, flash droughts can have more negative impacts in spring and summer, than in the fall and winter.

Twin Cities Almanac for October 11th:

The average MSP high temperature for this date is 61 degrees F (plus or minus 11 degrees F standard deviation), while the average low is 43 degrees F (plus or minus 8 degrees F standard deviation).

MSP Local Records for October 11th:

MSP records for this date: highest daily maximum temperature of 85 degrees F in 2015; lowest daily maximum temperature of 39 degrees F in 1959; lowest daily minimum temperature of 22 degrees F in 1876; highest daily minimum temperature of 63 degrees F in 1997, and record precipitation of 1.36 inches in 1881. Record snowfall is 0.5 inches in 1977.

Average dew point for October 11th is 41°F; the maximum dew point on this date is 67°F in 1962 and the minimum dew point on this date is 11 degrees F in 2012.

All-time state records for October 11th:

The state record high temperature for this date is 95 degrees F at Moorhead (Clay County) in 2015. The state record low temperature for this date is 10 degrees F at Ada (Norman County) in 1935. The state record precipitation for this date is 3.61 inches at Crookston (Polk County) in 2021. The statewide snowfall record for this date is 12.0 inches at Mount Iron (St Louis County) in 1909.

Past Weather:

A very early season winter storm brought snow to many parts of Minnesota over October 11-12 of 1909. Many climate observers reported 1 to 3 inches of snow, while up north on the Iron Range, Stephen’s Mine reported 7 inches and Mount Iron reported 12 inches, records for so early in the autumn season.

Over 75 percent of the state landscape reported frost on the morning of October 11 in 1935. Many northern areas reported morning low temperatures in the teens, while Ada in the Red River Valley was just 10°F. Combined with the record-setting cold temperatures over a dozen climate stations also reported snow.

October 11 of 2015 was arguably the warmest in state history with most climate stations reporting afternoon temperatures of 80°F or greater. Twenty climate stations reported 90°F or greater. After a morning low of 45°F Bemidji residents saw the afternoon high temperature climb to 92°F.

Outlook:

Generally sunny, but much cooler over the weekend, with temperatures averaging well below normal. There is a chance for showers in northern areas of the state Saturday into early Sunday. There will be widespread chances for frost on Sunday, Monday, and Tuesday mornings. By Wednesday a warming trend will begin and bring warmer than normal temperatures back to the state. By next weekend there will be a better chance for showers statewide.