Minnesota Weather Review for 2007
2007 began with a Snow Drought that persisted until the end of February. The lack of snowfall was most acute in central and northern Minnesota. The landscape was so bare in fact that grass and cattail fires occurred in mid-January. Season snowfall totals through mid-February were two to three feet short of normal from the Twin Cities northward. Some exceptions were a few places in southeast Minnesota such as Rochester, which benefited from an early November 2006 snowstorm.
"Old Man" winter did stage somewhat of a comeback with a double whammy of snowstorms for the final week of February into March. The first snowstorm was a whopper that dumped a foot of snow across parts of central and southern Minnesota. La Crosse, Wisconsin reported its largest snowstorm total ever with 21 inches of snow. The second storm was also formidable. This one began as a classic "Texas Panhandle Hooker" type of storm that dumped a foot or more of snow across central and southern Minnesota and along the north shore of Lake Superior. The University of Minnesota in the Twin Cities closed during the afternoon on March 1st marking the first time since January 18, 1994 that the University closed due to a weather event. Another memorable aspect of this storm was the blizzard conditions in the Duluth area causing 10 to 15 foot high snowdrifts on Minnesota Point along the south shore of Lake Superior. There were also blizzard warnings in the Red River Valley and in southern Minnesota.
Seasonal snow totals for 2006-07 were generally below average, with the exception of Rochester and parts of southeast Minnesota, which happened to be at the epicenter of the largest snowstorms of the year. Duluth finished near average while International Falls, St. Cloud and the Twin Cities were all below average. The total snowfall for the season at the Twin Cities International Airport was 35.5 inches. The winter season came to a close at the end of March when a soggy system brought heavy rains over much of the state. There was some record warmth too with highs in the low 80ís across southern Minnesota. The Twin Cities had a daily record high of 81, with a daily record high of 72 in Duluth.
The first week of April was dominated by an artic air mass that plunged temperatures to the single digits in the north. One of the coldest spots was a low of zero at Itasca on April 5th. Some snow accompanied the cold as well. Temperatures rebounded by the middle of the month and highs in the 60ís and 70ís were common.
Mirroring 2006, spring and summer of 2007 was marked by a significant drought. Some of the precipitation deficits were carried over from 2006, especially in the north. The May 15 US Drought Monitor depicted "extreme drought" over north central and northeastern Minnesota. Smoke from a large fire in the Boundary Waters reduced visibility in eastern Minnesota and western Wisconsin on May 11. The drought intensified in July and August and had reached its zenith by the second week of August. A good chunk of Minnesota was under the US Drought Monitorís "Severe Drought" category except the northwest and southeast corners.
A singular event from August 18-20 was on par with the drought as the biggest weather story of the year for Minnesota. A series of thunderstorms moving along a stalled frontal boundary dropped extremely heavy rain on much of southern Minnesota. The most intense precipitation rates occurred during the afternoon and evening hours of Saturday, August 18, and the early morning hours of Sunday, August 19. The heaviest rainfall reports came from Winona, Fillmore, and Houston counties, where 36-hour totals exceeded 14 inches. The largest multi-day rainfall total reported was 20.85 inches observed near the town of Houston in northern Houston County. An official National Weather Service climate observer near Hokah in Houston County reported a storm total of 16.27 inches. Of this total, 15.10 inches fell within the observer's 24-hour observation cycle ending at 8:00 AM on Sunday, August 19. This is the largest 24-hour rainfall total ever recorded by an official National Weather Service reporting location in Minnesota. The previous Minnesota record was 10.84 inches, measured at Fort Ripley in Crow Wing County on July 22, 1972. That same site also set the new state record for the most precipitation for any month of the year: 23.86 inches, breaking the old record of 17.90 in July 1987 at the Twin Cities International Airport.
While this heavy rain all but erased the drought in the southeast, September and October proved to be very wet across for the rest of Minnesota and eroded away at the areas of drought. The Twin Cities had its wettest August-October on record with 18.99 inches, breaking the old record of 18.63 inches. Heavy rains also drenched the Iron Range on September 6, 2007 and chipped away at the drought in the arrowhead. The highest total reported from that event was nearly 9 inches north of Virginia in St. Louis County. By the beginning of November, the drought was effectively eliminated in much of the state except for a stubborn pocket in west central Minnesota. As the ground began to freeze in November, this area of moderate drought persisted into December.
To the enjoyment of many winter recreational enthusiasts (and the cursing of people driving on snow covered roads), the winter of 2007-08 got an early start with two snowstorms that left the state under a blanket of significant snow. By December 6th, snow depths were roughly 8 to 15 inches from the Twin Cities north to the Canadian border and from 2 to 8 inches south of the Twin Cities. An early and enduring snow cover has been rare in Minnesota recently. The last time the state was broadly covered by this much snow, this early in the winter, was late-November and early-December of 1996. More snow fell during the final week of December insuring that the New Year will start off looking a lot like winter.
The 2007 tornado season got a late start with the first twister sighted on May 23. It was sighted near Dennison in Goodhue County. The last tornado to be reported was a weak one sighed in Woodbury in Washington County on September 20. The total for 2007 is 18 tornadoes, the least amount of tornadoes sighted since 1990 when there were 13. There were no injuries or deaths caused by tornadoes in 2007 in Minnesota.