Map showing total changes for Minnesota on the US Drought Monitor over the 8-week period from September 3rd through October 29th. Note that the entire state experienced "degredation," as drought conditions spread quickly over the state. Areas showing in orange showing ("3 Class Degredation") went from no drought into "Severe" drought during that time. Courtesy National Drought Mitigation Center.
A period of exceptional dryness and warmth blanketed Minnesota for over 50 days, from the first day of September into the fourth week of October 2024. The warm and dry conditions caused a rapid and widespread expansion of drought in the state, with some areas dropping three categories on the US Drought Monitor in just 8 weeks--going from no drought to having "severe" drought.The dry conditions were far more than a localized or even a regional phenomenon. In fact, after a rather active end to August, featuring
24 hours of heavy rain and severe weather, things quieted down quickly, with dry conditions spreading over much of the US. The flow of moisture from the Gulf of Mexico was all but cut off, causing dew point temperatures in Minnesota to drop into the 30s and 40s F for much of the month. If and when weather systems would come through the region, they had little if any moisture to work with and therefore produced little if any precipitation. A series of landfalling hurricanes and tropical storms in the southeastern US were some of the only sources of significant precipitation anywhere in the country for a period of about seven weeks. As moisture levels dropped throughout September, clouds became scarce, allowing bright sunshine to take over. As a warm air mass moved into the region in the middle of the month,
a period of unusual warmth set in, and then continued off an on throughout October. Although this period did not have any particularly dangerous heat (as had occurred
in 2023), unusually late occurrences of 80-degree F (or higher) temperatures were observed October 20th through 22nd, and again on the 29th and 30th. September was the warmest on record for the state, and at a dozens of long-term stations, many of which broke records set during the
bizarre September of 2023!In the Twin Cities, September became the driest on record, with 0.06 inches. No other measurable precipitation fell until October 24. Over 30 other stations around Minnesota also had a record-dry September, and from September 1 through October 23, many observers recorded less than 5% of their normal precipitation.
Wetter conditions began affecting Minnesota later in October, but the high-quality, multi-generational observing site at Milan missed out on most of the precipitation and recorded on 0.02 inches for the month--a record. For the rest of the state, October precipitation was low, but did not set records. Posted December 17, 2024
KAB
