Since early February, temperatures in the nation's northern tier have risen nearly 40 degrees above normal at times. Many places that are usually buried in snow have bare ground and temperatures more typical of spring.
Snow-free Minneapolis spent much of this week with highs in the 50s, setting records on Tuesday and Thursday. Its average high in early February is in the mid-20s.
“I've seen reports of tick sightings, tulips emerging, even some (very early) baseball practices. What month is this again?” meteorologist Paul Douglas wrote on a weather column for the Minnesota Star Tribune.
The warm spell is reminiscent of December's weather, when many of the same areas experienced extreme heat. Parts of northern Minnesota were snow-free on Christmas for the first time. During the month, 31,230 warm weather records were set in the United States, compared to only 53 cold weather records.
The El Niño climate is known to tip the odds toward mild winters in the northern United States, and this year's pattern is the fifth strongest in history.
In addition to El Niño, human-induced climate change from the burning of fossil fuels increases the likelihood of such extreme heat. The European Union's Copernicus Climate Change Agency announced on Thursday that the planet had its warmest January on record and that the past 12 months had averaged more than 1.5C above pre-industrial levels for the first time.
There are indications, however, that this warm spell will end from west to east over the weekend into early next week.
How warmth and records have evolved
Record warmth began the week stretching from the Desert Southwest to the Upper Midwest and slowly moving eastward.
As the atmospheric wave responsible for the California deluge earlier in the week shifted east, it helped pull spring moisture northward into Canada. On Thursday, Wisconsin saw its first February tornado as high temperatures in parts of the state surpassed previous records by around 10 degrees.
Ahead of the severe storms, much of the Midwest was in record heat. Places that set calendar-day highs on Thursday included Cedar Rapids, Iowa, at 66 degrees. Rockford, Ill., at 59 degrees. and La Crosse, Wis., at 59 degrees.
As of Thursday, several weather observation sites had set multiple record highs this month, including:
- 5 in Waterloo, Iowa.
- 4 in Sault Ste. Maria, Mich.
- 3 in Rockford, Ill.
- 2 in Green Bay, Wis., and more
Several cities have also seen record low temperatures, including North Platte, Neb. Sioux Falls, SD; and Huron, SD — which have seen five this month.
So far, February is the warmest or second warmest on record for most of the Midwest and Great Lakes, according Meteorological Service data. Most of Minnesota is running at least 20 degrees above normal for the month. The average temperature in Fargo, ND, was 27 degrees above normal through Thursday.
Due to the extent of bare ground in normally snowy locations, snow covered just 27.6 percent of the contiguous United States from Friday morningone of the three lowest rates recorded for the date.
Record heat spreading east
Temperatures that will soar into the 50s and 60s are expected to break more records in the Great Lakes and Northeast on Friday and in the mid-Atlantic and Northeast on Saturday. Dozens of record warm lows are forecast in the same areas over the weekend.
Record highs at risk Friday, about 20 to 30 degrees above normal, include:
- Detroit: The forecast is 63 degrees. The record is 56 degrees in 2001.
- Fort Wayne, Ind.: The forecast is 61 degrees. The record is 61 degrees in 2001.
- Syracuse, NY: The forecast is 59 degrees. The record is 59 degrees in 1902.
On Saturday, the following record highs — about 15 to 25 degrees above normal — are possible:
- Washington Dulles International Airport: The forecast is 63 degrees. The record is 63 degrees in 2001.
- Hartford: The forecast is 56 degrees. The record is 55 degrees in 1909.
- Albany, New York: The forecast is 55 degrees. The record is 53 degrees in 1955.
- Burlington, Vt.: The forecast is 52 degrees. The record is 46 degrees in 2001.
Toledo, Cleveland, Pittsburgh, Buffalo, Washington and Roanoke could all see record warm lows over the weekend as morning temperatures are forecast to be 30 to 40 degrees above normal over a large area.
As a cold front moves across the Midwest and sweeps up the East Coast early next week, the widespread unseasonable heat will end.
While the weather pattern will turn colder, there is no definite signal for an extreme cold snap. An active jet stream across the southern United States may mean cool, windy weather from California across the South and up the East Coast, but extreme cold may continue to escape the north-central states.
Jason Samenow contributed to this report.
