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Extended Outlook: Shifting Back to Colder than Normal for Late December

The latest Climate Prediction Center outlooks have shifted back to colder than normal temperatures and near to below normal precipitation for eastern North Dakota and the northwest quarter of Minnesota for the second half of December. Read More >

Looking back on 2015, there were several memorable weather moments. First off, we had the seemingly mild and nearly snow-free winter of 2014-2015 and the resultant lack of spring snowmelt runoff or subsequent flooding. But there were some other items of interest as well, as noted below.

 

Precipitation

The winter season of 2014 into 2015 was by most accounts a fairly dry, as far as precipitation totals, and un-stormy winter. This was largely due to a dry northwest flow pattern set in place by a predominant warm ridge of high pressure anchored along the Pacific Northwest coast, in turn anchored by anomalously warm ocean water off the Pacific Northwest coast. This oceanic and atmospheric pattern set up shop in late autumn 2014, with the dry pattern experienced over the plains into the start of 2015.

After a dry start to spring and an elevated fire risk, the spring rains came in May. The multiple rain events brought the annual precipitation back to normal or above normal by the end of the month. Thunderstorm events continued to be rather steady through the summer months, keeping precipitation near normal across much of the region by September 1st. A dry fall then commenced and continued into December, keeping precipitation averages slightly below normal by the end of the year.

 

Fargo Precipitation - 2015 (click for larger image)

Grand Forks Precipitation - 2015 (click for larger image)

Percent of Normal Precipitation - 2015 (Courtesy: High Plains Regional Climate Center)

PercentNormalPrecip

 

Temperatures

The see-sawing temperatures experienced at the end of 2014 continued into early 2015 (Warm-Jan, Cold-Feb, Warm-Mar). All in all, last year's winter averaged out to be slightly above normal. February was the coldest month by far, when the Grand Forks Airport reached its coldest low of the season, -28 degrees, on February 19th. Fargo's coldest low of -19 degrees occurred on the 19th also, and again on the 22nd. The warmest days were August 14th at Grand Forks (96 degrees) and October 11th at Fargo (97 degrees).

After slightly warmer than average temperatures overall for the summer, the autumn was quite mild, with both Fargo and Grand Forks recording average temperatures for the Sep-Nov period among the top 5 warmest on record.  The year ended on a warm note, with temperatures averaging 6 to 10 degrees above average for December. Overall, temperatures for the year averaged around 2 to 4F above average over much of the region. At Fargo, 2015 was the 4th warmest year on record, going back to 1881. The Grand Forks Airport also recorded its 4th warmest year on record, dating back to 1941.

 

Fargo Temperatures - 2015 (click for larger image)

 

Grand Forks Temperatures - 2015 (click for larger image)

 

2015 Monthly Departure from Normal Temperature at Fargo and Grand Forks

Monthly Temp Departures

 

Departure from Normal Temperature - 2015  (Courtesy: High Plains Regional Climate Center)

TempDeparture

 

Winter Weather

The most notable winter storm from the last year was the blizzard on Jan 2nd/3rd. Snowfall of 6 to 8" fell across northeastern ND and northwestern MN including 8" near Cavalier, ND and 7.5" in Greenbush, MN. The heavy snow combined with wind gusts in the 40s (mph) resulted in blizzard conditions across this area. A write-up of this event can be found here.

The 2014-2015 total winter snow (October 2014 through May 2015) was 17.0 inches in Grand Forks and 16.0 inches in Fargo, which was well below the averages of 47.1" and 50.1" at Grand Forks and Fargo, respectively. This winter (2015-2016) has started off a bit drier as well, with snowall of 10.6" at Fargo and 18" at Grand Forks so far. 

 

Lack of Spring Runoff and Heightened Fire Weather Concerns

The drier than average winter last year led to an uneventful spring in regards to snowmelt and river flooding. River flooding was nearly non-existent across the Red River Basin in the spring of 2015.

However, the lack of moisture led to an increased concern for wildfires in the spring of 2015. Several Red Flag Warnings were issued during the period of late March through early May. Below is a Weather Story graphic issued on April 15th.  

 

 

Summer Thunderstorms

June 27th Tornado Outbreak

A tornado outbreak occurred in eastern North Dakota Saturday afternoon into the evening on June 27, 2015.  The NWS in Grand Forks issued 21 Tornado warnings and 2 severe thunderstorm warnings during the afternoon and evening.  A very unstable air mass combined with strong wind shear to produce at least 19 distinct tornadoes. Most of the tornadoes were concentrated in northeast North Dakota, with reports into extreme southeast North Dakota.  Fortunately, most tornadoes occurred over open country with no known structural damage. Click here for more photos, here for a radar loop, and here for tornado reports for the day.

 

Photo of tornado near Park River, ND on June 27th, courtesy of Dr. Aaron Kennedy.

Several additional severe weather episodes occurred during the summer over our area, including an event which produced two tornadoes and multiple reports of wind damage on July 23rd. A recap of this event is found here.  Another severe weather event on August 12th produced hail in excess of 4" in diameter in northwestern Minnesota (click here for summary).

 

Fall Fire Weather Conditions

By early October, much of the southern Red River Valley was experiencing "Abnormally Dry" conditions as noted by the U.S. Drought Monitor. As October 11th approached, concerns for dangerous fire weather conditions increased once again. Wind gusts to 55 mph blew across parts of the Northern Plains that afternoon. The strong winds combined with high temperatures in the 90s and low humidities resulted in numerous fires across the region. The most notable was a fire near Wahpeton on I-29 that closed traffic on the evening of October 11th. 

 

Links to 2015 Annual Climate Summary Products

Grand Forks Airport

Grand Forks NWS

Fargo