March 2010 Saint Cloud Weather Summary

Saint Cloud Weather Summary for March 2010

Tournament Heat Wave??

Third Warmest and Seventh Snowless March

March has the reputation for the potential snowstorms, but this March went almost completely storm-free. And, with the increasingly warmer weather as the month went on, the deep snow cover melted and drained into area rivers with a smaller impact flood than seemed possible a month ago.

No Snow in March

The Saint Cloud Regional Airport did not observe a single flake of snow during March 2010. This is only the second March since snowfall records began in the winter of 1899-1900 without even a flurry at the official St. Cloud observing site. Since local residents have told me that they had seen flurries this month (and I observed a couple myself), perhaps the more appropriate statistic is that March 2010 is the 7th March in St. Cloud records without any measurable snowfall. We have had a couple of low snow Marches recently: only 1.0 inch fell in March 2005 and no measurable snowfall fell in March 2000. In fact, March 2000 was similar to this past March in other ways, to be documented below.

Normally, 8.5 inches of snow fall in March. In addition, local weather lore indicates that there should be at least one major snowstorm during the high school tournaments in regional sports. Much of this is lore, not fact, as noted by the Minnesota State Climatology Office's report on tournament snowstorms. As noted by research done by Ron Trenda, there has only been a snowstorm of at least 4 inches during the high school basketball tournament in 9 out of 97 years since 1913. In comparison, the odds of seeing a 50-degree high is four times greater than getting the snowstorm. This lore has been expanded to cover all high school tournaments, so any March snowstorm of at least 4 inches qualifies.

Still, this snowless March extended through the entire state of Minnesota. None of the long-term reporting stations in Minnesota recorded more than the 0.2 inch of snow seen in International Falls. The reason for this quiet weather pattern was that the persistent storm tracks stayed far enough away from Minnesota to keep us dry. There was an active storm track across the Southern US, which kept the all of the moisture from the Gulf of Mexico from moving further north than the Central US. And, the northern storm track mostly stayed to the north of Minnesota, keeping any narrow bands of moderate snowfall stuck on the north side of that track. We ended up in between, getting dry westerly flow from off the east side of the Rockies.

Snowless, But Not Dry

There was one exception to the dry weather pattern: a mid-March rainstorm. Between March 9 and 12, St. Cloud picked up 1.21 inch, but it was all rain. St. Cloud only received another .02 inch during the rest of the month. The total of 1.23 inches ended up only .29 inch short of the normal rainfall. Since the rain fell when there was still snow on the ground and the ground was frozen (see that the frost on the MnDOT frost depth map for Otsego only came out after March 15), much of the snow went straight into area streams and rivers. The dried out vegetation left behind became fuel for grass and wildfires during the second half of the month. According to the Minnesota Department of Natural Resources, there have already been 364 fires this year, burning nearly 6700 acres. In central Minnesota, these fires have been from the Mississippi River eastward.

Warmest March in 82 Years

The rest of the March story was that it was incredibly warm. The average March 2010 temperature was 37.6°F, 9.2°F warmer than normal. So, March 2010 ranks as the third warmest March in St. Cloud temperature records, which date back to 1881. Only 1910 and 1918 (average temperature of 37.8°F) had warmer March temperatures. Again, notice that fourth place is held by March 2000, similar to this March in both temperature and lack of snow. Despite the warmth, there was only record temperature tied during the month, the 35-degree low on March 10.

March 2010 had 27 of its 31 days with warmer than normal temperatures. In fact, more than half of the days (16 of 31) had an average temperature more than 10 degrees above normal. The first 60-degree high of the spring was recorded on March 14, among the earliest 10% of first 60 highs and more than a month earlier than average. The first 70-degree high of the spring, and the warmest temperature of the month, was recorded on March 30, again a month earlier than average.

The very warm temperatures meant that the deep snowpack at the start of March (10 inches of snow in St. Cloud on March 1 and 8-12 inches of snow in the area), melted in less than two weeks from St. Cloud south and east. The 18-24 inches of snow in southwestern Minnesota in late February was almost completely gone three weeks later.

Flooding Dominated March Weather News, But Not As Bad As Last Year

The deep snow pack did result in river flooding in central, northwestern, and all of southern Minnesota. In the St. Cloud area, the Sauk River was out of its banks from March 16 through with a peak level of 6.81 feet (flood level is 6.00 feet). That ranks as the 10th higher stage recorded at the St. Cloud gauge, but was 1.3 feet short of last year's crest. The Mississippi River in St. Cloud never got to flood stage, but reached 8.99 feet at the St. Cloud dam on March 21. That was the fourth highest crest at St. Cloud, but was short of last year's level. There was significant flooding due to ice jams along the Mississippi River at Little Falls and in north Sartell, affecting Little Rock Lake (more ice jam pictures from the Chanhassen National Weather Service)

The Minnesota and Red Rivers, whose tributaries drain the area with the deepest snow pack, have had the worst flooding. Still, flooding only reached the major stage in Montevideo, St. Paul below the Minnesota River mouth into the Mississippi, and along the Cottonwood and Redwood Rivers in southwestern Minnesota. There has been major flooding along the Red River, but the river levels were not as high as they were just last year. The improvement in the Fargo-Moorhead dam system kept the floods from having the highest impact, but a large amount of overland flooding occurred as the snow melted.

The high volume of water in southern Minnesota streams produced much flooding in the southern third of the state and was aggravated by ice jams. The National Weather Service showed a satellite picture on a clear day, demonstrating the changes due to swollen rivers and overland flooding on March 21.

Flooding is still occuring along the Red River with minor flooding on the Minnesota River. Southwestern Minnesota and northwestern Iowa are still seeing flooding along the Upper Des Moines River. To our west, the James River continues to have the worst flooding.

The warm weather also has pushed the ice out process into central Minnesota on time or up to two weeks early, according to the State Climatologist Office. This is a major recovery from the deep ice present on most area lakes thanks to the cold December and early January.

Relief from Dry Conditions Coming?

Today's front coming through will tap enough moisture to produce some showers and thunderstorms, but there's a good chance that these storms won't produce much rain until they get to the east of St. Cloud.

What's up for April? Forecasts for the upcoming week show a more west-to-east storm track. At this point, some of the forecasts are showing a closed off low in the middle atmosphere moving into our area sometime between Tuesday or Wednesday. While there's no doubt that the computer forecasts have improved their forecasts on the possibility of storms up to a week in advance, I'm not sure I trust that this storm will track far enough northward to affect us. Despite our recent warmth, being in the middle of the storm track could produce a really cold rain and perhaps some wet snow somewhere in the Northern Plains.