53 F. average high on April 7.
57 F. high on April 7, 2012.
1-2" rain possible this week.
Wintry mix possible Wednesday and Thursday (sleet, freezing rain, even a period of accumulating snow Wednesday night into Thursday).
Latest from Alerts Broadcaster:
A major storm is spinning up for the central USA, capable of impacting towns from Denver to Dallas to the Twin Cities from Monday thru Thursday of this week with a wide variety of potentially disruptive weather:
- Significant tornado outbreak possible the first half of this week. Tuesday looks like the most violent day from Dallas and Oklahoma City to Kansas City and St. Louis, with a few large, violent, long-track tornadoes expected.
- Heavy wet snow will fall from Wyoming and Colorado's Front Range across the Dakotas, potentially plowable amounts of slush into part of Minnesota, Wisconsin and Lower Michigan by Wednesday and Thursday. Yes, this is unusual for the second week of April.
- Flood risk. The ground is still frozen over most of the Upper Midwest - any heavy rain will run off into streets, streams and rivers. I expect river flooding (and urban flooding) to be on the increase over the next 72 hours. Details:
Summary: The calendar says April, but the weather maps still look like something out of early March. An unusually intense spring storm will elevate the risk of heavy wet snow (western Plains and Upper Mississippi Valley), significant river flooding from some 1-4" rainfall amounts, and a substantial risk of severe storms, hail, damaging winds and a few large, violent tornadoes by Tuesday from Dallas to Kansas City. After peaking in the 60s earlier today Denver will see 5-10" snow Monday night into Tuesday; I expect numerous delays and cancellations at KDEN Tuesday. We'll watch the storm unfold and provide updates as needed.
- Snow depths range from zero in the
southern one-third of Minnesota to over 20 inches west central
Minnesota, north central Minnesota, and in the Lake Superior highlands.
[see: NWS Snow Depth Estimation Map | Snow Depth Maps]
- The amount of water content in the snow pack
is estimated to be in excess of five inches in some west central and
north central Minnesota counties. The large amount of water on the
landscape, lying upon an impervious frozen surface, has led to a high risk for major flooding in the Red River basin.
[see: NWS Snow Water Equivalent Estimation Map]
- The U.S. Geological Survey and Minnesota DNR report that stream discharge values
vary widely across the state. After the initial flush of snow melt
runoff recedes, stream discharge values will quickly fall below
historical medians unless there is a very wet spring.
[see: USGS Stream Flow Conditions | MNDNR Weekly Stream Flow Maps and Tables]
- Water levels on most Minnesota lakes are low due to the dry summer and autumn of 2012. Lake Superior's water level is approximately one foot lower than its historical average for this time of year.
The paper looked at three factors that go into the maximum precipitation value possible in any given location: moisture in the atmosphere, upward motion of air in the atmosphere, and horizontal winds. The team examined climate model data to understand how a continued course of high greenhouse gas emissions would influence the potential maximum precipitation. While greenhouse gas increases did not substantially change the maximum upward motion of the atmosphere or horizontal winds, the models did show a 20-30 percent increase in maximum moisture in the atmosphere, which led to a corresponding increase in the maximum precipitation value..."
Graphic credit above: Wesley Bedrosian
- Seek the cheapest price for energy with the implication that environmental consequences should not be tallied as part of the cost.
- Complete a transition to renewable energy as quickly as possible while drastically reducing the burning of fossil fuels.
- Replace all fossil fuel energy with nuclear power..."
Photo credit above: "Sea level rise is swamping coasts. Rodanthe in the Outer Banks of North Carolina is pictured."(Photo: Andrew Kemp, Yale University)
Photo credit above: "The flooded Red River surrounds houses near Fargo, N.D., in 2010. Scientists say climate change will produce more intense storms, increasing the risk of damaging floods." (M. Spencer Green / Assoicated Press / March 21, 2010)
* The Los Angeles Times has another perspective on the potential for more extreme rains here.