Weekend trends sunnier, 60s return next week

Welcome to the last weekend in April.

Minnesota winters are a long haul event. It seems like we're never really "safe" until June. But this spring has come well ahead of last year. Farmers are in the fields a month earlier than last year. The April numbers tell the tale.

• +7.8 degrees this April vs. last April at MSP Airport

• 7.0 inch snowfall at MSP last April

• 0.3 inch snowfall at MSP this April

• 2 days at or above 70 degrees last April

Our weekend skies transition from steel gray to bright blue. The sun pokes out Saturday afternoon as rain-bearing low pressure pushes east, and Sunday looks sunny and bright as high pressure noses in from the north.

Here's a more detailed breakdown of the weekend and a nice looking Monday for planning.

Warm start to May?

I'm still seeing signs that May opens with warm notes. The jet stream lifts north, and southerly winds over the western half of the U.S. push a bubble of warmth east toward Minnesota by late next week.

The European model is cranking out 60s most of next week, and 70s to near 80 degrees (and maybe some thunder) by next weekend.

Solar revolution ahead?

The cost of solar is plummeting. As solar installations provide a greater percentage of renewable into the grid, power companies are paying attention.

The American Southwest is the Saudi Arabia of solar power. But solar is more effective in Minnesota than many think.

University of Washington Professor Cliff Mass has a look at the meteorology of emerging solar boom.

There is a quiet revolution in energy production that will change the lives of many: the solar energy revolution.

 With the cost of photovoltaic solar systems dropping rapidly, there has been a rapid expansion of solar power installations, both commercial and residential, around the U.S., with particularly rapid growth in California.

 Consider the geographical distribution of the resource:  where are the best locations in the U.S. for solar power?

By considering both solar angle, cloudiness, and other factors,  NREL (National Renewable Energy Lab) has produced solar energy resource maps for the U.S.   Here is the annual average values (per day in kilowatt hours per square meter).   The southwest U.S. is the Saudi Arabia of solar energy, with the highest values stretching from western Texas to California.    It is really better than Saudi Arabia, since there is huge population hungry for energy  in the Southwest (e.g., Los Angeles, San Diego, Las Vegas, Phoenix, Tucson, etc.)  Lots of sun during the day, exactly when folks need it for air conditioning and their daily lives.

Drones in the Arctic: Bird's eye view of changing sea ice

Why not? Climate Central takes a look at how drones are the next tool in the remote sensing arsenal.

For these last two weeks of April and the first week of May, Zappa and several colleagues will be launching their drones, which fly autonomously, on alternating four-hour sorties westward over the ice to measure water and ice temperatures; ocean salinity; albedo (that is, the reflectivity of the ice) and more.

“Satellite observations are important, but they only give you a big-picture sense of how much ice is there,” Zappa said. Research ships come much closer to the action, but they only let scientists study limited areas of ice.

“With drones, we can study melting and other processes as they’re happening, on a very fine scale,” Zappa said. And they can cover hundreds of square miles of ice and ocean with every flight. “They’ll go about halfway to Greenland and back on every flight,” he said. It takes just two people to launch and recover the drones, which take off and land like conventional winged aircraft.

Unlike the high-altitude Global Hawk drones NASA uses to study hurricanes, the unmanned vehicles that Zappa uses, known as Manta UAVs, are modest in size and cost. They run between $100,000 and $250,000, compared with a Global Hawk’s price tag of more than $200 million; they have an 8-foot wingspan compared with the Hawk’s 130 feet; and they carry up to 10 lbs. of scientific instruments vs. the bigger aircraft’s ton and a half.