47 F. average high for March 29
59 F. high temperatures on March 29, 2010.
83 F. record high (March 29, 1986).
* Probably mild enough aloft for rain late Thursday and Thursday night in the Twin Cities (couple inches of slush possible far northern suburbs to Duluth).
* Saturday: still the sunnier, drier, nicer day - shot at low 50s.
* Models hinting at a half inch of rain Sunday and Monday, possibly ending as wet snow up north.
* Dry much of next week - string of 50s possible as we turn the corner into a more springlike pattern. Cue "Hallelujah Chorus".
* First 60 on or around April 10? The GFS says so - we'll see. The maps are finally starting to look a bit more springlike.
Inching Closer To Average. Here in the Land of Low Weather Expectations 40s are a pretty big deal (after the winter we just endured). 42 to be precise. We're down to 1" of snow on the ground in the Twin Cities, 2" at St. Cloud and 5" left up at International Falls.
Paul's Conservation Minnesota Outlook for the Twin Cities and all of Minnesota:
SATURDAY NIGHT: Cloudy with rain possible late. Low: 38
Contrails Warm The World More Than Aviation Emissions. The New Scientist has an article about jet contrails - how they often spread out into cirrus clouds, which keep nighttime temperatures warmer: "The innocuous white vapour trails that criss-cross the sky may not be as harmless as they look. In fact, they might have contributed to more global warming so far than all aircraft greenhouse gas emissions put together. High-altitude clouds like cirrus warm the planet by trapping heat. Contrail "cirrus" does the same thing, but the question is: how much? We know that contrails trap some extra energy in the atmosphere: their radiative forcing trapped 10 milliwatts per square metre (mW/m2) in 2005, according to an estimate by the Intergovernmental Panel on Climate Change. That compares with 28 mW/m2 trapped by all of the CO2 released by aircraft engines since the start of aviation. However, the IPCC estimate only took into account relatively fresh, visible vapour trails that exist for just a few hours. Afterwards they spread out and become indistinguishable from normal cirrus. In this form they may trap energy in the atmosphere for many more hours. "Only a small part of the problem has been studied," says Ulrike Burkhardt of the Institute for Atmospheric Physics in Oberpfaffenhofen, Germany. With her colleague Bernd Kärcher, she set out to discover how much heat contrail cirrus traps."