Good & Lukewarm (a nice week shaping up - first frost 11-13 days away?)

74 F. high on Sunday.
69 F. average high on September 22.
60 F. high on September 22, 2012.

Sprinkle or light shower possible Tuesday, much better chance of rain late Friday & Saturday.

Frost 11-13 days away? 

Summer Afterglow

I'm a fan of September: lukewarm sun without the crowded campsites, I-94 parking lot conditions, dreadful dew points & raging T-storms. What's not to like? Take full advantage of 70s all this week; a perfect spell to close up the cabin or wrestle with the dock. ECMWF guidance hints at 40s & 50s by the middle of next week; an early dose of October. So make the most of a mild, quiet week.
For the month temperatures are running 4-5 F warmer than average in the Twin Cities.

The calendar says autumn, but Meteorological Autumn really began closer to September 1, marking the end of the 90 warmest days of the year, historically.

Take nothing for granted. The first frost of the season is probably less than 2 weeks away for the metro. First flurries? Maybe 3-4 weeks from now. Something to look forward to.

As much as I'm enjoying blue sky, mild breezes and unlimited visibility, we still need rain. Ham Weather calculations show 2 to 5 inches are required to pull out of the drought across most of Minnesota.

A fine, blue-ribbon week of weather ends with 80F and late-day thunder Friday; maybe a period of steadier rain much of Saturday. Sunday looks like the drier, nicer day for the Renaissance Festival.

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Redefining "Crystal Clear". One of many things to appreciate about September: less haze and much less humidity, meaning visibility is as good as it gets during the warm season, over 60 miles in some cases. No smoke from Canadian wildfires either. The image above is from NASA's MODIS Terra satellite, with 1,000 meter resolution.

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Today's Weather Map. Skies clear over the Great Lakes, a cool, jacket-worthy breeze lingering over New England - while a stalled frontal boundary sparks more heavy showers and T-storms for the Gulf Coast. The Upper Midwest is warming up, while a significant Pacific storm pushes squally showers into Seattle and Portland. Map above valid 1 PM today courtesy of UCAR.

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Rainfall Needed To End The Drought. Most of Minnesota has to pick up 2-5" of additional rain to erase our sudden "flash drought", according to NOAA and USDA. Map above: Ham Weather.

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Sprinkling Optional Southeast and Northwest. Here is NOAA's 5-Day rainfall forecast, showing 2-3" amounts form near New Orleans to Tampa and Orlando; heavy rains for the northern Rockies and Pacific Northwest. Dry weather prevails most of the week from the Great Lakes to New England and across the Southwest.

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Lukewarm. I like that word - I know I use it too much; one of many character flaws. Temperatures run 5-10 F. warmer than average this week, the only significant chance of rain coming late week: a few T-storms may pop ahead of a cool front late Friday - steadier rain possible Saturday before we cool down again early next week. Graphic: Weatherspark.

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Hints Of Autumn. The 12 km. NAM model shows a cool bias for New England and much of the Northwest looking out 84 hours in Wednesday, while a ridge of high pressure building over the Plains and Midwest forces mild air northward. Loop: Ham Weather.

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First Frost For Twin Cities? Long-range GFS guidance shows a more significant surge of chilly air the weekend after next; nighttime lows dipping to or below freezing a couple of night around October 5-6. We'll see.

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Summer Of 2013 National Highlights. Here's an excerpt from NOAA NCDC:

• The summer contiguous U.S. temperature of 72.6°F was 1.2°F above the 20^th century average and the 15^th warmest summer on record for the nation.
• The West and parts of the Northeast were much warmer than average during summer. In the West, eight states, from New Mexico to Washington, had seasonal temperatures that ranked among the ten warmest on record. In the Northeast, four states had one of their ten warmest summers on record.
• Below-average summer temperatures were observed in the Southeast and parts of the Ohio Valley, but no state had summer temperatures ranking among the ten coolest.
• The Alaska statewide average summer temperature was 2.7°F above the 1971-2000 average and ranked as the second warmest summer in the 96-year period of record for the state. The warmest June-August occurred in 2004 when the statewide temperature was 4.1°F above average.
• The summer precipitation total for the contiguous U.S. was 9.53 inches, 1.28 inches above average. This marked the eighth wettest summer on record and the wettest since 2004.

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Superstorm Sandy And Tropical Storm Irene No Match For Hurricane Of 1938. They called it "The Atlantic Express", because it came on suddenly, with precious little warning (no fancy weather satellites back in '38). Here's an excerpt of a very interesting article at The New Haven Register: "If a hurricane with the fury of the storm that slammed us in 1938 were to hit today, it would be deadly serious event. But the good news:

• We’d know it was coming a lot sooner, and we’d know how big a storm it really was.

• We’d be able to get out of Dodge (or Milford or New Haven), evacuating to higher, farther-away ground, so we likely wouldn’t lose as many lives.
Now the bad news:

• We’d lose at least as much of our power and our property — houses, cars, trees, railroad tracks, backyard swing sets — because there are a lot more trees, a lot more houses on the coast, and it would be far too costly to rebuild them to withstand another Atlantic Express, as the ’38 storm was called..."

Photo credit above: "The tide tore away the railroad tracks in New Haven."

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TODAY: Sunny and windy. Winds: SE 15-30. High: 75

MONDAY NIGHT: Clear and cool. Low: 53

TUESDAY: More clouds, sprinkle possible. High: 72

WEDNESDAY: Mostly sunny and mild. Wake-up: 49. High: 74

THURSDAY: Blue sky, mild breeze. Wake-up: 53. High: 76

FRIDAY: Warmest day, morning sun - late-day T-storm. Wake-up: 62. High: near 80

SATURDAY: Steadier rain possible. Wake-up: 56. High: 68

SUNDAY: Partly sunny, drier day of the weekend. Wake-up: 48. High: 69

* highs may hold in the 50s by the middle of next week.

Climate Stories....

Climate Change: IPCC Cites Global Temperature Rise Over Past Century. The Guardian has the article; here's a clip: "...According to the report, more than half a trillion tonnes of carbon – from coal, oil and gas – have now been burned in factories, cars and homes and dumped in the atmosphere since the Industrial Revolution. Burning a further half a trillion tonnes would add a further degree centigrade to global temperatures, it adds. Such is the rate of fossil fuel burning, which is spiralling across the planet, that a second half a trillion tonnes is likely to be consumed in a few decades. The result could be catastrophic. A further jump in temperatures could trigger events that would accelerate global warming: by releasing plumes of the greenhouse gas methane from the thawing Arctic tundra and destroying polar ice caps that play a role in reflecting solar radiation back into space. Global warming could then start to spiral out of control..."

Photo credit above: "The report dismisses climate change denier's suggestions that recent global warming is explained by variations in the sun's energy." Photograph: John Mcconnico/AP.

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Despite What You May Have Read, Global Warming Continues. Nature rarely moves in a perfectly straight line. True, surface air temperatures aren't rising as fast as they did in the 80s and 90s, for a combination of reasons: an especially long La Nina cooling phase may be masking some of the atmospheric warming signal, more aerosols and volcanic eruptions have had a slight cooling effect. Climate scientists estimated that 90% of the warming is going into the world's oceans, where monitoring is limited. But every recent decade over the last 50 years has been warmer than the previous one. Doug Craig has a good explanation at his excellent Climate of Change blog at redding.com; here's a clip: "...The world is continuing to grow warmer. It just isn't warming as fast as predicted. So what does this mean exactly? Chris Mooney explains, "First, 'global warming' never meant that temperatures increase relentlessly, year after year - it's more complicated than that. "there's always more than one thing going on in the climate system," explains climate researcher Jerry Meehl of the National Center for Atmospheric Research in Boulder, Colorado. There are really hot years and there are less hot years. But since the 1950s each successive decade has been hotter than the last, according to the World Meteorological Organization, and the 2000s were the warmest decade "since the start of modern measurement in 1850..."

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Evidence Of Climate Change In Half Of The 12 Extreme Weather & Climate Events Of 2012. Details from NOAA: "Human influences are having an impact on some extreme weather and climate events, according to the report “Explaining Extreme Events of 2012 from a Climate Perspective” released today by the Bulletin of the American Meteorological Society. Overall, 18 different research teams from around the world contributed to the peer-reviewed report that examined the causes of 12 extreme events that occurred on five continents and in the Arctic during 2012. Scientists from NOAA served as three of the four lead editors on the report. The report shows that the effects of natural weather and climate fluctuations played a key role in the intensity and evolution of the 2012 extreme events. However, in some events, the analyses revealed compelling evidence that human-caused climate change, through the emission of heat-trapping gases, also contributed to the extreme event..."

The world is continuing to grow warmer. It just isn't warming as fast as predicted. So what does this mean exactly?
Chris Mooney explains, "First, 'global warming' never meant that temperatures increase relentlessly, year after year--it's more complicated than that.
"'There's always more than one thing going on in the climate system,' explains climate researcher Jerry Meehl of the National Center for Atmospheric Research in Boulder, Colorado. There are really hot years and there are less hot years. But since the 1950s, each successive decade has been hotter than the last, according to the World Meteorological Organization, and the 2000s were the warmest decade 'since the start of modern measurements in 1850.'
- See more at: http://blogs.redding.com/dcraig/archives/2013/09/despite-what-yo.html#sthash.dgxVL9La.dpuf

The world is continuing to grow warmer. It just isn't warming as fast as predicted. So what does this mean exactly?
Chris Mooney explains, "First, 'global warming' never meant that temperatures increase relentlessly, year after year--it's more complicated than that.
"'There's always more than one thing going on in the climate system,' explains climate researcher Jerry Meehl of the National Center for Atmospheric Research in Boulder, Colorado. There are really hot years and there are less hot years. But since the 1950s, each successive decade has been hotter than the last, according to the World Meteorological Organization, and the 2000s were the warmest decade 'since the start of modern measurements in 1850.'
- See more at: http://blogs.redding.com/dcraig/archives/2013/09/despite-what-yo.html#sthash.dgxVL9La.dpuf

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I Believe: Climate Change Requires A Conscious Change Within Society. Here's the intro to an Op-Ed at The Burlington Free Press: "I’ve been thinking a lot about climate change. We’re currently on a path to steadily add more carbon dioxide to the atmosphere and consequently have more natural disasters. Burning fossil fuels, the largest source of CO2 emissions, is perceived as vital to our society and economy. Civilization’s status quo for continued and growing use of fossil fuels is a big problem. How do we move toward an energy future and an economy that yields a hospitable Earth rather than increasing environmental calamities? Climate change is an inconvenience and will require a conscious change within society...."

Photo credit above: "The Brayton Point Power Station in Somerset, Mass., was the site of a recent protest against fossil fuels." / AP FILE.