New U.S. daily high temperature records in October outpace record lows by nearly 5-to-1
ENDLESS SUMMER: For all the talk of plummeting ocean temperatures, last month was tied for the second hottest October in the UAH satellite record (with 2003, 2006, and 1998 — October 2005 was slightly hotter). And we had the rare event of “two simultaneous hurricanes in the Atlantic Ocean on October 30,” as Meteorologist Jeff Masters noted (see below).
In this country, Steve Scolnik of CapitalClimate reports:
… new record high temperatures are outpacing record low temperatures in the U.S. for the 8th consecutive month. Preliminary data from the National Climatic Data Center (NCDC) for October show over 1500 new record highs, vs. slightly more than 300 lows, giving a ratio of 4.75 to 1. For the year to date, new highs are exceeding new lows by a ratio of 2.8 to 1….
new record warm minimum temperatures also exceeded record high maximums as they have in nearly every month so far in 2010. The excess of high minimum records was particularly strong in the summer, when as many as 3761 were reported in August alone.
I like the statistical aggregation across the country, since it gets us beyond the oft-repeated point that you can’t pin any one record temperature on global warming. If you want to know how to judge whether the 4.75-to-1 ratio for October is a big deal, here’s what a 2009 National Center for Atmospheric Research study found for 1,800 weather stations in continental US over the past six decades:
NCAR explained their findings this way:
Spurred by a warming climate, daily record high temperatures occurred twice as often as record lows over the last decade across the continental United States, new research shows. The ratio of record highs to lows is likely to increase dramatically in coming decades if emissions of greenhouse gases continue to climb.
“Climate change is making itself felt in terms of day-to-day weather in the United States,” says Gerald Meehl, the lead author and a senior scientist at the National Center for Atmospheric Research (NCAR). “The ways these records are being broken show how our climate is already shifting.”
So a 4.75-to-1 ratio is indicative of a hot month and 2.8-to-1 indicates a hot year.
Last month, the hottest September in UAH satellite record, puzzled Roy Spencer with its “stubborn” temperatures. He now concedes that this year is likely to tie 1998 for the hottest year in the UAH satellite record:
For those following the race for warmest year in the satellite tropospheric temperature record (which began in 1979), 2010 is still within striking distance of the record warm year of 1998. Here are the 1998 and 2010 averages for January 1st through October 31:
Note that the difference between the two is not statistically significant “¦ just symbolically.
As Spencer’s figure makes clear, even in his much-rejiggered UAH satellite data, the planet just keeps getting hotter, which is especially impressive because we’ve been in “the deepest solar minimum in nearly a century.” It’s just hard to stop the march of manmade global warming, other than by sharply reducing greenhouse gas emissions, that is.
October was definitely a month for the record books of extreme weather (see Masters: “Strongest storm ever recorded in the Midwest smashes all-time pressure records”: ‘Weather bomb’ hits Midwest with power of major hurricane). Masters puts the Atlantic hurricane season — and the unusual late season hurricanes — in perspective:
Tomas’ formation ties 2010 with 1995 and 1887 for 3rd place for most number of named storms in an Atlantic hurricane season. Only 2005 (28 named storms) and 1933 (21 named storms) were busier. Atlantic hurricane records go back to 1851, though there were likely many missed named storms prior to the beginning of satellite coverage in the mid-1960s. The intensification of Shary and Tomas into hurricanes today brings the total number of hurricanes this season to twelve, tying 2010 with 1969 and 1887 for second place for most hurricanes in a season. The record is held by 2005 with fifteen hurricanes, and I don’t think we’ll beat that record this year!
The formation of Tomas so far south and east this late in the season is unprecedented in the historical record; no named storm has ever been present east of the Lesser Antilles (61.5°W) and south of 12°N latitude so late in the year. Hurricane Six of 1896 came close–it was also a tropical storm south of 12°N and east of 61.5°W on October 29, but nine hours earlier in the day. That storm recurved to the north and missed the Lesser Antilles. Tomas’ track through the southern Lesser Antilles so late in the year is unprecedented. There have been only two other tropical storms that formed after October 15 south of 12°N and east of 61.5°W: Hurricane Jose, which was a tropical storm in that region on October 18, 1999, and Tropical Storm Nicolas, on October 16, 2003….
Another unusual aspect of Tomas’ formation is that we now have two simultaneous hurricanes in the Atlantic Ocean on October 30. There has been only one hurricane season since 1851 that had had two simultaneous hurricanes later in the year–1932, when Hurricane Ten and Hurricane Eleven both existed November 7 – 10.
But this kind of extreme weather is going to be the norm this decade. A recent analysis by NASA’s James Hansen concluded, “Given the association of extreme weather and climate events with rising global temperature, the expectation of new record high temperatures in 2012 also suggests that the frequency and magnitude of extreme events could reach a high level in 2012″ “” see Hansen: Would recent extreme “events have occurred if atmospheric carbon dioxide had remained at its pre-industrial level of 280 ppm?” The “appropriate answer” is “almost certainly not.” So 2012 may feel a lot like 2010.
For new readers, here’s the caption on the top figure:
Total number of daily high temperature, low temperature, and high minimum temperature records set in the U.S. for spring 2010 (March-April-May) and monthly from June through October 2010, data from NOAA National Climatic Data Center, background image © Kevin Ambrose (www.weatherbook.com). Includes historical daily observations archived in NCDC’s Cooperative Summary of the Day data set and preliminary reports from Cooperative Observers and First Order National Weather Service stations. All stations have a Period of Record of at least 30 years.
- Labor Day 2060: Endless summer
- Masters: “It appears that this year’s record [sea surface temperatures] have significantly expanded the area over which major hurricanes can exist over the Atlantic.”
- NASA: The 12-month running mean global temperature has reached a new record in 2010: “We conclude that global temperature continued to rise rapidly in the past decade” and “there has been no reduction in the global warming trend of 0.15-0.20°C/decade that began in the late 1970s.”