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Posted at 01:04 PM ET, 11/08/2012

October cooler than average across U.S., breaking streak of 16 straight warm months


Differences from normal in pressures at about 18,000 feet - which approximate temperatures near the ground. Blue areas are cold, yellow-red areas warm. (NOAA)
After 16 straight months of above average temperatures in the Lower 48 states, October ended the streak. NOAA reports the average temperature was 0.3°F below average for the month.

Link: NOAA State of the Climate, October 2012, National Overview

The streak of warm months - including the hottest month on record in July 2012 - began way back in June 2011. It was killed by a prevailing dip in the jet stream over the middle part of the nation, flooding the region with cooler than normal air.


How states compared to normal temperature-wise in October. (NOAA)

19 states - mainly from the northern Plains through the Midwest into the South - had temperatures below average, with the Southwest and Northeast the only regions where temperatures were above normal.


Year-to-date temperature evolution of 2012 (in red) compared to other years. The top five warmest years (excluding 2012) are in orange, and the top five coldest years are in blue. The years in between are in gray. View big. (NOAA)

Despite the relatively cool October, the calendar year of 2012 remains the warmest on record to date, some 3.4°F above average. 21 states have had their warmest year on record so far. The last 12 months rank as the 6th warmest 12-month period on record. The last 7 12-month periods have all been among the 7 warmest 12-month periods on record.

Precipitation during October was slightly above normal, aided by the Superstorm Sandy’s deluge along the East Coast and hefty mountain snows to end the month. October’s small precipitation surplus shrunk the widespread drought over the country from 64.6 percent to 60.2 percent.

Link: From the devastating surge to crippling snow, Hurricane Sandy by the numbers


Drought conditions over the Lower 48 on October 30. (U.S. Drought Monitor)
“Drought conditions improved slightly across parts of the Midwest and Central Plains, while drought conditions worsened across the Northern Rockies,” NOAA said.

By  |  01:04 PM ET, 11/08/2012

Categories:  Latest, Climate Change

 
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