Wednesday, November 24, 2010

Incredible Early Winter cold - Nov. 2010 - A La Nina Pattern


The map shows the morning low temperatures on November 24, 2010.


Note the temperature of -18 F in Wyoming, -21 F in Montana and -33 F in southern Alberta.


Mild temperatures have been the norm this Autumn across the Great Plains with 80 F and 70 F temperatures earlier during the month of November. The cold air has been bottled up in Southern Canada due to the primary jet stream being located further north than normal and blocking the southward movement of this cold air. As a result, the temperatures have continued to plunge in southern Canada reaching levels normally only seen in mid Winter. Some of this bitterly cold air has begun to spill southward into the northern Plains. Ironically, the temperatures remain summer-like in the upper 80's in southern Texas. The temperature range across the Plains is over 110 degrees.
This pattern of an extreme cold airmass across southern Canada and extreme warm airmass across the deep south is typical of La Nina winters. Nebraska, being right in the middle should experience constant contrasts as these two opposing airmasses battle for supremacy this coming winter.








Tuesday, November 23, 2010

White Thanksgiving

I'm dreaming of a White Thanksgiving. Ok, so that's not how the Irving Berlin song goes, but there have been White Thanksgivings in Lincoln. Since 1970, this has happened five times, but the last was in 1993.

*Note: To be considered a White Thanksgiving, there had to be one inch or more of snow on the ground at the time of observation. Thus, a trace of snow does not count. If you count a trace of snow, then the last one was in 2007.

The next question that you may be asking is "Well if we have a White Thanksgiving, then we'll be guaranteed to have a White Christmas right?" Not so much. In fact, the last time Lincoln technically had BOTH a White Thanksgiving and a White Christmas was in 1952. But the average high in this area of the country in late November is still over 40, so it is unusual for a pre-Thanksgiving snow to hang around for more than 4-5 days. But barring a major surprise, the streak of not having both a White Thanksgiving and a White Christmas will continue at least another year.

The Thanksgiving holiday can be quite cold in Lincoln. Those of you who shivered through the OU-NU game in 1993 may well remember a game time temperature in the low 20's. But the coldest Thanksgiving in recent times was in 1985 when a chilly high of 15 was in the middle of an impressive early season cold snap. How impressive was it? Consider that from November 19-December 3 of 1985, the average temperature in Lincoln was 14 and almost every single day featured single digit minimum temperatures. On the other hand, 60 degree weather around Thanksgiving can occur and one only has to go back to last year to find that (it was 67 the day after Thanksgiving last year).

In case you're curious, Lincoln has had a White Christmas approximately 37% of the time in the last 40 years and a White Valentine's Day almost 50% of the time.

Snowfall Statistics

Most of the Region has not seen snow yet and this leaves some people wondering when the latest snowfalls have occurred. The High Plains Regional Climate Center has compiled a list of average, earliest, latest, and season-to-date first snowfalls for selected locations across the Region. (All data derived using products built on the ACIS framework.)

Colorado

Average, Earliest, Latest, and 2010 First Snowfall

Average

Earliest

Latest

2010-2011 Snowfall Season

Period of Analysis

Alamosa

Oct 31

09/03/1961

12/23/1939

Oct 25

1932-2010

Colorado Springs

Oct 25

09/03/1961

01/12/1918

----------

1895-2010

Denver

Oct 18

09/03/1961

01/07/1931

Nov 15

1882-2010

Grand Junction

Nov 17

09/18/1965

01/05/1980

Nov 15

1893-2010

Pueblo

Nov 5

09/17/1971

12/10/1963

----------

1948-2010


Kansas

Average, Earliest, Latest, and 2010 First Snowfall

Average

Earliest

Latest

2010-2011 Snowfall Season

Period of Analysis

Concordia

Nov 21

10/09/1970

12/31/2006

----------

1948-2010

Dodge City

Nov 20

09/21/1995

01/04/1956

----------

1893-2010

Goodland

Nov 1

09/20/1995

01/24/1949

----------

1924-2010

Topeka

Nov 28

10/09/1970

02/10/1923

----------

1887-2010

Wichita

Dec 2

10/22/1996

02/07/1979

----------

1931-2010


Nebraska

Average, Earliest, Latest, and 2010 First Snowfall

Average

Earliest

Latest

2010-2011 Snowfall Season

Period of Analysis

Grand Island

Nov 15

09/20/1995

01/07/1936

----------

1895-2010

Lincoln

Nov 17

09/29/1985

12/31/2006

----------

1948-2010

Norfolk

Nov 9

09/28/1985

01/14/2007

----------

1948-2010

Omaha

Nov 14

10/09/1970

12/31/2006

Nov 12

1885-2010

North Platte

Nov 4

09/20/1995

12/23/1939

----------

1893-2010

Scottsbluff

Oct 23

09/11/1995

12/09/1963

Nov 9

1919-2010

Valentine

Nov 2

09/20/1995

12/10/1962

Nov 11

1889-2010


North Dakota

Average, Earliest, Latest, and 2010 First Snowfall

Average

Earliest

Latest

2010-2011 Snowfall Season

Period of Analysis

Bismarck

Oct 28

09/12/1903

12/14/1999

Oct 26

1886-2010

Fargo

Nov 1

09/04/1933

12/14/1999

Oct 26

1893-2010

Grand Forks

Oct 30

09/17/1991

12/14/1999

Nov 20

1932-2010

Williston

Oct 26

09/02/1961

12/12/1923

Oct 26

1894-2010



South Dakota

Average, Earliest, Latest, and 2010 First Snowfall

Average

Earliest

Latest

2010-2011 Snowfall Season

Period of Analysis

Aberdeen

Nov 5

09/21/1995

01/09/1962

Oct 27

1932-2010

Huron

Nov 6

09/24/1912

12/24/1939

Oct 27

1893-2010

Rapid City

Oct 21

09/13/1970

12/01/2007

Nov 17

1949-2010

Sioux Falls

Nov 6

09/25/1939

01/08/1944

----------

1894-2010


Wyoming

Average, Earliest, Latest, and 2010 First Snowfall

Average

Earliest

Latest

2010-2011 Snowfall Season

Period of Analysis

Casper

Oct 7

09/08/1962

11/18/1953

Nov 9

1940-2010

Cheyenne

Oct 8

09/08/1929

11/20/1900

Oct 25

1883-2010

Lander

Oct 7

09/07/1941

12/07/1914

Nov 9

1911-2010

Moose

Oct 18

09/15/1982

11/25/1999

Oct 25

1959-2010

Thursday, November 18, 2010

October 2010 Global Climate Update


October 2010 and Year-to-Date Climate Facts: Additional Information

•October 2010 was the 308th consecutive month with a global temperature above the 20th century average. The last month with below average temperatures was February 1985.
•According to NOAA data, the warmest October on record occurred in 2003.
•The year-to-date globally-averaged temperature is virtually tied (with 1998) as the warmest January-through-October on record.
•Breaking the planet down into belts, the Northern Hemisphere tropics (between the Equator and 30°N) had its warmest year-to-date on record. In contrast the polar and near-polar Southern Hemisphere (from 60°S to the South Pole) is registering its 49th coolest (82nd warmest) year-to-date on record.

Tuesday, November 16, 2010

NOAA: Review Concludes Lower atmosphere is Warming

Review of Four Decades of Scientific Literature Concludes Lower Atmosphere is Warming

The troposphere, the lower part of the atmosphere closest to the Earth, is warming and this warming is broadly consistent with both theoretical expectations and climate models, according to a new scientific study that reviews the history of understanding of temperature changes and their causes in this key atmospheric layer.

Scientists at NOAA, the NOAA-funded Cooperative Institute for Climate and Satellites (CICS), the United Kingdom Met Office, and the University of Reading in the United Kingdom contributed to the paper, “Tropospheric Temperature Trends: History of an Ongoing Controversy,” a review of four decades of data and scientific papers to be published today by Wiley Interdisciplinary Reviews - Climate Change, a peer-reviewed journal.

The paper documents how, since the development of the very first climate models in the early 1960s, the troposphere has been projected to warm along with the Earth’s surface because of the increasing amounts of greenhouse gases in the atmosphere. This expectation has not significantly changed even with major advances in climate models and is in accord with our basic physical understanding of atmospheric processes.

In the 1990s, observations did not show the troposphere, particularly in the tropics, to be warming, even though surface temperatures were rapidly warming. This lack of tropospheric warming was used by some to question both the reality of the surface warming trend and the reliability of climate models as tools. This new paper extensively reviews the relevant scientific analyses — 195 cited papers, model results and atmospheric data sets — and finds that there is no longer evidence for a fundamental discrepancy and that the troposphere is warming.

“Looking at observed changes in tropospheric temperature and climate model expectations over time, the current evidence indicates that no fundamental discrepancy exists, after accounting for uncertainties in both the models and observations,” said Peter Thorne, a senior scientist with CICS in Asheville, N.C and a senior researcher at North Carolina State University. CICS is a consortium jointly led by the University of Maryland and North Carolina State University.

This paper demonstrates the value of having various types of measurements — from surface stations to weather balloons to satellites — as well as multiple independent analyses of data from these observation systems.

“There is an old saying that a person with one watch always knows what time it is, but with two watches one is never sure,” said Thomas Peterson, lead scientist at NOAA’s National Climatic Data Center. “The controversy started with the production of the first upper-air temperature ‘watch’ in 1990, and it was only later when multiple additional ‘watches’ were made by different ‘manufacturers’ that we learned that they were each a few minutes off. Although -researchers all agree the temperature is increasing, they disagree how much.”

And while this is the first comprehensive review of the scientific literature on this topic, it is not the last word on the tropospheric temperature trend.

“Looking to the future, it is only through robust and varied observations and data analyses that we can hope to adequately understand the tropospheric temperature trend,” said Dian Seidel, a NOAA scientist at the Air Resources Laboratory, in Silver Spring, Md.

Sunday, November 14, 2010

Unusual Snowfall, SE Nebraska, Nov. 12, 2010











An Unusual November Snowfall in Eastern Nebraska, November 12, 2010.


A very narrow band of snowfall occurred in Eastern Nebraska on Friday evening, November 12, 2010.


The satellite image (from the NWS) shows the snow on the ground stretching from near Beatrice to Omaha. On the NW side of Lincoln, at the official NWS site at the Lincoln Airport, there was no measurable snowfall. On the Southeast side of Lincoln near 112th Street and Hwy 2, there was 2 inches of snowfall. During the entire time of the snowfall it was raining to the west and east of Lincoln on either side of the snowband (note the attached radar image).
Snowfall Amounts around the area:
Lincoln Airport: Trace (snow observed, but not enough to measure)
Lincoln, southeast edge: 2.1 inches
Gretna: 4.0 inches
Springfield: 3.4 inches
Omaha Eppley: 2.8 inches
Raymond: 2.0 inches
Offutt Air Force Base: 1.7 inches
Papillion: 2.8 inches
Syracuse: 1.5 inches
Beatrice: 0.5 inches

Tuesday, November 9, 2010

Warmest Summer in Greenland Since Records Began in 1873


Warmest Summer in Greenland

Since Records Began in 1873.


Map: Difference (days) in summer 2010 melt duration compared to the 1979-2007 average. Credit: NOAA Arctic Report Card.

From Andrew Freedman: "According to the report card, last summer was Greenland’s warmest since instrumental records began. Collectively, marine-terminating glaciers lost an area of 419 square kilometers, which is 3.4 times the loss rate seen during each of the previous eight years".

“There is now clear evidence that the ice area loss rate of the past decade is greater than loss rates pre-2000,” the report card states. The report also notes an expansion of the area and duration of Greenland ice melt during 2010, compared to past years".

“What happened in Greenland really was exceptional in the observational record.”

See the interactive feature “Envisioning Ice Loss” as well as field reports and graphics of climate change in the far north.