Wednesday, February 29, 2012

First Ever February Nebraska Tornado

Historic February Tornado in Nebraska

A First Ever Occurrence
On February 28, 2012 a tornado was observed
and photo documented in western Nebraska. This was the first observed and documented tornado during the month of February for any year since records began in 1950.

Can a tornado occur in Winter in Nebraska?
Yes. It's not impossible to have tornadoes in Nebraska during the Winter months, it is just that it is very rare. Since 1950, there have been 3 tornadoes in November, 2 tornadoes in December and 6 tornadoes in January. In each of those winter months, the right combination of weather variables had to come together for tornadoes to occur.

Prior to February 28, 2012, the total number of
observed tornadoes for each month for the 1950-2011 time period (61 years ) was
as follows:
January : 6 tornadoes
February: 0 tornadoes
March: 58 tornadoes
April: 218 tornadoes
May: 733 tornadoes
June: 917 tornadoes
July: 358 tornadoes
August: 165 tornadoes
September: 57 tornadoes
October: 75 tornadoes
November: 3 tornadoes
December: 2 tornadoes

The total of all months, 1950 through 2011 was 2,593 tornadoes.

More information on
the monthly totals of tornadoes in Nebraska can be found at: http://www.lincolnweather.unl.edu/data/Nebraska-tornado-Totals-1950-2011.asp

Friday, February 24, 2012

Global Temperature Anomalies, 1880-2011

videoGlobal Climate Change, 1880-2011
The video is from NASA. It isa 26-second animation depicting how temperatures around the globe have warmed since 1880. That year is what scientists call the beginning of the “modern record.” You’ll note an acceleration of those temperatures in the late 1970s as greenhouse gas emissions from energy production increased worldwide and clean air laws reduced emissions of pollutants that had a cooling effect on the climate, and thus were masking some of the global warming signal. The data comes from NASA's Goddard Institute for Space Studies in New York, which monitors global surface temperatures. As NASA notes, “in this animation, reds indicate temperatures higher than the average during a baseline period of 1951-1980, while blues indicate lower temperatures than the baseline average.”

Thursday, February 16, 2012

Global Temperature Anomalies January 2012





Janaury 2012 Global Temperature Anomalies



From NOAA/NCDC.
The combined global land and ocean average surface temperature for January 2012 was the 19th warmest on record. This January is the coolest January since January 2008.

However, it also marks the 26th January and 323rd consecutive month with a global temperature above the 20th century average. The last month with below average temperatures was February 1985.

Separately, the global land surface temperature was the 26th warmest January on record. Warmer-than-average conditions occurred across most of North America, the northern latitudes of Europe and Asia, southern South America, and most of Australia. Cooler-than-average regions included China, Mongolia, Kazakhstan, south central Russia, much of the Middle East, northern India, north Africa, and southwestern Greenland.

Separately, the global land surface temperature was the 26th warmest January on record. The Arctic Oscillation climate pattern played a large role in temperatures in the Northern Hemisphere during January. The positive phase during the first half of the month contributed to well-below average monthly temperatures across Alaska and above-average temperatures across the contiguous United States. The negative phase during the second half of the month contributed to warmth in Canada and also to a cold snap that began during the last week in January across Central and Eastern Europe and North Africa.

The January global ocean surface temperature was the 17th warmest January on record. The warmth was most pronounced across the north central and southwestern Atlantic Ocean, the central and western Pacific, and the southeastern Indian Ocean.

Wednesday, February 15, 2012

El Niño and La Niña . 2012 Outlook

El Niño and La Niña 2012 Outlook
The graph to the left is from The International Research Institute for Climate and Society (IRI).

Any value of +0.5 or higher is consdiered to be a an El Niño phase and any value less than -0.5 is considered to be a La Niña phase. The current observation "OBS" is a -1.1 and indicative of a moderate La Niña .

There are multiple numerical forecast models shown on the graph. The fact that there is so much variation between the models is indicative of the fact that this is an area of meteorology forecasting with large amounts of uncertainty.

The majority of the numerical forecast models push the climate into "neutral" conditions by Summer (JJA) between +0.5 and -0.5, i.e. the current La Niña would end and but an El Niño would NOT begin. A few models indicate that the current La Niña could linger into Summer but it would be very weak. And a few of the models push the climate dramatically into an El Niño. Based upon the consensus of the majority of models, the current La Niña should fade away into "neutral" conditions by Summer 2012.

Tuesday, February 14, 2012

White Valentine's Day

Many people desire snow on Christmas Day and Mother Nature cooperates with a White Christmas a little more than 30 percent of the time in Lincoln. I'm not sure we would call the 2009 Christmas blizzard an act of cooperation on her behalf, but I digress.

On the other hand, for those of you who think having snow on the ground makes Valentine's more romantic, your chances of having snow on the ground are statistically better on Valentine's than on Christmas. Over the last 40 years, 1 inch or more of snow has been on the ground on Valentine's Day 18 times, or right at 45 percent of the time.

Valentine's Day is statistically a bit warmer than Christmas though and we're getting into that time of year where the differences between the record low and record high can approach 100°F. For example, today's record low of -15°F and record high of 75°F is a difference of 90°F. The difference between the record low maximum and record high maximum is almost as impressive: -4°F and 75°F. In other words, the high for Valentine's in Lincoln has been as cold as -4°F and as warm as 75°F. Today's forecast of 39° is well, painfully average. But there's snow at least right?

Tuesday, February 7, 2012

January 2012 Statewide Temperature Rankings

U.S. January 2012 Climate Summary
From NOAA/NCDC.

This monthly analysis is based on records dating back to 1895.

The average contiguous U.S. temperature in January was 36.3 degrees F, 5.5 degrees F above the 1901-2000 long-term average — the fourth warmest January on record, and the warmest since 2006.Warmer-than-average temperatures were widespread across the contiguous United States during January. Nine states — AZ, KS, MN, MO, NE, ND, OK, SD, and WY — had January temperatures ranking among their ten warmest. FL and WS were the only states with temperatures near average, and no state was cooler than average. Many locations across the Northern Plains exceeded all-time warm January maximum temperature records during the month, including Minot, North Dakota, which reached 61 degrees F on January 5th. This surpassed the previous record of 59 degrees F for the city, set on January 28th, 1906.In contrast to the contiguous United States being much warmer than average, several towns across Alaska had their coldest average January temperatures on record — Nome (-16.6 degrees F), Bethel (-17.3 degrees F) McGrath (-28.5 degrees F), and Bettles (-35.6 degrees F).

Monday, February 6, 2012

February 3-4, 2012 Snow Totals

February 3-4, 2012 Snowfall Totals

The map to the left (from NWS Omaha) shows the snowfall totals for the February 3-4 snow storm. There was a sharp gradient to the south with very little snowfall along the Nebraska-Kansas border in SE Nebraska. One of the most interesting features of this event was how the major snowstorm died out once it reached mid-Iowa. Usually these types of systems will track across the country but n this case after dumping more than a foot of snow from Denver to eastern Nebraska, it never made it past the Mississippi River. The official measurement for Lincoln, NE was 11.1 inches of snowfall making this the 4th greatest daily snowfall in the 1948-2012 data records. More information about this storm can be found on previous Climate Corner Posts.

Click on the above map to see a larger version.

Sunday, February 5, 2012

Nebraska Snow Cover

Satellite Image, February 5, 2012

The attached satellite image shows the extent of snow cover (white color) following the snow storm of February 4, 2012. The red lines note the northward and southward extent of the snow cover. The letter "P" indicates the Platte River Valley which is very evident on the satellite image. The letter "M" notes Lake McConaughy which can be seen as an area even darker than the snow free area. The letter "L" notes Lincoln, Nebraska which is a darker grayish white color since the snow has been removed from all of the streets making the landscape darker. The letter "H" is the Harlan County Reservoir. The northwestern portion of Nebraska is snow-free as is the far southeastern portion of Nebraska and right along the Kansas border in southeastern Nebraska.

February 4, 2012 Snowfall

February 4, 2012:
4th Largest Daily Snowfall Lincoln, NE
11. 1 inches of snow fell in Lincoln, NE at the official measuring location of the Lincoln Airport. There was a total of 11.8 inches at my house in Lincoln as showninthe photo to the left.

Although we have monthly data extending back to 1900, we only have daily snowfall data extending back to 1948.

Looking at this 1948-2012 daily data set, the 11.1 inches of snowfall on February 4, 2012 was the 4th largest daily snowfall for any calendar day in Lincoln.

Here are the top daily snowfall records:
#1: 19.0 inches on February 11, 1965
#2: 13.2 inches on October 26, 1997
#3: 11.4 inches on January 3, 1971
#4: 11.1 inches on February 4, 2012
#5: 10.0 inches on March 8, 1998

Thursday, February 2, 2012

Lincoln January 2012 Climate Summary

January 2012 Lincoln, NE,
Climate Summary




Highest temperature: 70 F on January 31

Lowest temperature: 4 F on January 13

Average January 2012 Temperature: 30.0 F
5.4 deg. above normal, AND,
20th warmest on record

January 2012 Precipitation Total: 0.16 inches
0.48 inches below normal

January 2012 Snowfall: 1.6 inches
(3.8 inches below normal)

Records:
January 4, Tied Record High Temperature of 59 F
January
5, Record High Temperature of 68 F (old record 61 F)
January 30, Record High Temperature of 70 F (old record 60 F)



Warmest January on record: January 2006: 36.7 F
Coldest January on record: January 1940: 6.4 F

U.S. Climate Records in 2011



U.S. Climate Records in 2011

The attached map shows the annual records broken or tied at selected stations for the year 2011, representing the warmest, wettest, coolest or driest calendar years on record for the location. This list was compiled from National Weather Service "Record Event Reports", and from cooperative observer locations with at least 60 valid years on record. This list should be considered preliminary and incomplete; December data from paper-based recording stations (about one-third of the reporting network) has not been fully processed, and final quality assurance has not been performed on the 2011 data. When the data are complete, the final number of stations with new annual records will likely be slightly larger.


2011 Wettest Year on Record:
Some of the precipitation records were shattered by a large amount. For example:

Bear Gap, PA 2011 precipitation 89.07 inches (old record was 59.35inches)
Harrisburg, PA 73.73 inches (old record was 54.63 inches)

2011 Driest Year on Record:

Some of the record dry amounts were also very impressive. For example:
Hobbs, NM 1.85 inches for the entire year! (old record was 4.69 inches)
Alpine, TX 3.17 inches (old record was 7.72 inches)
Seminole, TX 3.72 inches (old record was 5.61 inches)


Wednesday, February 1, 2012

U.S. Year 2011 Record Climate Extremes




NOAA: 2011 a year of climate extremes in the United States
NOAA announces two additional severe weather events reached $1 billion damage threshold, raising 2011’s billion-dollar disaster count from 12 to 14 events.


According to NOAA scientists, 2011 was a record-breaking year for climate extremes, as much of the United States faced historic levels of heat, precipitation, flooding and severe weather, while La Niña events at both ends of the year impacted weather patterns at home and around the world.


For more information, NOAA Link: U.S. Year 2011 Record Climate Extremes

G

Year 2011 Global Temperature Anomalies

Global Temperatures: Highlights from NCDC


This year tied 1997 as the 11th warmest year since records began in 1880. The annual global combined land and ocean surface temperature was 0.51°C (0.92°F) above the 20th century average of 13.9°C (57.0°F). This marks the 35th consecutive year, since 1976, that the yearly global temperature was above average. The warmest years on record were 2010 and 2005, which were 0.64°C (1.15°F) above average.

Separately, the 2011 global average land surface temperature was 0.8°C (1.49°F) above the 20th century average of 8.5°C (47.3°F) and ranked as the eighth warmest on record. The 2011 global average ocean temperature was 0.40°C (0.72°F) above the 20th century average of 16.1°C (60.9°F) and ranked as the 11th warmest on record.

La Niña, which is defined by cooler-than-normal waters in the eastern and central equatorial Pacific Ocean that affects weather patterns around the globe, was present during much of 2011. A relatively strong phase of La Niña opened the year, then dissipated in the spring before re-emerging in October and lasting through the end of the year. When compared to previous La Niña years, the 2011 global surface temperature was the warmest observed during such a year.

Changes on the horizon?



After coming off the 20th warmest January on record (unofficial results), including tying or setting 3 record highs, it appears winter may be making an appearance toward the end of the week. From this morning's OAX Forecast Discussion:

1 TO 2 INCHES OF WATER EQUIVALENT IS POSSIBLE ACROSS THE SOUTH WITH AN INCH OR LESS IN THE NORTH. THE 00Z RUNS TRACK THE HEAVIER SNOW FROM WEST OF A LINE FROM BEATRICE TO LINCOLN TO BELLEVUE AND OAKLAND IOWA WITH 6+ INCHES OF SNOW POSSIBLE. THE GARCIA METHOD ALSO SHOWS THE POTENTIAL FOR HEAVY SNOW BASED ON THE DURATION OF LIFT AND MOISTURE AVAILABLE. GUSTY NORTHEAST WINDS OF 15 TO 30MPH WITH HIGHER GUSTS CAN ALSO BE
EXPECTED DURING THE STORM.

So for those of you who wondered how we were going to pay for this incredibly mild stretch of weather, there's your answer. It's still a few days out but the storm certainly bears watching. Any moisture from the storm will be welcome though as the past six weeks has been pretty dry in this region.

However, even if we had a significant storm this weekend, it would still pale in comparison to the change that happened at this time in 1989. Record warmth spread across much of Kansas, Nebraska, Iowa, and Illinois on January 31, 1989 with temperatures in the 60's and 70's. This was a fitting end to one of the warmest January's on record for this region but BIG changes were lurking to the north and northwest. By midday February 1, the front had passed through much of the Midwest and many places in Nebraska saw 50 degree temperature drops in a short time. Case in point, Lincoln's temperatures from the afternoon and evening of 1/31/89 into early morning on 2/1/89.

4 PM: 70
5 PM: 66
7 PM: 52
10 PM: 30
12 AM: 22
6 AM: 10 (Wind chill of -11)

Temperatures in Lincoln went below 0 late in the afternoon on Groundhog's Day and didn't go above 0 again until the afternoon of the 5th. Starting with 1/31/89 and ending with 2/5/89, here are the respective highs at the East Campus AWDN site: 72, 20, 4, -4, -2, 5. To further illustrate the difference are two figures (see above) from WeatherScope: one from 3 PM on 1/31/89 and another from 3 PM on 2/2/89.

February 1989 ended with an average temperature of 16.3 and snow on the ground for most of the month. A repeat of 1989 does not seem likely this year but that doesn't mean winter is over for us...