For Entertainment Purposes Only

For almost a week there has been a persistent rumor that another snowstorm is on the way.  I traced this back to radio spreading the rumor that Farmers’ Almanac had predicted the past two snowstorms and was predicting a third.  I was frequently asked if there was another snowstorm on the way, for which I answered no.  The response was almost always “Well, Farmers’ Almanac is predicting another snowstorm and it predicted the last two.” What?

So I investigated this claim.  First let me point out that there is a Farmers’ Almanac (dating back to 1818) and an Old Farmer’s Almanac (dating back to 1792).  It was Old Farmer’s Almanac that was predicting snow.  Second the forecasts are so vague as to be of little value.  Neither ever forecasted sleet or freezing rain and thus the ice that was so devastating.

Yet there were a few that were adamant that Old Farmer’s Almanac got it right.  If that is the case, then why ever watch the media.  Let’s explore the claim.

I do not have the forecast breakdown for January, but I did get it for February.  For the period of February 7-14, the forecast is for “periods rain and snow, then sunny, cold”.  It was during this period that the snowstorm occurred (11-13).  But, wait!  The forecast is for the entire region from south Georgia to southeast Virginia.  It also includes the Piedmont as well as coastal areas.

Does this forecast apply equally to all locations?  Are we to apply this with rain in the south and snow in the north?  If so, where is the rain/snow line?  Where is there any mention of ice?  Where does it even say snowstorm?  Merriam-Webster Dictionary defines snowstorm as a disturbance of the atmosphere marked by a heavy amount of precipitation in the form of small white ice crystals.  In their forecast how much snow will fall?

Weather? Climate? Confused?

Have you noticed the attention the weather has been getting in the media?  The cold blast for much of the U.S. & Canada, the trapped ship in the Antarctic, and the storms hitting Europe around Christmas are just a few examples.  Other news reports that you may not have been aware were the floods in southern Brazil and in the Caribbean, the heat wave in Argentina, the usually cold weather in the Middle East.  These are all weather events.

Some media outlets are reporting the cold events indicate that we have little to fear from global warming.  Yet global warming does not cancel the seasons.  In fact what we know about our changing climate is to expect more weather extremes worldwide.   Not just heat waves, but more floods, droughts, and even energized storm systems.  This is how a changing climate translates into daily weather.

Often many in the media confuse the difference between weather and climate.  Don’t worry, because some meteorologists do too.  The weather is basically composed the events that unfold in the present.  Meanwhile climate looks at the long term average of weather.  By definition this is a 30-year period.  We can look at shorter term trends to look at how changes are progressing, but we still have to look at the climate period of 30 years.

The Winter 2013-14 Outlook

The Climate Prediction Center (CPC) released its latest outlook for the coming winter this morning.  This year’s forecast is challenging as there are few climate signals that are strong enough to give clues as to what to expect.  Thus the outlook is based more on trends.

Climate outlooks are probabilistic forecasts meaning that they give you information about the chances of seeing departures from the average.  It cannot tell you when or where snowstorms will occur.  The outlook is designed to tell you what the average conditions will be.

This year warmer than normal conditions are expected for the Southwest, the South-Central U.S., parts of the Southeast, New England and western Alaska.  The Northern Plains and the Alaskan Panhandle are expected to see colder than normal conditions.  South Carolina has an equal chance of seeing warmer, near normal, or colder conditions as there are no clues to guide the forecast.

The temperature outlook for the 2013-14 winter.  Click on the image for a larger view.  Image Credit: NOAA.

South Carolina's Wettest Summer

This past summer was cool and wet for Columbia and this was the topic of a previous post.  It turns out that Columbia was not alone.  In fact some areas had much more rain than Columbia.  The mountains of South Carolina saw record rainfall for the summer with an average of over 40 inches.  On August 6^th over 5 inches of rain fell in the Upstate resulting in one drowning death in Pickens County.

Summer rainfall averaged for the mountains of South Carolina (division 1) since 1895.  2013 was the wettest on record.  Click on the image for a larger view.  Image Credit: NOAA/NCDC.

The wettest areas were in the Upstate, Pee Dee, north coastal, and central divisions of South Carolina.  These divisions saw record summer rainfall while all other divisions were at least in the top 10 wettest.

A ranking of summer rainfall for South Carolina since 1895.  Click on the image for a larger view.  Image Credit: NOAA/NCDC.

A ranking of summer rainfall for South Carolina since 1895 with other states in the U.S.  Click on the image for a larger view.  Image Credit: NOAA/NCDC.

The Cool, Wet Summer of 2013

This past summer (June 1-August 31) was a great relief from the past three scorching summers.  Remember that the summer of 2010 and 2011 were back to back the warmest summers on record.  Last summer wasn’t quite as hot, but we did see the all-time record high temperature for South Carolina broken when it reached 113 F in Columbia.

It was during this time that much of the region was also battling drought.  There was some rainfall during the normal wet season of summer, but there were few wet months beginning in 2010.  In fact there were only 8 wet months out of 36 ending in 2012.  It looked like it would never change.

However, the weather pattern began to change in February of this year.  Rains began to increase, but it also got colder.  There were shifting patterns throughout the spring, but it too was cool and wet.  Then summer began with a very sluggish pattern that dominated June and July.  It was not as dominate in August, but it was still enough to keep the month on the cool side.

This weather pattern persisted for much of June and July.  Click on image for a larger view.  Image Credit: WLTX-TV.

From One Extreme To Another

June was a month of extremes across the U.S. Record heat dominated the West, where all time record June temperatures were being set in multiple states. Meanwhile, the same weather pattern that supported the prolonged, intense heat across the West locked in an extremely wet set up across the East. Not only were numerous daily rainfall records set, but both Philadelphia, PA and Macon, GA, ended up with their wettest June ever.

Some of the extreme weather across the U.S. in June 2013.  Click on image for a larger view. Image Credit: Climate Central.

You can also add Augusta, GA, to the wettest June on record.  Bush Field in Augusta received 10.83 inches of rain which was 6.11 inches above normal. An observer near Martinez, northwest of August, received 16.02 inches for June.  This is remarkable since that area of Georgia and South Carolina had been suffering from nearly 3 years of drought until recently.

From Wet To Steamy

Drought has been the rule since the fall of 2009 in parts of South Carolina.  Only 6 out of the next 36 months saw above normal rainfall in Columbia, South Carolina until 2013.  Then the pattern changed and 2013 has been wetter than normal.  In fact, 4 out of the last 6 months have been above normal and July is likely to add to that total.

The first week of July has been extremely wet. The airport has seen 2.19 inches of rain while the city has received 4.35 inches of rain in just six days.  July is normally the wettest month of the year, but this year has been wetter than normal.  In fact, the last two weeks have been quite wet.

The map below shows the observed rainfall across South Carolina for the past two weeks ending on July 6.  Note that the area east of a line from Lancaster to Columbia to Barnwell has seen the greatest rain with 10 to 15 inches of rain in eastern Orangeburg and southeastern Clarendon counties.  The rain has been less west of the line until you get into the upstate of South Carolina.

The 14-day observed rainfall ending at 8 a.m. July 6, 2013.  Click on image for a larger view.  Image Credit: NOAA/AHPS.

Heavy rainfall has resulted in significant rises in many of the rivers with minor flooding of the Congaree River in the Columbia area.  The Congaree Swamp has seen considerable flooding over the past month closing some of the trails.  This is likely to continue as much of the flood waters from the Upstate have yet to pass through the Midlands.

So, why is this happening?  It turns out that our weather is linked to a pattern which has caused record heat in the Southwest and cooler than normal conditions in the Midwest.

When Weather Becomes Climate

Note: It has been a busy three weeks which included a week of much needed vacation.  Much has happened in the interim.  I am working on a number of posts which will be rolled out in May.

Meanwhile, many people often confuse weather with climate.  You have heard the refrains like it is so cold, how could the earth be warming?  Or how can we be in a drought when we’re having a flood?  Just when does weather become climate?  Good question!  Meteorologists at the European Space Agency have produced an answer to that question.

The following video is about 12 minutes long, but it is well produced and worth the time to view it.  They have a wealth of information with which to determine climate change and it is interesting comparing weather in the early 1800’s to weather today.  I hope you enjoy this production.

Click here: When Weather Becomes Climate

Spring 2013: DELAYED

It’s spring!

The vernal equinox on March 20, 2013.  It is that time of year again (it happens twice) when the relative angle of Earth is perpendicular to the Sun, causing equal incoming solar energy to the Northern and Southern hemispheres - as well as equal day and nighttime. At 7:02 ET on March 20, 2013, Earth was at its equinox. At 7:45 ET, the GOES-13 satellite captured this full disk image of Earth.  Click on the image for a larger view.  Image Credit: NOAA.

Both meteorological and astronomical springs have arrived.  The vernal equinox marks the beginning of spring in the Northern Hemisphere.  This is when the vertical rays of the sun are directly over the earth’s equator and crosses the equator on its northward journey.

Funny, it doesn’t feel like spring.  Let me check the forecast:

The 5-day forecast for March 20, 2013 for Columbia, SC.  Image Credit: WLTX-TV.

Remember those groundhog forecasts from six weeks ago.  A couple of them got it right, but most got is wrong.  Not only did spring not come early, it does not appear to be in sight.

Groundhog Predictions

This past Saturday (February 2) was Groundhog Day, a day of anticipation by many tired of winter.  Each year people wait to see what the groundhog has to say about the coming spring.  The most famous groundhog is Punxsutawney Phil in Pennsylvania and has the longest running record.  Predictions from 1888 to 1900 were intermittent and became regular after that time.

Punxsutawney Phil comes out of his hole each Groundhog Day, like clockwork, to tell us if we can expect an early spring or another six weeks of winter. If Phil sees his shadow, he’ll go back underground to wait out the next chilly month and half. If there’s no shadow, Phil — and the rest of us — know that spring is right around the corner.

Average temperature for Columbia, SC, from February 2 - March 16.  Image Credit: Climate Central.

The six-week period that starts on February 2nd has been getting gradually warmer in Columbia since 1887. The warming hasn’t been uniform: you can see from the graph above that some years are cooler than average and some are warmer, but the overall trend is slowly upward. This is consistent with the rising global temperatures that climatologists have predicted with increasing certainty for decades.

Climate Matters Wins

The 93^rd annual meeting of the American Meteorological Society (AMS) has been going on this week in Austin, Texas.  An awards banquet was held Wednesday evening where I received the Award for Excellence in Science Reporting by a Broadcast Meteorologist.  The award was for the pioneering program Climate Matters which began in July, 2010.  I am the seventh recipient of the award.

Climate Matters Page on the WLTX website.  Image Credit: WLTX.

Climate Matters is a program that attempts to educate viewers about climate change and how it is already affecting their lives.  Many of the segments are localized to the effects on South Carolina, but may also apply to other regions.  The reports use only peer-reviewed published work of scientists involved in climate change research.

However, let me tell you how this came about.  It started with my own interest in climate change.  I was at a retirement party for Dr. John Carpenter who was in the Geology Department and longtime director of the Center for Science Education at the University of South Carolina.  During that party a couple of professors came up to me and ask if I thought climate change was real.  I told them that I thought it was, but had not really given it much thought.

A Not So Merry Christmas!

'Twas the night before Christmas, when all through the house
Not a creature was stirring, not even a mouse;
The stockings were hung by the chimney with care,
In hopes that St. Nicholas soon would be there;
The children were nestled all snug in their beds,
While visions of sugar-plums danced in their heads;
And mamma in her 'kerchief, and I in my cap,
Had just settled down for a long winter's nap,
When out on the lawn there arose such a clatter,
I sprang from the bed to see what was the matter.

From The Night Before Christmas

For some there were no children snug in the beds with visions of sugar-plums dancing in their heads.  No time to settle down for a long winter’s nap.  The winds were howling and the snow was flying, while tornadoes danced south keeping everyone on edge.  This year Mother Nature would be part of the tale.

Meteorologists were kept busy forecasting what’s next;

Many monitored each storm and sent out the text;

For many the weather was not so genteel;

Like the tornado that passed through the heart of Mobile;

Most were quite nervous as the storms moved east;

Not knowing what to expect from this awesome beast;

But most survived Mother Nature’s disorder;

Because they were warned by meteorologists and reporters.

There was no surprise from the Christmas Day storm.  It had been forecast well in advance.  The European model hinted that it might take place as I mentioned on-air a week before it happened.  What happened?

Give Thanks for Quiet Weather

Thanksgiving Day is the fourth Thursday in November so that the date changes each year.  This year it is on the 22^nd which is the earliest that it occurs.  For Christmas shoppers it means you have more time between Thanksgiving and Christmas to get those gifts.  Next year, 2013, Thanksgiving Day will fall on the 28^th which is the latest date that it occurs.

The weather can be bitter or balmy or anything in between.  Research by Climate Central shows that in Columbia, SC, the warmest Thanksgiving Day was in 1900 with 81 degrees F.  The coldest temperature recorded has been 21 degrees F in 1970.  It is interesting that 1 inch of snow fell in 1912.  However, there has not been a measurable snowfall on Christmas Day in Columbia.

Click on the image for a larger view.  Image credit: Climate Central.

The Global Weather Pattern Shifts

The previous post described how changes in the Arctic were causing changes in the weather and climate.  These changes extended down in the mid-latitudes where the impacts included cold, snowy winters.  However, the impacts of a warming earth do not end there.  Research shows that mankind is shifting the entire global atmospheric circulation.

Background

Meteorologists have developed an idealized view of the global atmospheric circulation over the past century.  It has long been recognized that there is too much heat at the equator and too little at the poles.  The atmosphere acts like “the great equalizer “ by transporting heat from the tropics to the poles.  If the earth were not rotating, this would be a simple straight-forward transfer.

The situation is complicated by the fact that the earth does rotate on its axis.  This has given rise to the three-cell global circulation model.  The three cells from the tropics to the poles are named: Hadley, Ferrel, and Polar.  This model is pictured below with the resulting wind patterns.

The three-cell general circulation model of the atmosphere.  This is an idealized model based on observations.  Image credit: NASA.

The Hadley cell (also known as the tropical cell) extends from the equator to 30 degrees latitude.  Many of the world’s major deserts lie at the poleward extent of the Hadley cell where the air descends from upper levels.  This produces a persistent dry climate with little rainfall.  The North American Desert, Sahara, Australian Desert, and Kalahari Desert all are products of this circulation.

The Heat Is On

Image Credit: Climate Central.

The January-August period was the warmest first eight months of any year on record for the contiguous United States. The national temperature of 58.7°F was 4.0°F above the 20th century average, and 1.0°F above the previous record warm January-August of 2006. During the eight-month period, 33 states were record warm and an additional 12 states were top ten warm. Only Washington had statewide temperatures near average for the period.

The statewide ranks of temperatures since 1895 and the top ten warmest January-August periods in South Carolina.  Image Credit: NOAA\NCDC.

Flood & Drought: Part 1

This is the first of a three parts examining changes in the hydrologic cycle, also known as the water cycle.  Our changing climate is changing the water cycle and the weather patterns that deliver precipitation.

Part 1 is a rewrite of a blog post that I published in 2009.  It is as important today as it was then.  Part 2 will be an update of the observed rainfall extremes in the Southeast and U.S.  Part 3 will look at drought and new research as to why drought is becoming more common across the southern U.S.

From 2009:

The idea for this blog came from two sources. The first source was a comment on an earlier story.

In the comment section, a reader wrote:

“By the way, the article above does not inform you that global warming does not cause droughts or dry weather. Global warming would mean MORE RAIN.
I would defer to Mr. Gandy on that though. Am I correct Mr. Gandy, wouldn't global warming mean more evaporation of surface water and snow and more evapotranspiration from plants, causing more rain?”

This seemed intuitive, more water vapor, more rain.  Just over a year ago I was at a panel discussion in Denver, Colorado, where Dr. Kevin Trenberth mentioned that water vapor had increased about 7% globally.  Dr. Trenberth was a lead author of the 2001 and 2007 IPCC Scientific Assessment of Climate Change and serves on the Scientific Steering Group for the Climate Variability and Predictability program.  He currently heads the Climate Analysis Section at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado.  This information has since been confirmed in several papers.

The top 10 daily rainfall totals for Columbia, SC.  Click on the image for a larger version.  Image Credit: Climate Central.

The second source came from a recent study (citation below) published 5 September 2009, in the Geophysical Research Letters (GRL).  It has changed my thinking after a careful review of the paper.

Scientists to Study Impacts of Thunderstorms on the Upper Atmosphere

Our thunderstorm season is about to get underway.  Spring is known for severe weather, but summer is known for its afternoon and evening thunderstorms.  These storms build up in the heat and humidity of the day and provide most of the rain during the summer.  A study will be conducted from May 15 to June 30 to measure the impact of thunderstorms on the upper atmosphere.  The following is a press release from the National Center for Atmospheric Research in Boulder, Colorado.

Press Release:

Scientists at the National Center for Atmospheric Research (NCAR) and other organizations are targeting thunderstorms in Alabama, Colorado, and Oklahoma this spring to discover what happens when clouds suck air up from Earth’s surface many miles into the atmosphere.

Thunderstorm in eastern Colorado. (Photo by Bob Henson.)

The Deep Convective Clouds and Chemistry (DC3) experiment, which begins the middle of this month, will explore the influence of thunderstorms on air just beneath the stratosphere, a little-explored region that influences Earth’s climate and weather patterns. Scientists will use three research aircraft, mobile radars, lightning mapping arrays, and other tools to pull together a comprehensive picture.

“We tend to associate thunderstorms with heavy rain and lightning, but they also shake things up at the top of cloud level,” says NCAR scientist Chris Cantrell, a DC3 principal investigator. “Their impacts high in the atmosphere have effects on climate that last long after the storm dissipates.”

Past field projects have focused on either the details of thunderstorms but with limited data on the atmospheric chemistry behind them, or on the chemistry but with little detail about the storms themselves. DC3 is the first to take a comprehensive look at the chemistry and thunderstorm details, including air movement, cloud physics, and electrical activity.

Drought Worsens in South Carolina

Droughts are hard to define.  Meteorological droughts are prolonged periods with less than average precipitation, but the prolonged period is nebulous.  How many weeks or months must go by before a drought is declared?  Again this depends on how much precipitation has occurred.  Obviously if no precipitation occurs then it doesn't take long to enter a drought.  Defining when a drought started can also be difficult.  Thus, you often do not know that you are in a drought until it gets serious.

Remember December 2009?  The precipitation total for that month in Columbia was 9.31 inches, almost three times the normal value.  It was a record wet December.  In addition the four month of September through December totaled 25.96 inches which was a record for that four month period.  What happened?  A strong El Nino was in progress and most of the rain that year came in just that four months.

Click on image for the larger version.

In the 28 months since that time there have only been four months of above normal rainfall.  So in retrospect we have been in a period of drought since January 2010.  The rainfall deficit has been enormous during this time.  The deficit in Columbia has reached 25.57 inches in the past 28 months.  However, it is much worse along the Savannah River where Augusta has amassed a deficit of 38.71 inches in the same time period.  Thus the western part of South Carolina is in worse shape than the northeastern part of the state and this is reflected in the USDA Drought Monitor.

Know Your Sun

Image Credit: NASA/Jenny Mottar

NASA has just released five new videos called "Mysteries of the Sun". The videos describe the science of the sun and its effects on the solar system and Earth. Scientists study the sun not only to better understand the orb that influences life, but also to study how it sends solar material out into space, filling up the bubble that defines the farthest reaches of the solar system. The sun can also impact Earth's technology: solar storms can affect our communications satellites and cause surges in power lines. These movies cover the breadth of solar, heliospheric, and geospace science, a field known as heliophysics.

The five movies, available online at http://missionscience.nasa.gov/sun and on DVD, cover five areas of heliophysics: Space Weather, Solar Variability, the Heliosphere, Earth's magnetosphere, and Earth's upper atmosphere.

The Windiest Time of the Year

Spring always seemed like the time of the year to fly a kite when I was growing up.  I didn't know much about what it took to get a kite high off the ground, but fortunately I had an older brother who did.  I can remember times when we got a box kite up to about three hundred feet above the ground.

Across most of the country, spring is the windiest time of the year.  Wind speeds and wind power tend to be 3-5 times stronger in March and April than in July and August.  In the dust bowl days most of the dust storms were in late winter and spring.  That continues to be the case in the Plains today.

Gusts may come and go, but on average there’s more wind now than at any other time of the year. The chart below shows the amount of electricity that would be generated by a single 1.5 megawatt wind turbine, with each point representing a running nine-day average. Historically, March 21st is the windiest single day of the year.
 
Click here for an interactive chart that represents the same data, but you can hover over any point to get the relative wind power for any given day (again, based on a nine-day average). 

Daily wind power generated at a single turbine, 9-day average (Wind Power (x 1000 kWh)).  Image credit: Climate Central.