Thursday, May 8, 2014

My Day at the White House


On April 23rd my news director, Marybeth Jacoby, received an email from NASA stating that the 3rd National Climate Assessment would be released on Tuesday, May 6th.  She forwarded the email with a note “How can we make this BIG?”  I started thinking about how I would approach it.

I received a call from the White House just after our 7 p.m. newscast on Thursday, May 2nd.  It was Keith Maley, Regional Communications Director, and he was inviting me to the White House for the release of the 3rd National Climate Assessment.  I was being invited because of my work in educating viewers about how climate change was already affecting their lives and how it would impact them in the future.  WLTX-TV partnered with the Center for Climate Change Communication at George Mason University and Climate Central to develop a program called Climate Matters.

The segments began airing in August 2010 and were highly focused topics used within the weathercasts.  Typically these segments ran from 30 to 60 seconds not including anchor interaction.

I was delighted to be able to accept their invitation.  What an honor!  As you can imagine there was a lot a planning to do at the last minute.  There was a scramble to book flights and hotel for an event taking place on Tuesday, May 6th.  I also responded to Marybeth’s email “It doesn’t get much bigger than a presidential interview. Mission Accomplished!"

My producer, Sharranda Neal, and I flew out of Columbia, SC, Monday morning and arrived in Washington, D.C., mid-afternoon.  We hit the ground running trying to shoot stand-ups for the evening shows and the morning show the next day.  There were a host of technical issues we had to overcome, but we managed to get the job done.

We returned to the hotel quite tired and prepared for the next day that we knew would be hectic.  We were not disappointed.

Sunday, April 13, 2014

"Years of Living Dangerously"

Climate change is a complex topic and even some of the experts have a difficult time grasping all of the implications.  As the climate changes so does the society and world in which we live.  The most recent findings of the Inter-governmental Panel on Climate Change (IPCC) point out what the science knows and the risks ahead.

Now a documentary series tries to bring the knowledge of climate change to the ordinary person.  It does this by telling the stories of people affected by climate change.  How does degrading the environment affect the world and the food you eat?  How does drought relate to climate change?  What are the risks involved in our future?

These are some of the questions addressed in a new Showtime series airing Sunday, April 13, 2014, at 10 p.m. called “Years of Living Dangerously”.  It is a nine-part series that will address a number of topics related to climate change.

The first episode is already available on the internet at the website .  If you do not get Showtime, you can watch it here.  Below is a discussion on the documentary and climate change from two of the participants in the program on a recent Face The Nation on CBS:

Wednesday, April 9, 2014

Time to Plant

I have been advising gardeners to delay planting tender plants this year due to a weather pattern that has been in place since late October, 2013.  The pattern made it more likely for a late freeze.  Normally the last freeze would occur in the Midlands by late March.  Most would simply wait until Easter, but Easter is quite late this year.  The latest freeze was on March 27th and it was a hard freeze with a low of 28° F.  It was very close to freezing on March 31st with a low of 33° F, but there was frost that morning.

Another cold, dry air mass is making its way south and computer models have been suggesting that a frost or freeze might occur on Thursday, April 10th.  High pressure will settle over the area with clear skies, light winds, and dry air for Thursday morning.  The forecast for Columbia is for a low near 40° F that morning, but outlying areas may drop into the mid 30s.  This would be enough for a light frost in low-lying protected areas due to radiational cooling at night.

This will likely be the last chance of a frost or freeze.  If it does not happen then the previous dates will be the last freeze or frost.  The chance of a frost or freeze on April 10th was strong enough to advise gardeners to wait.  The seven-day forecast reveals that it will be time to plant this weekend.

The 7-day forecast made Wednesday, April 9, 2014 for Columbia, SC.  Click on the image for a larger view.  Image Credit: WLTX-TV.

Thursday, March 13, 2014

A Normal Winter?

The National Climatic Data Center (NCDC) released its analysis of the past winter today and the assessment for South Carolina? Near normal. The statewide average turned out to be the 66th coldest and 65th wettest winter on record.  The ranking was based on 120 years of data.

The statewide rank of temperatures (top) and precipitation (bottom) based on 120 years of records (since 1895).  A rank of 1 for temperature would be the coldest while for precipitation it would be the driest.  Click on the image for a larger view. Image credit: NOAA/NCDC.

Sunday, March 2, 2014

Coming in the Back Door

This winter has been a wild one for temperatures in South Carolina.  There have been big swings from hot to cold and back again.  Now that meteorological spring has begun (March 1st) the pattern continues.

A dramatic change to our weather is about to take place.  Cold arctic air is already in place across much of the central U.S.  Normally a cold front moving in from the west would bring the cold air to our state.  However, occasionally it comes in through the “back door”.

High pressure builds east and the cold air slides down the eastern seaboard faster than it can come in from the west.  It becomes trapped between the ocean to the east and the Appalachians to the west.  The cold front that surges south is known as a “back door” cold front.

Typically a wedge of cold air stays in place until something comes along to move the cold air out, which is a very difficult thing to do.  The result can be days of overcast skies and chilly northeast winds.

This time the back door cold front will be accompanied by a dramatic temperature drop.  When the front passes the temperatures will likely drop 20-25° F in an hour or two.  The front will be preceded by a band of rain which will begin the temperature drop.  Winds will shift from a westerly direction to a northerly direction as the front passes.  The winds will increase and there will be a wind chill to worry about in the late afternoon.

The RPM model forecast for 1:30 p.m. EST on Monday, March 3, 2014.  This is from the 21z run of the model using the 12 km grid.  Click on the image for a larger version.  Image Credit: WLTX-TV\WSI.

Wednesday, February 26, 2014

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?

Saturday, February 22, 2014

Remembering #WinterMess 2

Little did we know that the winter storm at the end of January would be the prelude to a bigger storm two weeks later (February 11-13).  A complex storm system came through South Carolina in two waves.  The first occurred on Tuesday with snow over the northern Midlands and rain/sleet elsewhere.  This was followed by the main batch of precipitation on Wednesday ending Thursday morning.

Most of the snow occurred over the northern half of the Midlands.  It was mainly sleet with some snow in Columbia, but the precipitation became more snow farther north.  The northern most counties of the Midlands saw a considerable snowfall.

Total snowfall as of 7 a.m. Thursday, February 13, 2014.  This is based on observations from the National Weather Service Forecast Office in Columbia, SC.  Image Credit: WLTX-TV.

South of Columbia it will a sleet/freezing rain mix.  The farther south you went the more freezing rain occurred.  The southern Midlands saw the greatest accumulation of ice as shown on the map below.

Total ice accumulation as of 7 a.m. Thursday, February 13, 2014.  This is based on observations from the National Weather Service Forecast Office in Columbia, SC.  Image Credit: WLTX-TV.

The Midlands ended up on the dividing line between snow and ice.  The northern half saw a snowstorm while for the southern half saw an ice storm.  Travel became difficult if not impossible through some sections.  The worst of the storm occurred over the southern Midlands with the accumulation of ice.  An estimated 350,000 people lost power at the end of the storm.  Some were without power for over a week.  Schools remained closed for Wednesday through Friday with some of the northern counties closing schools on Tuesday.

Tuesday, February 18, 2014

The #BigMelt

There is finally some relief after a week of snow and ice followed by an earthquake.  It was quite cold this past week following the 12th coldest January on record for Columbia.  It was the 11th coldest for South Carolina as a whole in January.  The weather warmed after the first winter storm at the end of January.  Little did we know that it was a warm-up act for the next winter storm.

Most of the snow and ice melted as the sun returned on Friday and a warming trend began.  A cold shot of air on Saturday only slowed the melt, but the warming trend continued on Sunday.  This week will be noticeably warmer this week.  In fact, temperatures will be in the mid to upper 70s by Thursday.

The 7-day forecast for Columbia, SC, for February 18-24, 2014.  Click on the image for a larger view.  Image Credit: WLTX-TV.

Monday, February 10, 2014

#WinterMess the Sequel

And this time she means business!

The big picture described in yesterday’s blog post is still on track, but the details are a little different.  This is based on the latest computer model runs.  Basically, an upper-level system now in the southwestern part of the country will combine with a disturbance moving in from western Canada and will intensify over the Southeast.  This will induce a surface low to form first in the Gulf of Mexico and then off the Southeast coast.  High pressure over New England will push cold air into the Carolinas setting the stage for winter precipitation.  It will be a “big ol’ mess” when all comes together.

A Winter Weather Advisory has been issued for the northern midland counties of Saluda, Newberry, Fairfield, and Kershaw.  This will be for an accumulation of snow and sleet mainly Tuesday morning.  The following is an update from the previous post.

As mentioned yesterday the forecast is a difficult one based on the timing and various forms of winter precipitation that will occur.  The Midlands will see it all; rain, freezing rain, sleet, and snow.  It appears that the onset of precipitation will be late tonight as rain moves into the area.  The rain will likely change to snow during the early morning hours for the northern part of the Midlands (Saluda, Newberry, Fairfield, and Kershaw counties).  There could be enough accumulation to cause travel problems, so travel through the northern Midlands needs to be monitored.  The snow will change to rain and taper off during the afternoon.  This will be the first surge of moisture into the region.

A computer model view (RPM) of precipitation at 6 a.m. Tuesday.  This is from the 21z RPM model run.  The bluish areas are snow and could contain sleet.  The green areas are rain.  The pink is for a wintry mix.  Click on the image for a larger view.  Image Credit: WLTX-TV.

Sunday, February 9, 2014

Another #WinterMess?

Just two weeks ago a winter storm moved through the region producing a combination of rain, freezing rain, sleet, and snow.  Many thought this was it for the winter, but Mother Nature had other ideas.  Look here for a rundown of WinterMess #1.

Incredulously another winter storm is headed through the Southeast.  This time it will be a little different from the previous storm (i.e., no two storms are identical).  A complex weather pattern will develop over the Southeast with an upper-level disturbance moving east and helping to develop a low pressure system off the Carolina coast.  A surge of cold air will be pushing into the Carolinas ahead of this which will turn the rain into a wintry mix.

The models are a little better in converging on a solution.  There is still considerable uncertainty due to the tight area that the worst will fall.  A difference of just 20 miles can make a huge difference in the forecast even at this time range (less than 48 hours).

This blog post is designed to give you a heads up on our thinking and the time frame that things will occur.  There is only moderate confidence in the details, but the overall picture has good confidence.  The scenario and forecast that follows was derived from the 09z, 12z, 15z, and 18z runs of the WSI RPM model along with the 12z runs of the WRF, GFS, ECMWF, and GEM models on Sunday, February 9, 2014.  Each model is slightly different, but the details were mainly from the RPM model.  This represents my best guess at this point.

Friday, January 31, 2014

A Look Back at the #WinterMess

The snow that everyone graved finally came to the Midlands.  The same storm system that affected Birmingham and Atlanta also affected Columbia, SC.  Rain and sleet began to fall before noon on Tuesday, but it wasn’t enough to measure and didn’t cause any problems.  The lower atmosphere was quite dry so that it would take hours of light precipitation to moisten the atmosphere enough to allow for any significant precipitation.

Finally a band of rain/freezing rain moved across the southern half of the Midlands just before dark.  This was followed by snow in the northern part of the Midlands.  It eventually reached Columbia in the form of freezing rain.  At WLTX we pick up an ice accumulation of 1/10 of an inch before the precipitation changed over to snow.  The southern third of the Midlands saw ice accumulations of a ¼ to ½ inch.

The air was chilled by the rain/sleet/snow mix and temperatures fell below freezing over all of the Midlands shortly after sunset.  The precipitation changed to snow which fell mainly from 7:30 p.m. to about 2 a.m. across the Midlands.  Snow ended from west to east and the amounts didn’t vary a great deal across the Midlands.

A map of the midlands of South Carolina showing total snow depth as of Wednesday morning January 29, 2014.  This is from preliminary data.  Click on the image for a larger view.  Image Credit: NOAA/NWS/CAE.

Amounts were generally 2 to 3 inches across much of the area.  It was a wet snow which made for great snowmen and snowball fights.  Here is a view of the region from the satellite the next day:

Tuesday, January 28, 2014

A Major #WinterMess

The National Weather Service issued a Winter Storm Warning for all of the Midlands of South Carolina beginning at 11 a.m. Tuesday and ending at 9 a.m. Wednesday.  The warning was issued for significant accumulations of winter precipitation.  While the warning covers all of the Midlands the effects of the winter storm will be quite nuanced.

First, the jet stream in the upper atmosphere is diving far to the south from the Arctic region.  The term polar vortex was used earlier in January to describe to cold weather seen at that time.  Well, it’s baaaaack!  This time a piece of the polar vortex is centered just east of James Bay in Canada.  Cold Arctic air is plunging south to the Gulf coast and covering much of the Southeast.

The 500 mb pattern for 00z Tuesday, January 28, 2014.  Click on the image for a larger view.  Image Credit: WLTX-TV.

All of the computer models have been signaling this for the past few days.  However, their solutions have differed as to how and when the precipitation will develop across the Southeast.  Some of the models have brought the cold air in too fast resulting in primarily a snow forecast.  Others have slowed the advance of the cold air which has produced forecasts of freezing rain, sleet, and snow.

Sunday, January 26, 2014

A #wintermess for Tuesday, January 28, 2014

The National Weather Service issued a Winter Storm Watch for the midlands of South Carolina Sunday afternoon.  It is for the time period from Tuesday morning to Wednesday afternoon.  Immediately everyone was jumping up and down for joy over the prospect for snow.  Not so fast bucko!  Everything is not as it seems.

It took quite a bit of careful analysis to decipher what the scenario would be.  The computer models have been all over the place with this system; from no snow to more than 15” of snow.  Even our own in-house model has seen big run-to-run swings with 2 to 4 inches of snow in one run to no snow the next.  So what to do?

I have decided that the American model (GFS) seems to be preforming the best for now.  The NAM model has been showing wild swings run-to-run and the European model (ECMWF) seems too cold.  None of the models are perfect, but the GFS seems to be closest to actual observations in the forecast.

Thus, here is the forecast for Columbia, South Carolina over the next seven days.  This was posted Sunday, January 26, 2014:

The seven-day forecast posted Sunday, January 26, 2014 for Columbia, SC.  Click on the image for a larger view.  Image Credit: WLTX-TV.

Tuesday, January 21, 2014

A Cold End to January 2014

A weather pattern we have seen many times since late October, 2013, has reappeared in its amplified form.  The ridge of high pressure in the upper atmosphere has been building since late last week along the Pacific Coast, stretching from northwest Mexico to Alaska.  This has pushed the jet stream far to the north into Alaska and the Yukon. 

The 500 mb pattern for North American at 00z January 21, 2014.  Click on the image for a larger view.  Image Credit: WLTX-TV.

The result has been unseasonably warm temperatures for this time of year.  It is still cold, but in Fairbanks the temperature averaged 24° F above normal on Monday.  There have been wild swings in Fairbanks, AK, this month with its coldest temperature of -41° F on January 12th & 13th, and its warmest temperature at 34° F on January 17th.  On that day the temperature averaged 32° F above normal.

Alaskan temperatures at midnight January 21, 2014.  These are warm readings for central Alaska in January.  Click on the image for a larger view.  Image Credit: WLTX-TV.

Tuesday, January 14, 2014

The Polar Vortex & More

The first major North American weather event of 2014 was the cold Arctic outbreak in the first week of January.  The term polar vortex became the buzz word (in the media) for the cold outbreak, though it was much more.  As a previous post notes this was a pattern extending back to late October of 2013.

The term polar vortex has been around since the 1940s.  From the American Meteorological Society Glossary of Meteorology:

Polar vortex - (Also called polar cyclone, polar low, circumpolar whirl.) The planetary-scale cyclonic circulation, centered generally in the polar regions, extending from the middle troposphere to the stratosphere.

The westerly airflow is largely a manifestation of the thermal wind above the polar frontal zone of middle and subpolar latitudes. The vortex is strongest in winter when the pole-to-equator temperature gradient is strongest. In the Northern Hemisphere, the vortex has two centers in the mean, one near Baffin Island and the other over northeast Siberia.

I prefer to use the term Arctic outbreak to describe what happened in early January.  The polar vortex was involved, but the overall pattern was much more than the polar vortex.  The winds in the upper atmosphere plunged from northwestern Canada into the southeastern U.S. due to an amplification of the ridge of high pressure off the West coast and the deep trough over the eastern part of North America.

NASA put together a movie of temperature observations from NASA's Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua spacecraft.  The Atmospheric Infrared Sounder, AIRS, in conjunction with the Advanced Microwave Sounding Unit, AMSU, sense emitted infrared and microwave radiation from the Earth to provide a three-dimensional look at Earth's weather and climate. Working in tandem, the two instruments make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, three-dimensional map of atmospheric temperature and humidity, cloud amounts and heights, greenhouse gas concentrations, and many other atmospheric phenomena. The AIRS and AMSU fly onboard NASA's Aqua spacecraft and are managed by the Jet Propulsion Laboratory, Pasadena, California, under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

The temperatures shown are at a pressure of 850 hectopascals (hPa, also known as 850 mbs) which is at an altitude of 4500 to 5000 feet over much of the U.S. It begins on December 1, 2013 and runs through January 7, 2014.  The most obvious feature of the movie is the tongue of cold air moving out of Canada and southward to cover much of the eastern United States during early January 2014.

This is a picture of the last day of the movie, Tuesday, January 7, 2014.  The dark blue areas start at -12° C and become purple at -24° C.  This was the farthest extent south and the surface temperature dropped to 13° F in Columbia, SC, with a wind chill temperature of 3° F.  Click on the image for a larger view.  Image Credit: NASA.

Tuesday, January 7, 2014

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.

Sunday, January 5, 2014

Arctic Cold? I'll take a Double!

The new year is taking up where the old year ended.  The weather pattern discussed in a previous post continues to dominate North America.  Each time the pattern amplifies with a strong ridge-trough-ridge look, cold air invades the U.S.  The pattern relaxes and becomes more zonal causing milder conditions to return.  This is the up and down pattern that has resulted in a roller coaster of temperatures.

This was the 500 mb pattern for North America at 12z December 9, 2013.  Note the ridge-trough-ridge pattern.  Click on the image for a larger view.  Image Credit: WSI.

This was the 500 mb pattern for North America at 00z January 6, 2014 (taken from the ECMWF model 12 hours earlier.  Note the ridge-trough-ridge pattern returns.  Click on the image for a larger view.  Image Credit: WSI.

However, this time there has been a bit of a twist.  A surge of cold, arctic air invaded much of the country at the end of last week.  The temperature in Columbia dropped to 22° F Saturday morning.  The high pressure center moved quickly to the east causing winds to shift bringing clouds back into the area before daybreak.  This locked in the cold air for the weekend and there wasn’t much of a rebound in temperatures.