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 27^th and it was a hard freeze with a low of 28° F.  It was very close to freezing on March 31^st 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 10^th.  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 10^th 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.

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.

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.

Southeast Drought Improves

What a difference a month can make.  The drought situation was becoming serious at the end of January as I wrote here.  Yet, February saw an abundance of rainfall creating a substantial surplus for the month.

Monthly rainfall for February in Columbia, SC.  Image Credit: WLTX-TV.

Monthly observed rainfall for February, 2013, covering South Carolina as well as parts of Georgia and North Carolina.  Click on the image for a larger view.  Image Credit: NOAA/AHPS.

In South Carolina the heaviest rainfall occurred over the southern half of the state.  Some parts of the low country saw over ten inches of rain for the month.  The least rainfall occurred over the north central section where rainfall was in the three to four inch range.  However, this area saw more rain in January so that the two-month total is substantial.

A series of storm systems moved through the Southeast pumping moisture from the Gulf of Mexico northward.  The heaviest rainfall occurred across southern Alabama, southern Georgia, and parts of northern Florida.  The drought was center in central Georgia which had experienced extreme to exceptional drought conditions for over a year and a half.

A Change In The March 2013 Outlook

The Climate Prediction Center (CPC) issues outlooks for the next month in the middle of the current month.  They will often issue an updated outlook near the last day of the current month.  Usually these projections do not vary much, but this month saw a substantial revision.

Computer models designed to forecast daily weather are run out to 15 days, four times each day.  Most are familiar with the 7-day forecast.  The CPC also issues 8-14 day outlooks for the second week of the forecast in additions to the monthly and seasonal outlooks that they make each month.

Beginning with the 8-14 day temperature outlook on February 21 and the one issued on February 28, it seems that the first half of March would be colder than normal for South Carolina as seen in the outlooks below.

The 8-14 day temperature outlooks.  The first one made February 21 and the second one (right) made February 28.  Click on the image for a larger view.  Image Credit: NOAA/CPC.

The reason for this projection is that the Arctic Oscillation (AO) has been in a negative phase with the forecast for it to become strongly negative next week.  This usually produces a cold outbreak for parts of the U.S.  Last year the AO was strongly positive and the U.S. saw the warmest March on record.

The Southeast Drought Continues

Droughts can be insidious.  Just when you think they’re gone, they’re back.  Actually it never went away in the Southeast, it just moved around.  The center of the drought began in northeast Florida in 2011 and moved to southern Georgia a year later.  Now the center of the drought is central Georgia and it is beginning to expand thanks to a dry January.

The Drought Monitor for the end of January 2011-13.  Click on the image for a larger view.  Image Credit: USDA.

The current drought began in the Southeast with the end of El Nino in 2010.  That was followed by two years of La Nina which brought drier than normal conditions particularly in the winter and spring.  The worst of the drought has been centered in central Georgia where extreme to exceptional drought conditions have persisted for two years.

However, drought conditions for southeast Georgia and northeast Florida actually disappeared this past summer thanks to two tropical weather systems (Beryl & Debby) which inundated the region with rain in late May and June.  Drought is creeping back into those areas.

Winter Outlook for 2012-13

The Climate Prediction Center released its early outlook for the upcoming winter this morning.  Much of the western U.S. will see warmer than normal temperatures while cooler than normal temperatures are expected for the Florida peninsula.  Equal chances of above or below normal temperatures are forecast for much of the East.

Much of the West will be dry particularly in the Pacific Northwest.  The Central Gulf region is expected to be wetter than normal.  This may help ease the drought in Georgia and South Carolina.

Click on either graphic for a larger version or go here for the temperature map and here for the precipitation map.  Image Credit: NOAA\CPC.

Midwest Gets A Break From The Heat, But Not The Drought

It has been a brutally hot summer from the Midwest to the southern Plains.  Add to this the lack of rainfall and you have the recipe for a devastating drought.  What was expected to be a record year for corn is likely to be the worst in decades.  The drought expanded quickly as all-time record highs were being set; some dating back to the Dust Bowl.

Look at two cities caught in the heat wave and drought.  Oklahoma City has endured 28 days from late June to mid August of 100 degree temperatures.  St. Louis has recorded 21 days during the same period.  Both cities tied their all-time record high temperatures at some point during the heat wave.

Now Mother Nature is about to give the central and eastern parts of the country a break from the heat.  A low pressure is going to develop aloft and become centered just south of Hudson Bay by early next week.  As the map below shows winds in the upper atmosphere will dip south into the U.S. bringing a cooler Canadian air mass.  If this were winter there would be talk of a cold wave, but this is summer and we will call it refreshing.

The forecast for winds at 500 mb (about 18,000 ft) for Monday, August 20, at 18z.  Click on the image for a larger view for all of the graphics.  Image Credit: NOAA/NCEP.

South Carolina Drought Update

Three months ago 99% of South Carolina was in a moderate drought or worse.  About 35% was in an extreme drought and it seemed to be getting worse.  Then the rains began to appear in mid-May.  This continued through mid-June and then the rains stopped.  It became brutally hot with some areas breaking all-time record highs.  The corn crop in the western part of the state suffered from the flash drought conditions.

The heat continued through much of July and it was the third hottest July on record for South Carolina.  We joined much of the central and eastern part of the country in that respect.

Average July Temperature rankings.  Image Credit: NOAA/NCDC.

Rains continued to fall across July with Columbia receiving over 9 inches of rain in the city.  The heavy downpours resulted in several instances of flooding of Rocky Branch Creek.

Flooding of the Rocky Branch Creek on June 11, 2012.  Image Credit: USGS.

It also occurred in June from some heavy rains in the middle of month.  This was a bit ironic occurring in the midst of a drought.  However, there have been five extreme rainfall events at the airport and city in the past three months.

The Drought Eases In South Carolina

It takes time to move into a drought.  Likewise, it takes time to move out of a drought.  The recent rains have definitely eased the pain for South Carolina.  According to the latest drought monitor from the USDA only 22% of the state is in a severe drought or worse compared to 32% the previous week.  Much of the Pee Dee region is out of the drought completely.

Click on image for a larger view.  Image Credit: USDA.

The first four months of the year were a continuation of the drought that started in January 2010.  Only four months out of the past 28 months had been wet by the end of April.  The total rainfall by then for 2012 was 8.71 inches at the Columbia Metropolitan Airport or just over 2 inches per month.

Drought Relief For Some Areas

Conditions were looking bleak at the beginning of May.  Only four months of above normal rainfall had occurred in the previous 28 months.  The details can be found in a previous blog post (here).  Much of the state was in a drought and the situation was getting worse.

Two events happened to change the course of the drought.  First, Tropical Depression Beryl brought much needed rain to parts of the drought-stricken Midlands.  However, there were still areas that received little rain.  This was soon followed by an upper-level pattern that brought copious amounts of rain to the Southeast, especially along parts of the central Gulf coast.  It eventually made its way to South Carolina bringing an abundance of rain.  More than 8 inches of rain fell in just four weeks in the Columbia area.  The result has been flooding of some of the creeks in the area.

Flooding of the Rocky Branch Creek closed the intersection of Main St. and Whaley St. on Monday, June 11.  Click on any of the images for a larger view.  Image Credit: USGS.

A Beryl of Trouble

Yes, this is a play on words, but I think you will understand as the story unfolds.  This is not just about the current tropical storm, but also about one of its past lives.  What?  You see, there are six lists of names for hurricanes and so the list are rotated every six years.  The only way that a name leaves the list is for it to be retired, like Hugo, Andrew, Katrina, and Irene.

Visible image at 6:45 p.m. EDT on May 27.  Image Credit: NEDIS.

Beryl transformed from a subtropical storm to a tropical storm Sunday afternoon.  By late afternoon the storm was getting better organized and strengthening.  It made landfall near Jacksonville Beach, FL, just after midnight (12:10 a.m. Monday).  Highest sustained winds were estimated at about 70 mph mainly in squalls over the open water.  This highest wind gust on land occurred at Mayport, FL, with a gust of 73 mph late in the evening.

The system is now a tropical depression and is likely to make a very slow turn to the northeast over southern Georgia.  This will likely take 12 to 24 hours which means that there will be a great deal of rain for some areas.  Rains are already causing some flood issues for northeast Florida.

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.

Video: Extreme Weather and Rapid Arctic Warming

This is a repost of an article that appeared today at Climate Central.  It was originally published on the Yale Forum on Climate Change and the Media.  The video is produced by videographer Peter Sinclair who produces a series called Climate Denial Crock of the Week.  I have added a link to series under the Climate Links on the right-hand side of the blog.  There is more to this story and I will have a post on this soon.  In the meantime enjoy this video by Peter Sinclair.

By Andrew Freedman (Climate Central)


Recently I reported on a study showing links between rapid Arctic climate change and shifts in the jet stream throughout the Northern Hemisphere. The study, led by Jennifer Francis of Rutgers University, suggests that there may be an Arctic connection to some extreme weather events, particularly ones that result from stuck, or "blocked," weather patterns.

The study shows that by changing the temperature balance between the Arctic and mid-latitudes, rapid Arctic warming is altering the course of the jet stream, which steers weather systems from west to east around the hemisphere. The Arctic has been warming about twice as fast as the rest of the Northern Hemisphere, due to a combination of human emissions of greenhouse gases and unique feedbacks built into the Arctic climate system.

Some Drought Relief

The winter has been warm and dry for much of the Southeast.  Weather patterns have been quite dry and much of the area has been slipping farther into drought.  The worst stage drought (exceptional drought) first showed up across southern Georgia about a month ago.

The exceptional drought as of last week stretched from southeast Alabama across southern Georgia into the low country of South Carolina.  Almost all of the low country of South Carolina was in extreme or exceptional drought and that extended along the Savannah River to north of Augusta.  Farmers in South Carolina were being hurt by the weather and high fuel prices as seen here.

Snow Drought: A Major Concern

In the previous post Andrew Friedman of Climate Central mentioned the warm winter and snow drought that is occurring in the U.S.  Information from the National Climatic Data Center (NCDC) reveals just how warm it has been for the winter months of December and January.

This winter has been influenced by La Nina and the Arctic Oscillation which have combined to produce the warmer than normal temperatures.  The precipitation picture has been mixed with wet conditions from parts of Texas northeastward to New York.  This has eased the extreme drought in some areas of Texas, but has not ended it for much of the state.  Meanwhile, southern Georgia is the center of an expanding drought in the Southeast.  Much of the West is experiencing drought particularly in the Southwest.