A dome of high pressure with sinking air is often associated with heat waves.

NOAA

It is going to be hot and sustained. The National Weather Service Eastern Region tweet sums up the heat expected over the next several day in the Southeast:

The Memorial Day weekend will feature the first extended heat wave of the season across the Southeast into the southern mid Atlantic region. High temperatures could approach record levels. Please take precautions to avoid heatstroke if you have outdoor plans the next few days.

The map below shows expected temperatures for Memorial Day in the Southeast. Temperatures range from the upper 90s to 100+ for much of the region. Before I discuss what is going on, it is instructive to define a “heat wave.” According to the American Meteorological Society Glossary of Meteorology, a heat wave is defined as:

A period of abnormally and uncomfortably hot and usually humid weather. To be a heat wave such a period should last at least one day, but conventionally it lasts from several days to several weeks. In 1900, A. T. Burrows more rigidly defined a “hot wave” as a spell of three or more days on each of which the maximum shade temperature reaches or exceeds 90°F. More realistically, the comfort criteria for any one region are dependent upon the normal conditions of that region.

On Saturday morning, the NWS Eastern region tweeted that several records heat records had already been broken on Friday, and it is only the beginning of the heat wave.

Memorial Day temperatures in the Southeast.

NWS

So what’s causing the extreme heat wave in the Southeast? The simple answer is that a strong upper level ridge of high pressure will remain in place for several days. A dome of high pressure (see opening graphic) will be prevalent over the region. Typically, a prolonged high pressure system results in heat wave conditions because formation of clouds is difficult and air sinks. Sinking air is compressed and warms (adiabatic compression). Whenever I see prolonged periods of heat, I also worry about drought conditions and an uptick in wildfires.

Such extreme heat is not normal for this time of year. If you are thinking, “isn’t it a bit early to see heat this extreme?” The answer is yes. Legendary South Carolina meteorologist Jim Gandy tweeted,

Eight days ago was only the second 90-degree day of the year. It has been 90+ every day since with today the hottest so far this year. Now we are in a heat wave that will see record high temperatures next week.

Gandy pointed out that the average temperature for this time of year is 86 degrees F in Columbia, South Carolina. The National Weather Service office in the Atlanta area also sounded the alarm about the potential for broken records. The Saturday morning forecast discussion read:

Temperatures will continue to be the big story with highs a bit higher than Friday with mid 90d across the metro and around 100 across the SE portion of the area. Outside shot of all time May record in Atlanta for today but more likely for Macon with 99 degrees forecast.

According to the NWS-Atlanta, here are some of the all-time record highs for May:

  • Atlanta: 97 degrees F in 1914 and 1941
  • Athens: 100 degrees F in 1918 and 1926
  • Columbus: 100 degrees F in 1916 and 1937
  • Macon: 99 degrees F in 1898, 1953, and 1967

I think that some of these records (and others) may be broken in the coming days.

Clearly, weather patterns explain this heat wave. I often cringe when people use a “cold day” to refute climate change. I also point out that “one hot” day or week doesn’t necessarily affirm it either. However, there is plenty of evidence that climate change is happening so resist the urge to use one day. The 2018 National Climate Assessment report (and most studies or statements from credible science organizations) released by the Trump Administration highlighted that extreme heat will become a “new normal.” For example, the figure below illustrates that the number of nighttime temperatures above 75 degrees F has increased dramatically. This is far more worrisome than daytime temperatures from the standpoint of human health according to scientific and health experts. The report points out:

Sixty-one percent of major Southeast cities are exhibiting some aspects of worsening heat waves, which is a higher percentage than any other region of the country. Hot days and warm nights together impact human comfort and health and result in the need for increased cooling efforts. Agriculture is also impacted by a lack of nighttime cooling.

Caption from the NCA18 report: the number of warm nights (minimum temperature above 75°F) has doubled on average compared to the first half of the 20th century and (bottom right) locally has increased at most stations. Sources: NOAA NCEI and CICS-NC.

NCA4

Heat isn’t telegenic but it is deadly. When I give public lectures, I always ask the audience what weather event kills more people in the U.S. each year. I usually get answers like tornadoes, hurricanes, or lightning. People are often surprised to learn that extreme temperature, particularly heat, is the deadliest form of weather. The figure below illustrates weather-related fatalities in the U.S. according to the National Weather Service. It is clear that heat is deadly (Note: the NWS seems to have a typographical error concerning the year range in the legend, but the data is correct). Historically, deadly heat waves in Chicago and Europe have been related to warmer than normal nighttime temperatures and vulnerable populations (elderly, kids, and people without inadequate cooling resources). High daytime temperatures can also be dangerous if strenuous activities are undertaken without proper hydration and acclimatization. As I write this, my thoughts and parental “alert” are heightened today because my son has a 7-on-7 passing league football game on an artificial turf. I will hope that tournament officials have adequate plans in place. However, I will not leave my son’s well-being up to a plan of “hope.” I will make appropriate decisions as warranted.

Be safe.

Weather fatalities

NWS

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As I searched social networks Friday, my Alpha Phi Alpha fraternity sibling Rontai Walker tagged me in this post,” Dear Dr. Marshall Shepherd, Why does Georgia presently seem like Las Vegas?” Walker, the associate director of Trainee Participation and the Trainee Center at Georgia Gwinnett College, is not picturing things. Parts of the southeastern U.S. will be sweltering through the Memorial Day weekend and beyond. Here are 3 things that you require to understand about the very first heatwave of the season.(** )

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A

dome of

high pressure with sinking air is frequently associated

with heat waves.

NOAA(************ )

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It is going to be hot and continual.(***************
) The
National Weather Condition Service Eastern Area tweet summarize the heat anticipated over the next a number of day in the Southeast:

The Memorial Day weekend will include the very first prolonged heat wave of the season throughout the Southeast into the southern mid Atlantic area. Heats might approach record levels. Please take preventative measures to prevent heatstroke if you have outside strategies the next couple of days.(** )

The map listed below programs anticipated temperature levels for Memorial Day in the Southeast. Temperature levels vary from the upper 90 s to(****************************************************************************** )+ for much of the area. Prior to I discuss what is going on, it is useful to specify a” heat wave.” According to the American Meteorological Society Glossary of Meteorology, a heat wave is specified as(**************** ):

A duration of unusually and annoyingly hot and typically damp weather condition. To be a heat wave such a duration ought to last a minimum of one day, however traditionally it lasts from a number of days to a number of weeks.

In1900, A. T. Burrows more strictly specified a” hot wave” as a spell of 3 or more days on each of which the optimum shade temperature level reaches or surpasses90 ° F. More reasonably, the convenience requirements for any one area depend on the typical conditions of that area.(** )(****************** )

On Saturday early morning, the NWS Eastern area tweeted that a number of records heat records had actually currently been broken on Friday, and it is just the start of the heat wave.

(*********************** )

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(********** )Memorial Day temperature levels in the Southeast.(** )(*********** )NWS

So what’s triggering the severe heat wave in the Southeast? The easy response is that

a strong upper level ridge of high pressure will stay in location for a number of days. A

dome of high

pressure( see opening graphic) will prevail over the area. Normally, an extended high pressure system leads to heat wave conditions since development of clouds is hard and air sinks. Sinking air is compressed and warms (adiabatic compression ). Whenever I see extended durations of heat, I likewise fret about dry spell conditions and an uptick in wildfires.

Such severe heat is not typical for this time of year.(************** )If you are believing,” isn’t it a bit early to see heat this extreme?” The response is yes. Legendary South Carolina meteorologist Jim Gandy tweeted,

8 days back was just the 2nd 90- degree day of the year. It has actually been90+ every day considering that with today the most popular up until now this year. Now we remain in a heat wave that will see record high temperature levels next week.(** )(****************** )

Gandy mentioned that the typical temperature level for this time of year is86 degrees F in Columbia, South Carolina.(**************************** )The National Weather condition Service workplace in the Atlanta location likewise sounded the alarm
about the capacity for damaged records. The Saturday early morning projection conversation read:

Temperature levels will continue to be the huge story with highs a bit greater than Friday with mid(********************************************************************************* )d throughout the city and around 100 throughout

the SE part of the location. Outdoors shot of perpetuity May
record in Atlanta for today however most likely for Macon with 99 degrees projection.

According to the NWS-Atlanta, here are a few of the all-time record highs for Might:

  • Atlanta:97 degrees F in1914 and(************************************************************** )
  • Athens:100 degrees F in(***************************************************************** )and(**************************************************************** )
  • Columbus:100 degrees F in1916 and(*************************************************************** )
  • Macon:99 degrees F in(********************************************************************* ), 1953, and 1967

I believe that a few of these records( and others) might be broken in the coming days.

Plainly, weather condition patterns describe this heat wave. I frequently flinch when individuals utilize a “cold day” to refute environment modification. I likewise mention that” one hot” day or week does not always verify it either. Nevertheless, there is a lot of proof that environment modification is occurring so withstand
the desire to utilize one day. The2018 National Environment Evaluation report( and most research studies or declarations from reliable science companies) launched by the Trump Administration highlighted that severe heat will end up being a” brand-new typical. “For instance, the figure listed below shows that the variety of nighttime temperature levels above75 degrees F has actually increased drastically. This is much more uneasy than daytime temperature levels from the perspective of human health according to clinical and health professionals(**************** ). The report explains:

(***************** )(* )Sixty-one percent of significant Southeast cities are showing some elements of intensifying heat waves, which is a greater portion than any other area of the nation. Hot days and warm nights together affect human convenience and health and lead to the requirement for increased cooling efforts. Farming is likewise affected by an absence of nighttime cooling.(** )

(********** )Caption from the NCA(***************************************************************************************** )report: the variety of warm nights (minimum temperature level above(*********************************************************************************** )° F )has actually doubled typically compared to the very first half of the20 th century and( bottom right) in your area has actually increased at the majority of stations.

Sources: NOAA NCEI and CICS-NC.

NCA4

Heat isn’t telegenic however it is fatal. When I provide public lectures, I constantly ask the audience what weather condition occasion eliminates more individuals in the U.S. each year. I typically get the answer like twisters, typhoons, or lightning. Individuals are frequently shocked to find out that severe temperature level, especially heat, is the most dangerous type of weather condition. The figure listed below shows weather-related casualties in the U.S. according to the National Weather Condition Service.

It is clear that heat is fatal( Note: the NWS
appears to have

a typographical mistake worrying the year variety in the legend, however the information is appropriate).(************************************ )Historically, fatal heat waves in Chicago and Europe have actually been connected to warmer than typical nighttime temperature levels and susceptible populations( senior, kids, and individuals without insufficient cooling resources). High daytime temperature levels can likewise threaten if difficult activities are carried out without correct hydration and acclimatization. As I compose this, my ideas and adult” alert “are increased today since my child has a 7-on-7 passing league football video game on a synthetic grass. I will hope that competition authorities have sufficient strategies in location. Nevertheless, I will not leave my child’s wellness approximately a strategy of” hope.” I will make proper choices as required.

(* )Be safe.

(************************************* )(**** )(****** )

Weather condition casualties(** ) NWS