The graphic below shows areas in an excessive heat warning (pink) and heat advisory (orange) overlaid with Afternoon High Temperatures for today.
The National Weather Service criteria for issuing Heat Advisories and Heat warnings are:
An Excessive Heat Warning is issued within 12 hours of the onset of extremely dangerous heat conditions. The general rule of thumb for this Warning is when the maximum heat index temperature is expected to be 105° or higher for at least 2 days and night time air temperatures will not drop below 75°; however, these criteria vary across the country, especially for areas not used to extreme heat conditions. If you don’t take precautions immediately when conditions are extreme, you become seriously illness or even due.
A Heat Advisory is issued within 12 hours of the onset of extremely dangerous heat conditions. The general rule of thumb for this Advisory is when the maximum heat index temperature is expected to be 100° or higher for at least 2 days, and night time air temperatures will not drop below 75°; however, these criteria vary across the country, especially for areas that are not used to dangerous heat conditions. Take precautions to avoid heat illness. If you don’t take precautions, you could become seriously illness or even die.
Thunderstorms may bring some relief to the heat in the Central Plains. However some of these storms may become severe with the primary threats being damaging wind and large hail, but an isolated tornado is also possible. The graphic below indicates the area of thunderstorm development for today with the slight risk identifying the areas for severe potential.
Heat Continues This Weekend
Afternoon highs will again top out in the upper 90’s to around 100 for much of Southern Plains Saturday and Sunday. Saturday’s high temperature forecast:
Sunday’s high temperature forecast:
However with the relative humidity, the high heat index dome extends into Kansas and Missouri. Saturday’s Heat Indices:
Sunday’s Heat Indices:
Thunderstorms will again be possible on Saturday, mainly on the northern edge of the heat dome. NWS SPC indicates a slight risk of severe thunderstorms across South Dakota, Iowa, Nebraska, Missouri and Kansas. The primary severe weather threats again are damaging winds and large hail, but an isolated tornado cannot be ruled out.
Impacts Of Heat On People
Exposure to excessive heat can lead to heat stress and even heat stroke. They occur when one’s body is no longer able regulates its internal temperature. Typically our bodies react to the heat by increasing blood flow to the skin and sweating. The evaporation of our sweat is a cooling process. However when someone is not able to cool by sweating, the potential for heat stress and heat stroke increases. People that have to wear thick protective clothing and or work in areas of poor ventilation or hotter inside environments are especially at an increased risk.
Altered mental state or behavior. Confusion, agitation, slurred speech, irritability, delirium, seizures and coma.
Alteration in sweating. For heatstroke brought on by hot weather, your skin will feel hot and dry to the touch. However, in heatstroke brought on by strenuous exercise, your skin may feel moist.
Nausea and vomiting.
Flushed Red skin.
Racing heart rate.
For those in the areas of the high heat and humidity, if possible limit your time outside especially in the afternoon and remain indoors in an air conditioned space. If you must be outside drink plenty of water or other non-alcoholic and non-caffeinated beverages to keep your body hydrated. If you start to see the signs of heat exhaustion or heatstroke, take action immediately. Heat Stoke can be life threatening; so seeking medical assistance is highly recommended if you see someone suffering from the signs of heat stroke.
For more tips on how to respond to the heat, see FEMA’s Ready.Gov site.
Impacts to heat on Livestock and Pets
Just as humans, animals also suffer from the stress of the heat. In an article by Drovers Cattle Network, David Fernandez, a Cooperative Extension Program livestock specialist at the University of Arkansas at Pine Bluff states, “Overheating causes animals to go off feed and increases their heart and respiration rates. Severely affected animals can become weak and unable to stand. Extremely elevated temperatures (over 107 degrees F) can result in death.”
For your pets, if you can bring them indoors, especially during the hottest parts of the day.
For outside animals, give them plenty of water, cold if possible, and keep the water shaded. Also provide shade for your livestock and decrease their afternoon activity. According to an article by the University of Florida, “Cattle are at particular risk of overheating due to the production of internal heat from fermentation in the rumen” So keeping cattle cool, especially dairy producers, is of utmost concern. Some other tips to consider for cattle include ventilation and supplemental cooling as well as altering their feeding to cooler parts of the day (early in the morning and late in evening).
For more on how to help your animals and livestock beat the heat, the Sam Noble Foundation has excellent information.
Proactive Activities for Severe Thunderstorms
For those at risk of Severe Thunderstorms, we encourage you to remain in tune for changing weather conditions and multiple ways to be notified of any watches and warnings that may be issued for your area.To prepare for the severe weather threat, if you have any loose items or equipment outdoors that could easily become airborne such as lawn chairs, umbrellas, pool toys, bring them inside. Also bring inside any items that could easily be damaged by large hail which includes vehicles. If Warnings are issued for your location, move into an interior room on the lowest floor and stay away from windows as severe winds especially when combined with large hail and or debris can shatter windows.
The team at WxIntegrations will continue to provide relevant information and resources to help you better understand and prepare for the forecast weather through incorporating weather impacts into your planning and response.
Heat Impact Today
High temperatures and humid conditions are leading to dangerous heat conditions across parts of the Central US. The continued rounds of rain over the past week have replenished moisture levels. So while actual temperatures are mainly in the upper 90’s to around 100, when you consider the dew points and/or relative humidity, Heat Indices are oppressive. Today’s heat indices will be in the middle to upper 100’s in Iowa, Nebraska, Kansas, Missouri, Oklahoma, Arkansas and even Western Tennessee and Northern Mississippi.
The graphic below displays today’s forecast heat indices.