Today leaders from the National Oceanic and Atmospheric Administration (NOAA) and the Centers for Disease Control and Prevention (CDC) together unveiled a new heat-related risk product ahead of the U.S.’s summer heat season. Known simply as “HeatRisk”, the new offering provides information and guidance for those who are particularly vulnerable to heat that need to take extra precautions for their health when the temperature rises.
HeatRisk provides historical context for high temperature forecasts, identifying how unusual the heat will be for any given time of year across a spatial area with coverage across the contiguous United States. It also identifies temperatures that are expected to bring increased heat impacts over a 24-hour period, up to seven days in advance. The experimental offering is available online a NOAA website at https://www.wpc.ncep.noaa.gov/heatrisk/. The product is experimental for now, giving the opportunity for its users to provide feedback to the National Weather Service before the product is finalized. People can send their thoughts of the product through an online survey located here: https://www.surveymonkey.com/r/ExpNWSHeatRisk_2024.
“Heat can impact our health, but heat-related illness and death are preventable,” said CDC Director Mandy Cohen, M.D., M.P.H. “We are releasing new heat and health tools and guidance to help people take simple steps to stay safe in the heat.”
The National Weather Service currently issues heat-related products as conditions warrant, with local offices collaborating with other local partners and agencies for when an alert should be issued for a local area. Currently, Excessive Heat Warnings or Watches, Heat Advisories, and Excessive Heat Outlooks are issued.
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 may become seriously ill or even die,” the National Weather Service warns.
Excessive Heat watches are issued when conditions are favorable for an excessive heat event in the next 24 to 72 hours. A Watch is used when the risk of a heat wave has increased but its occurrence and timing is still uncertain.
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.
Excessive Heat Outlooks are issued to keep the population aware of potential problems with heat. The outlooks are issued when the potential exists for an excessive heat event in the next 3-7 days. An Outlook provides information to those who need considerable lead-time to prepare for the event.
Ken Graham, Director of the National Weather Service, tells us they will apply learnings from this new experimental product and further refine their messages and watch and warning products.
Beyond the existing heat-related products the National Weather Service issues today, the HeatRisk product describes the threat on a 5 color code scale over a 7 day period at 24 hour intervals. Designed to supplement their other heat products, Heat Risk takes into consideration how unusual the heat is for the time of the year, the duration of the heat including both daytime and nighttime temperatures, and whether or not those temperatures pose an elevated risk of heat-related impacts based on data from the CDC.
