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Public Information Statement National Weather Service Miami FL 1135
AM EDT Thu Jun 20 2024

...New, Experimental Heat Advisory and Excessive Heat Warning
Criteria for Broward County...

Beginning July 1st, the National Weather Service Weather Forecast
Office in Miami (WFO Miami) will test a change to the Heat Advisory
and Excessive Heat Warning criteria for public forecast zones in
Broward County. This change is in conjunction with the current pilot
project in Miami-Dade County which has been in place since 2023. The
new criteria for Broward County is better aligned with local
climatology, as well as recent health data which indicate that
significant health impacts from heat occur at heat index values
lower than the current advisory/warning criteria.

Broward County will now have the same heat advisory/excessive heat
warning criteria as Miami-Dade County, which is as follows for each
public zone in those counties:

UGC Forecast Zone Number    Weather Forecast Zone Name FLZ073 Inland
Miami-Dade FLZ074     Metro Miami-Dade FLZ173 Coastal Miami-Dade
FLZ174      Far South Miami-Dade FLZ071 Inland Broward FLZ072 Metro
Broward FLZ172 Coastal Broward

- Heat Advisory: Heat Index of 105F or higher for at least 2 hours

- Excessive Heat Warning: Heat Index of 110F or higher for at least
2 hours

The remaining WFO Miami public forecast zones below will continue
with the existing heat advisory/excessive heat warning criteria
(Advisory: Heat Index 108F or higher for at least 2 hours, Warning:
Heat Index 113F or higher for at least 2 hours):

UGC Forecast Zone Number    Weather Forecast Zone Name FLZ063 Glades
FLZ066                    Hendry FLZ067 Inland Palm Beach FLZ068
Metro Palm Beach FLZ069     Coastal Collier FLZ070 Inland Collier
FLZ075 Mainland Monroe FLZ168 Coastal Palm Beach

The new, experimental criteria for Broward County, which will match
the existing Miami-Dade County criteria, is based on local
temperature climatology and frequency of heat index values at or
above the newly defined criteria. The new criteria better aligns
with the historical frequency of heat index values above the newly
defined criteria, and is closer to heat index values at which
significant health impacts from heat can occur.

Evaluation of this experiment will take place during and after the
2024 heat season to determine if these changes will become official
policy in future years for parts or all of the WFO Miami service
area.

For any questions, please contact:

Robert Molleda, Meteorologist-in-Charge

Robert.Molleda@noaa.gov, 305-229-4522 ext. 222

$$