Excessive Heat Decision Support Briefing #4 As of 5:00 PM July 18, 2019 Changes since last Briefing: Current Hazards Excessive Heat Warning in effect for NE NJ, NYC and the Lower Hudson Valley on Friday, Heat Advisory for LI and Southern CT. Excessive Heat Warning for entire area Saturday and Sunday Weather Forecast Office New York, NY Follow us on Twitter Follow us on Facebook Presentation Created 7/18/2019 5:16 PM Main Points Hazard Heat Impacts Location Extreme heat can cause illness and death among atrisk population who cannot stay cool. NE NJ, NYC, and the Lower Hudson ValleyExcessive Heat Warning for Friday through Sunday The excessive heat may quickly cause heat stress or heat stroke, especially during outdoor exertion or extended exposure. Long Island and Southern CTHeat Advisory for Friday into Friday Night, Excessive Heat Warning Saturday and Sunday. Weather Forecast Office New York, NY Follow us on Twitter Follow us on Facebook Timing Max heat Index values will range from: • 100 to 107 Fri • 105 to 115 Sat • 105 to 110 Sun Peak Heat Index Values will be between 2 and 5pm. Presentation Created 7/18/2019 5:16 PM Summary of Greatest Impacts Heat: Entire Tri-State Region None Limited Elevated Significant Weather Forecast Office New York, NY Follow us on Twitter Follow us on Facebook Extreme Presentation Created 7/18/2019 5:16 PM Excessive Heat Warning in Effect Excessive Heat Warning for NE NJ, NYC, and Lower Hudson Valley starting Friday. Excessive Heat Warning for the entire Tri-State Region Saturday and Sunday. Hazards: Excessive Heat Warning Current Hazards  Max heat Index values will range from:  100 to 110 Fri  105 to 115 Sat  105 to 110 Sun  Overnight lows in the upper 70s and lower 80s Fri Night and Sat Night Impacts:   Extreme heat can cause illness and death among at-risk population who cannot stay cool. The excessive heat may quickly cause heat stress or heat stroke, especially during outdoor exertion or extended exposure. Timing :  The peak heat Index values will occur between 2 to 5 pm. Weather Forecast Office New York, NY Follow us on Twitter Follow us on Facebook Presentation Created 7/18/2019 5:16 PM Max Heat Index Values Friday Peak Heat Index Values between 2 and 5pm Weather Forecast Office New York, NY Follow us on Twitter Follow us on Facebook Presentation Created 7/18/2019 5:16 PM Low temperatures Friday Night into Saturday Morning Heat indices only drop to 85-90 F for NYC and NE NJ Metro. Weather Forecast Office New York, NY Follow us on Twitter Follow us on Facebook Presentation Created 7/18/2019 5:16 PM Max Heat Index Values Saturday Peak Heat Index Values expected between 2 and 5pm Weather Forecast Office New York, NY Follow us on Twitter Follow us on Facebook Presentation Created 7/18/2019 5:16 PM Low temperatures Saturday Night into Sunday Morning Heat indices only drop to around 90 F for NYC and NE NJ Metro. Weather Forecast Office New York, NY Follow us on Twitter Follow us on Facebook Presentation Created 7/18/2019 5:16 PM Max Heat Index Values Sunday Peak Heat Index Values expected between 2 and 5pm Weather Forecast Office New York, NY Follow us on Twitter Follow us on Facebook Presentation Created 7/18/2019 5:16 PM Heat Safety Information Weather Forecast Office New York, NY Follow us on Twitter Follow us on Facebook Presentation Created 7/18/2019 5:16 PM Heat Safety Information Weather Forecast Office New York, NY Follow us on Twitter Follow us on Facebook Presentation Created 7/18/2019 5:16 PM Heat Safety Information Weather Forecast Office New York, NY Follow us on Twitter Follow us on Facebook Presentation Created 7/18/2019 5:16 PM Forecast Uncertainty or Scenarios  High Confidence on Dangerous Heat and Humidity levels Friday through Sunday.  There is a low probability for isolated Strong to Severe Thunderstorms late Friday Afternoon into Friday Evening, particularly from NYC and points north and West.  The main threat for severe weather appears to be northwest of the local Tri-State region, but with a hot and unstable airmass over the area a minimal threat exists into the region.  Strong to Damaging wind gusts would be the main threat with this activity. Weather Forecast Office New York, NY Follow us on Twitter Follow us on Facebook Presentation Created 7/18/2019 5:16 PM Event Summary  Dangerous heat and humidity Friday through Sunday for the entire Tri-State Area.  Air Quality alert is in effect for most of the Tri-State Region on Friday due to elevated air pollution and ozone concentration levels.  There is a low probability for isolated Strong to Severe Thunderstorms late Friday Afternoon into Friday Evening, particularly from NYC and point north and West. Weather Forecast Office New York, NY Follow us on Twitter Follow us on Facebook Presentation Created 7/18/2019 5:16 PM Contact and Next Briefing Information Next Briefing By 600 AM July 19 Email Web: http://www.weather.gov/okx/ Facebook: http://www.facebook.com/NWSNewYorkNY Phone (public): 631-924-0517 Twitter: http://www.twitter.com/NWSNewYorkNY E-mail: okx.operations@noaa.gov YouTube: https://www.youtube.com/user/NWSNewYor kNY Do not use this briefing after 400 AM July 19 Weather Forecast Office New York, NY Follow us on Twitter Follow us on Facebook Presentation Created 7/18/2019 5:16 PM