Heavy Rains, Coastal Flooding and Strong Winds Late Tonight Into Friday Night
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Heavy Rains, Coastal Flooding and Strong Winds Late Tonight into Friday Night Decision Support Briefing #3 Current Hazards As of: 4:30 PM Dec 20, 2018 What Has Changed? Coastal Flood Warning issued for much of the coastline Wind Advisories have been expanded further north into Eastern Connecticut Gale Warning extended through Friday night Weather Forecast Office Presentation Created New York, NY Follow us on Twitter Follow us on Facebook 12/20/2018 5:18 PM Main Points Hazard Impacts Location Timing • 2 to 3 inches, locally 4 inches. Late Tonight through Friday • Flooding of urban, low lying, and Night Flooding poor drainage areas Entire Tri-State Region Heaviest Rainfall expected on • Flooding of small rivers, streams and creeks. Friday • Widepsread Minor to Moderate Vulnerable locales along coastal flooding. During the times of high tide Coastal • Inundation of 2 to 3 ft , above NY/NJ Harbor, Jamaica on Friday morning Impacts ground in vulnerable areas. Bay, S and E Bays of LI, • Areas of dune erosion, localized and LI Sound washovers • 20 to 35 MPH with gusts to 45 to Strong 55 MPH. Highest winds will occur • Scattered downed trees and across Long Island Late Tonight through Friday Winds power lines, and power outages • Wind gusts of 40 to 45 KT. • Seas of 12 to 16 ft on the Ocean All Nearshore Waters Late Tonight through Friday Marine and 3 to 5 ft on LI Sound. Night Weather Forecast Office Presentation Created New York, NY Follow us on Twitter Follow us on Facebook 12/20/2018 5:18 PM Summary of Greatest Impacts Flooding: Entire Tri-State Region None Limited Elevated Significant Extreme Coastal Impacts: Vulnerable locales along NY/NJ Harbor, Jamaica Bay, S and E Bays of LI, and LI Sound None Limited Elevated Significant Extreme Strong Winds: Highest winds near the coast None Limited Elevated Significant Extreme Marine: All Nearshore Waters None Limited Elevated Significant Extreme Weather Forecast Office Presentation Created New York, NY Follow us on Twitter Follow us on Facebook 12/20/2018 5:18 PM Heavy Rain/Freshwater Flooding Hazards: (Flood Watch in Effect from 1am thru Late Friday Night!!) Rainfall of 2 to 3 inches expected. Locally around 4 inches possible. Rainfall rates of 1“/hr are possible Friday morning into Afternoon. Impacts: Flooding of urban areas, low-lying roads, and poor drainage areas. Minor to moderate flooding along fast responding streams, particularly northeastern New Jersey and Lower Hudson Valley. Moderate Flooding is forecast along the Passaic River at Pine Brook in Essex County Friday Night. Flooding will likely be exacerbated in coastal locales as heavy rain coincides with the Friday morning high tide. Timing: Heaviest rain from Friday morning into afternoon. Uncertainty: Location and timing of heaviest rain swaths will become clearer as the event unfolds. Weather Forecast Office Presentation Created New York, NY Follow us on Twitter Follow us on Facebook 12/20/2018 5:18 PM Heavy Rain/Freshwater Flooding Weather Forecast Office Presentation Created New York, NY Follow us on Twitter Follow us on Facebook 12/20/2018 5:18 PM Heavy Rain Weather Forecast Office Presentation Created New York, NY Follow us on Twitter Follow us on Facebook 12/20/2018 5:18 PM Widespread Minor to Moderate Coastal Flooding Coastal Flood Hazards and Impacts: Widespread minor to moderate coastal flooding Inundation of 2 to 3 ft above ground in vulnerable coastal locales Numerous waterfront road closures, with widespread flooding of adjacent properties. Vehicles parked in vulnerable coastal areas may be damaged Shoreline Hazards and Impacts: High surf and elevated water levels will cause areas of dune erosion, with localized wash overs possible Minor damage to shoreline structures possible Timing: Widespread minor to moderate coastal impacts during times of high tide Friday morning Minor coastal flooding possible with the Friday evening and Saturday morning high tides Weather Forecast Office Presentation Created New York, NY Follow us on Twitter Follow us on Facebook 12/20/2018 5:18 PM Strong Winds Hazards: SE winds of 20 to 35 mph with gusts 45 to 55 mph, highest across Long Island. Impacts: Scattered downed trees and tree limbs Scattered power outages. Damage to unsecured holiday decorations Peak Wind Gust Image Timing: Strongest winds from late Tonight through Friday. Scenarios: Isolated thunderstorms Friday morning into afternoon may produce damaging wind gusts in excess of 60 mph. Strong winds may linger across E LI and SE CT into Friday evening Weather Forecast Office Presentation Created New York, NY Follow us on Twitter Follow us on Facebook 12/20/2018 5:18 PM Most Likely Maximum Winds Gusts Note: Isolated thunderstorms Friday morning into afternoon could produce damaging wind gusts in excess of 60 mph. Weather Forecast Office Presentation Created New York, NY Follow us on Twitter Follow us on Facebook 12/20/2018 5:18 PM Forecast Uncertainty or Scenarios Localized swaths of 4 inches of rainfall are possible. Heaviest rainfall is favored along the hill terrain of interior, and with any training of heavy downpours and/or thunderstorms. Exact location will not become clear until event unfolds. Damaging wind gusts in excess of 60 mph are possible in isolated thunderstorm activity. Highest threat across Long Island Strong winds may linger across eastern Long Island and Southeastern Connecticut into Friday evening. Minor coastal flooding possible with Friday evening and Saturday morning high tides. Weather Forecast Office Presentation Created New York, NY Follow us on Twitter Follow us on Facebook 12/20/2018 5:18 PM Event Summary Heavy rain expected tonight into Friday night, with areas of urban, poor drainage, and river and stream flooding likely. Widespread minor to moderate coastal flooding is expected during times of high tide Friday morning. High wave action will result in areas of dune erosion and localized overwashes along the Atlantic Ocean beachfront Friday morning. Strong sustained winds of 20 to 35 mph with gusts 45 to 55 mph, highest along the coast, late tonight into Friday. Isolated thunderstorms Friday morning into Afternoon may produce damaging wind gusts in excess of 60 mph. Gale conditions expected on all nearshore waters tonight through Friday Night. Weather Forecast Office Presentation Created New York, NY Follow us on Twitter Follow us on Facebook 12/20/2018 5:18 PM.