Hurricane Irene21-29 August 2011

NOAA Service Assessment

Frank Marks and Wes Browning(Co-team leads)

November 27, 2012

Results

Hurricane IreneService Assessment

While Hurricane Irene tested technical, human, and hydrometeorological capabilities of NWS, performance was generally outstanding. In particular: NHC forecast track of Irene accurately, and worked successfully with

federal, state, and local EM partners to warn and protect those in storm’s path.

ER & SR WFOs along Irene’s track, worked in close partnership with NHC, HPC, SERFC, MARFC, and NERFC to deliver accurate, clear, & compelling forecasts, watches, and warnings.

Despite an extremely accurate HPC 5-day forecast of historic rainfall, the magnitude of inland flooding threat was not effectively conveyed to those most at risk.

NHC forecast intensity of Irene was too high during the slow weakening phase. Approximately 10-20 % of this high bias during Irene’s weakening can be attributed to initial (analysis) intensity error.

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Results

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Hurricane IreneService Assessment

• Identified 3 Main Issues NWS must address:1) Inland Inundation (Flood)2) Coastal Inundation (Surge)3) Improved guidance products for DSS (HLS)

Prattsville, NY

Rodanthe, NC

(1) Inland Inundation (Flood)

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Hurricane IreneService Assessment

Waitsfield, VT

Paterson, NJ

(1) Inland Inundation (Flood)

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Hurricane IreneService Assessment

• Inland flooding continues to be a major and deadly impact of hurricanes,

• NWS did not clearly convey threat for historic flooding and its associated catastrophic impacts.

• Dramatic changes in river levels in both longevity and magnitude (characteristic of flash flooding in small streams).

• NWS must improve how it communicates risk of inland flooding and educate public, media and EMs on that risk.

(1) Inland Inundation (Flood)

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Hurricane IreneService Assessment

• Recommendation: Even though rainfall forecasts and inland flood threats are outside NHC’s focus, FEMA and national media briefings should give attention to all storm related threats until a storm is no longer affecting the Nation.

• Recommendation: NWS should support the creation of a Warning Coordination Meteorologist (WCM) at HPC to deliver more effective briefings to key partners.

• Recommendation: NWS should establish and implement a baseline standard for annual hydrologic training at all WFOs. Regional Directors will ensure this hydrologic training is integrated into their WFOs’ and RFCs’ seasonal readiness training.

• Recommendation: NWS should determine strategy and training to effectively maximize river flood warning lead time in high-confidence, high-impact situations such as hurricanes

• Recommendation: NWS should partner with media and social scientists to educate public on inland flooding threat associated with land-falling storms, especially in areas where such events are rare.

(2) Coastal Inundation (Surge)

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Hurricane IreneService Assessment

East Haven, CT

Manhattan, NY

• Storm surge of 3–6 feet caused hundreds of millions of dollars in property damage in NYC, as well as damage in Long Island and parts of Connecticut coastline

(2) Coastal Inundation (Surge)

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Hurricane IreneService Assessment

• Recommendation: NOAA Storm Surge Roadmap, … needs to be top NWS and NOAA priority.

• Recommendation: NWS should train and provide additional storm surge and wave experts to work at NWS Regional and WFO levels answering storm surge and wave-related questions from EMs and better coordinate with SSU.

• Recommendation: NOAA, leveraging resources such as NOAA Storm Surge Roadmap, IWRSS and NWC needs to provide inland and coastal flood forecast inundation maps that are interactive and GIS-based. Maps should use official NHC surge and RFC river-model forecast guidance driven by QPF. Additional parameters such as map overlays for current weather radar, storm total QPE, river gages, and infrastructure also should be developed to help convey impacts.

• NWS must communicate storm surge information more clearly and succinctly with focus on impacts.

• Graphical depiction of inundation due to coastal flooding is essential to addressing partner and user needs

8 pages

(3) Improved guidance products for local DSS (HLS)

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Hurricane IreneService Assessment

“(HLS products) were too long if you were trying to deal with multiple offices, too much to read.” And “…it was difficult to find the HLS on NWS web sites.”

Brian Norcross, The Weather Channel

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Hurricane IreneService Assessment

• Recommendation: NWS should modify the HLS using input from social scientists. Changes to the HLS should include:• Structuring it in a bulleted format like the NWS winter storm/non-

precipitation/red flag warning products• Reducing the product’s length• Including event-driven, impact-based updates, as opposed to static

update times• Reducing generation time by at least 30 percent

• Recommendation: NWS should develop requirements for a Web-based HLS using input from social scientists. These requirements should include:• Putting location of impacts first• Including graphics, images, and video depicting all expected impacts• Adding a site-configurable template to allow forecasters to populate

the HLS with pertinent information, similar to selecting Calls to Action• Offering ability to automatically populate with NDFD grids

(3) Improved guidance products for local DSS (HLS)

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Hurricane IreneService Assessment

• Recommendation: There should be a comprehensive NWS Website that includes coverage of all threats and impacts of tropical cyclones.

• Recommendation: Building on the experimental tropical cyclone impacts graphics, NWS should dedicate specific resources and work with social scientists to develop a GIS-compatible, all-hazards graphical suite depicting tropical cyclones impacts.

• Future products and services should be interactive, Web-based, user-friendly, and contain societal impacts verbiage to articulate clearly severity and urgency of the hazard

(3) Improved guidance products for local DSS (HLS)

Questions?

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