June updates: Tropical Weather Outlook, active storms, and more

By HURREVAC Support

Default behavior when HURREVAC opens The Tropical Weather Outlook (TWO) map layer is now turned on by default when you log into HURREVAC. This change is intended to help users maintain situational awareness of emerging hazards, even when there are no active systems. Active storms are also loaded when you log into HURREVAC, but with one change for the 2024 season. Now, only Atlantic basin storms are checked on by default in the Active Storms folder of the storms tab. Storms in all other worldwide basins are still tracked and listed as options in the folder, but the user must select that storm to load its track on the map and then zoom to that location. In other words, when the program is opened it will not automatically plot and zoom to a storm unless it is in the Atlantic basin. Tropical Weather Outlook interface Several slight improvements to the TWO window were recently implemented. The timeline slider now shows dots to indicate the times when the TWO product was issued by the NHC or CPHC. You can click on the dot to show the previous versions of the product and observe trends in the forecast. This change also makes it easier to detect when there has been a special TWO issuance outside the routine cycle of 2 AM, 8 AM, 2 PM, and 8 PM (EDT). The map symbols that depict all active storms were also enlarged for better visibility. If a storm’s track is not already displayed via the active storms tab, you can click the symbol to load its track details. The TWO interface also has a simplified date selector. To view an archived TWO, expand the calendar window and press and hold the left/right arrows in the header to quickly shuttle to earlier/later months. Then, click a date within the month. The valid time of the TWO is designed to show the latest information by default, or closely match whatever storm advisory you have selected. If you load a hurricane track from August 2023, for example, the TWO will snap to show how it would have looked when that advisory was issued. But selecting a new time in the TWO interface will not alter the storm track you have loaded on the map. Other updates The multi-location wind probabilities report has been discontinued. The program contains probability and timing data in report formats that are more efficient to generate and access. Users can still right-click for point-specific wind probability analysis in 6-hour intervals. Note to users in Georgia: the state’s latest Hurricane Evacuation Study (HES) data has been implemented in the program during recent months. This includes new Evacuation Zones and HES documents in the Resources tab, and new clearance times in the Evacuation Timing window. If you missed our annual training webinar series during the week of June 10, or would like to review the information again, all session recordings and handouts are available on our User Guides and Tutorials page. We’d like to thank everyone who attended this year, and thank our partners at NOAA, FEMA and the U.S. Army Corps of Engineers for presenting the latest information about hurricane forecasts and evacuations. A reminder to anyone with Desktop HURREVAC: this previous version of program was discontinued after the 2019 season and is no longer being upgraded, monitored, or supported. To see all of the latest NOAA products and functionality in HURREVAC, please be sure to register for a new account on the current web-based platform.

Updated Storm Surge Modeling for North Carolina

By HURREVAC Support

Emergency managers in North Carolina now have access to an updated SLOSH basin in HURREVAC. The associated high-resolution MEOWs are available in the Storm Surge (SLOSH) Explorer to help users understand their storm surge risk for both planning and operational decision-making. The North Carolina basin, identified as nc1, was updated by the National Hurricane Center Storm Surge Unit and released by the National Hurricane Program in May 2024. The nc1 update includes improvements to both resolution and geographic extent, and is intended for use between the South Carolina-North Carolina border and the North Carolina-Virginia border. This new data replaces the previous Wilmington (il3) and Cape Hatteras/Pamlico Sound (ht3) basins. Questions pertaining to nc1 data should be directed to Cody.Fritz@noaa.gov at the National Hurricane Center. General questions about storm surge tools in HURREVAC should be directed to support@hurrevac.com. Other recent updates The River Gages layers in the Conditions tab now link users to NOAA’s NWPS, which recently replaced the AHPS system. The interface and symbology in HURREVAC are unchanged. The Potential Track Area (Error Cone) rates for 2024 have been incorporated for all basins. As a reminder, when using an archived storm, HURREVAC now uses the error statistics from its year of occurrence to show the cone as it would have appeared at the time (more information is in the January announcement). HURREVAC always plots exercise storms and simulated storms with the current season’s error cone definitions, regardless of when it was created or the date of the scenario. The HURREVAC team is currently working on improvements to the display of active storms and the Tropical Weather Outlook, and will have more to share about that project and other planned changes for this season during our annual training webinar series (June 10-14).

Updates to Storm Surge Modeling for South Carolina and Georgia

By Karen Townsend

Emergency managers in Georgia and South Carolina should use the updated Charleston basin (CH3) and associated high-resolution MEOWs in HURREVAC to understand their storm surge risk as it relates to both planning and operational decision-making. The Charleston basin, identified herein as CH3, was updated by the National Hurricane Center Storm Surge Unit and released by the National Hurricane Program in February 2022. The CH3 update includes improvements to both resolution and geographic extent, with the intended area of use to extend from the Florida/Georgia border to the South Carolina/North Carolina border. The National Hurricane Program is coordinating with stakeholders and program partners to evaluate impacts to the current Hurricane Evacuation Study in-progress in Georgia. Questions pertaining to CH3 should be directed to Cody.Fritz@noaa.gov at the National Hurricane Center. Questions about the use of the data in HURREVAC should be directed to support@hurrevac.com.