Tropical Storm Claudette (17 June – 21 June , 2021) was already the third named storm of the 2021 Atlantic hurricane season but the first tropical system that targeted both the Gulf and the Atlantic coasts.
We used high resolution storm surge model meshes for the States of Louisiana and North Carolina and a vortex wind model to represent the NHC consensus track wind fields and the associated predicted storm surge through the ADCIRC Surge Guidance System.
The Compound Flood Inundation Guidance System delivered flood guidance showing compound threat predictions from surge and rainfall for watersheds in Louisiana once daily from June 16 through June 19 and an after-storm guidance on June 21.
Potential Tropical Cyclone Three has formed in the Northern Gulf and might strengthen into a tropical system before making landfall along the southern Louisiana coastline. After two short-lived tropical systems in the Atlantic, this would already be the third named storm of the season 2021 – Claudette.
The LSU Coastal Emergency Risks Assessment (CERA) visualization tool was recently listed by The Coastal Protection and Restoration Authority as one of their frequently used sites in a CPRA Board Meeting presentation.
CPRA LA uses CERA as an emergency assessment tool to view the impacts of modeled storm surge for hurricanes and tropical events delivered by the ADCIRC Surge Guidance System (ASGS). The ASGS was developed by Seahorse Coastal Consulting, a long-term partner of CERA.
Additionally, compound flooding guidance will become operational to CPRA for the upcoming 2021 hurricane season through the Compound Flood Inundation Guidance System (CFIGS) developed by CE Hydro. The CFIGS model will capture combined influences of storm surge and precipitation for watersheds in Louisiana that are of particular interest to CPRA for emergency response tasks. The CFIGS model results will be presented on the CERA interface through inundation animations (depth of water above ground) and hydrographs for water level comparison to model prediction (50 stations from USGS, USACE, and NWS).
One lesson learned from the 2020 hurricane season was that it is difficult to identify the areas of highest risk based solely on inundation mapping. CFIGS will therefore also introduce a new flood hazard layer to quickly identify areas during an event with a high risk of structural flooding.
On May 22, the National Hurricane Center started issuing advisories for subtropical storm Ana that had formed near Bermuda – the first storm of the 2021 Atlantic hurricane season which officially starts on June 1.
The Coastal Emergency Risks Assessment (CERA) Group at Louisiana State University provides storm surge and flood inundation guidance through its interactive visualization portal all season. Please check our CERA storm surge tool at cera.coastalrisk.live for updates and get connected with our partners through Seahorse Coastal Consulting at LinkedIn.
On May 20, NOAA issued it’s 2021 hurricane seasonal outlooks for the Atlantic and East Pacific basins. For the Atlantic, an active season is predicted.
According to NOAA, several climate factors that favor increased activity are reflected in this outlook, including: – the ongoing high-activity era that is in place since 1995 – ENSO Neutral or LaNina (will not suppress hurricane activity) – warmer-than-average sea-surface temperatures – reduced vertical wind shear – weaker Atlantic tropical trade winds – an enhanced African monsoon.
“Forecasters predict a 60% chance of an above-normal season, a 30% chance of a near-normal season, and a 10% chance of a below-normal season. However, experts do not anticipate the historic level of storm activity seen in 2020.”
According to a statement released by NOAA on April, 9 2021, the Atlantic hurricane season averages have changed.
“Beginning with this year’s hurricane season outlooks, NOAA’s Climate Prediction Center (CPC) will use 1991-2020 as the new 30-year period of record. The updated averages for the Atlantic hurricane season have increased with 14 named storms and 7 hurricanes. The average for major hurricanes (Category 3, 4 or 5) remains unchanged at 3. The previous Atlantic storm averages, based on the period from 1981 to 2010, were 12 named storms, 6 hurricanes, and 3 major hurricanes.”
CERA visualizes time series for water levels, wind, and significant wave height for any location on the map. To use this feature, click on the time series button on the left of the map, then click on the desired location on the map.
CERA’s 2021 release now allows downloading the selected time series as a .json file. The download link is in the top right of the time series chart.
If finding a time series for a specific coordinate point is desired, click on the time series button, then click on the location search button on the left of the map. If you already have a chart open, the coordinate pair is pre-filled in the search box. If you would like to find another place, enter the coordinate as [latitude, longitude]. CERA will open the time series chart automatically.
What is the Compound Flood Inundation Guidance System (CFIGS)? CFIGS is a compound flood prediction system developed at CE Hydro, capable of predicting flooding due to the combined influences of precipitation and storm surge/tidal fluctuations. It provides flood inundation guidance to promote understanding of the timing and extent of flooding before the event.
With CERA’s headquarters at the Louisiana State University (LSU), the team is excited to include this local and unique model prototype on immediate display for users to view and operate. View it here on CERA.
CFIGS was made possible with the support from Coastal Protection Restoration Authority (CPRA), Louisiana SeaGrant, Louisiana State University (LSU), Seahorse Coastal Consulting and Freese and Nichols, Inc (FNI).