Hurricane Lee is currently a Category 1 storm expected to make landfall in Nova Scotia late on Saturday, September 16th. It is forecast to bring extreme weather, including coastal flooding, to New England and Atlantic Canada.
Multiple free-drifting Spotter buoys from Sofar’s global network made direct observations of extreme wave conditions generated by Hurricane Lee as it moved through the Atlantic Ocean this week.
On Thursday, September 14th, SPOT-1207 and SPOT-1184 each passed through the most intense region of the storm, with SPOT-1207 observing significant wave heights up to 12.7 m (~42 ft). On Friday, SPOT-1255 and SPOT-010418 also drifted close to Hurricane Lee’s most intense region, with both buoys observing significant wave heights over 11 m (~36 ft). Significant wave height observations of this magnitude correspond to maximum wave heights of 70-80 ft likely observed by these four Spotters.
In the image below, we overlay GOES-16 satellite imagery of Hurricane Lee with the drift tracks (green lines) of Spotter buoys (yellow pentagons) from our global network that are currently in the Atlantic.
Hurricane Lee’s wide field passed over more than a dozen Spotters as it moved north, a testament to the value of maintaining a dense fleet of marine sensing devices in tropical cyclone-prone open ocean areas to collect in situ data. Sofar and its collaborators in the National Oceanographic Partnership Program's Hurricane Coastal Impacts project use direct observations like these to validate and improve existing forecast models of hurricane impacts.
The direct observations made by the 10 Spotters airdropped in Hurricane Idalia’s path were made accessible on the U.S. Geological Survey (USGS)’s Flood Event Viewer via the Sofar API. The public-facing map is an essential, real-time source of extreme event information for coastal communities.
The ground truth Spotter observations complemented the observations made by USGS’ network of over 8,000 streamgages and other sensors. This data informs the USGS’ critical assessments of high-water events and storm surge for coastal communities.
Below, we show a time series of significant wave height observed by one of the airdropped Spotters, accessed via the USGS Flood Event Viewer. This buoy, SPOT-30103D, passed close to the eye wall of Hurricane Idalia and recorded a peak significant wave height of ~7.5m (~24.6ft). Check out our Hurricane Idalia update from August 30th (below) to view more ground truth data collected by SPOT-30103D.
Early on the morning of Wednesday, August 30th, a fleet of 10 airdropped Spotters in the Gulf of Mexico made direct observations of extreme conditions near Hurricane Idalia’s eye wall. The Spotters — which were deployed on Monday, August 28th, ahead of the storm by U.S. Naval Research Laboratory Scientific Development Squadron VXS-1 — passed through the Category 3 hurricane shortly before it made landfall in northwest Florida’s Big Bend region.
Below, we overlay a CIRA/NOAA satellite image of Hurricane Idalia with the positions of each airdropped Spotter (yellow pentagons), as of approximately 4:40am ET on Wednesday, August 30th. This timestamp was selected because it is when a subset of the airdropped Spotters — including SPOT-30103D (red pentagon) — was closest to the hurricane’s eye wall. Hurricane Idalia made landfall near Keaton Beach, Florida at approximately 7:45am ET.
SPOT-30103D made particularly noteworthy observations near the eye wall of Hurricane Idalia. Below, we plot SPOT-30103D's observed significant wave height, sea surface temperature, and barometric pressure from Monday afternoon (August 28th) to Wednesday afternoon (August 30th). The vertical blue line in each time series marks 4:40am ET to correspond with the timestamp for the CIRA/NOAA satellite image and Spotter positions above.
As the time series approach 4:40am ET on Wednesday, August 30th — when SPOT-30103D was near Hurricane Idalia's eye wall — we observe:
Hurricane Idalia is rapidly intensifying in the Gulf of Mexico and is expected to make landfall in northwest Florida’s Big Bend region early on Wednesday, August 30th. It is forecasted to become a major Category 3 hurricane and cause dangerous storm surge along the Florida Gulf Coast.
On Monday, August 28th, the U.S. Naval Research Laboratory Scientific Development Squadron VXS-1 airdropped 10 Spotters in Hurricane Idalia’s path. The Spotters, which were deployed from 1,000 feet by an NRL P-3 aircraft traveling at 150 mph, will drift freely in the Gulf of Mexico and sample Hurricane Idalia’s extreme wave conditions, including the particularly dangerous right front quadrant, in real-time as it approaches the coast.
Using the interactive Sofar weather dashboard below, zoom in on Hurricane Idalia's forecasted storm track and locate the 10 airdropped Spotters arranged in an array along the northwest coast of Florida. Click on each Spotter to view its current position and latest observations.
The observations made by the fleet of airdropped Spotters will improve our ability to understand hurricane dynamics, predict hurricane impacts, and protect coastal communities.
Specifically, the Spotter data will accelerate research conducted by Sofar and its private, academic, and government partners in the National Oceanographic Partnership Program’s (NOPP) Hurricane Coastal Impacts (NHCI) project. NOPP NHCI teams will use the ground truth observations made by the Spotters — along with microSWIFT and A-DWSD devices — during Hurricane Idalia to validate and improve existing forecast models.
To access government resources for Hurricane Idalia, visit NOAA's National Hurricane Center.
