Researchers are expecting a relatively small hypoxic zone this summer in the Northern Gulf of Mexico. A NOAA-sponsored ensemble of models has forecasted a ‘Dead Zone’ of 10,800 sq km. The best estimate from the NCSU/Obenour Lab model is 11,400 sq km, approaching the size of the state of Connecticut. This estimate reflects substantially below-average flow and nutrient loading from the Mississippi River this spring, coupled with moderate westward winds to deliver nutrients and freshwater over the Louisiana-Texas shelf.
These predictions include substantial uncertainty due to summer hydro-meteorological variability. However, there is <1% chance that a record hypoxic zone (>22,700 km2) will be measured by the LUMCON shelfwide cruise this summer. It is also important to note that extreme weather can temporarily reduce the hypoxic zone, as in the case of Hurricane Hanna in 2020.