Researchers are expecting a moderately large hypoxic zone this summer in the Northern Gulf.  A NOAA-sponsored ensemble of models has forecasted a ‘Dead Zone’ of 14,400 sq km. The best estimate from the NCSU/Obenour Lab model is 14,300 sq km, roughly the size of Connecticut and Rhode Island, combined. This estimate reflects moderate flow and nutrient loading from the Mississippi River this spring.  Interestingly, while flows have been above average, loads have been below average, suggesting a reduction in mean nitrogen concentrations in the River. In addition, moderate westward winds are expected to provide the typical delivery of 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.