Researchers are expecting severe hypoxia this summer in the Northern Gulf of Mexico. A NOAA-sponsored ensemble of models has forecasted a ‘Dead Zone’ of 6700 sq mi, substantially larger than the state of Connecticut. The best estimate from the NCSU/Obenour Lab model, which is included in the NOAA ensemble, is 17,200 sq km (6600 sq mi). This estimate reflects above-average flow and nutrient loading from the Mississippi River this spring (as determined by USGS), coupled with average westward wind velocities that deliver nutrients and freshwater over the Louisiana-Texas shelf.
Model forecasts are compared to observations from the midsummer LUMCON shelfwide cruise. Considering typical weather variability and other system uncertainties, we estimate less than a 5% chance of observing a record (>22,700 sq km) hypoxic area this year. There is almost no chance of observing a hypoxic area of less than 5000 sq km (management goal), unless a major storm disrupts the hypoxic zone prior to the monitoring cruise.