Harmful Algal Bloom Forecasts

Lake Erie Harmful Algal Bloom Forecast

NOAA provides forecasts for seasonal blooms of cyanobacteria (blue-green algae) in Lake Erie, typically from July to October when warmer water creates favorable bloom conditions. Western Lake Erie has been plagued by an increase of HABs intensity over the past decade. These blooms consist of cyanobacteria or blue-green algae, which are capable of producing toxins that pose a risk to human and animal health, foul coastlines, and impact communities and businesses that depend on the lake. A combination of satellite image (for bloom location and extent), a forecasting and mixing model provide information on the current status of the bloom, forecasted position both at the surface and at depth, and toxicity from field samples. See individual products and our FAQs for more information.

Forecast Products


The Microcystis cyanobacteria bloom is present in western Lake Erie but cloud cover and winds prevent determining the area. The bloom extends from Maumee Bay north to Pointe Mouillee, MI and east from Maumee Bay to Catawba Island, OH. Sandusky Bay has a local bloom of cyanobacteria, which is persistent in most years.
Toxins have been detected above the recreational limit. They can be highly concentrated in scums! If you see scum, keep your pets and yourself out of the water. In the satellite imagery or bloom forecast position products, any areas that are orange or red are likely to have scum, especially during calm winds, see Mixing Forecast product. --A. Hounshell 08/08

The past few days of imagery can be seen at the HAB monitoring site. The Lake Erie Forecast is operated by the National Centers for Coastal Ocean Science. Contact hab@noaa.gov for technical Questions. Last Updated: 2022-08-09 07 AM EDT


Observed Bloom Position

(from most recent satellite image)

Current satellite imagery from the Ocean Land Color Imager (OLCI) and true color imagery showing bloom location and extent.

Forecasted Bloom Position

(from modelling)

Forecasted extent and position of the bloom for a minimum of 96 hours, based on a combination of a hydrodynamic modeled currents and satellite imagery for initial bloom location.

Vertical Mixing Forecast

Forecast of the potential for mixing over the next at least 96 hours, to determine the likelihood that the bloom is at the surface or subsurface.

HAB Alerts

HABs in Lake Erie pose a risk to human and animal health, foul coastlines, and negatively impact communities and businesses. Sign up to receive Lake Erie HAB updates via email.

2022 Western Lake Erie Projections

The early season projection estimates bloom severity based on Maumee River discharge and modeled phosphorus loads. It is issued weekly from May until the seasonal forecast is announced.


2022 Lake Erie Seasonal Forecast Event

The official seasonal forecast for Lake Erie will be announced the end of June during a live webinar hosted in collaboration with Ohio Sea Grant.

Additional Resources

For other data on Lake Erie HABs, visit one of these websites:

For safety information on these blooms, visit the Ohio EPA website.