It can be challenging to detect disturbances during seasonal periods of transition such as Fall or Spring in the eastern deciduous forest. The baseline conditions we use to compare with current conditions harbor a lot of normal variation that results from the onset and progression of cold temperatures. In the upper Midwest, Fall is typically reflected by a gradual drop in NDVI during September, then a more rapid decline in October. By the beginning of November during most years, this decline in NDVI is largely complete.
ForWarn identified a disturbance near Roanoke River, North Carolina. The persistent disturbance may be attributed to an ice storm causing damage to foliage. The confirmed cause for the departure is currently unknown.
ForWarn identified anomalies in the Lyon and Johnson Mountains, New York. There are several possible causes for this event. Clouds may obstruct the detector providing a false anomaly, insects may be defoliating the area, the phenology of the plants could play a part in departure, or sever weather causing damage to foliage.
ForWarn detected a decline in the Eastern Highland Rim of Tennessee. Severe weather is the possible cause for the vegetation departure.
ForWarn detected a decline in southeast Asheville, North Carolina. Severe weather is the possible cause for the vegetation departure.
ForWarn identified an anomaly in Franklin and Bedford Counties of Virginia. The linear decline in vegetation greenness is attributed to a hail storm event which damaged foliage, declining vegetation greenness.