Albany, NY

Weather Forecast Office

Snowfall Bias MAE

Using GAZPACHO to Create Forecast Snowfall Bias / Error Maps Stratified by Flow Regime

The following maps were created by comparing observed snowfall and forecast snowfall as a function of wind direction.

Observed snowfall from 56 snowfall events was compared to forecasts from WFO Albany. Winds at 850 mb and 925 mb

were derived from the local sounding at Albany. Wind direction and speed were determined at times close to the mid-point

of each storm.

A positive bias indicates that forecasts were higher than observed, while negative biases indicated snowfall forecasts

less than what was observed. Errors are mean average error. I

It is hypothesized that some of the larger biases and errors can be attributed to terrain influences in favored upslope / downslope

areas in the Albany county warning area.

925 mb Bias:

0-90 degrees, 0-19 kt	0-90 degrees, 20-39 kt	0-90 degrees, 40+ kt
90-180 degrees, 0-19 kt	90-180 degrees, 20-39 kt	90-180 degrees, 40+ kt
180-270 degrees, 0-19 kt	180-270 degrees, 20-39 kt	180-270 degrees, 40+ kt
270-360 degrees, 0-19 kt	270-360 degrees, 20-39 kt	No events in the 270-360 degrees, 40+ kt category

925 mb MAE:

0-90 degrees, 0-19 kt	0-90 degrees, 20-39 kt	0-90 degrees, 40+ kt
90-180 degrees, 0-19 kt	90-180 degrees, 20-39 kt	90-180 degrees, 40+ kt
180-270 degrees, 0-19 kt	180-270 degrees, 20-39 kt	180-270 degrees, 40+ kt
270-360 degrees, 0-19 kt	270-360 degrees, 20-39 kt	No events in the 270-360 degrees, 40+ kt category

850 mb Bias:

850 mb MAE: