GFS Forecast Model: Precipitation Totals with MSL Pressure Contours - Real-time

This dataset shows us what is happening at the surface of the Earth as opposed to high up in the sky. This is the view of the forecast from the surface, combining the weight of the air (pressure) with the resulting rain and snow.

The lines on this map represent Mean Sea Level Pressure. They act like a map of atmospheric weight.

• Low Pressure (L): When air rises, it leaves behind less weight at the surface. These areas are usually centers of storms, where air is swirling inward and upward to create clouds and rain.
• High Pressure (H): When air sinks, it pushes down with more weight. These areas act like a heavy blanket, clearing out clouds and bringing calm, dry weather.

The colorful shading shows the total amount of water (rain or melted snow) predicted to fall over the forecast period.

• Green and Yellow: Indicate light to moderate rainfall.
• Orange and Red: Highlight areas where heavy, potentially impactful precipitation is expected.

This visualization is powered by the Global Forecast System (GFS). By solving complex math equations, the GFS predicts how areas of Low Pressure will move and strengthen. Generally, the tighter the pressure circles are packed together, the stronger the winds and the more intense the precipitation will be.

GFS accumulated precipitation and mean sea level pressure are taken from GRIB2 output of NOAA's Global Forecast System, obtained through NCEP NOMADS. The animation shows modeled precipitation totals with MSL pressure contours for synoptic context. The visualization is updated once per day and shows a 180-hour forecast sequence. Python was used to process and visualize these fields.

• Time frame: Real-time, updated once per day
• Frequency: 1 frame every hour
• Range: 180 hours (7.5 days)
• Variable: Mean Sea Level Pressure (mb) and Precipitation Totals (mm)