Question about wind shear maps

[Tom Mull]

On the 850 and 500 mb Winds Map on the SPC Mesoanalysis, I assume the blue wind barbs indicate the winds at 500 mb and the red wind barbs represent the winds at 850 mb.

What I don't understand is what the solid blue and solid red lines indicate. Does anyone know what those lines represent?

Thanks.

 

[Paul Knightley]

They are just isolines joining the equal wind speeds at each level - so the red lines show the 850 hPa wind speed contours, starting at 20 knots, and the 500 hPa are in blue, starting at 30 knots. The lines are called 'isotachs'.