In the early morning hours of 5 July 2013 thunderstorms produced very heavy rain and small hail near Havre. Post frontal stratus was pushing southward through Cut Bank where ceilings had lowered to 700 feet. Here’s the VIIRS nightime Microphysics RGB image for this event, with surface obs and 15-min lightning overlaid. The image clearly shows the difference between the low stratus (ivory/pink) and the cold convective clouds (red/orange). The lightning plot is for 10-10:15Z, and the image is valid 10:20Z, so the convection appears to have moved a bit east of where the lightning activity is located. Interesting that there appears to be a signature of cloud shadows to the west-southwest of the taller storms east of Great Falls. At 4:20am, one would observe a brightening of the NE sky.
By comparison, consider the corresponding IR image
Here’s the METAR for CTB:
KCTB 051056Z AUTO 34014KT…
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