I was just texting with my boss. There’s snow coming to Nebraska Monday. Our conversation was about how much.
Weather is a seven day a week job. You have to follow it daily or you lose the rhythm. I always look at maps on the weekend. More this weekend.
A weak low moving from Mexico into Texas begins tapping Gulf moisture and explodes. The central pressure drops, wind field intensifies and precipitation shield grows.
Now the storm turns to the north northeast (on a map, just right of straight up) and brushes Nebraska with snow on its trailing, colder, western edge.
Forecasting in the Plains is more straightforward than New England. This storm will have little Rocky Mountain or Atlantic Ocean influence.
A rule-of-thumb for snow, the temperature at 850mb (around 5,000 feet) must be less than 0ºC (32ºF). The 0C/850 line is often the focal point for the heaviest snow. Midday Monday the 850mb temperature is in -5ºC neighborhood.
Monday’s snow comes from an inversion layer. -5ºC at 850mb is actually warmer than air closer to the ground! That’s the opposite of normal.
Climatology says snow in Northeast Nebraska averages a 12:1 snow:water ratio. It’s fluffier and more susceptible to drifting than New England snow, especially with Nebraska’s propensity for wind.
QPF, quantitative precipitation forecasts, are among our least successful weather pursuits. Let’s say 2-4″ in Norfolk, our headquarters, with slightly higher amounts east and lesser amounts west. Your actual mileage may vary.