Kevin Myatt is The Roanoke Times' weather columnist.

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Somebody east of the Mississippi River and north of Interstate 40 is going to get an amazing amount of snow for late October about Friday or Saturday.

A deep, southerly dip in the jet stream will deliver some very cold air for the season far to the south over the Eastern United States, and very likely spin up a strong low pressure system somewhere in the East.

The probable scenario, based on a growing plurality of forecast model runs and on the particulars of the pattern, favors a more inland path for the low and the likelihood of any heavy snow developing to our west and northwest in the Ohio Valley, possibly as far east as West Virginia, extending into the Great Lakes and part of the Northeast.

The North Atlantic Oscillation is not solidly in a negative phase right now, which would mean that high pressure over Greenland would be present, and that often locks in a more coastal track for low-pressure systems. There also isn't the upper-level low near Newfoundland that in winter often helps steer storms more along the coast rather than letting them go inland.

And besides all of that, it's just exceedingly difficult to get everything to come together for a winter storm at this latitude in late October.

But the chance of seeing some snowflakes across much of Southwest Virginia is pretty good next weekend. As the low moves north of us, cold northwest winds sweeping off the Great Lakes and over the Appalachians will squeeze out snow as the air is lifted, the common "upslope snow machine" we see with most cold front passages in the winter. This time, the cold air will be deep enough that some flakes could get down to the lower elevations -- flurries even in Roanoke, possibly.

A major shot of cold air next weekend appears to be the most certain aspect of it all. Before that arrives, we'll shoot back into the 70s for highs today through Wednesday.

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