Temperatures in the northern United States will get relatively cool next week, with models suggesting temperatures ranging 10 to 20 degrees below normal. The cause is something we'll call the SummerPolarVortexmageddon, because it sounds cool and (still) nobody knows what a polar vortex is, anyway.

The western United States is famous for its calm, predictable weather, so it's noteworthy when extreme weather happens. Parts of California and Oregon have been sweltering under heat exceeding 100 degrees in some spots, and it's making people ask "what gives?"

For those of you baking in the center of the country today, fear not — a cool-down is coming. The NAM is predicting highs only reaching the 90s tomorrow in areas where it's reached the 100s for the last few days. As always, relief comes with a price: severe weather is expected both tomorrow and Thursday.

The cold front is pretty easy to spot in Oklahoma this afternoon — it was 92°F in Tipton while temperatures dropped into the 50s a few counties away. A line of severe thunderstorms is announcing the arrival of the cooler air, bringing temps as cold as the low 20s by tomorrow night.

A strong ridge of high pressure is starting to bake the southwestern United States right on schedule for this time of year — with several areas expected to reach the triple digits today — but winter isn't done with the rest of the country yet.

In a shining example of "correlation does not imply causation," two reporters for the Baltimore Sun were unable to determine whether or not the cold weather in Baltimore this winter made people less likely to murder each other.

A strengthening low pressure system over South Dakota this afternoon is producing a pretty striking temperature gradient across the northern Plains. The system is causing blizzard conditions over much of the Dakotas with temperatures as low as 10°F, while just a few dozen miles away, the town of Shenandoah, Iowa is sitting at a comfortable 79°F.