Flight reaches 801 mph as a furious jet stream packs record-breaking speeds

Tuesday is a nice day across the Northeast. Temperatures near 40 in New York, light winds out of the north at 5 mph to 10 mph, and wall-to-wall sunshine sound like a tranquil day — especially by February standards. But high up in the atmosphere, it’s a different story.

The jet stream, the high-altitude air current along which storms travel, is furious. The river of air was clocked at more than 230 mph over Long Island on Monday. That measure comes from the 250 millibar pressure level, meaning it was at a height above 75 percent of the atmosphere’s mass. It sets the record for the fastest 250 millibar wind speed ever recorded over New York and, probably, the country.