
© Weather BellThursday’s High temperature forecast from the NOAA National Digital Forecast Database.
As forecast several days ago, unusual warmth has flooded the eastern half of the U.S. this week. Temperatures from the Great Plains to the East Coast have been running
10 to 20 degrees above normal.
On Tuesday, Minneapolis hit 71°F, Boston was 73°F, and Pittsburgh topped out at 74°F. Detroit set a new high temperature record for the date, reaching 76°F. The pattern continues into Thursday, with warm air surging across the Great Lakes and continuing into New England. And in an overall warming world, these types of fall warm spells are likely to become more frequent.
Climatologically, when this type of warmth settles in this late in the year, it usually does not end in a whimper.
Surges of cold air often follow, and given the warm air previously in place, strong thunderstorms should be expected before that transition.Additionally, that warmer air leads to more evaporation, meaning
more fuel for stronger thunderstorms. It is one of the reasons that fall brings a secondary peak to the annual severe weather year.
Comment: Severe storms, huge hailstones, 'tornado', batter south eastern Australia