A potentially epic December heat wave is set to blanket much of the contiguous U.S. over the next two weeks, potentially leading several cities and states to set records for the warmest first month of winter on record.
The big picture: In a major pattern shift, the jet stream is poised to dive south toward the western U.S., bringing much-needed rains and mountain snows to a parched California and other western states. But to the east of this jet stream dip, or trough, a potentially record strong ridge of high pressure is projected to set up over the Central U.S.
A tranche of blood and stool samples that have been in storage since 1984 are now helping scientists learn more about HIV and AIDS.
Why it matters: Applying modern science to these decades-old samples offers a glimpse back in time into the role gut microbes may have played in the early spread of HIV and AIDS.