  We report results from 8 hours of JWST/MIRI LRS spectroscopic monitoring
directly followed by 7 hours of JWST/NIRSpec prism spectroscopic monitoring of
the benchmark binary brown dwarf WISE 1049AB, the closest, brightest brown
dwarfs known. We find water, methane, and CO absorption features in both
components, including the 3.3 $\mu$m methane absorption feature and a tentative
detection of small grain ($<$ 1$\mu$m) silicate absorption at $>$8.5 $\mu$m in
WISE 1049A. Both components vary significantly ($>$1$\%$), with WISE 1049B
displaying larger variations than WISE 1049A. Using K-means clustering, we find
three main transition points in wavelength for both components of the binary:
1) change in behavior at $\sim$2.3 $\mu$m coincident with a CO absorption
bandhead, 2) change in behavior at 4.2 $\mu$m, close to the CO fundamental band
at $\lambda >$ 4.4 $\mu$m, and 3) change in behavior at 8.3-8.5 $\mu$m,
potentially corresponding to silicate absorption. We interpret the lightcurves
observed with both NIRSpec and MIRI as likely stemming from 1) a deep pressure
level driving the double-peaked variability seen in WISE 1049B at wavelengths
$<$2.3 $\mu$m and $>$8.5 $\mu$m, 2) an intermediate pressure level shaping the
lightcurve morphology between 2.3 and 4.2 $\mu$m, and 3) a higher-altitude
pressure level producing single-peaked and plateaued lightcurve behavior
between 4.2 and 8.5 $\mu$m.
