From Bham NOAA: forecast discussion
Monday night through next Saturday)
Issued at 1235 PM CST SUN JAN 1 2023
A complicated forecast scenario to kick off the extended period.
Synoptic guidance is somewhat in agreement
deepening a surface low
across the Central Plains on Monday. The attendant upper low will
lift northeast toward the Midwest/western Great Lakes on Tuesday.
The surface low begins to fill with time with the attendant
occluded
front approaching the region Tuesday night/early
Wednesday.
As the previous forecast discussions have already mentioned, some
competing factors at play here in terms of precipitation
potential and certainly
convection - intensity of
convection. We
are getting into the window of the CAMs now and they`re really
struggling with initiating/sustaining
convection along or ahead of
the
front due to very limited forcing and the
dynamics lifting
quickly away from the region.
Dewpoints should recover fairly quickly late Monday into early
Tuesday well into the 60s. And deep layer southerly/southwesterly
flow will lead to effective bulk
shear of 40-50 knots. Model
soundings show decent mid level lapse rates with
MLCAPE generally
500-1250
J/kg. As such, current feelings are that the CAMs are
undergoing the precip and will trend toward the higher
PoPs in
the synoptic and blended guidance. As a caveat, there is some hint
of a potential split in development with one area in the
proximity of the
front across our far north/northwest and another
in our south/southeast in the vicinity of the higher
theta-e and
moisture transport (with a potential minimum somewhere in the
middle). Did not try to get that cute with the spatial extent for
now given we are still 48 hours out.
The other trend with the 12z guidance has been a slight slowing of
the system - particularly when it comes to the sensible weather. Not
sure I`m ready to fully latch on to that solution just yet but did
maintain fairly high
PoPs in the southeast through early Wednesday.
The remainder of the forecast looks fairly benign but generally cool
with the
thermal trough lingering across the Tennessee Valley
through at least Friday. Some slow warming by next weekend.