From RAH:
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 211 AM Sunday...
The main weather story for the long term period will be the winter
storm system on Wednesday that may have lingering impacts through
the late-week period. The complex upper pattern driving all of this
is a
deepening s/w
trough over the Midwest that will close off and
move east across the Great Lakes. Deep layer ascent
invof the right
entrance region of the eastern
jet streak will prompt
sfc low
development over the northern Gulf Coast which will become a Miller-
A type
sfc low that moves from the FL Panhandle northeastward up
along the Southeast coast. The ascent with the aforementioned
jet
streak and
sfc low coupled with the antecedent cold airmass over our
area will result in a period of mixed wintry precip types with the
usual distribution of snow across our northern counties, rain
across our far south and southeast counties, and a mix of sleet and
freezing rain in between...beginning Wednesday morning and
continuing through at least Wednesday evening. It`s definitely worth
noting that the
ECMWF is much colder than the
GFS, so it suggests
that wintry p-types will occur across our entire
CWA, even our far
south and southeast zones.
What`s interesting about the models` evolution of this system is
that there`s good agreement with the overall pattern but differences
in the QPF and warm nose strength and placement, and ultimately p-
types and amounts for the various parts of our CWA. Interestingly...
the right entrance region of the eastern jet streak and the left
exit region of the western jet streak do not overlap...so the models
show that our area gets dry-slotted pretty quickly. Yet the ECMWF
and Canadian have much higher QPF than the GFS. Needless to say, if
the wetter and colder ECMWF verifies, this winter storm system could
have major or perhaps even extreme impacts for central NC, both due
to snow accum across our north and northwest zones and ice accum for
our south and east zones. The GFS on the other hand, while
impactful, would result in much less dire amounts and impacts for
central NC. There`s still plenty of time for things to change, so
stay tuned!
Thursday and Friday now look to be dry with well below-
normal temps
as the next cold high pressure builds in behind the departing low.
Another s/w
trough will move across the Miss Valley on Saturday, but
right now the models keep the developing
sfc low and deep
moisture
suppressed to our south.
&&