3 paragraph essay with the long term...
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
As of 420 PM Sunday...
Given the complexity of the forecast flow aloft across the CONUS
this week, there not surprisingly remains amplitude and timing
differences with individual shortwave perturbations embedded within
that flow. While the GFS remains a deep outlier with respect to 500
mb heights over the cntl Appalachians/middle Atlantic at 00Z-12Z
Wed, it has trended toward an otherwise relatively good model
consensus during that time; and the associated QPF signal east of
the Appalachians in recent days is consequently absent, or very
light. As such, no measurable precipitation will be forecast in cntl
NC at this time, with instead a chance of sprinkles over the
Piedmont Tue night, and again over the ne Piedmont and nrn Coastal
Plain with diurnal heating Wed, related to the passage of a
secondary shortwave trough and associated similarly strong height
falls and mid level Fgen. As previously noted, any very light
resulting precipitation during either time would be liquid based on
forecast (wet bulb) thermal profiles.
It will otherwise be colder through the end of the week, as the
trough aloft and cP high pressure migrate ewd across the srn
Appalachians and sern US - coldest Thu, when highs will be in the
40s and lows solidly in the 20s. A reinforcing cold front, and
leading edge of a fresh, stronger cP high, will then move swd
through VA/NC late Fri-Fri night, setting the stage for the arrival
of a srn stream system, or two, next weekend.
The ewd progression of the parent, significant closed low forecast to
migrate through split flow across the ern N Pacific, to near srn CA
by the end of the week, has slowed in recent model cycles - perhaps
not surprisingly given that such closed lows often take longer to
eject ewd than what the models would suggest. As such, the arrival
of resultant precipitation in cntl NC will likely be slower than
previously indicated, particularly so given the presence of the
aforementioned cP high and dryness extending from the upr Midwest,
ewd and then swd in damming fashion east of the Appalachians.
While forecast details remain uncertain, pattern recognition with a
favorably positioned, cold high, and significant cyclogenesis from
the GOM to the sern and middle Atlantic coast, favors wintry
precipitation over the middle Atlantic states, including
particularly the climatologically-favored areas of cntl NC. Given
the time range and uncertainty, forecast p-types of only rain and
snow will be included at this time. However, there would most likely
be some degree of broader mixed p-type transition zones given that
the parent trough aloft is forecast to remain west of the
Appalachians through the weekend, with probable mid level warming
across portions of the Carolinas.