Raleigh forecast discussion. Interesting
A great deal of uncertainty in the long term pattern but there
are indications of colder temperatures and the potential for wintry
precipitation at the end of the period...
Sunday into Monday: a surface low will be exiting the Outer Banks on
Sunday morning as the northern stream upper level trough axis moves
across the southern Appalachians. The main precipitation shield will
be lifting northeast away from central NC through the mid morning
hours with some light lingering drizzle or light rain persisting for
a couple of hours before the upper trough axis clears the area.
Boundary layer temperatures will be near and just above freezing
across the northern Piedmont. As the low shifts east, the above
freezing warm nose around 750mb cools which could result in a brief
rain/snow mix across the northern Piedmont. The potential for this
is offset by drying aloft and decreasing moisture in the ice
nucleation region. At this point, little impact is expected. Cold
advection will counteract increasing amounts of afternoon sunshine
with highs ranging in the mid 40s near the Virginia border to the
lower 50s across the south.
High pressure centered over the northern Plains and south-central
Canada will extend into the Great Lakes and Mid Atlantic on Sunday
night and into the Carolinas on Monday. With clear skies and light
winds, lows Monday morning will range in the mid to upper 20s with
some of the typically colder spots having lows closer to 20. Fair
weather with some mid and high clouds are expected on Monday with
highs moderating a bit into the mid 40s north to lower 50s south.
Forecast confidence goes out the window for the remainder of the
work week as a broad upper trough over much of central and eastern
Canada and the U.S. A wave will likely transit the eastern U.S. on
Tuesday with a general westerly flow across the south. With time,
the trough amplifies across the central U.S., Arctic air spills
south, and the flow becomes increasingly active and southwesterly
across the South and the Carolinas. Indications are that the flow
will become amplified on Thursday into Friday as a storm system
moves across the Southeast. With a piece of the Arctic high setting
up over eastern Canada, there is a potential for some wintry
precipitation although details are impossible to resolve at this