Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Raleigh NC
820 PM EDT Friday may 22 2015
Synopsis...high pressure will build into the region from the north
tonight...then linger along the middle Atlantic coast through early
Near term /through tonight/...
as of 820 PM Friday...
Only a few cirrus were observed around sunset... otherwise the
skies were clear across NC. Satellite data suggests that any
additional cirrus will not arrive until very late tonight and will
be limited in coverage. Clear skies expected in the forecast
overnight. Lows generally expected to be in the middle 40s for the
rural northern Piedmont... near 50 in The Triad and Triangle
areas... and lower 50s south.
Short term /Saturday and Saturday night/...
as of 1200 PM Friday...
An upper level low (centered over Southern California at 15z) will track
east through the intermountain west into The Rockies Sat/Sat night.
Height falls /DPVA/ attendant the approaching upper trough will aid
in the development of widespread convection /latent heat release/
across the Central Plains late Sat/Sat night. This...in turn...will
amplify the downstream ridge along the MS River Valley and result in
additional height rises across the Tennessee/Ohio Valley and mid-Atlantic. As
a result...expect surface high pressure to remain anchored in vicinity
of the middle-Atlantic coast and continued dry/pleasant conditions over
central NC with highs ranging from the low/middle 70s far NE coastal
plain to lower 80s SW Piedmont. Expect lows Sat night in the low to
middle 50s. -Vincent
Long term /Sunday through Thursday night/...
as of 225 PM Friday...
The extended period will largely be warm and dry as an upper level
ridge and surface high pressure remain over...or in close proximity
to...the Carolinas. The chances for precipitation will increase
slightly late in the period...predominantly in the western portions
of the area...as the ridge weakens and an upper level shortwave
impinges upon it from the northwest. However...confidence in precipitation chances
decreases with time as the model differences increase. The GFS is a
bit wetter than the European model (ecmwf) as it breaks down the ridge faster...
allowing the upper level shortwave to progress faster and farther
east...thus having a greater impact on central NC. Generally...
expect gradually warming temperatures through the period...highs in
the middle to upper 80s Sunday increasing into the upper 80s and low
90s by the end of the week. Lows will follow a similar trend...
around 60 degrees Sunday night and middle to upper 60s by late week.
Also...expect best chances for showers and storms in the west...
increasing late in the week...although there is a possibility that
much of the area could remain dry into Friday.
Aviation /00z Saturday through Wednesday/...
as of 725 PM Friday...
24-hour taf period: VFR conditions will persist throughout the current
taf period as high pressure gradually builds over the region from
the northwest. Skies will be mostly clear with only a few high
clouds at times and winds will be light and variable.
Looking ahead: expect VFR conditions to prevail through early next
week as high pressure lingers offshore the middle-Atlantic coast... with
a surface ridge axis extending westward into the Carolinas. Expect an
increasing potential for sub-VFR ceilings during the late night and
early morning hours by middle/late next week as high pressure shifts
further offshore and southerly return flow commences.