Scientific Forecaster Discussion
fxus62 krah 181424
Area forecast discussion
National Weather Service Raleigh NC
1020 am EDT Wed Oct 18 2017
surface high pressure over the mid-Atlantic will extend across
the region into the weekend. A cold front will approach the
area from the west early next week.
Near term /through tonight/...
as of 1020 am Wednesday...
High pressure at the surface and aloft will provide central NC with
clear skies and seasonably cool temperatures through tonight. After
a chilly start to the day which saw morning slows down into the 30s
across much of the Piedmont, temperatures ate late morning had
recover into the 50s. Temperatures appear on track to reach the
forecast highs in the upper 60s to around 70. Under clear skies this
evening, temperatures will cool quickly after sunset, falling
through the 50s early this evening, and into the 40s across the
Piedmont after 10 PM. Min temps in the upper 30s-lower 40s common,
slightly warmer over the southern coastal plain where patchy low
clouds may develop prior to daybreak.
Short term /Thursday through Thursday night/...
as of 300 am Wednesday...
A quiet weather regime continues into Thursday and Thursday
night as surface high pressure remains in control. A short wave
trough pushes across the Carolinas on Thursday and offshore on
Thursday night resulting in some transient and patchy cirrus
clouds. Some shallow moisture could result in some patchy fog or
stratus across the coastal plain toward daybreak Friday.
Otherwise, skies should be generally clear. Highs on Thursday
will range in the lower to mid 70s with lows Thursday night in
the lower to mid 40s. -Blaes
Long term /Friday through Tuesday/...
as of 305 am Wednesday...
Surface high pressure over the region to start the period late week,
will shift offshore this weekend. Meanwhile, mid/upper level ridging
will move across the region from west to east late week into the
weekend. This will yield quite/dry weather during this time frame,
with some increasing moisture by late Saturday into Sunday. Expect
highs temps will be above normal during this period, generally
ranging from the mid to upper 70s to even some lower 80s. Low temps
are expected to range from the mid 40s to mid 50s during this time
frame (coldest on Saturday morning).
Chances for showers and possibly some thunderstorms will increase
early next week as a surface cold front approaches. However, model
guidance continues to show very poor run to run continuity, along
with a large spread in the ensembles, with regard to the evolution
of the mid/upper level flow pattern across the Continental U.S. Next week.
Strength of the next system along with the timing remains in
question. However, chances for some decent precip appear to be
increasing for the period of early to mid next week, though which
day(s) will have the highest chances is still very much in question
(along with temps for the period). For now will generally go with
chance pops for early next week, with both pops and temps hedging
towards a bit slower frontal passage (which is more in line with the
00z/18th GFS and 12z/17th European model (ecmwf) and the previous forecast). Thus,
will go with highs Monday in the 70s, to lower 80s and highs on
Tuesday generally from 70-75.
Aviation /12z Wednesday through Sunday/...
as of 645 am Wednesday...
High confidence of VFR conditions through the 24-hour taf
period. Surface high pressure and weak ridging aloft will result
in generally clear skies and fair weather during the period. A
few wisps of cirrus will move into the area from the west during
the day. Light northeast to easterly surface winds will range
between 3 and 8kts today with very light to calm winds expected
early this morning and again tonight.
Looking beyond the 24-hour taf period, surface high pressure
will persist across the region into the weekend. Some patchy
stratus or fog is possible across the coastal plain impacting
the kfay/krwi around and just prior to daybreak on Thursday and
possibly Friday mornings. -Blaes