Turner Downs Forecast Discussion

FXUS62 KRAH 221932

National Weather Service Raleigh NC
330 PM EDT Sun Sep 22 2019

High pressure will extend from near Bermuda west to the
southeastern U.S. through Monday. A dry cold front will move
across the Virginias and North Carolina late Monday and early
Tuesday. High pressure will build back into the region through
the middle of the upcoming week.

As of 230 PM Sunday...

The latest surface analysis shows an elongated area of surface high
pressure extends from near Bermuda southwest to northern GA. A weak
surface trough was noted across the eastern slopes of the
Appalachians in western VA and NC. Surface dew points across much of
central and western NC along with SC are in the upper 50s with a
region of higher dew points in the lower to mid 60s across eastern
VA. A ridge of high pressure aloft was centered over AL and GA with
595m 500 hPa heights observed at Atlanta and Birmingham.

Skies are mainly clear across central NC although a region of
cumulus has developed as expected in a region of enhanced moisture
under the subsidence inversion across southern VA and across the
northern Piedmont of NC. There are no radar returns at this hour but
an isolated shower or sprinkle is possible near and just to the
northwest of the RAH CWA. Otherwise, mainly clear skies and dry
conditions are expected for the remainder of the afternoon and
overnight. The trend of moderating nighttime lows will continue.
Lows tonight will range in the 60 to 65 range. -Blaes


As of 240 PM Sunday...

A strong, eastward advancing trough with a belt of 75+ kt flow at
500 hPa on Monday morning will shift east across the Great Lakes on
Monday and into New England on Tuesday afternoon. At the surface, a
lee trough will persist east of the Appalachians on Monday and
sharpen as a surface ridge of high pressure across the eastern
Carolinas shifts offshore. A cold front extending across the eastern
Great Lakes on Monday morning will push east, merge with the lee
trough across the western Carolinas and VA late Monday night and
then shift east reaching the NC coast by Tuesday afternoon.

The best forcing associated with the front will remain well north of
central NC and the amount of moisture with the front will be
limited. Scattered convection across WV and western VA Monday
afternoon will likely fade and fall apart as it approaches NC after
dark. Will continue to maintain a dry forecast through the period.

Highs will continue to range above normal on Monday and with little
change in air mass, low level thickness values will be similar to
today and range in the 1395 to 1405m range at 12Z Monday. Expect
highs in the upper 80s to around 90s. Don`t expect much change in
air mass so Monday nights lows will range in the lower to mid 60s.
Highs on Tuesday will be a little cooler and range in the mid to
upper 80s. -Blaes

As of 330 PM Sunday...

High pressure will remain in command Tuesday and Wednesday. A front
will approach the region on Thursday, but similar to what is
forecast to happen tomorrow, the parent low will be well north of
the region and dynamical forcing will be lacking. Since there is
still very little moisture around, this should be another dry
frontal passage. While the deterministic models show high pressure
reestablishing itself across the southeastern United States, the GFS
ensemble has several members showing scattered showers/thunderstorms
both Saturday and Sunday. However, considering the dry spell that we
have been under, will not add any pops at this point until models
come into a little bit more agreement. Temperatures will come down
slightly on Tuesday and Wednesday behind the front, although these
values will still be well above normal. Afterwards, highs will climb
back into the upper 80s and lower 90s across the region.


As of 135 PM Sunday...

24 hour TAF period: High confidence of fair weather and VFR
conditions across central NC during the TAF period. A ridge of
surface high pressure will continue to extend along the
Southeast coast as an upper level ridge extends across the
Carolinas from the Deep South. The result will be a period of
fair weather, VFR conditions, and a light southwesterly flow at
the surface. A couple of patches of early morning fog are
possible Monday morning but the coverage and extent will be very

Looking beyond the TAF period: VFR conditions are expected
through most of the upcoming work week. A moisture-starved cold
front that will cross the region early Tuesday and another
front approaching the region late in the work week are unlikely
to produce much in the way of adverse aviation conditions.


Record High Temperatures (Year)
       GSO         RDU         FAY
9/26   93 (1986)   93 (1933)   96  (1933)
9/27   90 (2017)   94 (1998)   94  (2017)
9/28   92 (1939)   95 (1998)   95  (2017)





NWS RAH Office Area Forecast Discussion