Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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FXUS62 KRAH 180053

Area Forecast Discussion
National Weather Service Raleigh NC
852 PM EDT Mon Jul 17 2017

An upper level disturbance over the region will provide the risk for
scattered daytime and evening showers and thunderstorms through the
mid-week period.  The weather will then turn very hot for the latter
half of the week as the heat currently building over the Plains
moves east toward the Carolinas.


As of 850 PM Monday...

Convection has died off this evening with nocturnal cooling underway
and lack of any significant trigger for additional convection this
evening. However, A slow moving weak mid level low, located along
the spine of the central/southern Appalachians, will slowly shift
eastward overnight. This will help to draw up a weak disturbance
along the Southeast U.S. coast tonight, potentially spreading some
precip into coastal portions of central NC. Thus, will lower pops
this evening into slight chance/no pops, then raise pops into the
slight chance/chance category across eastern portions of the area
after midnight. Any deeper convection overnight will have the
potential to produce heavy rainfall with PW`s of around 2 inches,
though any minor flooding should remain quite isolated. Otherwise,
expect another round of low clouds to develop across the eastern
half of the area, with lows by Tuesday morning generally around
70/lower 70s.


As of 300 PM EDT Monday...

Another short wave moving across the Ohio Valley will drop into the
base of the long wave trough and close off over central NC on
Tuesday.  As mid level  flow backs with the approach of the wave, we
may see pwat increase a bit westward compared today, but still the
bulk of the moisture and best rain chances appears to be across the
eastern third of our CWA and eastward.  Thus, PoPs Tuesday afternoon
and evening will range from 20-25% west to around 35% east.  Highs
Tuesday will once again be dependent on morning cloudiness and how
long it lingers, but forecast soundings and bulk of MOS guidance
suggest highs in the upper 80s across most of our CWA. Given that
the greatest cloud coverage is expected across the eastern half of
our CWA, Tuesdays highs may be warmest across our western zones.

A few showers, associated with the upper trough axis, may linger on
well into the evening or early overnight hours, but QPF where it
rains is expected to remain less than 1/4 inch. Lows once again
around 70.


As of 230 PM Monday...

12Z model guidance diverges significantly, particularly late this
week/next weekend, as mesoscale convective systems on the N/NE
periphery of a central CONUS ridge further complicate an
increasingly complex mid-latitude synoptic pattern over the lower
48. Confidence is below normal with regard to both temperatures and
precipitation chances. In general, expect temperatures several
degrees above normal mid/late week through next weekend as the
central CONUS ridge gradually builds eastward into the Deep South.
The timing, coverage, and overall probability of convection can be
difficult to anticipate in the first 24 hours of the forecast this
time of year, let alone 96-168 hours out in such a complex pattern.
Wit the above in mind, will indicate climatological chances for
convection late this week through this weekend. -Vincent


As of 800 PM Monday...

24 hour TAF period: Conditions across the area this evening are VFR
with only light rain remaining in the vicinity of KRDU, otherwise
all convection has ceased at this time. Models showing the potential
for low stratus again overnight across the eastern half of the
forecast area. Some models hinting at some fog possible in the Triad
as well but confidence is low especially since no fog was observed
last night but one difference today is that both KINT and KGSO
received rain so that could be the difference tonight in observing
some decreased visibilities during the overnight hours.

Long term: Day and evening showers and storms will be possible
through Wednesday along with the possibility for fog/low stratus
each morning. Then rain chances will decrease for the latter half of
the week with generally VFR conditions expected.




LONG TERM...Vincent
AVIATION...Ellis/np is the U.S. government's official web portal to all federal, state and local government web resources and services.