Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC-- Remove Highlighting --
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FXUS62 KRAH 260007
Area Forecast Discussion
National Weather Service Raleigh NC
807 PM EDT THU AUG 25 2016
High pressure will extend across the region through Saturday.
.NEAR TERM /THROUGH TONIGHT/...
As of 320 PM Thursday...
18Z meso analysis depicts the best low level instability
immediately west-nw of the Triad, where isolated convection
occurring. Steering flow from the nw, so it is plausible that a
shower or storm could drift into the nw piedmont by 4 or 5 PM.
However, flow remains anti-cyclonic and lift rather meager away from
the higher terrain. Thus, feel that a 20 percent PoP should cover
this scenario. Also, not seeing much if any activity along the
seabreeze at mid-afternoon. Thus expect little if any convection to
threaten sections of Sampson, Wayne or Cumberland counties.
Expect clear-partly cloudy skies later this evening into the
overnight hours. Could see pockets of fog across the region though
most places will have unlimited visibility. Overnight temps will be a
couple of degrees warmer, owing to a modifying air mass. Min temps
in the upper 60s to around 70.
.SHORT TERM / FRIDAY and FRIDAY NIGHT/...
As of 320 PM Thursday...
Mid/upper level anti-cyclone currently positioned over the Deep
South relocates over our region on Friday. Subsidence associated
with this feature will limit cloud production, as well as inhibit
convective initiation. The subsidence warming will lead to afternoon
temps several degrees above normal for this time of year. High temps
in the low-mid 90s will be common. While sfc dewpoints will creep
back up to around 70, heat index values do not get too ridiculous,
averaging within a degree or two of 100 degrees. The exception may
be the sandhills. If temps reach the upper 90s, heat index values
will approach 105 degrees.
While the low level air mass will be more than adequately unstable
to support isolated/scattered convection, mid level subsidence
inversion should inhibit development.
It should feel noticeably more muggy Friday night with dewpoints in
the lower 70s. Overnight temps in the low-mid 70s.
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 235 PM Thursday...
Saturday through Sunday night: The weekend is setting up to be
mostly dry as an upper level ridge sits directly on top of central
NC. At the surface a high pressure system will start Saturday over
the Great Lakes before progressing to the northeast through New
England and the Canadian Maritimes. Models try to generate a few
showers, particularly on Saturday afternoon across the western
portion of the CWA. Will put slight chance in the forecast but
confidence on this actually occurring is fairly low given the strong
subsidence overhead. Saturday will be hot with maximum temperatures
in the mid 90s but dewpoints should stay in the low 70s. This will
result in heat indices creeping into the 100-105 degree range but
probably wont be enough for a heat advisory. Temperatures will drop
back to near 90 degrees on Sunday afternoon.
Monday through Thursday: Model solutions begin diverging early next
week so details will be hard to pin down at this point but we do
know that the upper level ridge should relax and upper flow will
become more zonal north of the area. To the south, the pattern will
largely be dictated by where the current tropical invest winds up.
Forecast model track spread is very large at this point as is the
Have increased chances for precipitation into the chance range for
the end of the forecast period to account for any possible effects
of the tropical system. Once the ridge breaks down the storm will be
allowed to recurve the question is how far west will it be by that
time and how quickly will it recurve. If the storm recurves before
reaching the Florida Peninsula we could see dry weather here in NC
as the storm goes out to sea. However if the storm recurves in the
Gulf further west, then we could see rainfall ahead of the storm as
early as Thursday morning. Highs near 90 each day with lows in the
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --As of 755 PM Thursday...
24 hour TAF period: High pressure will continue to extend across the
area through the 24 hour TAF period, resulting in generally dry and
VFR conditions with light and variable winds. The one possible
exception may be around daybreak when some MVFR/IFR visbys may
develop at the eastern TAF sites, primary KRWI and KFAY (with KRWI
standing the best chance).
Outlook: This area of high pressure is expected to maintain its
influence over our region through early next week. This suggest an
extended period of VFR conditions, aside from patchy early morning
MVFR/IFR fog and possibly some isolated convection from this
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