Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC-- Highlight Changed Discussion --
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FXUS62 KRAH 260551
Area Forecast Discussion
National Weather Service Raleigh NC
145 AM EDT Thu May 26 2016
.SYNOPSIS...Bermuda high pressure will extend over the area through
Friday producing above normal temperatures. Meanwhile, a storm
system will develop over the sub-tropical Atlantic and drift toward
the Southeast U.S. coast through the holiday weekend.
.NEAR TERM /through tonight/...
As of 903 PM Wednesday...
Weak shortwave energy over the Tn Valley and Southern Appalachians
will continue dissipate as they move east, encountering the upper
ridge in place over the area. While a few showers are possible over
the NC mtns, central NC will not see much more than some thin
mid/high clouds, mainly across the northern and northwest Piedmont.
Under the increasing influence of Bermuda high pressure, min
temperatures tonight a tad warmer than the previous night with
continued increasing low-level moisture.
.SHORT TERM /Thursday through Friday Night/...
As of 315 PM Wednesday...
Summer like weather pattern will prevail across central NC Thursday
and Friday. Bermuda high pressure will extend across central NC,
maintaining a very warm and mostly dry forecast. The addition of mid
level moisture tonight, strong heating, and presence of a weak lee
side trough may be enough to trigger/support an isolated
thunderstorm during peak heating on Thursday. The convective threat
will mainly be confined to the Piedmont, as a modest mid level cap
will inhibit convective development over the rest of the forecast
area. Similar conditions probable Friday afternoon.
Low level thicknesses around 1415m (+/- 4m) will support afternoon
temperatures well above normal, with max temps in the 85-90 degree
range. Continue modification of the atmosphere will result in
relatively warm overnight temperatures in the low-mid 60s.
.LONG TERM /Saturday through Wednesday/...
As of 300 PM Wednesday...
The general overall pattern for the weekend and into early next week
will be characterized aloft by a ridge over the SE U.S. and a trough
over the Midwest. A low pressure system in the mid to upper levels
will develop off the FL coast beneath the ridge. At the surface, the
high that was ridging westward into the Carolinas will be pushed
northward and largely out of the region by the developing low
as it moves north-northwestward along the FL coast.
The aforementioned low pressure system will develop off the FL coast
Friday night into Saturday and could develop tropical or sub-
tropical characteristics as it moves northwestward. Though there are
still plenty of model differences on the evolution of this low,
there is fairly good model agreement and thus high confidence that
it will develop. The general track is expected to take it NW toward
the SE U.S. coast on Saturday resulting in an increase in moisture,
clouds, and chances for convection through the day and into the
overnight hours. Beyond Saturday, the low could remain near the
SC/GA coast through the remainder of the period. The exact coverage,
location, and timing of convection is dependent on how the low
evolves. However, the convection is expected to be largely diurnal
in nature, with the highest chances in the aft/eve and a lull
overnight. Rainfall amounts through the weekend and early next week
will depend on the path of the low and given the uncertainty of
that, will hold off speculation of totals for now.
Temperatures through the period: with the increasing clouds and
chances for rainfall, expect highs to decrease from the mid 80s on
Saturday, to upper 70s to low 80s Sunday through Wednesday, with the
potential for some mid 80s to creep back into the SW by Tuesday.
Overnight lows will remain fairly steady in the mid to upper 60s.
.AVIATION /06Z Thursday through Memorial Day/...
-- Changed Discussion --As of 145 AM Thursday...
Strong high pressure over the Southeast US will continue to promote
VFR conditions through the TAF period. Dewpoints have come up a few
degrees since last night, so there may be a few pockets of MVFR
visibilities by 12z despite the thin high level debris clouds
drifting overhead. Otherwise, a light southwesterly wind will
prevail today, with just a small chance of a brief shower or storms
at KINT/KGSO after 20z as convection drifts east off the mountains.
Long term: More chances for sub-VFR conditions for the end of the
week as a plume of moisture moves in from the southwest Atlantic
that could affect the area for several days.
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