Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC-- Highlight Changed Discussion --
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FXUS62 KRAH 241651
Area Forecast Discussion
National Weather Service Raleigh NC
1250 pM EDT Tue May 24 2016
.SYNOPSIS...High pressure near the surface and aloft will build
into central NC through midweek.
.NEAR TERM /through tonight/...
As of 1055 AM Tuesday...
Little change required to the near term forecast.
As a strong upper level low continues to pull farther away from
central NC this afternoon and tonight, an area of high pressure near
the surface and aloft will expand over our region. The subsidence
associated with the rising heights/pressure will deter vertical
growth of the cumulus this afternoon. Abundant sunshine will aid to
warm temperatures in the the 78-83 degrees range, very close to
normal for this time of year. -WSS
The surface high will quickly shift off the Southeast coast tonight,
but the pressure gradient will remain weak, resulting in strong
radiational cooling and lows dipping back into the mid 50s. -22
.SHORT TERM /Wednesday and Wednesday Night/...
As of 340 AM Tuesday...
The warming trend will continue on Wednesday as a 588dm H5 ridge
builds over the Deep South and return flow develops around the
offshore high. Given better heating into the mid 80s to near 90, a
thermally enhanced Piedmont trough should develop, but moisture
return will will be slow with PW remaining below one inch, and a mid-
level subsident cap will stifle any destabilization or convection.
Some mid-clouds may drift in from the west late Wednesday night as
disturbances emanating from Central Plains convection start to
encroach on the region. Otherwise, another mostly clear night and
lows in the low/mid 60s.
.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 355 AM Tuesday...
The pattern aloft this period will be characterized by a western
CONUS trough and an a ridge from near Bermuda to Ontario/Quebec.
At the base of/beneath the eastern ridge, southern stream energy --
the lead of which is now crossing the lower-middle MS Valley-- will
help re-develop a mid to upper-level low INVOF the Bahamas during
the next couple of days. A shear axis, or weakness between sub-
tropical ridge centers near Bermuda, and across much of the Gulf of
Mexico and north-central Mexico, will extend north from the low over
the Bahamas, into the southeastern U.S.
The trend in model guidance in the past 24 hours has been toward a
more pronounced surface reflection in association with the Bahamas
low, which subsequently would get steered --at the base of the sub-
tropical ridge near Bermuda-- toward the southeast U.S. coast this
Thu-Fri: Subsidence in association with the sub-tropical ridge near
Bermuda, along with the absence of lifting mechanisms and incomplete
modification of the initially cool and dry continental air mass over
the eastern U.S., will help suppress deep convection over central NC
late this week.
Sat-Mon: There remains a high degree of uncertainty in the details,
but the overwhelming trend toward a more substantial influence from
the aforementioned low pressure near the southeast U.S coast
suggests we are likely to see an increase in clouds and
precipitation chances as the weekend wears on, some of which may
linger into early next week, as whatever becomes of the
aforementioned low pressure may get trapped beneath the higher
latitude ridging to the north. Thicknesses support temps slightly
above normal, though tempered by the increase in clouds.
.AVIATION /18Z Tuesday through Sunday/...
-- Changed Discussion --As of 1250 PM Tuesday...
An area of high pressure at the surface and aloft will result in
mostly clear skies and generally (less than 10kts) light winds
through Wednesday night.
The VFR conditions are expected to continue Thursday and Friday
though there will be a threat for isolated-scattered convection each
The threat for adverse aviation weather conditions will increase
Saturday through Monday as an area of low pressure is expected to
develop then move slowly along the coast.
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