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000
FXUS62 KRAH 250159
AFDRAH

AREA FORECAST DISCUSSION
National Weather Service Raleigh NC
959 PM EDT Fri May 24 2019

.SYNOPSIS...

A backdoor cold front will move through central NC tonight, bringing
a slightly cooler airmass to the area for Saturday but a strong
upper level ridge will help to keep persistent hot and mostly dry
conditions through the weekend and well into next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1000 PM Friday...

A backdoor cold front is right on the doorstep of the northeastern
border of the CWA this evening. This will continue to advance
southwestward through the area overnight and is anticipated to make
it to near the South Carolina border by sunrise on Saturday. Not
enough moisture to support any more precipitation overnight therefore
expect mostly clear skies and temperatures bottoming out in the mid
to upper 60s with a few 70 degree readings possible in the south.

&&

.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
As of 320 PM Friday...

The NW flow aloft today backs to a more wly direction Saturday as
the ridge axis drifts east and extends across our region. While this
will tend to suppress convective development, a minor perturbation
currently approaching the crest of the ridge over the TN Valley is
projected to cross our region Saturday afternoon. This system,
interacting with the available moisture and weak-moderate
instability will support the development of a few t-storms late
Saturday into Saturday night. The main factor that would inhibit
convective development will be a pocket of warm air aloft. Some
model forecast soundings have this "lid" weakening by early evening,
potentially allowing isolated convection to fire. if this occurs,
potential for isolated convection to occur across the region into
the overnight hours.

Light nly flow initially behind the departing backdoor cold front
will lead to slightly cooler afternoon temperatures Saturday across
the far north-northeast. Meanwhile, late summer-like temperatures
expected again across the south. Highs Saturday will vary from
around 90 north, to the low-mid 90s south. Overnight temperatures
Saturday night in the upper 60s to around 70.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
As of 330 PM Friday...

Hot weather and generally low pops will continue during much of this
period, with the heat likely peaking Tue/Wed, but a trend toward
more seasonable temps and an uptick in pops will emerge late in the
week.

We should see a lingering small chance of showers/storms in the far
E early Sun morning as the isolated storms Sat night depart to the
E. Otherwise, the mean mid level ridge will hold firm over the Gulf
States and Southeast through at least mid week, albeit with minor
wavering of its axis to the W then to the E. A shortwave trough
(likely convectively induced) over the central Plains Sat night will
cross IN/OH Sun before sliding off the Mid Atlantic coast late Sun
night. A surface low and backdoor front will accompany this feature,
but the front is not expected to dip into NC, holding just to our N
through Mon morning. Nevertheless, the preceding surface trough will
push SE through central NC to near the coast, potentially bringing
some slight cooling to far N and NE sections, and a few showers or
storms can`t be ruled out near the VA border late Mon into Mon night
given the relative height weakness near the Eastern Seaboard. The
front retreats well back to the N and NE by early Tue, with a strong
low level thermal ridge setting up through central NC, along and E
of the surface pressure trough, as the mid level ridge axis inches
back E and strengthens overhead. While Tue/Wed look like the hottest
days, the strong heating and mixing may hold dewpoints down just
enough during the hottest part of the day to keep heat indices just
under advisory threshold over much of the area. Still, E and S
portions of the CWA may need a heat advisory given the consecutive
days of high heat and decreasing cooling at night, creating extra
stressors on people and pets.

The Western US low/trough finally shows signs of filling midweek,
with a portion ejecting NE and merging with burgeoning polar low
pressure over south central Canada. The exact placement and depth of
this low varies quite a bit among the models as we head into
Thu/Fri, but it appears likely that it will be deep enough as it
shifts E to tamp down and flatten the SE ridge, allowing a mid level
shear axis and corresponding surface cold front to push ESE into and
across VA/NC Thu/Fri. Strengthening mid level flow, an erosion of
warm capping aloft, and increasing low level moisture influx should
help prompt better shower/storm coverage as the column moistens and
stabilizes, better supporting convection. Will bring in chance pops
(still at or below climatology) late Thu through Fri.

Highs are expected to be generally in the 90s areawide through Thu,
but readings should approach or perhaps exceed 100F over S and E
sections Tue and Wed. Thicknesses drop but stay above normal late in
the week, so still expect highs in the upper 80s to near 90. Daily
lows will be in the upper 60s to lower 70s, but mid 70s will be
common in many areas Wed and Thu mornings. -GIH

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
As of 755 PM Friday...

High confidence in VFR conditions dominating over the next 24 hours,
although a couple of time periods present a small chance of adverse
aviation weather. Isolated pockets of fog are possible early Sat
morning 10z-12z at RDU/RWI/FAY, but the potential of it being a
prevailing condition appears low at this time. By late Sat, isolated
storms are possible, tracking NW to SE over central NC, mainly after
19z at INT/GSO and after 21z at RDU/RWI/FAY. Any storms are expected
to be few in number and circumnavigable and are unlikely to be a
prevailing condition for more than a half hour. Otherwise, any cigs
will be well into VFR territory. Surface winds will become light
mainly from the NW shifting to N then NE overnight as a frontal zone
drops SW into the area. This front will dissipate on Sat, allowing
surface winds to be from the SW for much of the day.

Looking beyond 00z Sun: MVFR stratus is possible early Sun morning,
mainly 08z-13z at RWI/FAY/RDU. Otherwise, aside from low chances of
a passing shower or storm, VFR conditions will prevail over central
NC through Wed. -GIH

&&

.CLIMATE...
Here are the record high temperatures and the year they were set for
the period May 24th-29th:

DATE       RDU        GSO        FAY
MAY 24TH   95/1944    93/1915    99/1938
MAY 25TH   93/2011    96/1926    98/2011
MAY 26TH   94/1953    95/1926    98/1926
MAY 27TH   96/1916    100/1911   100/1953
MAY 28TH   99/1941    98/1916    102/1941
MAY 29TH   98/1941    99/1914    102/1941

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...Ellis
NEAR TERM...Ellis
SHORT TERM...WSS
LONG TERM...Hartfield
AVIATION...Hartfield
CLIMATE...RAH