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230
FXUS62 KRAH 170716
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
313 AM EDT Mon Jun 17 2024

.SYNOPSIS...
Deep high pressure will build over the Mid Atlantic and Carolinas
through much of this week. A wave of low pressure will track
westward into the Southeast on Thursday into Friday, bringing rain
chances to our southern sections.

&&

.NEAR TERM /THROUGH TONIGHT/...
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As of 313 AM Monday...

Water vapor imagery this morning depicts strong upper ridging along
the eastern seaboard. A few mid-level perturbations were evident
across the deep south migrating northward towards the TN valley.

At the sfc, a weak boundary was observed along the inner
banks/coastal Plain, extending westward into our southwestern areas.
There were a few isentropic-driven showers along this boundary
earlier, but they have since diminished the past few hours. Low-
level esely flow will persist today, but the deeper
moisture/instability axis will shift further northwest into the TN
Valley. Most afternoon convection will follow suit, as central NC
remains primarily dry. A few stray showers could trickle into the
Triad late this afternoon, but overall expect mostly dry and hot
weather again today. Daytime highs will reach the upper 80s/lower
90s.
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&&

.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
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As of 313 AM Monday...

The anchored mid-level ridge will strengthen to ~2 standard
deviations above climatology on Tuesday, amplifying across New
England. Anomalous moisture will continue to migrate north and west
of our area, promoting dry conditions across central NC.  Some drier
air may mix into our eastern areas, promoting decent mixing of dew
points Tuesday afternoon (into the lower 60s). This should keep heat
indices contained to the upper 80s/lower 90s. Still, the actual
temperatures will rise once again into the upper 80s/lower 90s.
Given the persistent hot conditions, we continue to advise those
spending considerable amount of time outdoors to practice heat
safety.
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&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 300 AM Monday...

Still anticipate below normal rain chances for much of this week,
with increasing heat potentially reaching dangerous levels by the
weekend.

Wed-Thu aftn: A strong mid level anticyclone will be stretched
across PA/NJ/MD early Wed. It will remain quite strong through Thu
and drift only slightly S, its center over the Delmarva by Thu
evening with the ridge oriented W-to-E. Meanwhile, at the surface, a
strong high centered out over the NW Atlantic well E/offshore of New
England will continue to extend ESE through NC, weakening a bit
heading into Thu. As we`ll have low level thicknesses slightly below
normal Wed/Thu capped by anomalously warm/dry/stable mid levels and
below normal PW, convection chances will be extremely limited, and
will maintain a pop-free forecast. The long-fetch low level easterly
flow won`t be particularly strong through Thu but may still draw
enough Atlantic moisture into southern NC for a few more clouds
there, but otherwise skies should be no worse than partly cloudy.
The low level thicknesses offset by decent sunshine should result in
temps near to slightly above normal.

Thu evening-Fri: Our focus briefly shifts to a possible low level
inverted trough or a closed surface low that is expected to develop
on the southern end of the surface ridge a few hundred miles E or
ENE of the northern Bahamas by mid week. Such a low or trough, if it
forms, may be tropical (warm core) in nature, not an unexpected turn
of events given long easterly low level fetch, the time of year, the
extremely warm ocean waters, and the models` consensus of very weak
upper level shear in this area. The latest runs of deterministic
models and ensemble systems generally favor an inverted trough
pushing W onto the Southeast coast Fri morning, which could result
in increasing clouds Thu night and a chance of showers and isolated
storms across our SE and far S sections Fri. But there is far from a
model consensus on this, and the low level flow on the NW side of an
onshore-moving trough could actually result in a backing low level
flow in our area to northeasterly with a reinforcement of low level
dryness and stability in central NC. Will lean toward the NBM`s
solution of low chance pops in our SE and S Fri afternoon for now.
With the mid level heat dome drawing closer, expect further warming
Fri to highs from around 90 to the mid 90s.

Sat-Sun: While we`ll start to see rain chances gradually trending
back toward climatology, the big story this weekend will be the
increasingly oppressive heat. Model differences predictably grow at
this range, but most indicate the mid level ridge center drifting SW
and expanding across NC Sat/Sat night before yielding a bit to a
broad northern stream trough and associated surface cold front
tracking through the Great Lakes region by Sun. The surface high
will push further out over the Atlantic, as a lee trough forms
through the W Piedmont well out ahead of the cold front. Our
thicknesses are expected to climb to around 10-15 m above normal Sat
and to 15-25 m above normal Sun, as our dewpoints rise through the
60s into the upper 60s/lower 70s. Shade air temps are expected to
peak at 94-100F both days, with heat indices of 95-106F and warm
lows mostly in the 70s, which when combined with sunshine and a
limited breeze will contribute to an increased risk of heat
illnesses. Regarding convection chances, with the trend to confluent
steering flow from the SSE through SSW and surface ESE flow pulling
in both Gulf and Atlantic moisture, the initially low PW through Fri
will rebound back over 1.5" over our far E and SE Sat and areawide
Sun. This, with lowering heights aloft due to the weakening mid
level ridge and approaching trough, will support small chance pops
mainly across the S each afternoon into early evening. -GIH

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
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As of 109 AM Monday...

VFR conditions will mostly prevail over the 24 hour TAF period.
However, a brief period of MVFR ceilings appears possible at KINT
and maybe KGSO near sunrise this morning.  Any linger stratus should
lift to VFR by mid morning.  Otherwise expect another day of mostly
light ssely sfc flow and mostly dry conditions (a few stray showers
could trickle into the Triad later today).

Outlook: VFR conditions should largely persist through Friday.
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&&


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

&&

$$

SYNOPSIS...Hartfield
NEAR TERM...Luchetti
SHORT TERM...Luchetti
LONG TERM...Hartfield
AVIATION...Luchetti