291
FXUS62 KRAH 070657
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
255 AM EDT Sun Jul 7 2024

.SYNOPSIS...
A weak frontal zone will remain stalled just east of the
Appalachians through early Monday. This front will weaken further
and dissipate Monday, as mid level high pressure builds over the
Southeast states and Carolinas Monday through Tuesday.

&&

.NEAR TERM /TODAY AND TONIGHT/...
As of 255 AM Sunday...

Fairly high coverage of convection is expected once again today. A
very warm and deeply moist air mass remains over central NC, east of
a diffuse frontal zone stretching SW-NE over the E slopes of the
Appalachians, according to the latest surface analysis. The vast
majority of the area saw rainfall yesterday (much needed, given the
ongoing dry/drought conditions, although a bit too much/too fast in
some spots). This ground moistening has led to some light/isold
fog/stratus development early this morning, although this should be
limited by both considerable higher debris clouds (esp in the W) and
by relatively dry air just off the ground, noted on 925 mb progs.
Persistence will largely be the rule today: The weak surface front
should hold in place while slowly weakening, with weak low level
flow to its east over central NC and anomalously high PWs (150-175%
of normal) likely to linger across the area. Central NC will also
remain within weak mid-upper level flow, in a col area between SW
steering flow from the S Plains across the Ohio Valley and an upper
low spinning well off the Carolina coast, while through the lower
levels, the subtle trough noted on the 07/00z 925-850 mb UA analyses
across GA and the Carolinas will likely hold in place with no
mechanisms to dislodge it. All told, today`s convection pattern
should behave much like yesterday, except perhaps a bit earlier
initiation. Moderate SBCAPE is again expected, but with modest deep
layer shear, so we may again see a few strong cells with the
potential for downbursts, and the slow-moving water-laden cores will
present a threat of heavy downpours and localized flooding as well.
Recent CAM runs from various modeling systems have frankly been
rather poor, fairly to accurately depict current/00H precip over its
last several runs, going back to last evening, and they aren`t in
very good agreement with each other. As such, have gone with a
precip pattern not far off Saturday`s, most closely replicated by
the 00z HREF mean. Expect coverage to peak at numerous/likely pops
mid afternoon into early evening, with again a slow decline in
coverage through tonight as elevated CAPE very slowly wanes, similar
to last evening/early this morning.

Expect highs today in the upper 80s to mid 90s, with clouds
tempering heating a bit amidst thicknesses near to just slightly
above normal. This will also keep heat index values below heat
advisory criteria, although areas south and east of the Triangle may
still see a few hours of 100-104F. Lows in the low-mid 70s. -GIH

&&

.SHORT TERM / /...
As of 230 PM Saturday...

To be updated shortly.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
As of 230 PM Saturday...

* Typical summer pattern expected with hot/humid conditions
* Daily diurnal thunderstorm chances, with greatest rain chances
  late in the week

The mid level pattern for much of next week will feature broad
southwesterly flow as the NC becomes positioned between longwave
troughing over the Great Lakes and an offshore ridge. It`s worth
pointing out that there will also be an upper low that lingers off
the NC coast for a period of time this week, but nearly all guidance
suggests it will be drawn southward away from our area and should
not be a player in our weather across central NC. Embedded within
the southwesterly flow aloft will be a series of weak perturbations,
all of which are difficult to track and time their arrival into NC,
but will ultimately promote daily afternoon/evening shower and
thunderstorm chances with areas across the Sandhills and western
Piedmont favored any given day. PW`s next will generally range from
1.75 - 2.25 inches during this time (90-95th percentile) with little
day to day variation while afternoon MLCAPEs should easily climb
into the 1000-1500 J/KG range. In short, precip chances next week
will closely mirror a typical climatological distribution for
early/mid July. An influx of additional moisture aloft late in the
week should support somewhat higher than normal precip chances and
PoPs have been trended upward slightly.

Hot/humid conditions will once again be the theme next week,
although values should be a bit lower than what has been observed
recently. Afternoon highs should reach the low to mid 90s, with the
highest values of the week possible Tuesday into Wednesday. The
arrival of additional moisture (and presumably cloud cover) should
hold temps back a bit (upper 80s to lower 90s) to close out the week
although heat indices could still approach the triple digits given
the humid airmass. Mild overnight lows in the low to mid 70s will
also be common.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
As of 1230 AM Sunday...

Adverse aviation conditions are likely to dominate across the
Piedmont terminals (INT/GSO/RDU) through mid morning, with scattered
showers and isolated storms expected to persist here through around
09z, with just isold showers thereafter through the morning. These
sites will also see variable sct-bkn IFR/LIFR cloud bases topped by
bkn-ovc VFR decks through mid morning, although the highest chance
of IFR/LIFR cigs will be 09z-12z. There will be less of a chance of
IFR/LIFR cigs at FAY/RWI. Any fog this morning should be MVFR at
worst and focused in the SW Piedmont, S and W of INT/GSO/RDU. As
cloud bases rise slowly this morning, VFR conditions should return
by 15z areawide, but redevelopment of scattered to numerous showers
and storms is expected by 16z-18z starting first in the W Piedmont
before quickly expanding across all of central NC, lasting through
the afternoon and evening, and aviation interests can expect a risk
of storms, with periods of sub-VFR cigs/vsbys and gusty/erratic
winds, across all terminals during this time, although coverage
should begin to decrease toward 04z. Outside of any storms, surface
winds will be light and variable, mainly from the SW at RDU/FAY/RWI.

Looking beyond 06z Mon, there is a high chance of IFR cigs and MVFR
vsbys in fog developing areawide shortly after 06z, forming first at
INT/GSO then expanding E. VFR conditions should return by 15z.
Another round of scattered showers and storms is expected Mon, with
coverage slightly lower than today. The general pattern of scattered
to numerous showers and storms each afternoon through evening will
continue through Thu, with at least some chance of early-morning sub-
VFR clouds/fog each day. -GIH

&&

.CLIMATE...

Record High Minimum Temperatures:

July 7:
KGSO: 73/2019
KRDU: 77/1900
KFAY: 78/2017

July 8:
KGSO: 76/2010
KRDU: 78/1986
KFAY: 79/2012

July 9:
KGSO: 76/1987
KRDU: 74/2014

&&

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

&&

$$

SYNOPSIS...Hartfield
NEAR TERM...Hartfield
SHORT TERM...
LONG TERM...DL
AVIATION...Hartfield
CLIMATE...RAH