-- Discussion containing changed information from previous version are highlighted. --
855
FXUS62 KRAH 231822
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
222 PM EDT Sun Jun 23 2024

.SYNOPSIS...
A hot and humid air mass will hold over the region through early
Monday. A strong mid level trough and accompanying surface cold
front will cross North Carolina late Monday and settle just to our
southeast Monday night, as weak high pressure passes over the area
through Tuesday. Hot and humid conditions will then return Wednesday
and persist into next weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 210 PM Sunday...

Isolated showers have developed across the northern Piedmont during
the past hour or so in an area of sfc convergence ahead an
approaching through that`s currently moving across the Ohio Valley.
Another area of isold showers are ongoing invof coastal areas and
eastern Coastal Plain along the seas breeze.  As the trough
continues to approach... the risk for isold showers will continue
across central NC during the rest of the near term period. The sfc
trough assoc with this system is expected to cross central NC during
the pre-dawn hours overnight, which will set the stage for the
highest PoPs at the start of tomorrow mainly along and east of I-95.
Locations that get to experience one of the these passing
showers/tstms will get some temporary relief from the heat.

Otherwise regarding the heat... will let the current heat advisory
run through its duration and expire at 8 PM.  Lows tonight in the
mid 70s.

&&

.SHORT TERM /MONDAY AND MONDAY NIGHT/...
As of 255 AM Sunday...

Mon will still be fairly hot across our SE, however we will start to
see some relief especially across the N and W. The potent shortwave
trough tracking over the western St Lawrence Valley late tonight
will continue to push E into the Northeast states Mon, resulting in
slight cooling aloft and a strengthening cyclonic mid level flow
over NC, which will take the cold front SE through much of the CWA
during the afternoon and early evening. Mid level lapse rates will
be 1-1.5 deg C higher than today, with improving upper divergence
over E NC, although strong prefrontal heating and possible deep
mixing may limit SBCAPE a bit. PW is expected to be aoa 2" over the
E (along and E of Hwy 1), so expect at least scattered to numerous
showers and storms, mostly in the SE Coastal Plain. Expect highs in
the low 90s NW and mid to isolated upper 90s SE. Pops should push to
our SE in the evening, with dry weather overnight as NW low level
flow takes over and draws in lower surface dewpoints post-front.
Lows in the mid 60s to lower 70s with clearing skies. -GIH

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --
As of 222 PM Sunday...

The extended continues to feature hot weather, along with some
chances of storms on the front and back end of the period with a
pair of cold fronts.

We will see a brief reduction in excessive heat Tue behind the cold
front as it settles somewhere over SC into far eastern NC, with high
pressure over the central/southern Appalachians. Highs will still be
in the 90s, although models are indicating dewpoints mixing out in
the upper 50s to mid 60s, resulting in heat indices ranging from 88
to 95. We cannot rule out a stray storm along the sea-breeze over
the far SE but Tue should be mostly dry.

On Wed and Thu, we will be in SW flow aloft ahead of a shortwave
trough over the Great Lakes. A trough axis will extend over the
MS/TN/OH valleys that likely won`t move through until Thu, although
the GFS continues its faster progression relative to the other
guidance. A cold front will approach during the evening hours over
the OH valley, though most guidance keeps us dry until late in the
evening/overnight, with best storm chances over the NW Piedmont. Low-
level thicknesses Wed/Thu will approach some 1430-1440 m, about 20-
30 m above average, easily supporting mid to upper 90s to even low
100s in Raleigh for Wed and heat indices in the low 100s over the
Triangle, Sandhills, and Coastal Plain. A better chance of storms
should exist Thu aftn/eve as guidance has the front and mid-level
shear axis near or just west of the US-1 corridor, along with ample
instability. Have continued high chance PoPs at this time. As a
result, highs Thu could be a few degrees lower with clouds/precip
but heat indices will remain high in the 100-105 range along/east of
US-1. Storm chances should diminish after midnight as the boundary
slides through.

Fri-Sun: A brief reprieve from the heat may be possible Fri as some
of the guidance shows the front settling into SC with ENE flow and
lower dewpoints. Highs from the ensemble data supports low to mid
90s with upper 90s heat indices. The heat, however, is expected to
return over the weekend as much of the ensemble data shows the mid-
level 595+ dm ridge building back east from the southern Plains.
This should bring back mid to upper 90s for highs and heat indices
over portions of the area between 100 and 105 degrees. As for rain
chances, guidance continues to show a second cold front/trough
approaching late Sun, with the GFS/CMC most bullish on rain chances.
Other ensemble members show continued ridging, with the front hung
up to our NW. For now, will hedge with low chances until there is
better agreement.
-- End Changed Discussion --

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
As of 210 PM Sunday...

Through 18Z Monday:  Isolated showers/tstms will cross central NC
the rest of today and tonight ahead of an approaching trough. These
storms may briefly reduce cigs to MVFR along with variable wind
directions as outflows occur; otherwise, outside of this activity,
VFR conditions can be expected. SSW sfc winds around 10kt with some
higher gusts up to 18kt will persist through sunset, then look for
winds to remain aob 10kt overnight, with wind direction gradually
shifting to NW around daybreak in the wake of the passing sfc
trough.

After 18Z Monday:  Scattered showers and tstms will be possible
mainly east of I-95 Monday afternoon and evening.  Mostly dry
weather will return by Tuesday morning.  Isolated late day storms
will be possible again mainly west on Wednesday, followed by a
better chance of afternoon/evening showers/tstms late in the week.

&&

.CLIMATE...

Record High Temperatures:

June 23:
KRDU: 100/1986

June 24:
KRDU: 99/2010
KFAY: 102/1914

June 25:
KRDU: 100/1952
KFAY: 102/1914

June 26:
KRDU: 102/1952
KFAY: 101/1951

June 27:
KFAY: 102/1998


Record High Minimum Temperatures:

June 23:
KGSO: 74/2015
KRDU: 77/1890
KFAY: 77/2017

June 24:
KGSO: 76/2015
KRDU: 76/1888
KFAY: 79/2010

June 25:
KFAY: 75/1952

June 26:
KGSO: 74/2010
KRDU: 76/1902
KFAY: 76/1997

June 27:
KGSO: 76/1969
KRDU: 76/1952
KFAY: 77/1998

June 28:
KGSO: 76/1969
KRDU: 76/1952
KFAY: 78/1914

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 11 AM this morning to 8 PM EDT this evening
for NCZ008>011-024>028-040>043-075>078-084>086-088-089.

&&

$$
SYNOPSIS...Hartfield
NEAR TERM...np
SHORT TERM...Hartfield
LONG TERM...Kren
AVIATION...np
CLIMATE...RAH