386
FXUS62 KRAH 141842
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
242 PM EDT Sun Jul 14 2024

.SYNOPSIS...
A strong subtropical ridge will remain over the Southeast through
early to mid-week. A cold front will approach from the northwest on
Wednesday and stall out over the region into the weekend, resulting
in unsettled weather to close out the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 120 PM Sunday...

Heat indices along and east of US-1 are currently between the lower
100s and 108-109, highest in the Sandhills to southern Coastal
Plain. The Heat Advisory will remain in effect until 7 pm as the
continued heat will pose a risk for those without effective cooling
or hydration. West of US-1, dewpoints have mixed out as expected in
the upper 60s, with some middle to low 60s in the Triad. This has
led to heat indices largely in the upper 90s.

Satellite imagery reveals two areas to watch for shower/storm
development. Visible satellite shows that one area is along the
Foothills tied to a lee trough, where some isolated storms have
already developed. The second area is along the southern Piedmont,
Sandhills, where some agitated cumulus have developed perhaps along
a subtle moisture boundary separating the low/higher dewpoints. The
latest CAMs show that nearly any location could see a spotty
isolated storm into early evening. However, the more focused chance
(30-percent) would appear over the west/northwest Piedmont along the
lee trough, as well as over the Sandhills to central Coastal Plain
along the subtle boundary and where instability is highest. While we
do not expect any organized severe into the evening, with some 20
kts of deep layer shear, cannot rule out an isolated storm putting
out some brief strong gusty winds with high DCAPE (900-1200 J/kg)
over the region.

Any storms will die out around sunset with the loss of heating.
Overnight lows will be quite mild and muggy with mid to upper 70s,
except low 70s in outlying areas of the Piedmont.

&&

.SHORT TERM /MONDAY AND MONDAY NIGHT/...
As of 240 PM Sunday...

...Heat advisory has been issued for the Coastal Plain, Sandhills,
and northeast Piedmont for Mon afternoon from 11 AM to 8 PM...

Dangerous heat will be the main hazard to start the work week.
Central NC will be situated between a weak mid/upper level trough
over the TN Valley and mid/upper level anticyclone positioned just
north of the Bahamas. This will direct a fetch a deep layer of
southwesterly flow over central NC and promote continued rises in
low-level thicknesses and 850mb temperatures, supporting highs in
the upper 90s to around 100. Surface dew points should start to mix
out once again into the mid 60s across the NW Piedmont, but remain
in the low/mid 70s from US-1 eastward. The combination of daily
record heat and rich surface moisture, heat indices will
quickly rise above 105 by late morning and peak between 105-109
through the afternoon. Reminder, this will be heat index values
in the shade, conditions will feel worse in the direct sun. With
little overnight recovery expected from Sun night and again Mon
night, with this level of rare and long duration extreme heat
will affect anyone without effective cooling and/or adequate
hydration.

An Excessive Heat Warning may be needed for eastern Sandhills
and portions of the Coastal Plain and NC Piedmont where heat
indices may approach/eclipse 110 degrees. It is also worth
noting that wet-bulb globe temp (WBGT) is forecast to exceed 88
degrees and Heat Risk reaches 3 to 4 (Major to Extreme
categories) in these regions as well Mon afternoon, which
highlights especially dangerous heat will be possible and can
affect anyone.

Diurnal showers/storms will again be possible along the lee trough
and the seabreeze with isolated development possible as convective
temperatures are reached. Severe storms are not expected, but strong
wind gusts may be possible if deep convection is able to develop
within the environment with deep inverted-V thermo-profiles and
DCAPE > 1000 J/kg.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
As of 200 PM Sunday...

The forecast for Tuesday has trended higher with regard to PoPs, as
it now appears that the combination of a Piedmont trough coupled
with a weak upper disturbance moving by just to our north will
result in widely scat showers/tstms developing over the higher
terrain to our west and will move east into our CWA during the
afternoon.  The coverage won`t be enough to limit temps, so we still
have an opportunity for heat advisory criteria heat indices Tuesday
afternoon, esp across our eastern zones where any shower/tstm
activity will arrive later in the day.

Daily (mostly diurnal) PoPs for the rest of the long term period
will be higher than climo as an upper trough deepens and moves
across the Great Lakes and Northeast regions and a cold front slowly
drifts south across the mountains and approaches us from the
northwest during the Wed-Thu time frame, and eventually stalling and
lingering across our region Fri-Sun.  High-chance to low-likely PoPs
are warranted Wed-Sun, which when coupled with increased cloud
coverage should subsequently result in temps at least closer to
climo, if not a few degree cooler than climo during the wettest
days, which right now appears to be Thu and Fri.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
As of 1255 PM Sunday...

While conditions are likely to remain VFR through the 24-hour TAF
period, there remains the chance of some isolated to widely
scattered diurnally driven storms that could impact the terminals,
mainly between 19 and 23z along a lee trough and upper disturbance
The best chance appears at RDU/FAY/RWI. There is no clear signal for
fog or low ceilings Mon morning, but if a shower impacts any of the
terminals, there could be some sub-VFR restrictions overnight.

Outlook: Isolated storms remain in the forecast early this week, but
generally VFR is expected. A better chance of widespread showers and
storms, and thus flight restrictions,  occurs in the Wed-Fri period
as a front settles into the region.

&&

.CLIMATE...
Record High Temperatures:

July 14:
KRDU: 101/1954

July 15:
KGSO: 97/1974
KRDU: 99/1997

July 16:
KGSO: 99/1915
KRDU: 101/1887
KFAY: 103/1937

July 17:
KRDU: 100/1887
KFAY: 102/1932


Record High Minimum Temperatures:

July 14:
KGSO: 77/1981
KRDU: 77/2017
KFAY: 80/2017

July 15:
KGSO: 74/2019
KRDU: 76/1992
KFAY: 78/2015

July 16:
KGSO: 75/2010
KRDU: 77/2010
KFAY: 78/1992

July 17:
KGSO: 75/2013
KRDU: 80/1887
KFAY: 77/2019

July 18:
KGSO: 76/1986
KRDU: 79/1887
KFAY: 77/2019

July 19:
KGSO: 75/2016
KFAY: 77/2023

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 7 PM EDT this evening for NCZ008>011-
025>028-040>043-075>078-084>086-088-089.
Heat Advisory from 11 AM to 8 PM EDT Monday for NCZ008>011-
024>028-040>043-075>078-084>086-088-089.

&&

$$

SYNOPSIS...Kren
NEAR TERM...Kren
SHORT TERM...Swiggett
LONG TERM...np
AVIATION...Kren
CLIMATE...RAH