831
FXUS62 KRAH 130816
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
415 AM EDT Sat Jul 13 2024

.SYNOPSIS...
A frontal zone will weaken and dissipate over the region through the
weekend. An upper level ridge over the SE US will bring another
period of dangerous heat to the area Sunday through the middle part
of next Week.

&&


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

The primary convective rain band(s) which has been closed aligned to
the mid-level vorticity shear axis will continue to push east and
will exit the the far eastern/coastal plain counties over the next
few hours. Through daybreak, we`ll continue to see some patchy
drizzle within the lingering low-level stratus layer. Will also
likely see some fog, potentially dense across the northern Piedmont,
where the cloud layer is shallower.

Thereafter, the slowly decaying frontal zone will oscillate over
central NC through tonight. Meanwhile, the 850-700mb trough and
accompanying axis of anomalously high moisture/PWATS will gradually
shift eastward through the day. Following an early day lull, diurnal
destablization should lead to scattered re-development of showers
and storms during the afternoon and evening, mainly from the
Triangle eastward. Highs ranging from upper 80s NE to lower 90s
elsewhere. The moist/humid dewpoint air in the lower to mid 70s east
of the front will result in heat indices in the upper 90s to around
100 from the Triangle eastward.

Convection will dissipate this evening, leaving dry conditions
overnight. Lows in the lower/mid 70s.

&&

.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
As of 345 AM Saturday...

The stalled front over central NC will wash out on Sunday, as the
surface flow turns southwesterly across our whole area thanks to a
Bermuda High. Looking aloft, the 850 mb trough will move further
offshore and we will be under the influence of weak zonal mid-level
flow between broad troughing over the Northeast US and SE Canada and
broad ridging extending from Bermuda to the Gulf of Mexico. With a
lack of upper forcing, any showers and storms from daytime heating
should be isolated to widely scattered and quickly diminish after
sunset. The best chances will be in the Sandhills and Coastal Plain
where CAPE could reach 1000-2000+ J/kg. Not concerned about severe
weather given the lack of shear. The bigger change will be the
return of heat, as high temperatures will reach the mid-to-upper-90s
in many areas with increasing low-level thicknesses. Even with dew
points mixing out in the afternoon, heat indices of around 105 will
be possible from the Triangle south and east. Lows Sunday night will
also be warm, in the lower-to-mid-70s.

&&

.LONG TERM /MONDAY THROUGH FRIDAY...
As of 410 AM Saturday...

Monday and Tuesday will turn drier with POPs only slight to low
chance at best both days, as the upper pattern stays fairly zonal
and PW values are near normal. Broad mid-level ridging will continue
to extend from the western Atlantic into the Southeast US. The best
chances for diurnal convection will be focused near the Piedmont
trough and sea breeze. While the ridging reduces the flooding
threat, it brings back the heat. Widespread highs in the upper-90s
are expected both days, with even some low-100s possible. Heat
indices are expected to reach 105-109 on Monday from the Triangle
south and east, and perhaps as high as around 110 on Tuesday when
the greatest combination of heat and humidity looks to be. Low
temperatures at night won`t provide a lot of relief, only dropping
to the mid-to-upper-70s.

Precipitation chances begin to increase again on Wednesday as mid-
level troughing moves into the Great Lakes associated with a closed
low over southern Canada. This will drag a strong cold front that
looks to reach the OH and TN Valleys on Wednesday/Wednesday night.
As the mid-level flow across central NC turns more southwesterly
again and brings in Gulf moisture, PW values will increase back
above normal. POPs increase to chance everywhere, highest NW.
Another hot day is expected, but temperatures may be kept down a bit
by the increase in clouds and precipitation. Still, forecast highs
are mostly mid-90s with heat indices around 105 possible in the
south and east.

Thursday and Friday will have the greatest rain chances in the
period as the cold front approaches central NC and slows down. Deep
southwesterly flow aloft ahead of broad mid-level troughing to our
west will bring in PW values of 2 to 2.5 inches. So there will be
plenty of moisture and instability for this front to tap. Capped
POPs at likely for now given this is Days 6-7, but they will need to
be increased further if trends continue. WPC QPF is around 1 to 2
inches each day on Thursday and Friday, so flooding could be a
concern once again. This will bring down high temperatures to upper-
80s/lower-90s on Thursday and only lower-to-mid-80s on Friday.

&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
As of 315 AM Saturday...

TAF period: Widespread LIFR to IFR flight restrictions will
persist through daybreak. Any VSBY restrictions should improve
rather quickly after sunrise. However, ceilings will be
slower to improve, lifting to MVFR during the mid to late morning and
then VFR by the afternoon. Scattered showers and storms are expected
to re-develop during the afternoon from KRDU eastward. However, given
limited coverage will only include VCSH at this time.

Outlook: Morning low stratus and/or fog will be possible again Sun
morning mainly at RWI and FAY, followed by primarily hotter and
mainly dry, VFR conditions until the next front settles into the
region late Wed through Thu.

&&

.CLIMATE...
Record High Temperatures:

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

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


Record High Minimum Temperatures:

July 12:
KGSO: 76/2011
KRDU: 78/2011
KFAY: 80/1935

July 13:
KGSO: 75/2017
KRDU: 78/2017
KFAY: 78/2017

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

&&

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

&&

$$
SYNOPSIS...MWS
NEAR TERM...CBL
SHORT TERM...Danco
LONG TERM...Danco
AVIATION...CBL/MWS
CLIMATE...RAH