221
FXUS62 KRAH 121830
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
230 PM EDT Fri Jul 12 2024

.SYNOPSIS...
Areas of low pressure will ripple along a quasi-stationary front
over the Piedmont through tonight. The front will weaken and
dissipate over the region this weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 218 PM Friday...

* Flood Watch remains in effect for all but the far western Piedmont
  counties until midnight tonight
* Potential exits for localized 4+ inches of rainfall over portions
  of the Piedmont and Coastal Plain

Sfc analysis this afternoon shows the sfc boundary stretching from
the southern Piedmont northeast through the northern Coastal Plain.
This area continues to see the strongest convection and rain rates.
A MCV was observed spinning over the Sandhills/central Piedmont when
looping radar scans. This feature, along with the instability axis
east of the boundary will continue to shift northeast over time
through this evening.

Latest high-res ensemble guidance (HREF/REFS/WoFS) all suggest the
possibility of higher rainfall rates falling first over the
southern/central Piedmont the next few hours, before pivoting up
into the northern Coastal Plain later this evening. There is a
signal for localized amounts as high as 5 inches in these areas.
Given the high rain rates thus far, the continued highly anomalous
moisture flux, and some reports of flooding, will continue the Flood
Watch through midnight tonight.

The bulk of the rain will pull north overnight tonight, but latest
runs of the HRRR do maintain the potential for some linger
showers/storms over our central/northern Piedmont.  Overall though,
most of the rain should be north of our area through sunrise
tomorrow.

Overnight lows will remain in the mid 70s with patchy fog possible.

&&

.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
As of 218 PM Friday...

While the sfc/mid-level low will have pulled bulk of the
precipitation north of our area by 12Z Saturday, anomalous moisture
will linger especially along and east of US-1.  As such, additional
showers and a few storms will likely develop Saturday afternoon
along the dissipating frontal boundary. Highest chances will focus
further east.  Flash flooding potential should be limited Saturday,
but we are still outlooked in a Marginal ERO from WPC across eastern
areas. FFG should be a bit lower given the heavy rain on Friday, and
thus urban areas could be susceptible to flash flooding. Although,
overall coverage should be more limited compared to Friday.

Temperatures will rise back into the lower to mid 90s, peaking
across the far southwestern Piedmont.  Dew points will likely max in
the 70s again Saturday afternoon (highest to the east). However,
some fleeting wnwly flow aloft may introduce a bit of mixing
(especially out west where it will be hotest). Thus, heat indicies
should stay below advisory criteria.

Warm overnight lows in the lower to mid 70s is expected.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY...
As of 330 AM Friday...

...Dangerous Heat Returns Sunday Through the Middle Part of Next
Week...

The main weather story will be the return of Dangerous Heat. Staying
under the influence of a ~591dm ridge and low-level W-SWLY flow,
1000-850 thicknesses and h8 temps are forecast to peak during the
Monday-Wednesday period, topping out ~1445m and 23-24C respectively.
Highs in the mid to upper 90s will be common place for Sunday
through Wednesday, with Monday or Tuesday currently forecast to be
the hottest day, with some lower 100s possible across central and
southern NC. There is a fairly strong and consistent model signal
for dewpoints to mix out into the lower 60s(and even quite possibly
into the upper 50s)across the western Piedmont each afternoon, which
should help to temper the heat risk over the western part of the
state. However, four consecutive days of heat indices in the 103 to
108 F degrees is likely from the Triangle eastward.

In terms of rain chances, a low-amplitude shortwave trough moving
slowly east through the mid-Atlantic region Sunday afternoon through
Monday will support isolated to scattered storm development Sunday
afternoon and evening, followed by mostly sea-breeze convection
Monday and isolated storms Tuesday, owing to the potential for weak
disturbances to move through the area. The approach of a front from
the NW and associated high rain chances late Wednesday and Thursday
will likely break the heat wave and could bring some widespread
significant rainfall to the area given the potential for the front
to slow down or stall out across the area to end the work week.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
As of 220 PM Friday...

Regenerative showers and storms will continue to focus over cntl NC
through at least early tonight, as a series of mid-level
disturbances and accompanying waves of surface low pressure track
along a front that will remain quasi-stationary across the srn
through ne Piedmont. While flight restrictions will be generally
MVFR, they will vary from LIFR-IFR in showers and storms with heavy
rain to occasionally VFR away from convection through this evening.
An unseasonably moist/humid airmass, and convergence along the
front, will favor the development of widespread LIFR-IFR conditions
later tonight-Sat morning. Drier air and wly flow behind the
aforementioned areas of low pressure will promote a quick return to
VFR at INT/GSO after 12Z Sat, whereas MVFR ceilings will be apt to
linger through late morning-early afternoon at RWI, FAY, and RDU,
the latter three sites where scattered convection will also be
favored to redevelop with afternoon heating.

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 11:
KGSO: 75/1992
KRDU: 77/1981
KFAY: 76/2019

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...
Flood Watch from midnight EDT tonight through Friday evening for
NCZ007>011-022>028-039>043-074>078-083>086-088-089.

&&

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