784
FXUS62 KRAH 091345
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
945 AM EDT Sun Jun 9 2024

.SYNOPSIS...
Weak high pressure will move offshore today. An upper level
disturbance and approaching cold front will cross the region late
today and tonight. Weak high pressure will build in from the north
early to mid week.

&&

.NEAR TERM /TODAY AND TONIGHT/...
As of 945 AM Sunday...

...Marginal Risk of severe storms across southern NC...

Only minor changes to the forecast with this update.

The 12Z surface analysis shows a sharp dewpoint gradient from the
Piedmont to the Coastal Plain, with mid to upper 60s dewpoints over
the Coastal Plain. Winds were generally swly at 5-10 kts. PWATs were
1.0 to 1.2 inches across central NC. The upper air analyses shows
the mid/upper low over SW Quebec, with the H25 jetlet centered over
southern Lake Michigan. There has been an increase in moisture in
the low levels, with dewpoint depressions around 5 degrees or less
noted at H7 and H85.

Model guidance suggests we could mix some lower dewpoints down
through early this afternoon, possibly down to the mid 50s in the
east, but may remain around 60 degrees in the west. Temperatures are
still expected to rise into the upper 80s NW to mid 90s SE this
afternoon. As the cold front moves into the area, expect some
advection of moisture from the WSW immediately ahead of it, with
PWATs rising to around 1.5 to 1.7 inches. MUCAPE appears somewhat
limited, a few hundred J/Kg or less, with effective shear around 20
kts, peaking just ahead of the front this aft/eve. Isolated to
widely scattered showers and storms are still expected ahead of the
front this afternoon into early tonight, with a strong/severe storm
or two still possible. -KC

Previous Discussion (as of 246 AM Sunday): An upper level
disturbance is expected to approach the region this afternoon. The
associated surface cold front over the OH Valley this morning, will
move across central NC later this afternoon and evening. Only
isolated damaging wind is expected with any of the stronger storms.
Expect generally isolated to widely scattered thunderstorms this
afternoon shifting to the S-SE this evening. Some CAMS have a few
more showers and isolated thunderstorms over the NE this evening
associated with the cold front. As the front moves through the area,
shower chances will decrease rapidly from northwest to southeast
through the evening/overnight hours. Lows tonight will range from
the lower 60s in the north to the upper 60s in the south. -Badgett

&&

.SHORT TERM /MONDAY AND MONDAY NIGHT/...
As of 246 AM Sunday...

...Lowering relative humidities and temperatures Monday and Monday
night.

Expect high pressure to build in from the north on Monday. Dry air
advection will lead to lowering dew points into the 40s north and
50s south. Actual temperatures will take a dip as well. Even with
skies becoming mostly sunny, highs will generally be in the 80s.
Lows Monday night will dip into the mid 50s to mid 60s N to SE.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 216 AM Sunday...

The extended will start off rather quiet and comfortable with near
to slightly below normal temperatures in the low to mid 80s Tue and
mid/upper 80s Wed. Humidity levels will also be low with dewpoints
during the day mixing out into the 40s and 50s. At mid-levels, this
period will feature troughing extending into the area from the NE US
and Mid-Atlantic Tue, that will transition to weak ridging Wed. High
pressure over the OH valley will settle into the region before
moving offshore with return flow later on Wed. While we are dry this
period, we cannot rule out a stray chance of a shower over our far
eastern zones with the departing trough and coastal low near the
coast Tue morning.

A return to hot and humid conditions and a return to potential
diurnal showers and storms is the main story in the Thu-Sat period.
The pattern in the guidance indicates quasi-zonal flow to weak
ridging to start. There is still some question as to what influence,
if any, could come from a developing system over the east and NE
Gulf Thu-Sat. A look at the ensemble guidance indicates the
uncertainty lies in how the system interacts with the mid to upper-
level flow over the Great Lakes to OH Valley. Some members have the
northern stream trough displaced further north and ridging off the
coast, allowing the Gulf system to advect higher moisture/PW`s into
the SE US for better chances of diurnal showers or storms. Another
ensemble camp shows the northern stream trough further south,
keeping the deeper moisture shunted to our south over FL and a
possible cold front late Fri or Sat. For now, given the uncertainty,
have low chances of showers/storms, and mainly for Fri and Sat,
where the synoptic pattern would possibly be more favorable. Highs
should hover in the low to perhaps mid 90s.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
As of 645 AM Sunday...

High confidence in generally VFR conditions today and tonight.
However, an isolated thunderstorm will be possible this afternoon or
evening (SE) with brief MVFR to IFR conditions. This chance is less
than 30 percent for any TAF site between 18z and 03z today/this
evening. Winds will be fairly light but frequent gusts around 20 kts
are likely today 15z-22z, and stronger gusts are possible in and
near any storms.

Looking beyond 06z Mon, VFR conditions are likely to hold at all
sites through Thu.

&&

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

&&

$$

SYNOPSIS...Badgett
NEAR TERM...KC/Badgett
SHORT TERM...Badgett
LONG TERM...Kren
AVIATION...Badgett