509
FXUS61 KPBZ 150901
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
501 AM EDT Sun Jun 15 2025

.SYNOPSIS...
Near-normal temperatures continue through early next week with
periodic shower and storm chances. Localized flooding will be
possible. Daytime highs return to above normal by the middle of
next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
KEY MESSAGES:

- Scattered showers and thunderstorms continue, mainly PGH and
  to the south
- Locally heavy rain may result in flash flooding
---------------------------------------------------------------

Patchy morning fog (especially at locations that observed rain
yesterday) should lift by mid-morning as lower levels begin to
mix out. PWATS remain 2-3 standard deviations above normal
today, >90th percentile of climatology. With that and weak flow,
low MBE velocities, 12-13k warm cloud depth, and the potential
for training storms, WPCs Slight Risk has been maintained for a
portion of the forecast area, with a Marginal Risk elsewhere.
Convection should be focused along the quasi-stationary
boundary parked near the Mason-Dixon line, and a Flood Watch
has been issued for locations from Allegheny county and south.

With the boundary slightly farther south, shower/storm chances,
and deep saturation, daytime highs should be slightly cooler
than observed Saturday, with lows around 5 to 10 degrees above
average yet again.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
KEY MESSAGES:

- Similar flash flood chances Monday, mainly south of
  Pittsburgh.
----------------------------------------------------------------

Mostly-diurnal shower and storm chances in weak flow continue
Monday, keeping flood chances in play. PWAT values do drop
somewhat, but potential primed locations mainly south of PGH
could have relatively low FFG values where WPC has a Marginal
Risk of excessive rain currently. Timing, again, seems to
highlight the noon to 8pm timeframe when heating and forcing
combine.
&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
KEY MESSAGES:

- A mid-week warmup will be followed by increasing late-week
  severe potential.
-------------------------------------------------------------------

By Tuesday and Wednesday, there is some indication of a return
to quasi-zonal flow to even weak ridging, with nearly 100%
membership in clustering suggesting heights between 583dm and
586dm and NBM highs back into the mid to upper 80s, there is
increased confidence similar heat lingers into at least Thursday
at this point with most ensemble spread encompassed in the 80s.

Beyond that, into Friday and beyond, there is some indication
of troughing with both timing and intensity uncertainty. Though,
in the last 24 hours this has trended farther east and weaker,
keeping much of the late week temperature spread in the low to
mid 80s, providing some, but not dramatic relief. We will also
be keeping an eye on severe potential in the transition from
heat to weak troughing, with CIPS and CSU machine learning
showing increasing probabilities into Thursday and Friday. Into
days 7 and beyond, the strength and progressiveness of this
trough will determine just how long it takes to warm back up
into what could potentially be another ridging pattern with
heat returning.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
Rain has ended across the region, save for a few isolated
showers near ZZV and IDI. IFR stratus has initially been slow to
develop, but all signs point to quick lowering into IFR/LIFR
within the next couple of hours. Guidance has been more
optimistic about ceilings lifting into MVFR from S to N after
dawn, with  periods of VFR possible this afternoon, favoring
locations west of PIT.

Increasing shower and thunderstorm coverage is expected after
16z as a wave of low pressure tracks along the stalled surface
boundary. Most of this activity should stay south of the I-80
corridor. Included predominant showers, and prob30 for
thunderstorms, at the most likely times for area airports. This
should peak in the afternoon and early evening hours, with
associated restrictions and potentially heavy rain.

Convection should quickly diminish near 00z Monday, with IFR
cigs returning into Monday.

Outlook...
Periodic restrictions are expected through Thursday as
disturbances track along the stalled frontal boundary across the
Upper Ohio Valley region. Late night/early morning stratus and
fog is likely, along with showers and thunderstorms peaking in
the afternoon and early evening. More organized showers/storms
are expected with a Thursday cold front.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...Flood Watch from noon EDT today through this evening for
     PAZ021-029-031-073>076.
OH...Flood Watch from noon EDT today through this evening for
     OHZ049-050-058-059-068-069.
WV...Flood Watch from noon EDT today through this evening for
     WVZ001>004-012-021-509>514.

&&

$$

SYNOPSIS...Milcarek
NEAR TERM...WM/Milcarek
SHORT TERM...Milcarek
LONG TERM...Milcarek
AVIATION...Rackley