-- Discussion containing changed information from previous version are highlighted. --
632
FXUS61 KPBZ 161154
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
754 AM EDT Sat May 16 2026

.WHAT HAS CHANGED...
Lower probability for severe weather today, otherwise overall
messaging remains unchanged.

&&

.KEY MESSAGES...
1) Well above-normal temperature early next week could impact
heat-sensitive populations, favoring those living in urban
areas.

2) Lowering severe risk today with a round of
showers/thunderstorms, but mid-week activity remains a period to
monitor.

&&

.DISCUSSION...
KEY MESSAGE 1...
The combination of height rises and warm advection as zonal flow
aloft today transitions to ridging/southwest flow Monday/Tuesday
fosters a gradual rise in area temperature toward well above
normal readings. Monday is likely to be the "warmest" day due to
the combination of heights aloft peaking and abundant sunshine
throughout the day. Though NBM bias-corrected temperatures
remain several degrees too high (prompting an adjustment to the
official forecast), maximum temperature that day is likely to be
in the mid to upper 80s (normal high in Pittsburgh: 72) with
long range ensemble data suggesting at 20% probability of
reaching/exceeding 90 degrees in the Pittsburgh metro area (and
far southwestern locations of CWA seeing those probabilities
approaching 50%).

Heat Advisory criteria, which is 100 degree heat indices or
greater, is very unlikely to be met but this early season heat
anomaly could still prove to be impactful to heat-sensitive
populations. Individuals in this sector, especially those
living within urban settings, should take necessary precautions
to reduce their heat risks.


KEY MESSAGE 2...
Previous messaging noted that severe weather potential today was
dependent on upstream evolution of a thunderstorm complex. That
complex is now active and driving along the WI/IL border as of
0530z. Greater convection-allowing model consensus shows that
the complex and associated mid-level wave are unlikely to reach
the forecast region into the latter morning hours today while
also encountering a fairly unfavorable storm environment devoid
of much SBCAPE (mean values less than 100 J/kg). Though elevated
CAPE may allow for some perseverance of the complex, it`s
increasingly likely that its decay will only continue as it
moves east. Additional showers and thunderstorms still develop
through the afternoon/early evening thanks to enough shortwave
lift and some destabilization with heating, but severe
parameters remain marginal at best and favors southeast OH
during the evening hours.

Beyond today`s round of rain and some lower probability chances
Sunday with a lifting warm front, the focus is on the
Tuesday/Wednesday period for the next potential hazardous
weather threat. A slow, eastward progression of height falls
plus weak low movement does strongly favor precipitation
areawide by Wednesday afternoon, but details in timing of any
pre-frontal troughs or impacts from increased cloud cover make
it difficult to assign proper severe context. That said,
analysis of AI/ML outlook models are becoming more pessimistic
in hazardous weather occurring; this forecaster`s best guess is
potential issues of timing of lift plus mid-level warm air caps
(which generally occur in SW flow patterns like the one
expected) limiting strong destabilization for either day.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
Expect mainly mid and upper level cloud cover through the
morning and into the midday period. VFR conditions are expected
through at least 18Z across much of the area. A trough tracking
ahead od a cold front will create enough instability for
thunderstorms moving through the area between 19Z and 01Z this
afternoon and heading into the evening. Expect IFR and below
conditions with thunderstorms.

The impact of convection should wane by 02Z - 03Z with low
stratus expected for the rest of the TAF period. The winds will
increase by the afternoon with gusts up to 25 knots in some
cases before decoupling after 00Z.

Outlook...
VFR returns Sunday and persists into early next week. The next
potential for widespread precipitation and restrictions may
arrive by Tuesday night or Wednesday.
-- End Changed Discussion --

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.

&&

$$

DISCUSSION...Frazier
AVIATION...Shallenberger