029
FXUS61 KPBZ 161821
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
221 PM EDT Sat May 16 2026

.WHAT HAS CHANGED...
Storms due to cross the area through this afternoon, though
severe chances remain low.

&&

.KEY MESSAGES...
1) Hot temperatures could impact heat-sensitive populations
early next week.

2) Crossing storms today; severe chances persist by the middle
of next week.

&&

.DISCUSSION...
KEY MESSAGE 1...
Height rises under upper ridging is expected today through
Monday, with a ridge breakdown favored sometime between Tuesday
and Wednesday. This will bring along a warming trend. The
deterministic NBM continues to be on the warm side of the
probabilistic envelope, while a non-BC model like the LREF shows
temperatures in the upper 80s are generally favored for most of
the area. The main deviations would be mid- to-low 80s favored
north of I-80 and in the highest terrain of PA/WV, and perhaps a
few 90F readings for urbanized valley locations. Of course,
temperatures may underpreform if storms are present (most likely
into Tuesday/Wednesday.

In accordance with prior shifts, to account for the NBM warm
bias, temperatures were lowered a couple degrees for the
daytime hours in the Sunday to Tuesday period, as well as Monday
night.

Heat risk continues to show mostly moderate heat risk across the
area, which corresponds to affects for sensitive populations and
those without cooling and hydration. Be sure to monitor for
signs of heat illness if you are particularly susceptible, and
hydrate for extended periods outdoors. While mid-day Monday is
most likely to be the warmest period, cumulative heat impacts
peak on Tuesday.


KEY MESSAGE 2...
Severe weather chances continue to decrease into the day today.
A line of storms has been observed in eastern Ohio as of noon,
which will sweep through northern WV and western PA through the
afternoon. While conventional diurnal heating would allude to
storms strengthening into the afternoon, SBCAPE generation in
the region generally remains less than 500 J/kg with bulk shear
less than 30kts on the RAP meso-analysis through the rest of
the day. Additionally the DCAPE maxima of 600 to 800 is
forecast to remain ahead of the line. Storms will continue to
fire off of mostly elevated instability. Storms tops have
struggled to top 20kft, while max surface wind gusts have only
been 25mph to 35mph in the line thus far. The "most likely"
scenario is storms continue across the area with these sub-
severe gusts, with minimal changes to the environment. Severe
potential would increase if wet-bulbing allows any storm in
particular to top 30kft, but this remains low probability for
now.

While rain chances remain low on Monday, if there is enough
moisture into the low levels with localized convergence on the
ridgetop in a high-DCAPE environment, downburst wind chances
could not be ruled out, although this remains low probability
for now. The ridge is forecast to breakdown Tuesday into
Wednesday, increasing severe weather chances. Chances are
generally the highest in the NW portions of the area Tuesday,
and SE portions of the area Wednesday due to the progression to
the warm sector ahead of a cold front (as indicated by CIPS and
various ML models). As with typical summertime ridge breakdown
events, the exact timing and scale of severe weather will remain
low probability with a low-horizon on temporal predictability.
We`ll need to continue to monitor conditions through the coming
days.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
An initial line of showers and thunderstorms has weakened and
has become an decreasing area of showers. Expect these to move
through the area and exit to the east by 20Z-21Z this afternoon.
Mainly VFR conditions area expected through this round. A brief
instance of MVFR vis can`t be ruled out.

The second round will arrive from the northwest with arrival
into the area by 22Z-23Z. Have added some MVFR conditions with
this line across the area. The impact of convection should wane
by 02Z - 03Z with low stratus expected for the rest of the TAF
period. This will lead to cigs dropping during the overnight to
MVFR and IFR. FKL and DUJ will experience further drops to
below IFR later tonight. Most terminals will begin to improve by
10Z tomorrow.

The winds will increase by the afternoon with gusts up to 25
knots in some cases before decoupling after 00Z. Light and
variable winds are expected during the overnight.

Outlook...
The next potential for widespread precipitation and
restrictions may arrive by Tuesday night or Wednesday.

&&

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

&&

$$

DISCUSSION...Milcarek
AVIATION...Shallenberger