764
FXUS61 KPBZ 121200
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
800 AM EDT Tue May 12 2026

.WHAT HAS CHANGED...
Frost and freeze potential will end this morning after sunrise,
with rain set to return overnight. Low probability severe
chances remain for Wednesday afternoon. A pattern shift alludes
to a rapid shift toward summer-like weather.

&&

.KEY MESSAGES...
1) Potential for frost and freeze conditions will abate after
sunrise this morning, with no additional risks expected over
next few weeks.

2) Rain returns overnight into Wednesday morning with a second
shot of showers Wednesday afternoon that offers a low
probability severe threat .

3) Long-range outlook favors a notable pattern shift that
creates summer-like conditions across the Ohio River Valley
region.

&&

.DISCUSSION...
KEY MESSAGE 1...
Patchy altocumulus along with enough surface wind have hampered
nocturnal cooling and reduced the risk for frost/freeze
conditions through dawn. Dissipation of this could deck could be
enough to initiation the frost/freeze process, so those
headlines will remain in effect through 8am but are more likely
to be seen in sheltered, low-lying areas.

KEY MESSAGE 2...
A deep trough will dig into the Great Lakes region in
conjunction with a surface low to spread rain northwest to
southeast generally after midnight tonight through the late
morning hours Wednesday. Ensembles favor the northwestern
portions of the forecast region for higher accumulations due to
closer proximity of mid-level jet ascent, but values are
unlikely to exceed 1" (only 10% near Franklin, PA through 2pm).

The more interesting portion of the event develops Wednesday
afternoon when the upper trough axis and surface cold front
sweep across the region. This feature will foster a secondary
round of rain (with a potential dry period in between it and the
morning session) that could see greater storm development
pending the degree of heating/destabilization that occurs. With
shear likely around 30kts (a general "minimum" threshold for
severe potential), hi-res modeling highlights scenarios with up
to 1000 J/kg CAPE ahead of the developing line IF strong-enough
heating occurs. This is not to dissimilar than the setup from
this past Saturday, but this forecaster is more pessimistic in
enough sunshine/heating to foster increased severe potential due
to a shorter time-interval between the morning rain and cold
front arrival. Even so, this bears monitoring as maximized
conditions could favor a convective line of
showers/thunderstorms that could have segments with strong to
damaging wind gusts (hail and tornado risks are too low for
mention).

KEY MESSAGE 3...
Temperature again falls well below normal after Wednesday`s cold
front, with residual NW flow resulting in scattered afternoon
showers and highs struggling to even reach 60 (roughly 10
degrees below average) Thursday.

Ensemble models suggest this may be the last notably cold snap
(meaning frost/freeze headlines may be done for the season) for
at least a week with a notable pattern shift this weekend into
early next week. This features rising heights that could
potential lead to a southeast CONUS ridge, resulting in
temperature quickly climbing to seasonal averages Friday and
approaching 10 degrees (or more) above normal Sunday. Subtle
features within this shift could still result in varied
precipitation chances and even non-zero severe risks for next
week, but that remains too fuzzy to discuss at this time. The
focus will be on the stark change of 30+ degree rises in high
temperature from Thursday to Monday that creates summer-like
weather across the entire Upper Ohio River Valley.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
High confidence VFR prevails through 06z tonight. Generally light
winds around 5-10 knots start from the east-northeast and gradually
veer to west-southwesterly by afternoon before backing again to more
southerly overnight into early Wednesday.

This evening, a cloud deck around 7.5-10kft will move in ahead of
the low pressure system as winds freshen up after midnight. By early
morning hours, rain will move into the area bring MVFR ceilings. For
most terminals, there is a low probability for IFR ceilings,
however, there is the possibility that ceilings could become low-end
MVFR (~1.5kft) after the initial round of showers moves through. The
highest probability for IFR ceilings (55%-60%) will be at
FKL/DUJ/MGW for a couple hours during the late morning.

With these showers, southwesterly wind is forecast to gust up to 20-
25kts during the day on Wednesday.

Outlook...
Restrictions will persist into Thursday morning due to the crossing
low pressure. VFR returns Thursday evening into Friday under high
pressure.

&&

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

&&

$$

DISCUSSION...Frazier
AVIATION...Lupo