Fairmont, West Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

646
FXUS61 KPBZ 011228
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
828 AM EDT Sun Jun 1 2025

.SYNOPSIS...
Dry weather with temperatures rising to above normal through
early next week. The next rain chances arrive late Wednesday
into early Thursday.

&&

.NEAR TERM /THROUGH TONIGHT/...
KEY MESSAGES:

- Dry day with rebounding temperatures.
- Smoke expected aloft.
-------------------------------------------------------------------

Update this morning focused on lowering dewpoints towards the
lower end of NBM guidance, towards the 5th/10th percentile, as
the 12Z sounding shows good potential for the mixdown of drier
air just off the surface later this morning. Also, lowered
temperatures slightly through the day due to the impact of smoke
aloft from Canadian wildfires, the concentration of which is
forecast to increase according to HRRR smoke products. Increased
sky cover to no lower than 30 percent across the board to
account for the impact to sky visibility, but will hold off on
haze mention for now. Also, only made this increase for today;
we will need to assess the need for future periods.

Previous discussion...

Upper troughing will begin to pull off to the east today giving way
to rising heights around +10 dam by this evening as ridging builds
from the west. Today will be day one of a temperature rebound with
plenty of sun and a well-mixed boundary layer likely promoting a
slight dip in afternoon dew points and a coincident bump up in
temperatures. The only caveat to this could be increasing smoke
aloft from Canadian wildfires muting heating by a degree or two;
HRRR/RAP smoke products suggest a period of increased concentration
in mid to upper level northwest flow from the mid-morning into the
early evening hours. So, while cloud coverage will be scarce, the
sky will have a hazy look to it.

Clear skies hold on tonight with wind favored to be calmer than
Saturday night as high pressure centers itself closer overhead. With
dew points still in the mid 30s, efficient radiating could drop lows
down low enough for more frost concerns especially in the sheltered
areas/valleys in the WV/PA ridges with increased probability also
showing up for those types of locations in Venango, Clarion,
Jefferson, and Forest.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
KEY MESSAGES:

- Temperatures turning 10-15 degrees above normal Tuesday and
  Wednesday with increased heat risk concern.
- Remaining dry through mid-week.
----------------------------------------------------------------

High pressure remains dominant headed into the upcoming work week.
The trend through Wednesday will be dry weather with increasing
temperatures. A number of ensemble members drag a trailing shortwave
through on Monday on the backside of the trough and introduce a low
probability chance of a scattered shower or two with a modest
increase in cloud coverage. HREF chances for measurable precip are
confined north and east of Pittsburgh but remain below 15%.
Otherwise, high temperatures will rise back to normal or just above
with increasing thickness values and rising heights.

The most notable warmth arrives Tuesday and Wednesday as the surface
high shifts off to our east and a tighter gradient induces warm,
moist advection in southerly flow. Ensemble 850 mb temperatures
increase to 15-17C under strong 588 dam ridging and 1380-1390 meter
1000-850 mb thickness values. All of these factors translate to
highs in the low to mid 80s on Tuesday with the airmass reaching
peak modification by Wednesday with prolonged southerly flow.
Probability of reaching 85F or higher on Tuesday is generally from
40-70% in the urban areas and southeastern Ohio. Probability for the
same on Wednesday jumps to nearly 100% across the board and up
to 40- 70% for 90F+. Precipitation chances and total cloud
coverage both are rather low on Tuesday but slightly higher on
Wednesday as upper level moisture increases from the west. The
biggest question will likely be eastern Ohio as a few ensembles
inch thicker clouds in a bit earlier. Confidence in temps is
highest across western PA at this time, though it is worth
noting additionally that the potential for high level smoke
could again mute temperatures by a degree or two. Overnight lows
will also remain quite mild with low probability that they dip
under 60F Tuesday night and especially Wednesday night. Combine
these factors with this being the first notable heat of the
year, and the Heat Risk levels increase to Moderate on Wednesday
and Thursday with heat-related impacts to most individuals who
are sensitive to heat.

&&

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

- Rain chances return for the latter half of the week with potential
  for severe.
- Temperatures come back down closer to normal.
-------------------------------------------------------------------

Rain chances ramp up late Wednesday/early Thursday as the upper
ridge is shunted and a surface trough drags through. Ensemble
clusters differ on timing with introduction of precip as early as
Wednesday night and others holding off until Thursday afternoon.
Time-dependent, non-zero severe weather chances will arise from this
feature pushing into a warm, moist airmass. Numerous machine
learning outputs suggest an increased severe potential but with a
lower probability broad brushed area likely owing to discrepancy in
trough location and timing. Would obviously want an afternoon
passage for the highest chance of severe weather, which some
ensemble members do favor, but will have to wait to see better
agreement until we can draw any more definitives.

What is higher probability at this point is that temperatures will
take a tumble back down closer to normal as heights fall and a more
zonal flow pattern establishes in the mid-levels.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
Lingering valley fog, generally not impacting terminals, is
expected to largely dissipate by 13Z or so. A high-confidence
VFR forecast continues through the TAF period as surface high
pressure remains in control.

Diurnal heating/mixing may foster a few to locally scattered
cumulus Sunday afternoon while generating NW wind gusts between
15 to 25kts. High clouds/cirrus coverage will be more tethered
to the presence of lofted smoke transported in from Canadian
wildfires. While the sky may have a hazy appearance, visibility
impacts at the surface are not expected.

Outlook...
High pressure and ridge building near the region is very likely
to maintain VFR through Wednesday, with surface wind generally
light until Wednesday afternoon (breezy SW wind as the surface
high shifts).

The next potential impact period will be late week when shower
and thunderstorm chances increases (and restrictions mainly tied
to convection) as a series of shortwaves cross over the ridge
axis.

&&

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

&&

$$

SYNOPSIS...MLB
NEAR TERM...MLB/CL
SHORT TERM...MLB
LONG TERM...MLB
AVIATION...CL