Fairmont, West Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

560
FXUS61 KPBZ 191532
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1132 AM EDT Sat Jul 19 2025

.SYNOPSIS...
Showers and storm chances tonight, then Sunday afternoon/evening
with chances of damaging winds and flash flooding. Dry and
seasonable early in the week, followed by a warmup with rain
chances late week.

&&

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

- A decaying convective system tonight will allow chances of
  damaging wind and flash flooding.
---------------------------------------------------------------

A notable trend in decreasing probabilities in convection during
the daytime has been noted, with the 12Z HREF showing a 0% to
10% chance of shower and storms before sunset tonight everywhere
save the ridges of northern West Virginia in a weak passing
wave to the south. Through noon-time, convection is not intense
enough to be materializing in  any flood concerns. Through the
afternoon, PoPs are likely to decrease meaning a low chance of
any flooding issues. Because of a decrease in daytime
convective coverage and a warm front moving north, highs are now
forecast to approach 90F in the valley and urban areas with
heat indices pushing 90F to 95F. This will bring moderate heat
risk.

Into tonight, chances of rain increase from west to east as a
decaying MCS is progged to drop across the region. The most
intense convection is most likely during the daytime hours in
western Ohio, with a general weakening trend expected into the
evening as the the system loses the best instability. By 8pm,
ensemble mean SBCAPE in nearly half the daytime maxima of 1500
J/kg, and there`s some semblance of weak surface decoupling.
Nonetheless, the system will have 30kts to 40kts of motion and
the potential to mix down that momentum in more potent cells.
This will introduce a marginal risk of damaging winds, but the
lack of robust instability will make hail generally likely.
Surface decoupling will also be unfavorable for tornadogenesis,
depending on the the depth of the stable inversion. The relative
highest severe chances will be in western Ohio, decreasing to
the east into PA/WV.

Because of storm motion, the system should preclude widespread
flood mentions; while HREF PWATs are a bit lower than recent,
closer to the 75th percentile. The only areas to watch out for
flooding are storms that are shear parallel with training, and
some of the recently harder hit areas in northern West Virginia.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
KEY MESSAGES:

- A more isolated flooding threat is possible Sunday with a cold
  frontal passage.
- Severe potential for Sunday, with damaging wind gusts being
  the most likely threat.
- High pressure keeping a dry Mon and Tue in place
----------------------------------------------------------------

Sunday will feature a cold frontal passage as the Michigan
surface low tracks into New England. Ensembles suggest a severe
threat perhaps as early as the late morning hours and into the
afternoon, with potential for 1000-1500 J/kg of surface-based
CAPE overlapping with 30-40 knots of deep shear, mainly from
Pittsburgh on south. This supports the day 2 marginal risk in
this area from SPC for mainly a wind threat. The flooding risk
will likely be confined to areas where east-west training may
occur ahead of the advancing front.

There is good confidence among the ensembles that strong ridging
builds over the Mississippi Valley and into the eastern CONUS next
week from Monday into Tuesday night. Along with crossing high
pressure to our north, a mainly dry pattern appears to extend
into Tuesday, with the potential for subsidence/warm air aloft
to suppress convection.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
KEY MESSAGES:

- Heat and humidity begin to increase during the middle part of
  the week.
- Shower/thunderstorm chances increase Thursday and Friday.
-------------------------------------------------------------------

The ridge continues to build into Wednesday leading to an
increase in temperatures and heat indices. NBM probabilities of
90+ highs increase to 40-70% over much of the area by
Wednesday, and then 50-80% on Thursday. Combined with high
dewpoints, heat risk is set to rise by the end of the forecast
period.

Shortwaves riding the top of the ridge may begin to suppress heights
slightly by the Thursday/Friday period.  This could lead to better
rain chances during this period. Longer-range machine learning
guidance suggests an uptick in severe storm potential as well, which
makes sense given the amount of instability/moisture that may be
available.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
Early morning satellite imagery and surface observations depict
a large MVFR to low VFR stratus deck near the stalled surface
boundary that is likely to persist through 14-18z.

Diurnal heating/mixing combined with slight lifting of the
boundary will slowly improve and eventually erode stratus decks
between 14z-23z. Approach of a shortwave may induce an isolated
shower/thunderstorm SE of Pittsburgh during the afternoon as a
warm front lifts north, but probability of terminal impact is
too low to mention. Will maintain this for the 12z update. The
most likely port to experience any rain and thunder before 00Z
is MGW from 14z to 16z, but that is only 20% for now.

Hi-res models suggest an MCS-like system may approach the region
after 00z from the western Great Lakes. Timing and its ability
to maintain are highly uncertain, but it may pose risk for
drastic visibility restrictions in heavy rain and gusty, erratic
winds, although there has been a downtrend in intensity with a
forecast later time of arrival. Tempo/prob30 groups are
maintained for now to time the most likely arrival time
overnight. Irrespective of this disturbance, there is at least a
70% to 100% chance of an MVFR low stratus deck at daybreak, with
a 40% to 70% chance of a IFR stratus deck.

The parent cold front is expected to pass during the day on
Sunday which may allow a higher chance of storms, particularly
for ports including and south of PIT (>50% chance).

Outlook...
Ensemble models are confident in high pressure promoting dry
weather Monday and Tuesday, with subsidence aiding a prolonged
period of VFR.

&&

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

&&

$$

SYNOPSIS...Milcarek
NEAR TERM...Milcarek
SHORT TERM...CL
LONG TERM...CL
AVIATION...Frazier/Milcarek