Fairmont, West Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

607
FXUS61 KPBZ 201556
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1156 AM EDT Sun Jul 20 2025

.SYNOPSIS...
Isolated showers/storms possible today with marginal severe
flood threats this evening/early overnight. Pleasant weather
early week with seasonable temperatures, no rain, and low
humidity. Heat, humidity, and storm chances return late week.

&&

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

- The marginal risk for severe weather has been reduced to just
  far southeast Ohio and a part or northern West Virginia, with
  a low probability of damaging winds from 6pm to midnight.
- A marginal risk of excessive rainfall overnight southwest of
  Pittsburgh.

---------------------------------------------------------------

Trends with the 12Z sounding indicate that severe weather
chances have reduced for most of the area today on a passing
cold front. There are a few reasons for this. First, a layer of
relatively moist air the the 0km to 3km layer will inhibit much
low-level instability generation even if profiles wet bulb.
Second, this aforementioned moisture has held a low stratus
deck through much of the morning, inhibiting efficient heating
near the surface needed for storm buoyancy. Third, a dry layer
between roughly 4km to 6km will be difficult to penetrate
without vigorous updrafts. This has prompted the SPC to "pull
back" their marginal risk for the majority of the area.

As the front moves farther south into southeast Ohio and
portions of northern West Virginia, there is some indication of
more mid-level moisture moving up from the west along the front
axis and a longer window to heat during the day, which might
suggest a higher chance of storms themselves, but lower modeled
DCAPE values between 300 to 400 J/kg would not be supportive of
damaging wind gusts. That would leave the only conditional
probability of severe weather dependent on storm motion alone,
mostly reliant on a cohesive shear-driven cold pool between
roughly 6pm and midnight. This low probability threat is
generally only possible for the southern fringes of the county
warning area.

Despite the lowered severe chances, a marginal risk for
excessive rain still persists, mostly overnight (10pm to 6am).
Though column moisture can be an inhibitor for severe, it is
more favorable for efficient rains. With PWATS pushing 2" with
warm rain processes in storms (HREF max suggestive of 1" to 2"
per hour rates), flooding is still possible, mostly southwest
of Pittsburgh, but would rely on shear parallel training with
storm motions of 20kts to 30kts. This would preclude widespread
flooding concerns, but the threat could not be ruled out with
HREF maxima suggesting localized 6hr totals of up to 2"
possible, bordering up against FFGs thresholds. Hence the
marginal risk for flash flooding persists.

Overnight lows south of and near the front in northern WV and
southeast Ohio will remain above average in low-moisture and
clouds, while areas north of Pittsburgh may see low below
average for the first time in a while with clearing, cold
advection, and dry advection. Patchy fog is possible in areas
that do see rain today.

&&

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


- High pressure keeping a dry Mon through Wed in place.
- Heat returns by Wednesday.

----------------------------------------------------------------

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.

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. The ridge may very well begin to break down by this
time but at this point, it seems Wednesday will be dry.

&&

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

- Heat and humidity increase for Thursday
- Shower/thunderstorm chances increase Thursday and into
  weekend.
-------------------------------------------------------------------

The heat is expected to increase on Thursday with a 60% to 70%
prob of seeing temperatures above 90 degrees. The dew points
being anomaly high this year will mean that the heat index
values may press into the upper 90s to near 100.

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. The activity will certainly continue into the week
with this pattern being more problematic with the continued
above normal temps, above normal dew points, and return flow
being the main driver of activity. The 500MB flow over the
normal may suggest a return to a MCS like pattern heading into
the weekend as well.

&&

.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
A weak 700mb wave will cross the region early this morning that
will promote scattered light to locally moderate rain showers
favoring KPIT and south. This mention was only included at MGW
tracking near term trends. Lightning probability will be low
(less than 20 percent), so the main shower impact is expected to
be rain that aids boundary layer moistening to develop MVFR to
low probability IFR cigs.

Diurnal mixing should lift ceilings by 18z, but the approach of
a surface cold front may cause MVFR cigs to linger slightly at
FKL/DUJ. The front will traverse the region NW to SE mainly
after 18z but weak forcing and limited heating due to various
cloud decks is trending to produce only isolated showers.
Lightning can`t be ruled out, but the probability of either
impacting a terminal is below 30% and thus left out of TAF
suite. Exception is a late mention at ZZV where it will be
closer to potential late day storm cluster movement but model
trends have shifted higher probabilities towards SW Ohio.

Ceilings are expected to fall again overnight with some cooling
and moisture along the cold front, which will be most likely
south of PIT. North, most models favor at least scattering to
clear skies with the arrival of drier air behind the front.
Because of this, the only port with a >50% chance of MVFR is MGW
for now near daybreak Monday. Mixing and scattering to
widespread VFR is likely thereafter.

Outlook...
High pressure and dry advection within NW flow should promote
VFR conditions Sunday night, though some lag in surface dry
advection may allow for low probability fog at valley sites.
There also appears to be a 30 to 40 percent probability for
convection along the exiting front between 00z to 06z Sunday
from ZZV/MGW that may cause impacts and aid cig/vis
restrictions.

High confidence exists in high pressure promoting dry weather
and VFR conditions Monday through at least Thursday morning
before precipitation chances return late week into next weekend.

&&

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

&&

$$

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