036
FXUS61 KPBZ 111353
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
953 AM EDT Tue Mar 11 2025

.SYNOPSIS...
Dry and above-normal temperatures expected through Friday. The
next chance of widespread precipitation arrives Saturday into
Sunday, as a powerful low pressure system will ride up the
Mississippi Valley.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
KEY MESSAGES:

- Dry and above-average temperatures today
- Wind gusts and low relative humidity may create fire weather
  concerns this afternoon
-------------------------------------------------------------------

Zonal flow aloft will continue to pump in dry air over the Upper
Ohio Valley today. A weakening cold front will cross the
northern half of the region this afternoon. The front will move
southward into the evening hours, finally drifting to the south
of the forecast area by late evening. Model analysis shows the
moisture associated with the boundary to be behind it in the
weak cold air advection. With so little moisture, and a lack of
strong upper level support, frontal passage is expected to be
dry. An increase in stratocu clouds is possible behind the front
late in the afternoon and through the evening hours.

Continued the trend of going a touch above NBM mean for max
temperature given good mixing expectations. Relative humidity
and wind gusts (between 20 to 30 MPH) may cause fire weather
concerns; more details are in the Fire Weather section below.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
KEY MESSAGES:

- A brief cool down on Wednesday but temperatures remain above
  normal.
- Temperatures warm again on Thursday.
--------------------------------------------------------------------

The boundary will stall over northern West Virginia late
tonight, then be slowly pushed back northward Wednesday as a
warm front due to minor upper level height rises. It appears the
front will only cross the southern half of the forecast area
during the day. This will setup a wide range of high
temperatures, where the far north may see highs in the low 50s,
while the far south may rest in the lower 70s. The stratocu
cloud deck will remain north of the boundary as well. Even as
the boundary heads northward on Wednesday, the lack of deep
moisture and upper level support will keep its second crossing
dry.

It will take most of Thursday morning for the warm front to
finally drift north of the entire forecast area. Another surge
of warm air is expected Thursday, this will push temperatures 20
to 25 degrees above normal.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
KEY MESSAGES:

- Much above-normal temperature likely into the weekend
- Strong low pressure system likely to bring widespread rain and
  falling temperature, with more uncertainty in other hazards
- Dry and cooler early next week
-------------------------------------------------------------------

The warmup continues into Saturday as eastern CONUS heights
continue to rise in response to a deepening central CONUS trough
and closed low. There remains a bit of uncertainty regarding
how high 500mb heights get, which of course could impact maximum
temperatures. Nevertheless, for Friday and Saturday, chances of
70+ highs are 90 percent or greater from Pittsburgh south, with
75+ highs at 60 percent or greater south of I-70.

Ensembles are in general agreement that overall stacked system will
lift across the Upper Mississippi Valley on Saturday, with a warm
front possibly lifting through that day, followed by a cold front
Saturday night/Sunday morning. Rounds of rain remain likely, with
locally heavy amounts possible as models suggest that precipitable
water values may approach the climatological maximum for mid-March.
While gradient winds will likely be elevated due to the dynamic
nature of the system (with advisory-level wind possible in the
ridges), the severe thunderstorm threat will be tied more closely to
the levels of CAPE that can develop. Models remain a bit pessimistic
on this front. There is good potential for decent deep directional
and speed shear however, so the severe threat may increase if better
levels of buoyancy can develop.

Regardless, there is decent confidence in these threats tapering off
Sunday afternoon and night behind the cold front, with drier weather
and temperatures much closer to normal for Sunday night and
Monday.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
There is high confidence in VFR through the TAF period. The
approach of a dry cold front will aid gusts between 15 to 25kts
this afternoon that will be initially SSW and veer NW near and
after the frontal passage between 21z-01z.

Patchy stratocu and speed sheer induced alto decks are possible
overnight into Wednesday as the boundary stalls near I-70.

Outlook...
As the stalled boundary lifts northward as a warm front
Wednesday, ensembles suggest a 30-50% probability for MVFR cig
development due to moisture convergence ahead of the leading
edge (BVI/FKL/DUJ). Lingering presence of the boundary into
Thursday may still offer low probability (30%) for MVFR at DUJ.

Otherwise, VFR is favored through early Saturday under the
influence of high pressure with surface wind quickly returning
to a predominant and occasionally gusty SW flow.

&&

.FIRE WEATHER...
Tuesday is the day this week where concerns about potential
fire spread will be highest. The arrival of a weak cold front
will not bring precipitation, but an increased surface pressure
gradient and efficient mixing could lead to wind gusts of up to
30 MPH from the west and southwest. Minimum relative humidities
were adjusted slightly downward given surface observations and
the 12Z sounding. Drops as low as 25% remain possible through
the day today. Fine fuels will also be drying with time given
the lack of precipitation through the week. Concerns have been
covered within a fire weather SPS for most of eastern Ohio,
northern West Virginia, and western Pennsylvania.

For now, wind and RH concerns are a bit lower for Wednesday
through Friday, but trends will be monitored.

&&

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

&&

$$

SYNOPSIS...Hefferan/22
NEAR TERM...22/Milcarek
SHORT TERM...22
LONG TERM...CL
AVIATION...Frazier
FIRE WEATHER...CL/Milcarek