PBZ issues Area Forecast Discussion (AFD) at Oct 27, 2:03 PM EDT214
FXUS61 KPBZ 271803
AFDPBZ
Area Forecast Discussion
National Weather Service Pittsburgh PA
203 PM EDT Mon Oct 27 2025
.SYNOPSIS...
High pressure, seasonable temperatures, and dry weather expected
through Tuesday. Rain chances, breezy winds, and cooler
temperatures return to the area mid to late week.
&&
.NEAR TERM /THROUGH TONIGHT/...
KEY MESSAGES:
- Dry weather and seasonable daytime highs.
- Cold and dry overnight with frost/freeze potential
---------------------------------------------------------------
High pressure maintains dry weather and pleasant temperatures
through the remainder of today. Decoupling is likely overnight
with winds weakening some under a nocturnal inversion. The area
will again remain cloud free save some patchy high clouds, most
likely south of I-70. This will keep lows a few degrees below
normal, with freeze chances (>50%) near I-80 and frost chances
(>50%) north of I-70 under effective radiative cooling, though
a light nocturnal winds may keep frost more patchy than
widespread. River valley steam fog is possible again, though
similar to this morning it shouldn't been as dense nor prominent
as Sunday morning given the amount of dry air that has settled
into the low levels.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
KEY MESSAGES:
- Slightly cooler and gustier Tuesday.
----------------------------------------------------------------
The surface high pressure will slightly move northward with a
surface low pressure developing over Arkansas. This will make the
pressure gradient slightly stronger by enhancing easterly flow with
occasional daytime gusts into the 25mph to 35mph. Easterly flow may
allow the advection of slightly cooler dammed cold 850mb
temperatures from east of the spine of the Appalachians.
Consequently, highs are likely to be slightly cooler and slightly
below average. Tuesday night, decoupling into light wind and mostly
clear skies is expected with lows similar to the night prior.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
KEY MESSAGES:
- Cool, wet, and windy weather favored late week.
-------------------------------------------------------------------
There is high confidence a longwave trough slides across the central
CONUS Tuesday into Wednesday, as a cut-off low ejects from it's
base. Guidance shows the upper low center somewhere near southern
Missouri with surface cyclogenesis favored in the Mississippi Valley
early Wednesday. This likely scenario with a cut-off capable of
pulling in a Northeast closed low back into the circulation, causing
the upper low track to progress across the spine of the Appalachians
late-week.
The surface low and it's affects would track eastward to the
Atlantic coastline before recurving northeast as it begins its
spiral into a vertically stacked low. In all scenarios, this would
bring rain chances increasing late Wednesday and into the weekend
and cooler temperatures with cooler air aloft. Most ensemble
guidance brings high temperatures around 5-10 degrees below average
Wednesday to Friday, with the most uncertainty in temperature on
Wednesday depending on the onset time of rain.
Within this regime, there are a couple of nuanced low behaviors that
could result in the higher end of ensemble rainfall or impacts. The
first would be a deeper upper-level low that occludes earlier over
West Virginia, bringing in a heightened southeast flow on the
northeast end of the low. This would, in turn, result in a conveyer
belt of moisture from the Atlantic and strong south-easterlies that
may support down-slope winds along the Laurels. This would represent
the 90th+ percentile of QPF near 3" to 4" (over 72 hours). The
second scenario is a low track that is slightly slower to occlude
and a bit farther east into central Pennsylvania. In this scenario,
the may be deformation on the backside of the low as it passes, with
a narrow band of high end (3" to 4" QPF) with most seeing less. In
the driest scenario, ironically, the low is slower to occlude and
tracks directly over the area, representative of more of the 25th to
50th percentile QPF of 1" to 2" (over 72 hours). All in all, this
looks increasingly likely to be a soaker of a system with increased
confidence in the forecast.
When the system is through, the low is expected to rejoin the flow,
but the exact timing of which it does is still a bit uncertain. The
earliest, but also most likely, scenario (50% of LREF ensembles)
takes the cut-off low into southern Ontario Saturday, alleviating
affects. Though some of the slower solutions (including the "south-
diving" low scenario) take until as late as Sunday to have the cut-
off depart. Obviously, the longer it takes for the system to leave,
the higher the chances of continued cool, wet, and windy weather.
After the low departure, eastern longwave patterns range anywhere
from reinforced troughing early next week to ridge building. This
leaves the 8-14 day period lower confidence, complicated more by the
return of the NAO to a more neutral state by mid-November.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
VFR conditions should continue for the next 24 hours. Light
winds out of the east-northeast continue through tonight. Low
pressure moving into the lower Mississippi Valley causes the
pressure gradient over the Ohio Valley to tighten, resulting in
a slight uptick in winds during the day Tuesday as they trend
closer to 10 knots sustained with gusts to 15-20 knots.
.OUTLOOK...
Areawide VFR continues through Tuesday as high pressure holds
firm. Another system could return rain and restriction chances
from the south by late Wednesday, with restrictions appearing
increasingly likely for Thursday and Friday. Breezy conditions
also return during the latter half of the week as surface low
pressure passes south of the area.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.
&&
$$
SYNOPSIS...Cermak
NEAR TERM...Cermak
SHORT TERM...Milcarek/Lupo
LONG TERM...Milcarek/Lupo
AVIATION...Cermak
Source:
PBZ issues Area Forecast Discussion (AFD) at Oct 27, 2:03 PM EDT---------------
If I'm using your data in a way that is against your terms please email the team at "threatweb@pupswoof117.com"! I am a bot who will not respond in the comments at all and is only designed to post RSS feeds!
