pa discuss
Office: CTP
FXUS61 KCTP 130108
AFDCTP
Area Forecast Discussion
National Weather Service State College PA
908 PM EDT Sat Jul 12 2025
.SYNOPSIS...
* Continued seasonably warm and humid through much of the coming
week
* Although at least hit and miss, afternoon and evening focused
showers and thunderstorms are expected through Monday, the
most widespread activity, featuring locally heavy downpours,
will be Sunday afternoon and evening.
* At this point, Tuesday looks like the driest day of the next
seven
&&
.NEAR TERM /THROUGH SUNDAY/...
Weak shear and high PWAT is resulting in isolated, slow-moving
showers and thunderstorms early this evening, some of which are
anchored by, and backbuilding over favored upslope area of
terrain features. Interaction with outflow boundaries from
earlier (and current) convection is also a factor in this
otherwise weakly-forced/low shear environment.
Two recent Flash Flood Warnings have been issued for 1) Somerset
Cty in SW PA and 2) Franklin Cty in Scent PA. These areas are
located along a subtle warm front across SW PA and weak meso
low near KHGR/KFDK where a band of MAX 925-850 mb Moisture Flux
Convergence was noted.
Hourly rainfall rates (that have maxed out near 3 inches/hr
across Franklin County, will gradually decrease between 01-03Z
and we don't really see any other areas of imminent
training/terrain anchored convection ATTM.
POPS will stay in the 10-30 percent range overnight as several
weak shortwaves embedded in the SW flow aloft drift across the
aforementioned weak frontal boundary over SW and Scent PA, where
highly localized, additional rainfall of up to 1 inch is
possible through 05Z.
Previous Disc...
Dewpoints in the 70s and U60s will not allow us any relief from
the muggy nights of late. Marine layer of moisture seeks to
move back into Sern PA and perhaps into UNV/IPT later tonight.
But, the signal is less strong/less certain than it was for Fri
night. Will paint high sky cover for the SE half of the CWA
tonight. Fog is also a probability, but perhaps not as
widespread as Fri night. Will mention patchy fog for much of the
area.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH 6 PM SUNDAY/...
Morning cloud deck over the SE will dissipate, and perhaps
faster than Sat AM. Sfc wind will still be light and out of the
SE. Shear will be light, but not near-zero like it was on Sat,
generally 15-20KT. An actual short wave trough will be advancing
through PA on Sunday. PoPs will be the highest (70-100) they've
been for many days. PWAT a little higher than today/Sat. With
all that going for it, the atmosphere is primed for more heavy
rainers, but also more chc for severe gusts. Hail (at least
large hail) less likely than severe wind gusts on Sun aftn and
evening. SPC keeping on with the MRGL risk for most of our CWA,
and WPC Slight risk for excessive rainfall also continues. Both
seem well-founded. We have been considering a flood watch for
Sun, but we'll let the rain fall where it wants today and show
it's hand before making a FFA. Passing it onto the later shifts.
Temps a secondary problem for Sun. The NBM looks fine with 80s
and perhaps someone touching 90F in srn Franklin Co.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
The aforementioned slow-moving cold front will continue to
progress across central Pennsylvania Sunday night and throughout
the day on Monday, with current guidance progged to have the
surface cold front overhead by sunrise on Monday. Little
residence time in the warm sector will allow for less
destablization across the area, with dry air west of the cold
front allowing for drier conditions to prevail west-to-east as
the day progresses. Front pulls further east and out of the area
Monday evening into Tuesday morning, allowing for a brief
period of no precipitation across central Pennsylvania through
the morning hours on Tuesday.
As the cold front continues across central Pennsylvania on
Monday, PWATs in the 1.50"-2.00" range will continue to promote
some potential for isolated instances of flash flooding across
eastern Pennsylvania which remains consistent with WPC's
Marginal Risk for Excessive Rainfall. Flooding potential will
also be exacerbated by antecedent rainfall, so will need to
continue to monitor rainfall trends through the weekend with
regards to the flooding threat on Monday.
Large-scale pattern remains fairly consistent; however,
allowing for continued chances for diurnally driven showers and
thunderstorms across central Pennsylvania throughout much of the
long-term forecast period. Focus for precipitation Tuesday
afternoon/evening will be stationed across the southern tier of
Pennsylvania with increasing coverage during the afternoon hours
on Wednesday, Thursday, and Friday.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
Expect isolated, slow-moving SHRA/TSRA to continue through 05Z
Sunday, especially between between KCBE and KHGR and KMRB (and
possibly as far NW as KMDT) where a stationary front at the
surface, intersects with a weak sfc low pressure center in that
area.
Elsewhere, look for VFR through shortly after midnight local
time, then a gradual decrease through MVFR to possibly IFR
VSBYS between 08-13Z Sunday.
Additionally, we fully expect another marine layer stratus cloud
deck to form and push inland bringing IFR to LIFR conditions
between 06-13Z Sunday (mainly impacting KLNS, KMDT and KIPT).
If anything, it could go a little farther westward by early
Sunday, with a low- level E-SE flow in place for at least parts
of the region. KLNS, KMDT, and KIPT have high confidence
(70-80%) of restrictions. We're less sure at KUNV and KAOO
(30-50%), while low cloud development seems unlikely at KJST and
KBFD. Fog is again expected, but only a 30-60pct chc of LIFR
conditions out away from the IFR/LIFR marine stratus deck.
Forcing moving in from OH on Sunday will cause a better/more
widespread round of SHRA/TSRA. The better shear thru the atmos
will help them move a little bit quicker. We have a high level
of confidence in a better-organized cluster of storms moving
from W-E across Central PA in the aftn and evening hours. While
this is mainly outside of the 18Z end time of this package,
we'll likely add more mentions of TSRA with later packages.
Outlook...
Mon...Cold front nears, but may stall out/not pass through
completely. Widespread SHRA/TSRA, mainly southeast.
Tue-Wed...Mainly VFR. Isold PM TSRA poss, mainly south.
Thurs...Sct/Nmrs SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Lambert/Dangelo
NEAR TERM...Lambert/Dangelo
SHORT TERM...Dangelo
LONG TERM...NPB
AVIATION...Lambert/Dangelo
Office: PHI
FXUS61 KPHI 130527
AFDPHI
Area Forecast Discussion
National Weather Service Mount Holly NJ
127 AM EDT Sun Jul 13 2025
.SYNOPSIS...
A cold front approaches the region today into Monday before
slowly crossing through later Monday into Tuesday. Thereafter,
the front stalls near/over the region before lifting back north
as a warm front later Wednesday into Thursday. Another cold
front approaches towards the end of week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Today looks mostly like a repeat of yesterday as easterly flow
continues to dominate. This means more low clouds and patchy fog
to start, with sun breaking through towards midday/early
afternoon. Also it means that convection will be mostly
confined to well inland/higher terrain locales, with I-95 and
points southeast seeing just slight chance of a shower or storm.
Highs well into the 80s with heat indices in the 90s.
Tonight, things start to change as a front approaches. Better
chance that some weakening convection from the west reaches our
western lower elevation zones than the last few days during the
evening, then remnant showers may cross the entire area
overnight. Otherwise, looks like another round of low
clouds/patchy fog by late at night. Lows mostly near or above
70.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
A cold front approaches our region from the west Monday while
slowing down and undergoing frontolysis. Very slowly, this front
makes its way through the region Monday into Tuesday before
eventually stalling over/near the region for the remainder of
the term.
Given this situation, expect the showery summertime pattern to
continue. Some spotty showers leftover from tonight could
linger for areas during the Monday morning time frame, depending
on the time frame of frontal movement. Another round of showers
and thunderstorms expected for the region Monday afternoon into
the nighttime period as the front only sags ever so sightly to
the southeast with time. While there is mainly only a slight
chance of PoPs for Tuesday, some spotty showers and
thunderstorms should not be ruled out for the afternoon time
frame onwards given the location/proximity of the stalled front.
Fog formation is possible for areas during the late nighttime
and early morning periods, but this will be dependent on
precipitation occurrence and mixing.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Stationary boundary looks to plague the region before an
approaching low pressure systems lifts it through as a weak warm
front Wednesday/Thursday. Thereafter, another cold front
approaches, looking to pass through sometime near/during the
weekend (e.g, late Friday/early Saturday).
Unfortunately, this synoptic situation supports a continuation
of the showery summertime pattern. Chances for showers and
thunderstorms Wednesday/Thursday/Friday, mainly during the
afternoon and evening time frames with diurnal heating in place.
End of the week/weekend cold front will be watched for exact
time frame of approach/passage, and its severe weather
potential.
Heat headlines may be needed for areas
Wednesday/Thursday/Friday. Guidance supports heat indices
approaching criteria.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Thru 12Z...Low clouds developing generally with most areas
seeing cigs drop to IFR or lower. The set up looks more
favorable for low clouds than fog, except near the coast,
including KACY, where both the lowest ceilings and lowest
visibilities are likely to occur. By 09Z, expect most locations
to have IFR conditions. Winds remain light (5 kt or less),
generally favoring the southeasterly direction, but could be
variable at times. High confidence in overall pattern, low
confidence in timing/placement of development of fog and
visibility restrictions.
Today...Once low clouds and fog dissipate, will see a return to
VFR conditions. Storms will begin to approach the area from the
northwest by 00Z, but impacts mostly confined to KRDG/KABE.
Moderate confidence,
Tonight...VFR with a few t-storms near KRDG/KABE to start, then
cigs drop to IFR again most terminals. A few showers could make
their way across the rest of the terminals after 6Z. Low
confidence.
Outlook...
Monday through Thursday...Overall, VFR conditions. However,
afternoon and evening SHRA/TSRA may result in brief periods of
sub-VFR conditions daily. Sub-VFR conditions are also possible
overnights/early mornings due to low clouds and fog, but
uncertainty remains on this potential, so confidence is low.
&&
.MARINE...
Winds and seas should stay below Small Craft Advisory criteria
through tonight.
Outlook...
Sunday night through Thursday...No marine headlines expected.
Winds generally remain 15 kt or less with seas around 2-4 feet.
Showers and thunderstorms are possible daily, primarily in the
afternoon and evening hours, with the greatest probability of
showers and storms being on Monday.
Rip Currents...
Today, winds will be out of the southeast at around 10 mph with
breaking waves around 1 to 2 feet. This combined with a lower
southeast swell and lower wave heights results in a LOW risk for
the development of dangerous and life threatening rip currents
at the Jersey Shore and at Delaware Beaches.
Rip currents occur often in the vicinities of jetties and piers
and the speed of the currents are generally maximized at low
tides.
For specific beach forecasts, visit weather.gov/beach/phi
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.
&&
$$
SYNOPSIS...RCM/Wunderlin
NEAR TERM...Johnson/RCM
SHORT TERM...Wunderlin
LONG TERM...Wunderlin
AVIATION...Cooper/DeSilva/Johnson/RCM/Staarmann/Wunderlin
MARINE...DeSilva/Johnson/RCM/Staarmann/Wunderlin
Office: PBZ
FXUS61 KPBZ 130551
AFDPBZ
Area Forecast Discussion
National Weather Service Pittsburgh PA
151 AM EDT Sun Jul 13 2025
.SYNOPSIS...
Hot and humid weather is forecast with with isolated
showers/storms this afternoon and evening. A frontal passage on
Sunday brings a bit higher risk for severe storms and isolated
flash flooding, with muted heat. A relatively drier period is
forecast next week with another heat concern by midweek.
&&
.NEAR TERM /THROUGH TODAY/...
KEY MESSAGES:
- Hot; high temperatures climb into the 90s and heat indices
approach 100 degrees in spots
- Isolated thunderstorms possible this evening into tonight,
especially across east-central OH
- Storms will be capable of producing damaging wind gusts and
localized flooding issues in heavy downpours
---------------------------------------------------------------
500mb heights remain elevated over our region this afternoon, as
we remain in the warm sector of surface low pressure over the
northern Great Lakes. The main initial impact is the heat this
afternoon. 850mb temperatures climb to around 19C this
afternoon, supporting high temperatures in the lower 90s.
Combined with dewpoints in the lower 70s, heat index values of
95 to 100 are forecast, highest in valley and urban locations.
Portions of eastern OH, the lowlands of northern WV, and far
southwest PA will likely see low temperatures of 70 or higher
tonight (>50% chance), offering little relief.
The elevated 500mb heights suggest lesser initial coverage of
popup showers/storms into early afternoon due to mid-level
subsidence, especially in southwest PA/northern WV. PIT ACARs
soundings support this, showing a skinny CAPE profile and
relatively warm mid-level air. Low-level convergence near the
ridges may allow for an isolated storm or two, although CAMs
suggest most of this remains to our east. In eastern Ohio, on
the western side of the ridge, isolated coverage is possible
during the early to mid- afternoon hours. Any storm that manages
to form and produce a strong enough updraft may be able to tap
into 800-1000 J/kg of DCAPE, suggesting a downburst wind threat.
This is conditional on storm development, which is still in
question, but the SPC marginal severe risk still seems
justified.
The evening hours may allow for a slightly better severe threat
in eastern Ohio. Storms have already fired in northwest Ohio
ahead of an eastward-moving outflow boundary. This boundary
will be moving into an environment with 2500-3000 J/kg of
surface-based CAPE and little capping, thus continued scattered
to numerous storms are expected in the SPC Slight Risk region.
These storms would present mainly a wind threat as they cross
Ohio, and should be beginning a weakening trend as they reach
the ZZV area by early to mid- evening as instability begins to
diurnally decrease. Still, an isolated risk of damaging wind
still exists, particularly if some cold pool conglomeration can
occur with storm clusters - overall shear levels are a bit weak
to support storm organization. Also of note - an isolated
flooding threat cannot be ruled out with PWATs in the 75th to
90th percentile, deep warm cloud depths, and slow storm motion.
Convective activity will become more isolated and reach a
relative minimum during the early overnight. Some nocturnal
scattered development is possible east of Pittsburgh overnight
in weak inverted surface troughing, with much of this activity
departing after sunrise.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
KEY MESSAGES:
- Slightly higher flash flooding threat Sunday; marginal severe
risk to the east of Pittsburgh.
- Lesser storm/shower chances Monday, mainly in the West
Virginia ridges
- Sunday/Monday temperatures in the mid to upper 80s
----------------------------------------------------------------
Frontal passage on Sunday still presents a bit better threat of
flooding as compared to today with the arrival of the surface
cold front. PWATs of 1.6 to 1.7 still represent 90th percentile
levels, and the same support for warm rain processes and slow
storm motions remain. Given better precipitation coverage with
the boundary, the ongoing WPC marginal excessive rainfall risk
seems reasonable. The severe risk remains in place as well,
particularly to the east of Pittsburgh in the SPC day 2 marginal
risk area, with sufficient MLCAPE and DCAPE to continue to
support a downburst wind risk. Overall, the flood risk looks to
be a bit more concerning than severe potential, but trends will
continue to be monitored. Although temperatures remain a bit
above normal Sunday, the clouds and precipitation will mitigate
the heat risk.
After a quiet and still balmy overnight period Sunday night, a
shortwave passage on Monday is still forecast. The axis looks to
be east of Pittsburgh by the time of peak heating, and may be
trending a bit faster. Chances for scattered showers/storms are
best in the WV ridges, but at this time, it appears that any
isolated severe/flooding threat would lie to the east of our
region. A slower timing could pull these threats back west.
Temperatures remain above normal with a very modest air mass
change behind the Sunday front.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
KEY MESSAGES:
- Mostly dry and warm Tuesday.
- Heat Wednesday, with rain chances increasing late week.
-------------------------------------------------------------------
Rain chances decrease into Tuesday with the arrival of surface high
pressure and general upper subsidence. Because of this, the region
will likely have light to calm winds with a slight decline in dew
points with mostly clear skies and mixing into drier air aloft. his
should keep conditions pleasant despite general upper ridging and
highs above normal.
Into Wednesday and Thursday, the high is generally expected to move
east off the Atlantic coast, allowing the return of warm and moist
southwest flow. This will likely result in Wednesday being the
hottest day of the work-week with overnight lows staying elevated
Thursday morning in moisture. Heat Risk tops out at "Major"
levels with the most recent update. There is still about five
degrees of temperature uncertainty Wednesday related to
precipitation chances and cloud cover. Depending on the speed of
a trough passage and cloud cover trends, temperature spread
increases Thursday. Thursday has the potential to be comparable
to Wednesday heat, through most ensembles are lower in clouds
and the best chances of rain this week as a shortwave skirts
south of the main surface front. Wednesday and Thursday also
have the highest proportional chances of severe weather and
flooding as indicated by machine learning, and CIPS analogs.
Rain chances linger through Friday as the probability for the main
surface front passage increases, though at this point, there are
varying solutions in clustered guidance with some solutions
suggesting ridging in the upper Great Lakes which would
maintain near 588dm heights and warmth, but some show trough
development which might sweep downstream and return temperatures
close to normal.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
VFR conditions prevail at all area terminals to start the TAF
period. Aside from passing mid and high clouds, conditions
should remain quiet with only some patchy fog possible towards
sunrise, particularly in areas that saw accumulating rainfall
during the day Saturday.
A cold front brings higher precipitation chances to the area
Sunday afternoon. The best coverage likely occurs after 18z,
though some isolated morning showers could bring rain (and
possibly a few rumbles of thunder) to terminals earlier than
that. VFR will prevail outside of showers/storms, with brief
restrictions possible in any precipitation. Some storms could
become strong and will be capable of producing damaging wind
gusts and frequent lightning. Convective activity will again
generally follow the summertime diurnal cycle, tapering after
sunset with the loss of daytime heating and giving way to
quieter weather Sunday night.
Outlook...
Ensemble models favor high pressure that drastically limits
convective potential Monday/Tuesday (but localized morning fog
can't be ruled out). Precipitation and restrictions become more
likely on Wednesday and Thursday as southwest flow and moisture
increase.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.
&&
$$
SYNOPSIS...CL
NEAR TERM...CL
SHORT TERM...CL
LONG TERM...Milcarek
AVIATION...Cermak
