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Office: CTP

FXUS61 KCTP 190949
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
549 AM EDT Thu Jul 19 2018

.SYNOPSIS...
High pressure will be overhead today and slide eastward on
Friday. A prolonged period of unsettled, wet weather starts on
Saturday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Clouds over the Laurels and SCent mtns seem to be near the
doldrums of a weak anticyclonic circulation of what appears to
be the 8H high. Have tried to keep the idea of the clouds
hanging around into mid-morning. They may then mix away - as
they are occasionally doing even at this early hour. However,
some diurnal cu is possible this afternoon. Fog has now spread
into all the valleys of the north thanks to temps well below the
water temps. The fog will burn off quickly as the dry air mixes
back in after sunrise. Temps should rise nicely except where
any low clouds remain into mid-morning. Maxes of mid 70s on the
ridge tops and m80s in the lowest elevations in the SE will be
really close to normal.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
More valley fog expected tonight, but maybe not quite as
extensive as this morning due to slightly milder temps/mins. As
the flow starts to veer to the S and the sunshine works on the
earth, the temps should rise back to normal or even warmer for
Friday aftn.

Well-stacked low pressure over the upper midwest on Friday will
begin to draw deep moisture up into wrn PA by the end of the
day. Have held onto a very low PoP for the far west, esp Warren
Co, for very late in the day. Otherwise, it should stay dry. The
eastward progression/translation of the low pressure/heights
will be slow, reaching only the western shore of LM by Sat
morning.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
By the weekend, ridge slides off the East Coast as low pressure
settles over the Ohio Valley, channeling moisture northward. A
compact wave of low pressure forms near the Carolinas and slides
northward toward NJ by Sat night - enhancing rain/convection
chances further. EC and GFS differ slightly on the intensity of
the coastal low. Will need to keep an eye on this feature as
could focus heavier rains over eastern portions of the state.
Sat and Sat PM could be dry over most of the CWA with us in
between systems.

After that coastal low passes by, the filling upper low
centered off to the west will keep mention of daily scattered
convection in the forecast through much of the week as a
tropical feel persists. An approaching cold front for late
week will again enhance precip chances. Have peaked the bell
curve of PoPs in mid-week.

Temperatures will be close to normal during the days and above
average overnights with the moisture and cloud cover.

&&

.AVIATION /10Z THURSDAY THROUGH MONDAY/...
Been looking the data over for the 06Z TAFS.

Will keep the fcst close to what was issued earlier for fog, but
think it will be very limited. Earlier shift did cut back on it
some.

Also a small patch of clds to the south, AOO has been BKN to OVC
all evening, but at least these are VFR CIGS.

Have to watch south to southeast flow late Thursday night and
Friday for lower clds to work in from the south, but at this
point not seeing this show up.

Earlier discussion below.

High pressure will keep mainly VFR conditions across the region
through Friday. The exception will be areas of morning valley
fog, mainly along the rivers. Have adjusted the 03z TAF updates
to cut back a bit on the severity of the fog, and also delayed
the onset based on current observations and trends.

Unsettled weather returns Saturday, and continues into early
next week, with occasional showers and scattered thunderstorms.
Best window for the most widespread rain and thunderstorms would
be sunday afternoon into early Monday.

.Outlook...

Fri...Morning valley fog, otherwise VFR.

Sat-Mon...Occasional SHRA/TSRA with associated MVFR/IFR
restrictions.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...Dangelo
NEAR TERM...Dangelo
SHORT TERM...Dangelo
LONG TERM...RXR
AVIATION...Jung/Martin



Office: PHI FXUS61 KPHI 190736 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 336 AM EDT Thu Jul 19 2018 .SYNOPSIS... High pressure will build across the region today before moving offshore on Friday. A low pressure system will move up the coast on Saturday. Another low pressure system will remain nearly stationary over the Midwest, affecting our area through the middle of next week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... High pressure is forecast to build from the Great Lakes across the northeastern states today. Other than some river valley fog in eastern Pennsylvania and northern New Jersey early this morning we are anticipating abundant sunshine. A north wind around 5 MPH this morning is expected to become variable in direction. Sea and bay breeze fronts will likely push inland during the afternoon. High temperatures are expected to favor the 80s in our region. The humidity should be relatively low with dew point readings mostly in the 50s. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/... The center of high pressure is expected to pass off the New England coast tonight. However, will will continue to experience dry weather under a mostly clear sky. A light and variable wind is forecast for tonight with low temperatures mainly in the upper 50s and lower 60s. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Friday and Friday night...High pressure slides offshore early Friday and this looks to be the last of the more pleasant days in this forecast. Very little moisture will be across the region through much of Friday and we should have mostly sunny skies across the region through the day. High temperatures will feel comfortable and in the low to mid 80s (mid to upper 70s across the higher elevations of the southern Poconos). As we head into Friday night, we will start to see some clouds moving into the area in response to a developing coastal low to our south. Some showers may start to edge their way into parts of our area, mainly southern Delaware and Maryland. Meanwhile, a strong upper level trough and strong surface low will start to push southeastward from the upper Midwest towards the Ohio Valley. Saturday and Saturday night...The coastal low will start to make its way up the coast on Saturday. The models continue to have differences with respect to timing, strength, and speed of the low as it moves up the coast but the solutions look much closer than did on last nights model runs. One of the biggest discrepancies is just how much precipitation will fall through Saturday. All the guidance suggests some pretty decent rainfall, especially near the track of the low, but with the exact track uncertain, it is hard to pinpoint just which areas may see the most rain fall. Should the low track right along/closer to the coast, we would expect to see fairly poor conditions across the region on Saturday. A slightly further offshore track will mean some areas may see a decent Saturday, albeit a cloudy/overcast one. Meanwhile, the upper level trough/closed low and strong surface low begin to settle in over the Midwest. Sunday through Wednesday...Not much change is noted as the upper low digs down deeper and into the Tennessee Valley. The associated surface low makes little progress as it continues to sit and spin over the Midwest, largely due to the strengthening surface high building over the Atlantic Ocean. The models show the surface low moving to the west southwest as the Atlantic high continues to strengthen. Unfortunately, the upper trough doesn't break apart as easily as the surface low and we will remain in an unsettled pattern through at least the midweek period. As the low spins, a warm front looks to be pushed northward into our area on Sunday. With a deep southerly flow in place, we will continue to see moisture rise across the region with PWATs running very high (ranging from 1.5 to 2+ inches across the area). Hard to pinpoint exactly where the heaviest rain will fall at this point but heavy, flooding rain will be likely in any storms that develop through this period and will need to be monitored as the forecast becomes clearer. For the most part through this period, the warmer air at 850mb remains suppressed to the south and west. While we will still see temperatures rise into the mid to upper 80s, we should be able to avoid temperatures reaching well into the 90s and the excessive heat that comes along with it when humidity rises. Apparent temperatures will likely start reach into the low to mid 90s but should remain below heat advisory criteria. However, with all of the moisture across the region, it will remain rather humid outside (on top of being mostly cloudy). && .AVIATION /08Z THURSDAY THROUGH MONDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Today...VFR with a mostly clear sky. North wind 3 to 7 knots becoming variable in the afternoon. Sea and bay breeze fronts are forecast to reach KACY, KMIV and KILG with the wind becoming southeasterly at those locations in the afternoon. Tonight...VFR with a mostly clear sky. Light and variable wind. OUTLOOK... Friday...Mainly VFR conditions expected. Southeast winds around 10 knots or less. High Confidence. Friday night through Sunday...Periods of MVFR/IFR as showers and thunderstorms overspread the region. East to southeast winds around 8 to 12 knots on Saturday, becoming more southerly on Sunday. Moderate Confidence. Monday...Periods of MVFR/IFR as showers and thunderstorms overspread the region. South winds around 10 to 15 knots with gusts up to 20 to 25 knots, especially closer to the coast. && .MARINE... High pressure is expected to influence the coastal waters of New Jersey and Delaware for today and tonight. A north wind around 10 knots this morning should become southeast to south 5 to 10 knots for this afternoon into tonight. Wave heights on our ocean waters should favor the 2 to 3 foot range. Waves on Delaware Bay are anticipated to be 2 feet or less. OUTLOOK... Friday...Sub-Small Craft Advisory conditions expected. Saturday...Increasing east to northeast winds. Gusts may near 25 knots at times during the afternoon/evening. Seas will build through the day and may exceed 5 feet Saturday evening. A Small Craft Advisory may be needed for Saturday evening. Sunday through Monday...Southeast winds around 10 to 20 knots. Gusts around 25 knots on Monday. Seas will remain elevated above 5 feet through Monday. A Small Craft Advisory will likely be needed. RIP CURRENTS... A light onshore flow and a medium period swell should result in a low risk for the development of dangerous rip currents for today. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...None. && $$ Synopsis...Meola Near Term...Iovino Short Term...Iovino Long Term...Meola Aviation...Iovino/Meola Marine...Iovino/Meola
Office: PBZ FXUS61 KPBZ 190940 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 540 AM EDT Thu Jul 19 2018 .SYNOPSIS... Dry weather is expected through tonight under high pressure. Periodic rain chances return Friday afternoon through the weekend with slow moving low pressure. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Dry weather and mainly clear skies should continue today under high pressure. Highs should return to near or just above seasonal levels as 500 mb heights rise. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... Dry weather should continue tonight as ridging slides to the E Coast. A vertically stacked low is progged to drift SE from the Upper Midwest to the OH Valley region Friday and Saturday. Shortwaves rotating around the low should return shower and thunderstorm chances to the area Friday, with the best chance expected across OH closer to the better shortwave support. The periodic shower and thunderstorm chances should continue through the rest of the period with the area in close proximity to the low. Depicted a diurnal trend to POPs in the forecast with the expected pattern. Clouds should limit instability and the potential for strong storms. Temperatures averaging near seasonal levels are expected. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... Maintained likely POPs for Sunday with the low progged to be centered over OH. The low is progged to move S to the Gulf Coast region early next week, though upper troughing is progged to persist across much of the NE CONUS through at least mid week. This troughing should maintain periodic rain chances through the rest of the period. Temperature are expected to average near seasonal levels. && .AVIATION /09Z THURSDAY THROUGH MONDAY/... High pressure will maintain VFR conditions and light wind through the TAF period. OUTLOOK... Periodic restrictions are likely across OH ports Fri, and the rest of the area over the weekend with slow moving low pressure. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. && $$