Area Forecast Discussion
Issued by NWS State College, PA
FXUS61 KCTP 310404
Area Forecast Discussion
National Weather Service State College PA
1204 AM EDT TUE MAY 31 2016
A weak cold front will push east of Pennsylvania tonight. A ridge
of high pressure will build east into the region for midweek. A
slow moving cold front will likely push into the region from the
Great Lakes by late in the week.
.NEAR TERM /UNTIL 7 AM TUESDAY MORNING/...
Line now weakening noticeably but slowing a bit as it crosses
through Harrisburg. However, the rainfall is not as heavy as half
an hour ago, so problems with flooding are not anticipated. The
convection elsewhere is also waning. NW wind at KMDT and KMUI show
that the outflow has gone through there and further, perhaps
rapid, weakening is anticipated in the next hour.
Line of showers and isolated thunderstorms along and ahead of the
wind shift and drier air is now through about 5/8s of the area.
Intensity has gone down noticeably in the past half hour. Will
hold onto a mention of strong storms in the hwo in the east for a
bit but latest HRRR and RAP have this line breaking up as upper
support slides east into northeastern PA and low-level convergence
decreases. Have attempted to time these showers as they move E/SE
for the next few hours and decrease POP as they do so with loss of
heating and support.
Weak cold front pushing into central PA at mid afternoon, providing
sufficient moisture convergence and llvl lift to overcome weak CIN
and maintain a line of isolated to scattered convection. mid level
lapse rates are lacking for super strong updrafts, but a few
cells could build to produce gusty winds and perhaps small
hail, and cooling heavy downpours. Latest hi res cams track
broken line of convection out of the Central Mountains and Laurel
Highlands by 21z, and the Lower Susq River Valley by 04z late
Skies will clear behind the front with sfc dewpoints falling into
the 50s. Light wind and areas of wet ground will lead to some patchy
fog late tonight. Lows will range from near 50F northwest to the
lower 60s southeast.
.SHORT TERM /7 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
Slowly rising heights aloft and sfc ridging will provide a mostly
sunny and warm day to PA on Tuesday. Superblend accepted for
temps with highs ranging from the u70s over the Allegheny
Plateau, to the m80s over the Susq Valley...although a few spots
could crack 87F far southeast.
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Not a lot of change from the last 2 days.
Made minor adjustments to the fcst package.
Still looks dry and warm for Wed.
Models show cold front moving into the area late Thursday into
Friday. 12Z NAM is showing large scale flow to be less amplified
and more zonal in a sense...so front not likely to slow down
quite as much for late Friday into Sat.
For Sunday into Monday...another weak system swings across the
area. Adjusted parameters to fit in with others. A slow cool
down as one heads into next weekend. At this time range...too
far out for not having some spread in model solutions from day
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
A ridge of high pressure will build in overnight and will continue
into midweek. The forecast question overnight will be the
development of fog/mist due to the calming winds and clearing
skies. Given the pattern and the last few nights, BFD, AOO, MDT
and LNS could see MVFR to IFR vsbys until around 13Z. More
settled weather building into the region through midweek should
stifle convection over the next few days with only early morning
Tue-Wed...No sig wx. Local fog reductions poss around dawn.
Thu...Chance of showers/tstms west. A.M. cig reductions poss
Fri...Cold front. Scattered showers/thunderstorms with
Sat...Mainly fair/VFR. Local fog reductions poss around dawn.