Area Forecast Discussion

WHAT HAS CHANGED

* Added slight chance of showers far western sections of central PA for into early evening. * Overall amounts of rainfall for Sunday trending lower.

KEY MESSAGES

1) Rain moves in tonight, heavy at times into Sunday.

2) Rainy pattern continues into much of next week, although uncertainty remains in the details. On the cool side as well.

DISCUSSION

KEY MESSAGE 1: Rain moves in tonight, heavy at times into Sunday.

Some dry air at low levels, most of the radar returns this morning so far have been at mid levels, but added slight chance POPS far western PA to match others, as some rain reaching the ground across the far west as of early aft.

High pressure over Quebec will give way to a fast moving low from the central states moving eastward across PA on Sunday. Trends are for the low to be a bit further south and faster now. Expect steady rain to move into western areas later this evening. Bulk of the activity is over by early evening. A few showers could linger into Monday.

The airmass is rather cool and dry to start. However, still have to watch the far south for thunder, given fcst temps. Thunder could be a bit further north, but mainly elevated in that case.

It has been wet, but with the trend with lower QPF and a bit faster movement, not really expecting hydro concerns at this pt.

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KEY MESSAGE 2: Rainy pattern continues into much of next week, although uncertainty remains in the details. On the cool side as well.

A large high over Quebec will push southward on Monday, giving the area the best chance for dry conditions. Monday looking like the best day to be outside.

As one heads into Tuesday and Wednesday, a wedge of colder and more stable air will be over the area, given this CAD pattern. At this time, the highest POPS are over the west and south, given an inverted trough.

Perhaps some improvement later Thursday, as a coastal low ramps up off the southeast coast.

While low temperatures will be not that far from normal, high temperatures will be colder than normal.

AVIATION /18Z SATURDAY THROUGH THURSDAY/

Sfc warm front lifting toward PA this afternoon, but probably won't come through, stalling just south of the state. Radar painted with small patches of very light RA flowing overhead, coming out of rather thin mid and lower decks. For now, everyone is VFR except for JST (and DUJ just to our W) where some heavier returns are showing up on the radar. A gradual lowering of the ceilings will lead to IFR at most sites for tonight. BFD/JST are certain to drop to IFR and have a 60% chc of LIFR for several hours in the late night and daytime Sunday. While HREF/RRFS are not as bullish on poor flying conditions, MOS has it pegged. Going to lean on MOS cigs and vsbys very much for the whole valid period. Most guidance does bring a 30-35KT LLJet up and across the CWA tonight, driving the rain. It will also get low enough and just fast enough to perhaps make some LLWS. Since the directional shear will be high, that bumps me into including some LLWS at all but JST and AOO tonight. It should wane toward morning. While there is a small chc for deep convection and thunder at JST/AOO, we'll keep away from mentioning it for the time being. However, Sunday will be a rainy day with widespread MVFR for everyone and occnl IFR at the higher terminals. The steadier moderate rain tapers off and moves to the south Sun night. But, some --RA and lower MVFR and IFR ceilings will last much of Sun night and Mon, esp across the higher elevs. Slightly higher cloud decks are expected for LNS and MDT.

Outlook...

Tue-Thu...Restrictions possible from -SHRA/BR and low ceilings, mainly S.

CTP WATCHES / WARNINGS / ADVISORIES

None.