textproduct: State College

WHAT HAS CHANGED

* Confidence rising in timing of frontal passage and related precip on Sunday and Sunday night along with refinement of QPF.

* Northwest wind gusts in the 30 to 40 mph range likely during the day Monday as colder air pushes into the region.

KEY MESSAGES

1) Temperatures start a steady climb today with dry conditions then a widespread light to moderate rain Friday into Friday evening.

2) Cold frontal passage Sunday should make widespread rain showers perhaps ending as a brief period of snow across the north, followed by windy and colder temps on Monday.

DISCUSSION

1) Temperatures start a steady climb today with dry conditions then a widespread light to moderate rain Friday into Friday evening.

Variable amounts of strato cu clouds will be found for the rest of today and tonight with nothing more than a brief sprinkle.

Next wave is a Clipper system with a sfc low that moves over Lake Michigan and Lake Erie, then thru the Finger Lakes. There is more moisture carried along by the system and it may actually tap a little Gulf moisture as it reaches our longitude. Consensus QPF is around 0.50" in the nrn tier and <0.25" in the Lower Susq and south-central mountains. The SHRA should arrive in BFD around or just before noon (when temps will be 35-40F), and 4 PM in JST- UNV-IPT. They should continue southward and be off into MD around 10-11 PM. A rumble of thunder is not out of the question over the west as they pass thru. Maxes will end up another 10F milder than the previous day (49-63F across the CWA fm N to S).

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KEY MESSAGE 2: Cold frontal passage Sunday should make widespread rain showers perhaps ending as a brief period of snow across the north, followed by windy and colder temps on Monday.

990mb sfc low over ND Sat evening will ride quickly to the east. The sfc low is progged by most models to be somewhere near BUF Sun evening. The warm advection precip looks like it will pass mainly north of PA for Sunday daytime. A little -RA may brush the far nrn tier during the daylight hours. More certainty exists in the passage of the connected cold front on Sunday night.

QPF Sun night actually looks very similar to Friday's amounts. Much of the precip will fall along and behind the front. The cold air being forced in from the N and the rainfall will quickly drop temps Sun night. Despite maxes in the upper 50s in the N (they'll be near 70 for the srn half of the CWA) on Sunday, the cooling will probably (50%) turn the rain to SN over the nrn mtns. If it does turn to SN there, it shouldn't over the central and srn two- thirds of the CWA due to the warmer start when the rain arrives. Maybe a little mix could happen on the top of the ridges of the central mtns. Mins will be 25-30F in the N, but just above 40F along the MD border (lower elevs). The precip will be S of the MD border around or just after sunrise Mon.

Mon-Tue look dry with temps a little below normal. Moderate pressure rises of 3-4 mb/3 hr will support NW wind gusts in the high 20s to mid 30s (KTS) during the daylight hours Monday. Went above NBM guidance by 10 kts or so in the wind category.

Wed should be a few degs warmer than normal and Thu much warmer with lots of places >=60F.

AVIATION /00Z FRIDAY THROUGH TUESDAY/

A few showers near UNV at this time, but most areas will have clouds into Friday. MVFR CIGS will be most likely at BFD, less likely elsewhere.

Main issue for Friday will be gusty winds in the afternoon into the evening, as strong jet stream results in more showers and gusty winds with a fast moving cold front late in the day. Some chance for a low topped thunderstorm, but left out of the 00Z TAF package for now.

Saturday at this points looks like the best day of the week so far.

Sunday will feature a strong north to south temperature gradient, as low pressure moves across the area. Most of the showers will be on back side of the front. Potential for more gusty winds Sunday into Monday, as the colder air works into the area. Also potential for more snow late Sunday night into Monday morning across the northwest.

Outlook...

Friday Night...Restrictions in rain showers. Sat-Sun...Mainly VFR. Sun Night - Mon...Cold front passage, restrictions in rain; some wintry mix possible across the north. Tue...Dry with VFR conditions expected.

CTP WATCHES/WARNINGS/ADVISORIES

None.