textproduct: Binghamton

WHAT HAS CHANGED

Added in more patchy fog tonight as the low levels remain quite saturated. Increased cloud cover on Monday with several cloud layers forecast. Increased PoPs and QPF Monday night into Tuesday across Northeast PA and the NY Southern Tier. There is no higher confidence for dry weather Wednesday and Thursday across the area.

KEY MESSAGES

1) Gradually drying out this evening, but staying mostly cloudy overnight into Monday as a northerly flow becomes established.

2) A wave of low pressure will move slowly east along a remnant frontal boundary Monday night into Tuesday, bringing rain to Northeast PA and perhaps the NY Southern Tier.

3) High pressure nudges in from the north, bringing dry, partly sunny and seasonably cool weather mid week.

4) Watching a potential coastal low for the end of the work week into next weekend that looks to meander along the southern New England shore.

DISCUSSION

KEY MESSAGE 1...

Drizzle and light rain will gradually taper off into this evening as the weak cold front presses south and east. The latest satellite loop shows plenty of low clouds in place across NY and PA this afternoon, fading to higher, thinner clouds over southern Ontario. The main forecast challenge tonight will be just how much partial clearing the area sees and therefore how much fog may form. Northerly winds also look to remain steady between 3-8 mph much of the night, but could decouple in the deeper valleys. Depending on how thin the higher clouds get will also impact temperatures overnight. The latest forecast sticks with the NBM ensemble bland, which brings quite cool conditions, with lows in the upper 30s to 40s for Central NY, and mid-40s to mid-50s for NE PA.

On Monday there will initially be some low level moisture trapped below 2500 feet agl over the region in the morning, with broken to overcast stratus clouds expected. By early afternoon the low level moisture mixes out, but high level clouds develop between 20k to 35k feet agl. Overall, this should generally mean mostly cloudy conditions for most of the day, but some filtered sunshine is also expected to occur. Temperatures will be seasonable in the 60s for highs. Northerly winds are slightly breezy between 6-15 mph through the day.

KEY MESSAGE 2...

The latest 12z model guidance is starting to come into better agreement on the forecast details Monday night into Tuesday as a wave of low pressure moves slowly east across Pennsylvania. Clouds should increase Monday evening, with rain developing over NE PA during the mid to late evening hours. The steadiest rain will be in and around the Wyoming valley area, continuing into the overnight hours (where around a half inch is expected by morning). The rain looks to extend northward very close to the NY/PA border, with the exact northward extent still uncertain...but probably close to the Rte 17/I-86 corridor. Some periodic light rain continues into Tuesday morning, while gradually shifting south and west as high pressure advects in drier air from the northeast. Other than a few lingering showers or sprinkles over the Wyoming Valley the area should dry out by Tuesday afternoon; but clouds will linger in NE PA. Further north across the rest of Central NY confidence is increasing that it will remain dry for this time period, with mostly cloudy conditions Monday night becoming mostly sunny Tuesday afternoon. Temperatures will vary considerably, with cool overnight lows in the 40s Monday night in most locations. On Tuesday it looks to range from the mid-50s to low 60s in NE PA, with low to mid-60s for most of Central NY (outside of the higher elevations, which may stay in the 50s). Winds remain out of the northeast for this timeframe, generally between 5 to 15 mph.

There will be a sharp south to north gradient in rainfall amounts Monday night into Tuesday. Expect potentially between 1 to 1.5 inches along and south of I-80 in NE PA, fading to a third of an inch near I-84 and less than a tenth of an inch for the NY/PA border region (Twin Tiers). This is still a tricky forecast when it comes down to pinning the exact rainfall amounts and locations...so please check back as we monitor and adjust for the latest model trends.

KEY MESSAGE 3...

There is now high confidence in the latest guidance that an expansive surface high and subtle rising 500mb heights will be over the area Wednesday into Thursday. This should provide dry, and partly to mostly sunny conditions both days for the entire forecast area. Low level winds remain out of the east-northeast so temperatures look to remain seasonable in the 60s for highs. Overnight lows could be chilly, in the upper 30s to mid-40s in most locations. Can't rule out some patchy frost for the normally colder locations if skies can clear and wind decouple enough.

KEY MESSAGE 4...

A complex weather pattern sets up late in the week into next weekend. A piece of upper level energy dives south out of Quebec into the local area. At the same time a closed upper level low drifts east across the Ohio Valley and off the Mid-Atlantic coast. By Friday morning these feature could phase/combine into a stronger mid and upper level low off the Delmarva region. Surface cyclogenesis occurs with a deepening low taking shape. There remains much uncertainty on where this low could ultimately develop and track. There is some potential for wrap around rain to push back to the west into some of our eastern forecast zones Friday into Saturday. Again, a lot of uncertainty and differences remain in the deterministic guidance. Ensembles means are beginning to pick up on this low development though, and this possible coastal low will certainly be tracked closely over the coming week.

AVIATION /19Z SUNDAY THROUGH FRIDAY/

Showers have moved through the TAF sites though pockets of drizzle will be possible this afternoon. Restrictions continue to bounce around for all terminals. Guidance does not handle conditions that change hour-by-hour well, so confidence is low on how much longer the low visibilities will stick around. Some clearing tonight will be possible at ELM, ITH, SYR, and RME which will lead to VFR conditions briefly. Low stratus and fog are then expected at all terminals early Monday morning. Winds may become too strong for fog to development, so confidence is once again low with the timing and category of visibility restrictions. VFR conditions are expected to return by Monday afternoon.

Winds will be variable this afternoon before finally settling out of the north tonight. Sustained speeds will be between and 10 kts. Gusts up to 15 kts will be possible at BGM, ELM, and ITH.

Outlook...

Monday Night and Tuesday...Possible restrictions with showers, especially NE PA and perhaps the NY Southern Tier terminals.

Wednesday and Thursday...Likely VFR most of the time.

BGM WATCHES/WARNINGS/ADVISORIES

PA...None. NY...None.