419 FXUS61 KBGM 111052 AFDBGM AREA FORECAST DISCUSSION National Weather Service Binghamton NY 652 AM EDT Sat May 11 2019 .SYNOPSIS... High pressure with dry air will build in today. Low pressure with more rain will start Sunday. && .NEAR TERM /THROUGH SUNDAY/... 630 am update... Minor changes. In Steuben County temperatures and dewpoints dropped a few degrees below forecast. Upped cloud amounts especially in the northeast where it will scatter last. 3 am update... A break in the wet weather today as high pressure over the western Great Lakes moves east today into southern Quebec tonight. Higher clouds are pushing southeast but stratus continues over the CWA. Clear skies in western NY will push east as the low level flow off Lake Ontario weakens and warmer air moves in aloft this afternoon. With 850mb temperatures only rising into the plus single digits, max temperatures will struggle into mostly the upper 50s and lower 60s. Tonight will be partly cloudy to start allowing temperatures to fall into the upper 30s and lower 40s. With light to calm winds, isolated frost may occur in the coldest valleys of the twin tiers north to Oneida County. This would be around midnight before the clouds and winds increase some after that. As a surface low and warm front move northeast tonight, rain returns starting in the south late tonight. The low will stay south of the area as it passes through Maryland Sunday afternoon. By daybreak Sunday rain will be in the Central Southern Tier of NY and most of NEPA. Midday Sunday it stalls near an Auburn to Oneonta line. Rainfall will be up to half an inch with the highest amounts in NEPA and Steuben County NY. With the rain and clouds, temperatures will be below normal. Highs in the mid 50s for Syracuse, Utica, Rome at the high end to around 50 for the rest of the CWA. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... A very damp, cool (and dreary) period is in store early in the week. The setup initially for Sunday night consists of a stalled frontal boundary to our south across the Mid-Atlantic region and an inverted surface trough that extends northward into Lake Erie. Looking aloft, a potent shortwave disturbance associated with an Alberta Clipper is forecast to dig around the base of the large-scale trough and start to close off as it approaches from the west by Sunday night. A secondary surface low is expected to develop near the Mid-Atlantic coast on Monday as the upper low continues to deepen/close off and significant height falls reach the eastern seaboard. Meanwhile, the primary surface low/inverted trough to our west will weaken as it drifts eastward and transfers its energy to the coastal low. The coastal low will eventually become vertically stacked near the New England coast by Tuesday. Forcing for ascent ahead of the closed low and across the baroclinic zone positioned to our south supports categorical PoPs on Sunday night for the Finger Lakes, Southern Tier of NY, and NEPA. There is some uncertainty regarding how far northeast the precip shield makes it owing to the residual influence of high pressure that will be retreating to our northeast. Accordingly, kept PoPs below categorical for our northeastern zones (NY Thruway corridor and northwestern Catskills) but did not buy quite buy into the outlier solutions like the 00Z NAM that kept these locations dry Sunday night. PoPs are categorical (near 100 percent) for Monday across the entire forecast area with the closed low nearby to our west and a TROWAL forming on the poleward side of the coastal low both providing sources of deep, organized lift overhead. Will have to monitor the evolution of the dry slot on Monday night- far southern zones in NEPA could potentially see a break in the rain if the dry slots advances far enough north. Wraparound precip will linger into Tuesday on the northern side of the closed low (especially C NY). Not really expecting flooding issues at this point with rainfall amounts Sunday night-Tuesday generally 0.50-0.75". A lack of instability north of the stationary front should preclude heavier rainfall rates from occurring. Easterly winds around the retreating Canadian high will keep the cool maritime airmass locked in through the period. Under this setup, daytime highs should be well (15-20 degrees) below normal and nighttime lows near or slightly (0-5 degrees) below normal (owing to the cloud cover). && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... Tuesday night and Wednesday...A brief respite from the rain as the upper low finally pulls away from the Northeast U.S. and high pressure builds in. This anomalously cold airmass moderates a bit on Wednesday as warmer air underneath the ridge shifts overhead. Assuming partial sunshine breaks through by the afternoon, highs in the low to mid 60s should be attainable. Wednesday night through Friday...A couple of northern stream clipper systems rotate southeastward across the Great Lakes and Northeast late in the week. There is considerable spread among the guidance as models seem to be having difficulty predicting the degree of interaction between these two systems: Do they phase into a closed low similar to what's happening early in the week or do they remain two separate, weaker systems?. PoPs were kept low (20-40 percent) given the high forecast uncertainty. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... 7 am update... MVFR cigs up to 14z at ITH/BGM/RME. At that point they will join the rest of the sites at VFR. VFR will continue into the overnight. At that point light rain starts to move in starting at 06z at AVP. At 09z rain gets into south central NY. At the same time cigs fall to MVFR there and at AVP. SYR/RME will stay dry and VFR through 12z Sunday. Northwest winds around 10 kts through the afternoon. This evening light northeast or variable winds. Late tonight east winds at 5 to 10 kts. Outlook... Sunday through Tuesday...Restrictions expected in rain. Wednesday...Any restrictions from lingering showers improving throughout the day. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...TAC NEAR TERM...TAC SHORT TERM...JRK LONG TERM...JRK AVIATION...TAC