940 FXUS61 KBGM 061438 AFDBGM AREA FORECAST DISCUSSION National Weather Service Binghamton NY 1038 AM EDT Mon May 6 2019 .SYNOPSIS... Skies will become partly to mostly sunny as high pressure briefly takes control of our weather. A cold front will drop through the area on Tuesday bringing showers and possibly a thunderstorm. High pressure will return for Wednesday before wet weather moves back into the area on Thursday and Friday. && .NEAR TERM /THROUGH TUESDAY/... 1035 AM UPDATE...cloud erosion has hit a temporary halt right at the I-81 corridor keeping the eastern zones in the gloom. Drier air over western NY and the strong May sun should continue to mix out the edges of the clouds so will continue to forecast slow clearing from west to east this afternoon. Adjusted the timing on the clouds and on the temps with this update. Previous discussion continues below. Scattered light rain continues across parts of central New York early this morning under a weak inverted trough. This activity will continue moving east and push out of the western Catskills during the mid morning hours. Weak mixing and persistent damp weather has brought patchy fog to the region along with a low overcast. After sunrise, ridging from the surface through 700mb will bring partly to mostly sunny skies to the entire area from mid morning in the west to early afternoon in the Catskills. Highs will range from the mid 60s in the Catskills to lower 70s in the valley areas of the southern tier. Tonight/Tuesday...Tonight will be dry through at least midnight as surface high pressure moves to the east coast. A cold front dropping through eastern Canada will bring a chance for showers across the northern forecast area toward daybreak. This cold front will drop through the region during the mid morning hours in the northern forecast area to mid afternoon hours in the Wyoming valley. Will carry likely POPs along the frontal boundary along with a chance for thunderstorms from the southern tier south through northeast Pennsylvania. Models continue to show several hundred joules of instability in the above mentioned area as atmosphere will have some time to destabilize before frontal passage. Severe weather parameters are not very exciting just a chance for generic thunderstorms. Highs will range from the upper 50s in the north to lower 70s in the Wyoming Valley. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... A frontal boundary will be dropping well south of the area by Tuesday evening, however a lingering shower or two cannot be ruled out across our NE PA zones into the first portion of Tuesday night. Clouds will be gradually decreasing from north to south as a Canadian high builds in. Light north winds, less than 5 mph and chilly temperatures expected. Temperatures will bottom out between 35-40 in Central NY and 39-46 for much of NE PA by daybreak Wednesday. A surface high remains in place north of Lake Ontario through the day Wednesday, as upper level heights also rise through the day. Northerly gradient, with surface winds 6-12 mph will keep dry, Canadian air advecting into the region in the low levels of the atmosphere through the day. Therefore, the daylight hours are now forecast to feature dry weather, under partly sunny skies. By late in the afternoon or evening a warm frontal boundary approaches from the southwest, and could bring an isolated shower by sunset. Seasonable temperatures, with highs in the upper 50s to lower 60s in central NY, and low to mid 60s in NE PA. Wednesday night surface winds turn easterly, then southeast and eventually southerly late at night as the previously mentioned warm frontal boundary lifts north. As the front lifts north still think there will be some showers around, especially for our northwestern zones...but overall rainfall amounts will be light in this period; less than a tenth of an inch. In fact, the latest 00z ECMWF actually keeps our CWA dry through 12z Thursday, as the frontal runs into upper level ridging that will still be overhead. Therefore, did not want to go too high with PoPs/ QPF for this period, and mainly held them at chance or lower (except low end likely for the NW Finger Lakes region). Still chilly north and east, with lows in the upper 30s to low 40s here...milder across NE PA with lows in 40s to near 50. By Thursday the low pressure system moves northeastward into lower Michigan, with a series of warm frontal boundary bisecting our area. There will be added isentropic lift along these boundaries and moisture will continue to increase as dew points rise and the entire column saturates. Therefore, periods of moderate rain are expected basically from the NY/PA border north...with showers also still likely down into the northern tier of PA. PoPs taper back to high end chance for the Wyoming Valley region as the best lift and jet support remain north. Rainfall amounts during the day Thursday could be around a half inch for north-central NY, around a quarter inch for the southern tier, and less than a quarter inch in NE PA. Breezy southeast winds 8-15 mph...temperatures remain cool east, with highs only reaching the low to mid 50s east of I-81....and the mid-50s to low 60s west. The atmosphere remains very stable through the day, so no thunder is expected. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... Active, very wet weather to start the extended period, then drying out some for at least part of the weekend. Low pressure system slowly moves into souther Ontario Thursday night and Friday...dragging a very slow moving cold front across our region. The system will be riding a broad southwest flow aloft with moisture access to the Gulf of Mexico. Periods of rain, some possibly heavy at times continue across the region. Very late at night instability starts to increase across western NY and PA as our area starts to enter the true warm sector of this system. Therefore cannot rule out a rumble of thunder late at night. PWATS and dew points rise later Thursday night and into the day Friday reaching 1.30 inches and the upper 50s to lower 60s, respectively. A wedge of instability moves across the region just ahead of the cold front... with latest guidance still indicating possibly upwards of 500-800 J/Kg of MLCAPE. This will combine with deep layer shear between 50-60 kts to produce a chance of thunderstorms for most the area on Friday. These storms could produce heavy downpours and perhaps other hazards such as gusty winds or even isolated hail. Overall it's still too early to know how strong the convection could be, especially if it trends towards a slightly earlier frontal passage, but this will need to be monitored...will mention the heavy rain potential in the HWO for now. Our recent wet pattern pre- conditioning soils will not be helpful in terms of ability to absorb this additional rainfall which could lead to some potential flooding. Mild with lows 45-55 and highs 65-75. The cold front sweeps east of the area by Friday evening, with drier weather expected Friday night and Saturday as another high pressure system approaches. Seasonable with lows in the 40s and highs in the upper 50s to 60s. Uncertainty increase by the end of the period, as the next upper level trough approaches by Sunday. For now have a chance of showers in the forecast with increased cloud cover; temperatures remain steady. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... Alternate Required/IFR conditions will improve this morning to VFR between 13Z-15Z with just scattered cumulus expected this afternoon. Overnight, an approaching cold front will bring increasing mid/low VFR ceilings into the terminals. Winds becoming northwest around 5-8 knots today then light and variable overnight. Outlook... Tuesday...Chance of restrictions as another cold front with rain showers drops across the area. Wednesday...Mainly VFR. Thursday...Restrictions expected in rain. Friday...Chance of rain and thunderstorms. Flight restrictions likely. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...DGM/RRM NEAR TERM...DGM/RRM SHORT TERM...MJM LONG TERM...MJM/MDP AVIATION...RRM