textproduct: Binghamton

WHAT HAS CHANGED

No significant changes to the forecast. Still anticipating some patchy fog and/or frost tonight and again Thursday night with the active and relatively cool pattern continuing.

KEY MESSAGES

1) A cool and moist pattern sets up tonight and continues through Thursday night with the potential for patchy frost and fog.

2) The next batch of rain will arrive late Friday night and continue into Saturday afternoon.

3) A cold front sweeps through the region on Sunday after a brief warm up which could trigger more scattered showers and a few thunderstorms. Cooler air settles in early next week.

DISCUSSION

KEY MESSAGE 1...

The persistent rain that has been moving through the region since last night is finally exiting the area to the east. Approximately a half to one inch of rain has fallen in the last 24 hours. As the rain and deep moisture move out of the region, a cooler and drier air mass will take its place starting tonight and continue into Friday.

A fairly widespread stacked low pressure system over the Hudson Bay is in place and is acting to pull southward a relatively cold air mass from northern Canada across the Great Lakes and into the Northeast. The colder air...850mb temperatures around -2 to -3 deg C...arriving tonight on the heels of the rain will allow for favorable conditions to produce patchy fog and/or frost in central NY. Surface temperatures will fall into the mid 30s in NY and into the upper 30s and lower 40s in ne PA. There appears to be a window where low clouds and fog are likely this afternoon and evening and into the early overnight hours before the drier air moves in later tonight and mixes out the moisture enough to produce slightly more cooling and eventual frost formation. Confidence is moderate to high that there will be patchy or isolated locations of frost, but not enough confidence for widespread frost in our active Finger Lake zones to issue a Frost Advisory.

High pressure builds in on Thursday and conditions remain quiet with another period of potential frost. The threat looks to be slightly higher Thu night/Fri morning with a longer duration of clearing which will lead to more cooling. Temperatures are expected to drop into the lower to mid 30s for much of cntrl NY and into the mid to upper 30s in ne PA. The potential for frost will likely be higher and Frost Advisories will likely be needed for the Finger Lakes and the Wyoming Valley.

KEY MESSAGE 2...

A series of short waves will round the bottom of the parent long wave trough Thursday night into Saturday, with the initial wave swinging through Friday sometime between late morning and late afternoon and the more potent wave riding across the region Saturday. There is still quite a bit of uncertainty regarding the north-south track of this wave with some members of our model guidance keeping the bulk of the rain to our south, while the majority of the members bring the rain right through our forecast area. Will keep with the consensus and the higher PoPs on Saturday. The amount of rain looks to be on the lighter side and relatively unimpactful...with generally around a tenth to a quarter of an inch...and the potential for up to half an inch.

KEY MESSAGE 3...

A solid return flow sets up on Sunday with temperatures climbing into the upper 60s and lower 70s, but dew point values only in the upper 40s and lower 50s. This is really going to limit the amount of solar heating and destabilization in the boundary layer that will occur Sun afternoon, and thus cut into the threat for thunderstorms. The counteracting feature will be the strongly forced trough rotating through the region that will supply the necessary forcing for ascent to support vertical motion and a few potentially strong thunderstorms. Will hesitate to mention any severe storms at this point given the very dry nature of the boundary layer, but it obviously cannot be ruled out completely given the strong dynamics.

Behind the front, the beginning of the week will return to below normal temperatures with highs in the 50s and lows in the 30s and 40s. This pattern looks to stay in place through most of the week with a potential warm shift by the following weekend.

AVIATION /00Z THURSDAY THROUGH MONDAY/

Steady rainfall has mostly cleared, though some drizzle may linger into the evening along with Fuel Alt to IFR ceilings. There is potential for ceilings to improve a bit to VFR before coming back down. Fog is expected to develop tonight, with the highest confidence at ITH/ELM/BGM. Confidence remains lower regarding exact timing and how restrictive conditions become, largely dependent on when winds calm.

Some clearing is possible overnight as clouds scatter out with high pressure building into the region, though uncertainty remains in how quickly this occurs. If skies clear out more efficiently, fog potential will increase. After any morning fog dissipates, VFR conditions are expected through the remainder of the TAF period.

Outlook:

Thursday afternoon through Thursday night...Mainly VFR; isolated afternoon showers possible around the CNY terminals. Friday night through Monday..Cool and unsettled period with intermittent chances for showers and restrictions.

BGM WATCHES/WARNINGS/ADVISORIES

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