textproduct: Binghamton

WHAT HAS CHANGED

PoPs and QPF were increased for the Monday night into Tuesday timeframe for areas along and north of the NY Thruway Corridor due to lake effect rain showers that are expected to develop.

KEY MESSAGES

1) A broad upper level low moving southeastward into the area tonight into Sunday is expected to lead to unsettled weather into early next week.

2) High pressure builds in for a brief lull in wet weather Wednesday, then additional showers and thunderstorms are expected to return Thursday into Friday.

DISCUSSION

KEY MESSAGE 1...

A broad upper trough will be setting up across the eastern U.S. this weekend with an upper low dropping southeastward out of Canada and becoming a closed low over the Great Lakes on Sunday. A surface low is expected to develop over the eastern Great Lakes region as well tonight into Sunday. These features are expected to be the main drivers of our weather into early next week.

Conditions have remained relatively stable this afternoon. This, combined with the lack of a forcing mechanism has allowed for the area to remain rain-free for now. Can't rule out an isolated shower later this afternoon, but otherwise most of the rain showers and isolated thunderstorms will hold off until tonight.

The surface low over the eastern Great Lakes is expected to lift north-northeast, passing just north and west of the area Sunday. As it shifts north toward the Ontario/Quebec border, it will drag a surface cold front across the region Sunday. Latest trends have this cold front moving through in the morning, which keeps the greatest chance of showers and thunderstorms during that timeframe. As the winds shift to more westerly following the passage of the front, isolated to scattered showers and thunderstorms may develop Sunday afternoon (greatest chance in Central NY), but coverage of these should be rather limited.

By Monday, the 500mb closed low moves overhead. This combined with with cooler air aloft moving over the Great Lakes with 850mb temps falling to +6C to +10C and a west to northwest flow in place, additional lake effect/lake enhanced rain showers are expected to develop. As the upper low lifts NE Tuesday, there could be a few lingering lake effect rain showers downwind of Lake Ontario near and north of the NYS Thruway before drier conditions return.

Near to slightly below normal temperatures are expected this weekend before turning noticeably cooler Monday with the upper low overhead with highs in the 60s and lower 70s.

KEY MESSAGE 2...

High pressure briefly builds in Tuesday night into Wednesday with dry conditions. Then Thursday into Friday, a similar pattern to this weekend will likely set back up with a potential low moving up from the south and another upper trough pushing in from the west that would bring the chance for additional showers and thunderstorms. As of now these features appear to be more progressive and look to move out of the region by next weekend.

AVIATION /18Z SATURDAY THROUGH THURSDAY/

Lowering cloud bases and CIGs move in from the south later this evening, with MVFR to IFR conditions expected at all terminals. IFR CIGs are forecast to spread north over much of the forecast area late tonight and early Sunday morning. There will also be increasing chances for showers and isolated thunderstorms heading into tonight and Sunday morning as a frontal boundary approaches. These could bring occasional IFR visibility restrictions and gusty/erratic wind gusts at times.

Outlook...

Sunday...Showers and potential thunderstorms with associated restrictions.

Monday...Scattered showers at the Central NY terminals with associated restrictions possible.

Tuesday through Thursday...Mainly VFR.

BGM WATCHES/WARNINGS/ADVISORIES

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