Marine Weather and Tide Forecast for Cortland, NY

KEY MESSAGES
1) High pressure will remain in control into early next week with temperatures trending warming. Hydro concerns decrease but some areas will need to be monitored.

2) Conditions turn colder for the second half of the week, supporting the return of wintry precipitation.

DISCUSSION
KEY MESSAGE 1...

High pressure will keep conditions dry through at least Tuesday.
West to southwesterly flow will continuously advect in warmer air into the region leading to a warming trend through the early part of the week. After 50s today, temperatures then climb into the 60s and even low 70s by Tuesday. Winds will also be slightly breezy on Monday as stronger flow aloft mixes down.

With clear skies and fairly calm winds, temperatures were bumped down below guidance for Monday and Tuesday nights. Then with sunny skies expected on Monday, temperatures were bumped up slightly using the NBM 50th percentile guidance.

Current river and stream rises are expected to peak today or tonight and then lower below action or flood stage by Tuesday. However, there remains quite a bit of snowpack in the Tug Hill Region.
Additionally, there is some snowpack over the Catskills and Upper Delaware Basin. While there are no additional points expected to reach action or flood stage, these areas will be ones to watch over the next couple of days for any sudden changes.

KEY MESSAGE 2...

Spotty rain showers will be possible Tuesday night as a warm front lifts north of the region. Shower chances will increase on Wednesday as an associated low pressure system tracks across the Great Lakes and into the Northeast. Elevated instability could support isolated thunderstorms as well. The low will then drag a cold front through the region early Thursday with rain changing to snow as T850 falls from around +12 deg C to -12 deg C. Accumulating snowfall will be possible as NBM probabilities are 15 to 25% for exceeding advisory criteria (4 inches) in portions of central NY. After a mild Wednesday, this colder air mass will bring down surface temperatures for the rest of the week.

A clipper system moves through the region late Friday into Saturday.
The track of this system will depend on what precipitation is observed and how far south precipitation will be. A more southern track would favor widespread precipitation and mainly snow. A more northern track would favor more rain with potential for snow and coverage would be more limited to central NY. Conditions then will dry out late Saturday as another system approaches the region for Sunday.

With the uncertainties of these systems, this forecast leans toward NBM guidance. A rain/snow mix covers part of the transition period of the cold front on Thursday. In addition, rain/snow mix is also forecasted for Friday until confidence increases on the track of the clipper system.

AVIATION /00Z MONDAY THROUGH FRIDAY/
High pressure building in across the area is expected to lead to VFR conditions through the 00Z TAF forecast.

Winds aloft will be increasing this evening and overnight and that can lead to the return of some borderline westerly LLWS at RME and SYR. The main window looks to be between 01Z-07Z for 30-35 knots of LLWS at 2000 feet AGL, but model soundings do show another increase in winds aloft toward the end of the forecast period that will be monitored.

Outlook:

Monday afternoon through Tuesday...VFR expected.

Wednesday...Rain expected with MVFR to IFR ceilings possible.

Thursday...Becoming cooler with rain showers and associated restrictions possible. Some wet snow can possibly mix in in at the northern terminals as temperatures fall.

Friday...A clipper system can lead to the chance of additional rain/snow showers and potential restrictions.

BGM WATCHES/WARNINGS/ADVISORIES
PA...None.
NY...None.