Marine Weather and Tide Forecast for Ithaca, NY

KEY MESSAGES
1) A gusty northwest flow, a few showers, and cooler temperatures is expected today.

2) High pressure brings sunny and seasonable weather for Thursday through Saturday.

3) Shower and chances for thunderstorms return to the forecast Sunday into early next week as the next upper level trough moves into the area.

DISCUSSION
KEY MESSAGE 1...

Upper level trough is rotating through the area today with much cooler 850mb temperatures advecting into the region. 850mb temperatures fall to around +8C this afternoon, which is just cool enough to create a limited lake effect response under the upper level trough (lake temperatures are near +23C). Therefore, expect scattered to broken clouds, and a few isolated showers today. The cold front slides off to the south and east this morning, with decreasing low level moisture as dew points fall into the 50s this afternoon. NW winds will be breezy, between 10-20 mph and high temperatures only reach the mid-60s to mid-70s, except upper 70s in the Wyoming Valley.

KEY MESSAGE 2...

High pressure begins building into the area from the west tonight.
Winds gradually diminish, becoming light and variable toward daybreak. Skies become mainly clear and areas of valley fog are likely to form overnight. It will be cool and crisp, with lows dipping down into the mid-40s to mid-50s areawide. Thursday sees high pressure build overhead, with mainly sunny skies. Low humidity continues and high temperatures are seasonably mild in the 70s. NW winds will be lighter, under 10 mph through the day. High pressure remains centered overhead Thursday night into Friday morning. This brings idea radiational cooling conditions once again. Lows dip down into the upper 40s to mid-50s with more valley fog expected.

Friday and Saturday look spectacular, with a zonal flow overhead and a gradual warming trend expected. Skies remain mainly sunny both days. Dew points stay low in the 50s, making it feel very comfortable outside. High temperatures will be in the upper 70s to mid-80s each day, with refreshing overnight lows in the 50s to low 60s forecast.

KEY MESSAGE 3...

The weather pattern will turn more active late in the weekend and into early next week as a broad upper level trough digs into the Northeast US. A new ridge develops over the western Plains by Sunday evening, with a shortwave dropping into the amplifying trough over the Northeast and Mid-Atlantic heading into Monday/Tuesday. Low level moisture and instability gradually increases Sunday, but especially heading into Monday and Tuesday. PWATs reach 1.50 inches by Sunday evening, and 1.75 inches by Monday evening as surface dew points also rise back into the 60s. Weak disturbances are expected to initiate scattered afternoon and evening thunderstorms each day.
A deeper, sharper trough may push into the area by Tuesday, increasing chances for showers and storms once again. The exact timing and details remain uncertain in the guidance this far out in time. High temperatures will be in the upper 70s to mid-80s Sunday, gradually dropping a few degrees early next week. Overnight lows look to be seasonable in the upper 50s to low 60s.

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/
A stratus deck of clouds is expected to bring widespread MVFR to Fuel Alternate ceiling restrictions for most of this morning, before returning to VFR by the late morning. KSYR and KRME may have these restrictions linger to the early afternoon with some lingering lake effect clouds present. There may even be a few isolated lake effect rain showers for KSYR and/or KRME this morning into the early afternoon, but confidence is not high enough to include in the TAFs at this time.

Northwest winds will become gusty later this morning into the afternoon (occasional gusts up to 20-25kts), before becoming light and variable this evening.

Outlook:

Thursday through Saturday...Mainly VFR; morning fog at KELM may result in restrictions.

Sunday...Scattered afternoon showers and/or thunderstorms may result in occasional restrictions.

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