Marine Weather and Tide Forecast for Minetto, NY

KEY MESSAGES
1) Unsettled, significantly colder weather will continue through Monday night with rain and/or snow showers. Showers today could contain a few rumbles of thunder and graupel.

2) After the cold start, another day to day warming trend is expected throughout the week.

DISCUSSION
KEY MESSAGE 1...Unsettled, significantly colder weather will continue through Monday night with mixed rain and/or snow showers. Showers today could contain a few rumbles of thunder and graupel.

GOES Water Vapor imagery this morning indicates a deep longwave trough extending down across the Mississippi Valley from near southern Hudson Bay and gradually trudging eastward. Over the next couple of days this trough will drag a Canadian Polar airmass across the Great Lakes while supporting chances for showery precipitation.

Colder temperatures...

Behind a strong cold front, 850mb temps of -4C to -7C this morning will bottom out around -13C by Monday morning. By comparison, 850mb temps on yesterday morning's 12z KBUF sounding were near +12C. This will translate to starkly different surface temperatures compared to the past week, with daytime highs today in the 40s, falling to the 30s to low 40s for Monday. Nighttime lows will be even colder, with widespread 20s and even teens at the higher elevations, especially Monday night.

Precipitation types and chances...

As of 815 am...area radars show a widespread swath of pcpn continuing from portions of the Finger Lakes eastward across the North Country...much of which is falling in the form of snow per regional surface obs and webcams, with the latter sticking and resulting in some accumulation on grassy surfaces, more so across the higher terrain east of Lake Ontario. Have bumped up PoPs and indicated more snow than rain across our central/ eastern zones over the next couple of hours...with some accumulations of 1-2" likely on grassy/elevated surfaces across the higher terrain of the North Country before this winds down later this morning.

The back edge of the upstream trough axis will not finish crossing the eastern Great Lakes until sometime later Monday. Until then, weak but steady broad scale height falls/DPVA, lake enhancement, and upslope effects will support on and off chances for showers, mainly south of Lake Ontario.

Through early this evening, thermal profiles should favor plain rain though some wet snow at times cannot be ruled out. 850mb temps will hover around either side of -6C, though the strong mid/late April sun angle will warm the low levels to promote melting of hydrometeors during the daylight hours. This said, model soundings south of Lake Ontario indicate a small dry layer below 900mb, which introduces some uncertainty in the potential for wet bulb cooling causing more wet snow to reach the ground in spots. Speaking of which, diurnal heating with steepening mid-level lapse rates may support 100-200J/kg of MLCAPE this afternoon, particularly where low- level convergence is favored from the Niagara Frontier to the Finger Lakes. With very low freezing levels (~2kft), could see this environment sparking a few thunderstorms and/or graupel showers.

The deepening colder air and lack of daytime warming allows for snow to become the dominant ptype tonight. Given how warm the ground still is, minor accumulations under an inch should be generally limited to grassy or elevated surfaces. Drier air begins to work in late tonight through Monday as the trough axis moves through, which will gradually taper off the precipitation chances. Still, widely scattered nuisance snow showers may persist well into the afternoon.

KEY MESSAGE 2...After the cold start, another day to day warming trend is expected throughout the week.

High pressure ridging at all levels will crest east of the forecast area early Tuesday, allowing for a return to southerly flow. This will cause temps to initially recover back to near seasonal averages with highs in the 50s to upper 40s. Behind a weak passing system Tuesday night, an even stronger amplifying ridge will build into the Great lakes which will cause temps to continue trending upwards each period, with well above average temps increasingly likely by late week.

AVIATION /12Z SUNDAY THROUGH THURSDAY/
Numerous showers will taper off from west to east across western and north- central NY this morning. Rain may mix with snow briefly before ending. VFR/MVFR conditions are expected across the region this morning.

Additional showers are expected to develop today. Daytime heating and steepening low-level lapse rates will result in a slight chance of thunder across far western NY. Can't rule out small hail in any thunderstorms. VFR/MVFR flight conditions are expected this afternoon.

A secondary cold front will move through the region tonight. A round of snow showers are likely across western and north- central NY this evening and MVFR/VFR conditions are expected.

Outlook...

Monday...Improvement to VFR with leftover scattered lake effect/upslope snow showers ending.

Tuesday...Mainly VFR with a chance of rain showers.

Wednesday and Thursday...Mainly VFR.

MARINE
Light westerly winds will continue across the eastern Great Lakes this morning.

Cold air deepening across the lakes and an increasing pressure gradient will cause westerly winds to freshen today. Winds will turn northwesterly tonight and remain elevated into Monday morning with speeds near 20 knots. This will support a period of small craft headlines on the eastern half of Lake Ontario and Lake Erie.

BUF WATCHES/WARNINGS/ADVISORIES
NY...None.
MARINE...Small Craft Advisory until 11 PM EDT this evening for LEZ040- 041.
Small Craft Advisory from 11 PM this evening to 2 PM EDT Monday for LOZ043.
Small Craft Advisory from 2 PM this afternoon to 2 PM EDT Monday for LOZ044-045.