Marine Weather and Tide Forecast for Eggertsville, NY

KEY MESSAGES
1) Cooler weather, with scattered snow showers and gusty winds are expected today.

2) Impactful snow possible for the Eastern Lake Ontario region late Friday morning through Saturday afternoon, especially over the higher terrain of the Tug Hill Plateau and western Adirondacks.

3. Windy conditions Friday through much of Saturday, with the strongest winds expected from Finger Lakes region westward.

4) Active pattern continues late this weekend into the first part of next week as another dynamic system brings the possibility for rain, snow, and strong winds, along with a return to winter-like temperatures for western and northcentral NY.

DISCUSSION
KEY MESSAGE 1...Cooler weather, with scattered snow showers and gusty winds are expected today.

An upper level trough centered over the Upper Great Lakes region and Mid-West early this morning will move across the eastern Great Lakes region today. A surface low is located over southern Quebec with an associated cold front just east of the forecast area. Cold air advection and drier air are moving into the region from west to east this morning. Lingering showers will change to snow showers across western NY this morning, however little to no accumulation is expected.

Cold air aloft with 850mb temperatures around -11C will move across the region today. Much cooler weather is expected today with temperatures in the 20s to low 30s around daybreak, and highs in the low to mid 30s, 20s on the Tug Hill. Low-level lapse rates and an uptick in upstream moisture will support widely scattered snow showers across western NY this afternoon. No accumulation is expected.

A broad area of 30-40 knots between 925-850mb will reside across the region this morning. Cold air advection and steepening lapse rates will support gusty, northwest winds 30 to 40 mph this morning, with the highest gusts near the lakeshores. Winds will diminish through the day.

KEY MESSAGE 2...Impactful snow possible for the Eastern Lake Ontario region late Friday morning through Saturday afternoon, especially over the higher terrain of the Tug Hill Plateau and western Adirondacks.

A compact, but strong surface low will track from the western Great Lakes Friday morning to far southern Quebec by Saturday morning bringing another round of precipitation. Precipitation will quickly overspread the area through the first half of Friday morning, starting off as a low impact wet snow across much of western NY, however warming temperatures will force a changeover to rain across the lower elevations, with a rain/snow mix possible across the higher terrain as surface temperatures climb well into the 30s and even some lower 40s. As the main precip shield moves into the Eastern Lake Ontario region later Friday morning into the afternoon, expect snow to start there as well, mixing with or changing over to rain across the lower elevations during the afternoon, with p-type remaining all snow across the Tug Hill and western Dacks where several or more inches may accumulate by late in the day. A cold front will move east across the area late Friday and Friday evening with another shot of colder air moving in behind the front. 850mb temps will fall into the -10C to -12C range Friday night. Wraparound moisture will help contribute to lake enhanced and upslope snows east of Lake Ontario, with an additional several or more inches possible across the Tug Hill and western Dacks Friday night through early Saturday afternoon before tapering off as the low pulls away from the region. Much lesser snow amounts are expected across the lower elevations east of Lake Ontario, with only minor accumulations expected elsewhere. Snow showers will taper off Saturday as deeper moisture is stripped away, with minor additional accumulations possible east of Lake Ontario. With impactful snows expected across the higher terrain east of Lake Ontario, a Winter Storm Watch has been issued for Lewis, Jefferson, and Oswego counties from Friday morning through Saturday afternoon.

KEY MESSAGE 3...Windy conditions Friday through much of Saturday, with the strongest winds expected from Finger Lakes region westward.

A compact, but strong surface low will track from the western Great Lakes Friday morning to far southern Quebec by Saturday morning bringing another round of strong winds. This system will drag a very strong 70 knot+ LLJ over the Ohio Valley and western Lake Erie basin by daybreak Friday, then into far western NY Friday morning. Of note, the system will weaken as it moves out of the western Great Lakes to far southern Quebec, leading to a weakening of the LLJ some 10-15 knots, as well as being within the WAA regime in advance of the system's cold front. Through Friday morning and potentially into the early afternoon, this should limit the magnitude of the strongest gusts. The exception will be over the typical downslope areas off the Chautauqua Ridge, where some localized warning level gusts look possible closer to the Lake Erie shoreline in Chautauqua County. Near warning level WSW to W gusts look possible just east of the lake Friday afternoon into Friday night in the CAA regime in the wake of the cold front. With this in mind, a High Wind Watch has been issued for Chautauqua County from Friday morning through late Friday night.

Once the cold front moves east through western NY mid to late afternoon, winds will become southwesterly while the residual LLJ remains overhead. Now within the CAA regime, deeper mixing will occur and funneling down the long axis of Lake Erie may lead to a period of 40-50 mph+ gusts across the Niagara Frontier and east of Lake Erie (especially immediately east of the lake and across the hilltops). As the LLJ continues to slowly weaken Friday night, it may still be strong enough to produce some 45+ mph gusts immediately downwind of Lake Ontario as it slides further east. The LLJ will slide east Saturday with winds gradually coming down through the day.

KEY MESSAGE 4...Active pattern continues late this weekend into the first part of next week as another dynamic system brings the possibility for rain, snow, and strong winds, along with a return to winter-like temperatures for western and northcentral NY.

As the active pattern continues across the northern CONUS, a stronger push of colder air will dig a deeper, larger scale trough across the eastern half of the CONUS for the start of the new work week. This larger scale system will have an expansive warm sector with a deep, warming southerly flow that will drive temperatures back above normal Sunday as the warm front lifts north with a swath of precipitation along and ahead of the boundary. Additional precipitation will accompany the system's cold front on Monday, with areas of lake effect snow showers developing under a cold west to northwest flow in the system's wake as 850mb temperatures plummet down into the -15C to -20C range (very cold for this point in the season). Latest model consensus continues to show a very strong LLJ associated with a deepening surface low moving north-northeast from eastern Michigan Sunday night into central Quebec Monday night that will need to be monitored for strong wind potential. Plenty of uncertainty remains with regard to the track of this system, which will have ramifications to p-type and strength of the winds across the area for Sunday through Monday night.

AVIATION /09Z THURSDAY THROUGH MONDAY/
A cold front has moved east of the region this morning. A few snow showers are possible this morning. MVFR conditions will continue across a majority of the region with IFR conditions across the higher terrain today. IFR conditions across the higher terrain is expected to improve to MVFR later this morning.

Cold air advection and steepening low level lapse rates will support gusty, northwest winds today. Wind gusts up to 40 knots are possible near the lakeshores this morning. Winds will diminish this afternoon into tonight. Widely scattered snow showers may develop across western NY today. A brief reduction in visibility is possible, however confidence is low.

Outlook...

Friday...Areas of MVFR/IFR with snow developing and then changing to rain across lower elevations. Windy.

Saturday...Mainly VFR with a slight chance of a snow showers. Windy.

Sunday.. MVFR/IFR with snow changing to rain. Windy.

Monday.. MVFR/IFR with rain changing to snow. Windy.

MARINE
Low pressure is located across southern Quebec this morning, with a strong cold front near the Hudson River. Strong, westerly winds will continue on the Lakes, with Gales on Lake Ontario this morning.
Winds will gradually diminish later today.

A series of Low pressure systems will cross the Great Lakes Friday through early next week, with multiple rounds of Gale Force winds.
Please note, most, if not all of the Lake Erie nearshore waters continue to be ice covered. Waves have been omitted from the forecast.

HYDROLOGY
Rainfall amounts of three quarters of an inch to an inch and a half were observed over the last 24 hours. Additional rain amounts of less than a tenth of an inch are expected this morning. Warmer weather over the last few days has resulted in snow melt, with a deep snow pack in place across the Black River basin. Significant snowpack and SWE remains across the higher terrain of the Tug Hill Plateau and western Adirondacks.

Rivers will continue to rise east of Lake Ontario from ongoing snowmelt and rainfall. The Black River will likely flood starting today, with flooding continuing through the weekend on this slow responding river. The latest forecast shows the Black River at Watertown reaching the high end of Minor Flood Stage, but moderate stage is possible by the weekend, which would result in more significant impacts.

Flooding is also possible on many other rivers that drain the Tug Hill Plateau and western Adirondacks tonight through the end of the week.

BUF WATCHES/WARNINGS/ADVISORIES
NY...Winter Storm Watch from Friday morning through Saturday afternoon for NYZ006>008.
Flood Watch until 5 PM EDT this afternoon for NYZ007-008.
High Wind Watch from Friday morning through late Friday night for NYZ019.
MARINE...Small Craft Advisory until 2 PM EDT this afternoon for LEZ020.
Small Craft Advisory until 5 PM EDT this afternoon for LEZ040-041.
Gale Warning from noon Friday to 4 AM EDT Saturday for LEZ040-041.
Small Craft Advisory until 2 PM EDT this afternoon for LOZ030.
Gale Warning until 11 AM EDT this morning for LOZ042>045- 062>065.
Gale Watch from Friday afternoon through Saturday morning for LOZ042-062.
Gale Watch from Friday evening through Saturday afternoon for LOZ043>045-063>065.