Marine Weather and Tide Forecast for Niagara Falls, NY

NEAR TERM /THROUGH TUESDAY/
Surface high pressure over the eastern Great Lakes will ensure generally dry and quiet albeit frigid weather remains in place through tonight. Temperatures remain some 15 to 20 degrees below normal tonight.

The surface ridge axis will slide south and east of the Great Lakes and past the spine of the Appalachians tonight. Low level flow should begin to turn southerly and the overhead airmass modify a few degrees as a result. Despite this, it will still be cold enough with winds remaining light enough such that with the snowpack across the region, temps should easily slide back into the single digits tonight, with many spots across the interior falling below zero.
Otherwise, a thin plume of low level moisture over Lake Huron/Georgian Bay this afternoon will advect over Lake Ontario tonight. Combined with diurnal land-breeze convergence and some enhancement from the lake, this should cause a band of snow to form over the eastern end of the lake. Models generally depict this band having minimal inland extent, though areas closer to the lakeshores from roughly Oswego to Watertown may pick up a dusting to perhaps a localized inch or so.

Our stretch of quieter weather will be cut short Tuesday as a weakening clipper system tracks through the Upper Great Lakes, becoming further disorganized and diffuse as it moves east. The mid- level shortwave driving this system will make its way through the forecast area Tuesday afternoon into early Tuesday evening, with a warm frontal segment moving through from west to east. This will cause light snow to once again overspread much of the region, with lake enhancement developing northeast of the lakes (mainly Lake Erie) late in the day. A stiff southerly flow and subsequent downslope drying/upslope enhancement will should yield minimal accumulations by the evening (generally 0.5" or less) in the Genesee Valley and Finger Lakes, as well as on the leeward side of the Tug.
The higher amounts are expected across the Niagara Frontier including the Buffalo Metro and east of Lake Ontario across the southern slopes of the Tug Hill Plateau itself. Snowfall in these areas should still be minor with 1-3" by the late afternoon, though more will be on the way as lake effect bridges the short gap until the next synoptic system arrives...More on that in the short term below.

SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/
A complex forecast scenario will unfold Tuesday night through Wednesday night as a strong clipper low passes by just to our north.
There continues to be enough spread in model guidance to bring considerable uncertainty to the forecast in terms of snowfall amounts, precipitation type, and wind potential.

Tuesday evening, a brief window of lake effect snow northeast of Lake Erie and Lake Ontario ahead of the clipper system may bring a few inches of snow to the Niagara Frontier (including the Buffalo Metro area) and northern Jefferson County. Ongoing warm advection and lowering inversion heights ahead of the clipper will then shut down the lake response overnight.

The surface low will likely pass just north of the area across southern Ontario Wednesday. The GFS remains on the southern edge of the guidance envelope, taking a weaker low directly over Lake Erie and Lake Ontario. If this were to verify, there would be much less wind, and precip type would stay snow for a greater share of the event. This low is not favored climatologically, and will thus favor the farther north solutions seen in other guidance.

A period of snow will break out late Tuesday night through Wednesday morning in the warm advection and isentropic upglide ahead of the system. Assuming the farther north track verifies, lower elevations of Western and Central NY will then mix with, or change to rain for a time Wednesday, while the high terrain of the Southern Tier has a better chance of remaining all snow, and also the higher terrain east of Lake Ontario. The lower elevation rain would then change back to snow Wednesday evening as cold advection ramps up following the passage of the clipper cold front, with wrap around upslope snow and the start of lake effect adding some additional accumulations Wednesday night.

As far as accumulations go, the greatest snow amounts will be found across the higher terrain of the Tug Hill Plateau and western foothills of the Adirondacks where upslope will enhance QPF, and precipitation is most likely to remain all snow. This area may see totals of 8-12+" from early Wednesday morning through Thursday morning. These higher amounts would be limited to the high terrain, with the surrounding lower elevations of the eastern Lake Ontario region seeing 3-6" accumulations.

Across Western NY, total accumulations from late Tuesday afternoon through Thursday morning may reach the 3-6" range across the Niagara Frontier, and 4-9" across the higher terrain of the western Southern Tier. It is important to note that this will fall in 3 different batches, lake effect Tuesday evening, then warm advection snow late Tuesday night/early Wednesday morning, then wrap around snow and lake enhancement Wednesday night. Each of these phases will produce a few inches each. There will be melting during the day Wednesday when temperatures rise well above freezing, especially across lower elevations.

It will turn windy as this system moves through the area, but uncertainty with low track, intensity, and associated wind fields makes this a highly uncertain wind forecast. If the farthest north and strongest solutions of the NAM/HRRR verify, we can expect high end Wind Advisory or low end warning criteria gusts (55+mph)
northeast of Lake Erie Wednesday, while the farther south and weaker GFS solution would keep winds well below wind advisory criteria.
Most model solutions are weaker than the worst case NAM/HRRR, so for now we kept forecast wind gusts near the low end of advisory range northeast of Lake Erie but expect adjustments as the event nears and forecast certainty increases.

Thursday through Thursday night cold air will pour back into the eastern Great Lakes, supporting accumulating lake snows southeast of the lakes. There is typical uncertainty with wind direction and snow amounts at this time range, but in general expect the potential for moderate snow accumulations across the western Southern Tier off Lake Erie, and near or just east of Rochester to Oswego County off Lake Ontario.

LONG TERM /FRIDAY THROUGH MONDAY/
An active and cold pattern will continue Friday through early next week as a deep longwave trough remains over eastern North America.
This trough will continue to support below average temperatures and almost daily chances of snow from a combination of clipper systems and lake effect.

Model guidance continues to show considerable run to run differences with the synoptic setup through the weekend, which results in uncertainty with respect to lake effect band placement and intensity. In general, the very progressive pattern with frequent clipper shortwaves will likely prevent wind direction and band placement staying the same for any length of time. This will limit the potential for a large lake effect event, but also spread the wealth of accumulating snow to a multitude of different wind directions and locations over time.

AVIATION /00Z TUESDAY THROUGH SATURDAY/
Mainly VFR through early Tuesday afternoon as surface high pressure over the region gradually slides south and east to the Eastern Seaboard. Winds will generally remain under 5kts through tonight.

Land-breeze convergence and lake enhancement will likely cause patchy low VFR clouds to develop near the southern shoreline of Lake Ontario tonight, which will then move northward as the prevailing flow becomes southerly overnight. A localized band of snow is expected to be develop as well first in the vicinity of KFZY before it too moves northward. Inland extent should be limited, but will cover the possibility of a few snow showers reaching KART with a PROB30 group.

Southerly winds increase on Tuesday as a clipper system passes to the north of the region. Snow is expected to begin overspreading western NY from the west after about 16z, with VFR deteriorating to MVFR (cigs/vsbys) and IFR/LIFR (vsbys). Snow will reach north-central NY late Tuesday afternoon, with visibility possibly lowering to MVFR/IFR at KART. South- southwest wind gusts to 30kts will be possible at KBUF and KIAG after 18z.

Outlook...

Tuesday night...Mainly MVFR/IFR with snow potentially mixing with rain late in the night.

Wednesday...VFR/MVFR with rain and snow showers. Breezy, with gusts 20-30kts in many areas. Gusts to 35kts possible at KBUF/KIAG.

Thursday...VFR, with MVFR/IFR in scattered to numerous snow showers.

Friday and Saturday.. MVFR/IFR east of the lakes with snow showers likely. MVFR/VFR outside the main lake effect areas.|

MARINE
High pressure across the lakes this evening will shift southeast of the lakes tonight with light winds and minimal wave action.

The offshore flow will increase and begin to turn southwesterly as a weak system moves east of the Upper Great Lakes Tuesday, which will then be followed by a more potent area of low pressure on Wednesday.
Depending upon the track of the surface low, gales are possible Tuesday - Wednesday, with Wednesday the more favorable day, especially over Lake Erie. A Gale Watch was issued for the eastern end of Lake Erie Wednesday.

Westerly winds will subside below gale force later Wednesday night into Thursday, though remain elevated through the end of the week.

BUF WATCHES/WARNINGS/ADVISORIES
NY...Winter Storm Watch from late Tuesday night through Thursday morning for NYZ006>008.
MARINE...Small Craft Advisory from 7 AM Tuesday to 4 AM EST Wednesday for LEZ040-041.
Gale Watch from late Tuesday night through Wednesday evening for LEZ040-041.