Lake Ontario - Open Waters from the Niagara River to Hamlin Beach Marine Forecast
|This Afternoon...East Winds 15 To 20 Knots. Rain Will Taper Off To Scattered Showers. Waves 2 To 4 Feet.|
|Tonight...East Winds 10 To 15 Knots Increasing To 15 To 20 Knots. A Chance Of Thunderstorms In The Evening, Otherwise Showers Likely. Waves 2 To 3 Feet.|
|Monday...East Winds 15 To 20 Knots. Showers Likely. Waves 1 To 3 Feet.|
|Monday Night...East Winds 10 To 15 Knots. Showers Likely In The Evening, Then Just A Chance Of Showers Overnight. Waves 1 To 2 Feet.|
|Tuesday...Variable Winds 10 Knots Or Less. A Chance Of Showers. Waves 2 Feet Or Less.|
|Wednesday...Northwest Winds 5 To 10 Knots. A Chance Of Showers. Waves 1 To 2 Feet.|
|Thursday...Northwest Winds 5 To 10 Knots. Waves 1 To 2 Feet. Winds And Waves Higher In And Near Thunderstorms.|
| Area Forecast Discussion|
National Weather Service Buffalo NY
205pm EDT Sunday April 11 2021
A front will slowly cross the region from southwest to northeast today with a period of widespread rain. An upper level low will then slowly cross the region tonight through Monday night, bringing more widespread showers to the region. The coverage of showers will decrease by Tuesday and Wednesday, although a few spotty showers will remain possible. Temperatures will be much cooler and more seasonable Monday through the rest of the week.
Near Term - Through Tonight
A compact mid level closed low will move from northern Indiana today to northern Ohio tonight, with a surface low becoming vertically stacked with time. A cold front spreading downstream of the system will become increasingly occluded as it moves into the eastern Great Lakes today. Moisture convergence along the nose of a 40 knot LLJ and deep moisture along the frontal zone will be aided by DPVA ahead of a mid level shortwave, resulting in a widespread area of rain along the frontal zone as it moves slowly northeast across the area today. The rain will reach the southeast corner of Lake Ontario by early afternoon, then slowly spread into the North Country by mid to late afternoon. The widespread area of moderate rain will begin to break down into lighter showers by the time it reaches the Eastern Lake Ontario region this afternoon, as the front continues to move out ahead of better forcing and into a drier incipient airmass.
Later this afternoon...modest insolation just behind the advancing area of widespread rain will result in SBCAPE of around 500J/kg across portions of Western NY and the Genesee Valley. This will support increasing coverage of showers during the afternoon and evening to the west of the initial area of widespread rain, and may also support a few scattered thunderstorms. Weak instability, poor lapse rates, and weak shear will keep the risk of any strong convection low, but a few storms may produce heavy downpours.
Any scattered thunderstorms that develop will end by mid evening as what little diurnal instability is left fades away. The showers in the evening will temporarily decrease in coverage during the late evening and early overnight, although they will not end altogether. Late tonight the mid level closed low will approach Western NY. Increasing low/mid level flow and the proximity of the old frontal zone will allow moisture transport and frontogenesis to increase across the eastern Great Lakes, supporting increasing coverage of showers from the Genesee Valley and western Finger Lakes westward across Western NY.
Short Term - Monday Through Wednesday
The new work week will start off with two upper level closed lows located across the Great Lakes region, one across the eastern Great Lakes and its counterpart across the Northern Midwest, over Minnesota and the Dakotas. The eastern most closed low will end up transferring its energy to the western most closed low Monday through Tuesday, while both lows slowly slide eastward. By Tuesday night some weak upper level ridging will quickly sweep across the area, while the aforementioned western most low, though now mature, spans across the central Great Lakes.
Meanwhile at the surface, the closed low will depart slowly depart the region Monday and Tuesday, supporting chances for showers throughout that time. A brief blip of surface high pressure will cross the area Tuesday night while its associated upper level ridge crosses overhead. The blip of the high pressure will allow a brief period of limited shower activity Tuesday night. Though the maturing low aloft over the central Great Lakes at this time, will support its own surface low. This pair of lows will eventually become stacked and cross overhead of the region Wednesday, supporting yet another day of showers.
Temperatures will continue to remain above normal Monday and Tuesday with highs in the upper 50s and low 60s. Cold air advection will bring drop temperatures into the low to mid 50s for Wednesday.
Long Term - Wednesday Night Through Saturday
The stacked system will enter the east coast where it will merge with another low riding up the Atlantic coast line. Depending on how far east the low will track, will depend on if the area will remain dry. A track further off the coast will support drier conditions. High pressure will build in across the area behind the stacked system, which will at least keep the areas across Western New York dry Thursday through at least Saturday.
Meanwhile, another upper level closed low across the northern Mid- West will weaken into a trough and allow a shortwave to pass through it. This will bring chances back into the forecast for some rain showers Saturday night and Sunday, though since this is so far out, kept POPs at only a chance.
Temperatures at 850 hPa will remain in the low single digits Celsius throughout the end of next week, which will support highs in the upper 50s and low 60s.
The passage of a stacked storm system will maintain light winds and negligible waves on Lake Erie through Monday night. Meanwhile... moderate easterlies will be found on Lake Ontario. The general offshore flow will keep the most significant waves on Lake Ontario will be found in International waters.
The only area of concern will be in the St Lawrence valley where fresh to strong northeasterlies will produce small craft advisory conditions into this evening.
NOAA Buffalo NY Office: Watches - Warnings - Advisories
Small Craft Advisory until 8pm EDT this evening for SLZ022- 024.