Lake Ontario - Open Waters from Hamlin Beach to Sodus Bay Marine Forecast
|Overnight...Northwest Winds 5 To 10 Knots. Waves 1 Foot Or Less.|
|Monday...West Winds 10 To 15 Knots Becoming South. Waves 2 Feet Or Less.|
|Monday Night...South Winds 15 To 20 Knots Becoming West. Waves 1 To 3 Feet Building To 3 To 5 Feet.|
|Tuesday...West Winds 15 To 20 Knots Diminishing To 5 To 15 Knots. Waves 3 To 5 Feet Subsiding To 1 To 3 Feet.|
|Tuesday Night...South Winds 10 Knots Or Less Becoming Southeast 10 To 15 Knots. Waves 2 Feet Or Less.|
|Wednesday...South Winds 10 To 15 Knots Increasing To 15 To 20 Knots. A Chance Of Rain Showers Wednesday Night. Waves 1 To 3 Feet Building To 2 To 4 Feet.|
|Thursday...South Winds 15 To 20 Knots Becoming Southwest. A Chance Of Showers During The Day, Then Showers Likely Thursday Night. Waves 2 To 4 Feet Building To 3 To 5 Feet, Then Subsiding To 2 To 4 Feet.|
|Friday...West Winds 10 To 15 Knots Increasing To 15 To 20 Knots. Rain Showers Likely During The Day. Waves 2 To 4 Feet Building To 3 To 5 Feet, Then Subsiding To 2 To 4 Feet.|
| Area Forecast Discussion|
National Weather Service Buffalo NY
1051pm EST Sunday Mar 7 2021
Dry but cold temperatures will continue through tonight, before day to day warming of our airmass leads to well above normal warmth by mid week. A slow moving boundary will allow for several opportunities for rain showers toward the second half of the week. Above average temperatures in combination with runoff from snowmelt, and eventually some rain later in the week will cause rivers and creeks to rise.
Near Term - Through Monday
Aside from some stubborn localized lake clouds east of Lake Erie through the early overnight, mainly clear to partly cloudy skies (high thin cirrus WNY overnight) and light winds will provide good radiational cooling conditions. This will allow for one more cold night with below normal temps, although warmer air will be starting to move in aloft over western NY later tonight as a sign of what's to come. Before that though lows tonight will drop back into the teens across the lake plains, with single digits across the higher terrain. Even sub zero readings possible for the Tug Hill and western Dacks.
Surface high pressure will settle southward across the Southeast Monday. Meanwhile, warm advection mid and upper level clouds associated with a weak and mainly dry warm front will move into western and northcentral NY, with the best chance for a stray rain or snow shower east of Lake Ontario later in the day. Otherwise, the start of our day to day warmup begins as temperatures rise into the low to mid 30s east of Lake Ontario, with low to mid 40s across the remainder of the area.
Short Term - Monday Night Through Wednesday
A weak warm front will be quickly followed by a weak cold front which will wash out as it moves into the area Monday night. This bring some light (mainly) snow showers to the North Country closest to its supporting shortwave. Otherwise, suspect mesoscale guidance is overdone with its upslope Quantitative Precipitation Forecast but there will be some clouds with a widely scattered rain shower possible elsewhere. Lows Monday night will range from the lower to mid 30s south of Lake Ontario to the mid to upper 20s across the North Country.
High pressure will build back into the eastern Great Lakes on Tuesday, with dry weather and clearing skies. Highs Tuesday will reach the upper 40s to lower 50s in Western NY, and low to mid 40s for the North Country.
High pressure will remain centered off the southeast coast Wednesday. Dry weather will continue, with just a modest increase in mid/high clouds during the afternoon ahead of the next system. Southwest flow and warm advection will ramp up over the Ohio Valley and New England, allowing a much warmer airmass to move into our region. Highs will reach the upper 50s to lower 60s for much of the area, with mid 50s for the North Country. A SSW wind direction will keep most of the lake induced cooling on the Canadian side of the border.
Long Term - Wednesday Night Through Sunday
A mid level trough will advance from the Northern Plains Wednesday night to the Great Lakes by Thursday night. Deep moisture will gradually increase Wednesday night, with a pre-frontal trough possibly bringing a few rain showers overnight. A better chance of rain showers will arrive Thursday night as a cold front and possibly a wave of low pressure slowly approaches and then crosses the eastern Great Lakes. 12Z ECMWF/GFS/GGEM guidance has trended slower, suggesting much of Thursday may remain dry. If this happens, then Thursday will be as warm or warmer than Wednesday. However the wind direction will likely be more southwest than Wednesday, bringing more lake cooling to areas northeast of the lakes including Buffalo. Showers will likely move through Thursday night before tapering off Friday morning.
Colder air will filter back into the region Friday as cold advection increases behind the cold front and the mid level trough reaches the eastern Great Lakes. The airmass rapidly dries out Friday night and Saturday behind the cold front, so despite colder northwest flow expect mainly dry conditions. Highs by Saturday will be back in the upper 30s to mid 40s before another cold front is forecast to push southward across the area by Sunday.
High pressure will build across the eastern Great Lakes tonight with light winds and negligible waves through Monday. A weak cold front will cross the Lakes Monday night with some elevated winds and waves briefly late Monday night and Tuesday morning, especially across southeastern Lake Ontario. High pressure will then build back in allowing winds and waves to lessen through Wednesday.
Pressure gradient will tighten Wednesday night in the wake of a warm frontal passage, with strengthening southerlies possibly increasing enough to bring the next round of low end Small Craft Advisory conditions.
A significantly warmer pattern will start on Tuesday and this will result in increasing snow melt and associated run-off. There is still significant snow pack in place, especially across higher terrain and in the woods. The warmest temperatures will be on Wednesday and Thursday, with showers Thursday through Friday morning adding some additional run-off in addition to the snow melt.
The first concern is the risk for ice jam flooding since this could potentially occur much earlier than flooding due purely to high flows. The greatest risk for ice jams is mainly near where several Buffalo area creeks flow into the Buffalo River, which is a common location for ice jams. High flows from last week left ice jams in place, and cold weather since then has frozen these in place. Flows on the creeks will rise Tuesday evening in response to warmer temperatures, before leveling off Wednesday morning. More significant rises can be expected Wednesday evening through Thursday night when there will be a prolonged period of temperatures in the 50s and 60s. This will eventually flush out the ice jams and pretty much any ice in place, but the big question is how firm the ice jams are. Gradual melting from modest rises on Monday into Tuesday may help erode some of the ice before the highest flows start. However the longer existing ice jams hold, the greater the risk. Ice jam flooding concerns are greatest Tuesday night through Wednesday night - but before the highest flows are expected.
There is also a risk for flooding from high flows. The timing on this would be considerably later, with the highest flows on faster responding creeks likely to be on Thursday with slower responding river flooding possibly extending into Friday and Saturday. Latest model guidance shows a longer period of warm weather, and also some risk of more Quantitative Precipitation Forecast (half inch or so) since the front will be slower to move through. This uncertainty is reflected in the MMEFS ensembles which show a risk for flooding in the Allegheny and Black River basins, in addition to the Buffalo creeks.
Probabilities for individual forecast points to reach flood stage are still low (generally 10-50 percent) but if these model trends continue a Flood Watch may be needed for this in addition to the ice jam risk. Timing is tricky because the risk starts with ice jams, and then varies by basin with much later start times in the Black River basin which has considerably more snow pack in place but is also slower to warm.
It does appear that the warm up this week will melt most of the snow and ice south of Lake Ontario.
NOAA Buffalo NY Office: Watches - Warnings - Advisories