Lake Ontario - Open Waters from the Niagara River to Hamlin Beach Marine Forecast
|Today...West Winds 5 To 15 Knots Becoming Southwest And Increasing To 15 To 25 Knots. Areas Of Drizzle This Morning. Waves 1 To 3 Feet Building To 3 To 6 Feet.|
|Tonight...Southwest Winds 15 To 25 Knots Becoming West And Diminishing To 10 To 15 Knots. Waves 4 To 7 Feet Subsiding To 1 To 3 Feet. Waves Occasionally Around 9 Feet.|
|Thursday...Northwest Winds 5 To 15 Knots Becoming Northeast And Increasing To 15 To 25 Knots. A Chance Of Showers In The Afternoon. Waves 1 To 2 Feet Building To 2 To 4 Feet.|
|Thursday Night...Northeast Winds 20 To 25 Knots. A Chance Of Rain Showers. Waves 5 To 8 Feet. Waves Occasionally Around 10 Feet.|
|Friday...Northeast Winds 15 To 20 Knots Becoming Northwest 5 To 15 Knots. Waves 5 To 8 Feet Subsiding To 1 To 3 Feet. Waves Occasionally Around 10 Feet.|
|Saturday...West Winds 5 To 15 Knots Becoming South 15 To 20 Knots. Waves 2 Feet Or Less Building To 2 To 4 Feet.|
|Sunday...Southwest Winds To 30 Knots Becoming Northwest. A Chance Of Rain Showers. Waves 2 To 4 Feet Building To 3 To 6 Feet.|
| Area Forecast Discussion|
National Weather Service Buffalo NY
431am EDT Wednesday Oct 28 2020
Lake effect rain showers will persist northeast of both lakes this morning. High pressure will then nose into the area from the Ohio valley this afternoon and tonight. A storm system will pass well to our south Thursday and Thursday night. While this will produce some widespread rain for our region, it could also support the first snowfall of the season.
Near Term - Through Thursday
Modest cold air advection will produce some lake effect rain showers northeast of both lakes this morning.
High pressure nosing into the region this afternoon and tonight will dry the area out.
A closed upper low will advance out of the Southern Plains tonight and Thursday, as the remnant tropical low tracks northeast from the Gulf of Mexico within the southwest flow aloft ahead of the upper low. The upper low is then expected to phase with a northern stream trough later in the day Thursday as it crosses the eastern CONUS, as the associated surface low tracks across the Ohio Valley/Mid Atlantic region. The combination of the remnant tropical moisture, and increasing jet and shortwave supported ascent will result in fairly widespread rain arriving into the region from the south through the day Thursday. General rainfall amounts ranging from around a half inch along the Southern Tier to perhaps just a few hundredths near Lake Ontario.
Short Term - Thursday Night Through Saturday Night
Parent surface low ejects out to sea off the Delmarva Coast Thursday evening, then is rapidly followed by a weaker secondary surface wave Thursday night. The main precipitation shield will then begin to pull away from the region as we progress through the overnight hours into early Friday morning. Colder air on the backside of the system will then rapidly filter in from the north as low level northeast winds increase in response to the incoming surface ridge over Ontario and Quebec. This will likely allow for the rain to mix with and change over to wet snow towards the end of the event. The best chance for any accumulations right now will likely be found across the higher terrain and especially across the Southern Tier. Otherwise, very little snowfall accumulation is anticipated elsewhere as the track has trended further to our south. There will also be a sharp cut off to the precipitation shield which may result in the North Country receiving very little precipitation from this event.
Synoptic precipitation will or should all be done by sunrise Friday then the surface ridge to our WNW builds into the Lower Lakes. While minor, there may be a brief window for some lake effect rain and snow showers with H850T dropping down to -6C to -7C. However, the incoming airmass is very dry which should put a lid on any lake response. It's likely that there will just be a fair amount of cloudiness under NW'erly upslope flow south and east of the lakes.
Any lingering cloud cover will then dissipate Friday evening with clearing skies. With the surface ridge overhead and light winds, it will then allow for good radiational cooling overnight. Should be the coldest night so far this fall season with temps found in the 20s along the lake plains to teens inland away from the lakes by daybreak Saturday.
High pressure exits out to sea Saturday but will maintain dry weather but chilly conditions and highs generally found in the 40s. Saturday night, the next system and its cold front approaches the Lower Lakes with increasing chance for showers as we head into Sunday.
Long Term - Sunday Through Tuesday
The next upper level trough and associated cold front is expected to track across the Great Lakes Sunday. The trough will sharpen over the Great Lakes by late Sunday, with the cold front reaching the eastern Great Lakes in the afternoon. This will bring increasing clouds and a chance of a few rain showers, especially in the afternoon.
Behind the cold front Sunday, strong cold air advection will bring a return to below normal temperatures Sunday night and Monday. WNW flow and wrap around moisture will likely support chances for lake effect rain snow showers Sunday night through Monday morning, especially southeast of the lakes.
Forecast uncertainty increases somewhat by Monday afternoon and Tuesday. A wave of low pressure and mid level trough pass to the north across Canada Monday evening into Tuesday. The ECMWF (European Centre for Medium-Range Weather Forecasts) and Global GEM are stronger and farther south with this feature than the flat wave depicted by the GFS. If the stronger solutions verify, a fresh batch of cold air would arrive later Monday into Tuesday with a few more lake effect rain and snow showers east and southeast of the lakes. For now, kept low chance POPS through this period.
High pressure will build south of the area today, allowing west to southwest winds to freshen. This will support a round of Small Craft Advisory conditions on both Lake Erie and Lake Ontario. Winds will then diminish later tonight.
Low pressure will move from the Ohio Valley to off the northern Mid Atlantic Thursday through early Friday. A period of stronger northeast winds will develop on the eastern Great Lakes as a tight pressure gradient develops between this low and high pressure building into Ontario and Quebec. This will bring another round of Small Craft Advisory conditions staring Thursday afternoon and lasting through Friday morning.
NOAA Buffalo NY Office: Watches - Warnings - Advisories
Small Craft Advisory from noon today to 11pm EDT this evening for LEZ040-041. Small Craft Advisory from 2pm this afternoon to 5am EDT Thursday for LOZ043-044. Small Craft Advisory from 2pm this afternoon to midnight EDT tonight for LOZ042. Small Craft Advisory from noon today to 5am EDT Thursday for LOZ045.