Marine Weather and Tide Forecast for Thousand Island Park, NY

KEY MESSAGES
1) Cool and unsettled with periods of lake enhanced rain showers through Monday morning.

2) Gusty winds today, especially across Western NY.

3) Colder and unsettled weather returns late in the week, with some wet snow potential.

DISCUSSION
KEY MESSAGE 1...Cool and unsettled with periods of lake enhanced rain showers through Monday morning.

A mid level closed low will move from the Gulf of Maine this morning to the Canadian Maritimes this afternoon, with moist cyclonic flow rapidly moving away as a narrow mid level ridge axis briefly crosses the eastern Great Lakes. A few showers across Central NY and the North Country early this morning will end by mid morning. Clouds will give way to rapid clearing from west to east this morning before the next round of clouds increase this afternoon.

Another fast moving and potent mid level trough will dig from the upper Great Lakes this evening to New England by Monday, with an associated cold front crossing the eastern Great Lakes tonight. The airmass is still cool enough to support a lake response even ahead of the cold front. Expect a few lake effect rain showers to develop east/northeast of the lakes late this afternoon and this evening as large scale forcing and synoptic scale moisture increase, and improve the background lake effect environment. Initial development will be near Buffalo and Watertown on WSW flow.

Boundary layer flow will veer to the WNW tonight and NW by Monday morning, carrying lake effect and lake enhanced rain showers southeast of the lakes. Synoptic scale forcing will be strong enough to support scattered to numerous showers even outside of lake effect areas overnight through early Monday. Lake enhancement will bring steadier rain and higher QPF east and southeast of the lakes, with the highest rain amounts across the Tug Hill Plateau and Oswego County. A few locations may pick up 0.50" to 0.75" of rain, with the steady translation of lake effect bands southward in veering wind profiles preventing any higher totals. Boundary layer and surface temps stay plenty warm enough for all liquid, although a few locations may see some graupel or small hail in convective lake effect showers.

Showers will continue through Monday morning, especially southeast of the lakes from ongoing lake enhancement and upslope flow. The mid level trough and associated deeper moisture will then pull away in the afternoon, with showers gradually ending from west to east. The last of the showers across Central NY and the higher terrain of the North Country will mostly end by mid to late afternoon.

KEY MESSAGE 2...Gusty winds today, especially across Western NY.

A tight pressure gradient will remain in place today across the Great Lakes as a potent mid level trough and associated cold front approach from the northwest. Forecast model soundings show a belt of 35 to 45 knots in the 2K to 5K layer, with lapse rates steepening sufficiently this afternoon to support mixing of stronger winds down to the surface. BUFKIT momentum transfer schemes and other model guidance suggests that gusts will stay just below advisory criteria, with peak gusts in the 40 to 45 mph range northeast of Lake Erie from the Niagara Frontier to near Rochester this afternoon.
Elsewhere, gusts will be in the 20 to 30 mph range today.

It will stay windy tonight through Monday morning, with boundary layer flow gradually veering to the WNW overnight. Gusts of 25 to 35 mph will be common across the entire region, with some 40 mph gusts possible across the higher terrain of the Southern Tier and Finger Lakes.

KEY MESSAGE 3...Colder and unsettled weather returns late in the week, with some wet snow potential.

Mainly dry and somewhat warmer weather will return Tuesday through Wednesday, with just a chance of a few light showers each day across the North Country as a series of shortwaves cross southern Canada.

The pattern becomes much more interesting Thursday through Saturday as a deep trough carves out over the Great Lakes, evolving into a broad closed low across the eastern Great Lakes and New England by Friday. Shortwave phasing from the upstream split flow regime will likely support surface low development across the Ohio Valley by Thursday, with a maturing system moving towards the Mid Atlantic and New England by Friday and Saturday.

Rain chances will increase Thursday through Thursday night as the system approaches. Colder air will be drawn southward through the Great Lakes as the trough deepens, which will eventually introduce the potential for a change from rain to wet snow by Friday and Saturday. The airmass is not particularly cold, so if a change to wet snow does occur amounts will likely be highly elevation dependent.

Forecast confidence is high on a turn towards chilly, unsettled weather at the end of the week, but there is very low confidence with wet snow potential, and this will continue to be the case for at least several more days. An ensemble approach is prudent, and individual deterministic model runs should be taken with a grain of salt at this time range. Probabilities from the NBM and the LREF Grand Ensemble suggest a 20-30 percent chance of greater than 2 inches of snow across the higher terrain Friday through Saturday, just to demonstrate the degree of uncertainty at this time range.

Once this system moves away, medium range models and ensembles suggest a return to dry weather and above normal temperatures by early next week.

AVIATION /12Z SUNDAY THROUGH THURSDAY/
Widespread low stratus will continue through early to mid morning with mainly MVFR CIGS for lower elevations and IFR across higher terrain. Showers will continue across portions of Central NY and the North Country early this morning, but end quickly by mid morning. The low clouds will then rapidly clear from west to east during the mid to late morning, with a return to VFR.

It will become quite windy today, especially northeast of Lake Erie where gusts from the southwest may reach or exceed 35 knots at KBUF, KIAG, and KROC this afternoon. Elsewhere, expect gusts in the 20 to 25 knot range. It will stay breezy tonight, with winds gradually veering to the WNW and gusting in the 20 to 30 knot range areawide.

Another fast moving and potent mid level trough will dig from the upper Great Lakes this evening to New England by Monday, with an associated cold front crossing the eastern Great Lakes tonight.
Expect lake effect rain showers to develop east/northeast of the lakes late this afternoon and this evening near KBUF and KART initially, with MVFR becoming likely. The passage of the mid level trough and ongoing lake enhanced rain will support numerous showers overnight, most persistent east and southeast of the lakes. MVFR CIGS will become widespread overnight in lake effect and upslope clouds, with some IFR possible across higher terrain. Some of the lake effect showers will bring MVFR/brief IFR VSBY as well.

Outlook...

Monday.. MVFR/IFR with showers likely in the morning, especially southeast of the lakes. Improving to VFR in the afternoon.

Tuesday through Wednesday...Mainly VFR. A chance of showers and MVFR across the Tug Hill region.

Thursday...Deteriorating to MVFR with rain become likely.

MARINE
Westerly winds will increase today ahead of an approaching trough and cold front, with sustained winds peaking at around 30 knots this afternoon through tonight on both lakes, along with some gale force gusts. This will support high end Small Craft Advisory this afternoon through tonight.

Small craft advisory conditions will continue through Monday, with winds gradually diminishing from west to east. There will be a brief break of somewhat lower winds Monday night before another round of Small Craft Advisory winds and waves develops on both lakes Tuesday.

Cool air aloft and periods of lake enhanced showers will also support a chance of waterspouts this morning, and again tonight through Monday morning.

BUF WATCHES/WARNINGS/ADVISORIES
NY...None.
MARINE...Small Craft Advisory until 10 AM EST Monday for LEZ020.
Small Craft Advisory until 4 PM EST Monday for LEZ040-041.
Small Craft Advisory until 7 PM EST this evening for LOZ030.
Small Craft Advisory until 7 PM EST Monday for LOZ042.
Small Craft Advisory until 3 AM EST Tuesday for LOZ043>045.