Marine Weather and Tide Forecast for Hamburg, NY

KEY MESSAGES
1) Another round of strong winds is becoming increasingly likely from Sunday afternoon through Monday night.

2) Cold weather returns with gusty winds and lake effect snow Tuesday through Wednesday.

DISCUSSION
KEY MESSAGE 1...Another round of strong winds is becoming increasingly likely from Sunday afternoon through Monday night.

Models continue to track a -3 to -4SD surface low from the Corn Belt states northward through western lower Michigan...with the surface low likely to deepen to around 980 mb. The models have trended a little farther westward with the surface low/LLJ...taking a track along western lower Michigan...as opposed to near Lake Huron in recent days.

For our region southerly to southeasterly flow within a warm air advection regime Sunday will increase through the day with the LLJ strengthening aloft. Downslope winds will begin to gust, not only for the typical Chautauqua Ridge and northwest face of the Tug Hill, but also off the hills of SW NYS and Finger Lakes region. By Sunday night gusts could reach 60 mph for the Chautauqua Ridge and Tug Hill...with higher end advisory level gusts elsewhere off the Boston Hills/Wyoming Hills and hills through the Finger Lakes. These gusts will weaken north of the New York State Thruway and closer to the Lake Ontario shoreline...for which low end advisory level gusts are anticipated.

South - Southeast wind gusts of this magnitude do not happen frequently for our region. A comparison event is the January 9th 2024 event...but even that event was much deeper with the surface low by 8 - 10 mb, a closer track of the surface low to Lake Huron, and a stronger and lower LLJ. As such, we should not see as much widespread warning level wind gusts late Sunday afternoon - night as the January 9th 2024 event...with high wind watches reserved for just the typical windier locations of the downslope Chautauqua Ridge and Tug Hill.

A strong cold front will cross our region Monday morning, likely just after 12Z...with the cold front passing through the eastern Lake Ontario region early Monday afternoon. Strong cold air advection will tumble temperatures from the lower 60s Monday morning ahead of the front into the 30s by Monday evening. Though mixing heights increase behind the front, the core of the LLJ resides in the warm sector, with a now 45 to 55 knot LLJ supporting southwest wind gusts Monday into the 35 to 50 mph range. Will carry the wind headlines through the day Monday to cover these gusty winds. Another low level will increases Monday night...which will continue gusty winds into the overnight hours.

Another factor with wind with this system will be convection ahead of the cold front. Instability may have time to increase ahead of the front and may result in a line of showers and possibly some thunder across the Finger Lakes and Eastern Lake Ontario region Monday afternoon with gusty convective winds.

KEY MESSAGE 2...Cold weather returns with gusty winds and lake effect snow Tuesday through Wednesday.

Behind a strong cold front an arctic airmass is expected to move into the eastern Great Lakes region Monday night through Tuesday night. Temperatures will take a dive Monday night with 850 hPa temperatures falling to the low negative teens Celsius by Tuesday morning. Steep low-level lapse rates with lake-induced equilibrium levels rising 6-8 kft will be supportive of lake effect snow development in the wake of this system for Tuesday through Wednesday. A broad area of 40 knots at 850 hPa and a well-mixed boundary layer will support gusty winds Tuesday. While Lake Ontario remains wide open and west-northwest flow likely providing a nice upstream connection to Lake Huron, there is more uncertainty surrounding what may develop off of Lake Erie. The northeastern half of Lake Erie remains mostly ice covered, but there is an area of open water closer to Long Point that may provide an opportunity for late season lake snows in western NY through midweek. While snow activity Monday afternoon through Tuesday night will likely be on the order of an inch or two each period, east of Lake Ontario a healthier band of lake effect snow could bring headlines worth snow accumulations to the Tug Hill region.

AVIATION /00Z SUNDAY THROUGH THURSDAY/
Area of 4-5K foot clouds exiting northern New York this evening.
Higher level clouds streaming in quickly from the west ahead of the next system. A period of light snow will arrive after 08z, lifting across the region from south to north. This looks like a 4-6 hour period where MVFR or even IFR will develop once the snow begins. The snow could end as a brief period of sleet or rain. Once the precipitation ends, conditions should go VFR quickly. Southerly winds will increase through the day Sunday with surface gusts of 25-35 knots by afternoon.

Outlook...

Sunday Night...Windy. LLWS possible.

Monday.. MVFR/IFR with rain changing to snow. Windy.

Tuesday and Wednesday.. MVFR/IFR with chances for snow east of both lakes. Breezy. Any IFR conditions will be localized to within lake effect snow bands.

Thursday.. MVFR/IFR with lingering snow showers.

MARINE
Low pressure will cross the Great Lakes Sunday night through Monday night, bringing the return of Gale Force winds. This surface low will track across MI Sunday night northeast towards Quebec Monday night with strong south-southeasterly low-level winds turning southwesterly Monday afternoon. Gale Watches have been issued on Lake Erie starting Monday morning and on Lake Ontario Monday afternoon and Monday evening.

Please note, most, if not all of the Lake Erie nearshore waters continue to be ice covered. Waves have been omitted from the forecast.

HYDROLOGY
The Black River continues to be in minor flood stage from Dadville to Watertown. The river crested at Watertown earlier this morning at 10.5 ft and has slowly been falling, but will remain at of just above flood stage until around midnight tonight. A Flood Warning remains in effect for this segment of the Black River.

Looking ahead, a warm-up is expected Sunday through Monday and will contribute to additional snowmelt across the Tug Hill region. Rain is expected Monday through Monday evening, before changing over to snow as temperatures rapidly drop across the region. Forecast rainfall amounts of 0.50-1.00" are expected across the Tug Hill region, and the combination of rain and snowmelt will likely cause rises on area rivers and creeks. Ensemble river forecasts show locations on the Black River rising back near action stage, but a very low chance (<5%) of reaching flood stage.

BUF WATCHES/WARNINGS/ADVISORIES
NY...Wind Advisory from 5 PM Sunday to 8 PM EDT Monday for NYZ001>006-010>014-020-021.
High Wind Watch from Sunday afternoon through Monday evening for NYZ007-008-019-085.
MARINE...Small Craft Advisory from 5 PM Sunday to 11 AM EDT Tuesday for LEZ020.
Small Craft Advisory from 11 AM Sunday to 8 AM EDT Monday for LEZ040-041.
Gale Watch from Monday morning through Tuesday morning for LEZ040-041.
Small Craft Advisory from 5 PM Sunday to 11 AM EDT Tuesday for LOZ030.
Gale Watch from Monday afternoon through Tuesday morning for LOZ042-062.
Small Craft Advisory until 2 AM EDT Sunday for LOZ043>045.
Gale Watch from Monday evening through Tuesday evening for LOZ043>045-063>065.