Marine Weather and Tide Forecast for Elma Center, NY

NEAR TERM /THROUGH TONIGHT/
A deep closed low will slowly meander into the Upper Midwest from the Northern Plains today, then begin to pivot into the western Great Lakes tonight. An occluded front well out ahead of this system's center will traverse Ontario Province through the day, with the corresponding warm and cold frontal boundaries closely trailing one another further south. This will force a slowly decaying area of convection into the region from the west early this morning.
Increasingly diffuse boundary forcing, waning instability and a decoupled BL should preclude most if not all potential for severe thunderstorms, though an isolated stronger wind gust or two cannot be completely ruled out.

The initial line of showers and storms will continue to diminish as it moves east of the Genesee Valley after daybreak. The trailing cold front and drier airmass will arrive in WNY by the afternoon, though out ahead of it in the warm sector there will likely be additional scattered shower and thunderstorm development. Greatest coverage will be east of Erie/Niagara county with enough shear present for a Marginal severe threat. Otherwise, it will be warm and humid today, though stiffening onshore flow off Lake Erie will keep the Buffalo Metro and surrounding areas cooler.

A period of areawide dry weather tonight as diurnally forced showers from the afternoon taper off. Another pair of frontal boundaries then tied to the western closed low will then begin to encroach on the region again, with a warm front likely bringing another round of showers and embedded thunderstorms late tonight. Again, there is a Marginal Risk of severe thunderstorms with this activity, though the poor timing should keep the vast majority of any convection elevated.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/
A closed low will rotate across our region this period, bringing unsettled weather and cooling conditions. To start Saturday moderate rain showers associated with a warm front draped over our region will favor eastern zones, while an approaching cold front will drive another line of showers and thunderstorms across our region.

An early day passage of the cold front may limit the severe threat, with marginal instability (MUCAPE 300-600 J/KG) over the Finger Lakes and eastern Lake Ontario region and 0-6 km bulk shear values increasing to 40-45 knots and steepening lapse rates building thunderstorms to strong to severe limits early afternoon...this before the cold front clears the region of downpours, humidity and mild temperatures. The main severe threats will be damaging wind gusts with the lower risk for small hail.

Behind the cold front a developing lake breeze will bring increasing amounts of sunshine and a gusty southwest breeze to the Buffalo region. Along this lake breeze boundary a few showers or garden variety thunderstorms will be possible through the evening hours.

Convection will wane Saturday night with the loss of instability, but we'll still have scattered activity overnight...with likely PoPs Sunday east of Lake Ontario as the upper level low slowly passes over the region. Drier air will bring some clearing skies to WNY Sunday night...with this drier airmass also diminishing the shower threat east of Lake Ontario.

LONG TERM /MONDAY THROUGH THURSDAY/
Fair weather Monday and Tuesday as a narrow ridge of high pressure squeezes between a stalled closed low to the east over northern New England and an upstream closed low over the Rockies.

Unsettled weather returns Wednesday and Thursday with multiple shortwaves collecting to form another closed low over the Great Lakes, with cool conditions continuing.

AVIATION /07Z FRIDAY THROUGH TUESDAY/
A closed low pressure system moving into the Upper Midwest from the Northern Plains will send an occluded front across southern Ontario today. A line of strong thunderstorms along this front will inevitably reach western NY early this morning, though it continues to diminish in strength as it moves east of Michigan. A brief period of MVFR/IFR conditions expected at KBUF/KIAG/KJHW between 09z and 11z with this line before it moves east to the Genesee Valley (KROC). Mainly VFR will prevail out ahead of it, though a warm frontal boundary out ahead of the main line is causing more widely scattered elevated showers/thunderstorms to develop, a few of which could reach as far east as KROC. PROB30 groups have been placed in the TAFs to cover this as confidence in timing and placement of this activity is much lower.

The line of showers will shift east of KROC and continue to decay after 13z. There will likely be a brief period of light stratiform rain in its wake, as well as a slightly more persistent MVFR stratocu across Western NY. While this is expected to clear with mainly VFR after about 16z, additional scattered shower and thunderstorm development is possible from the Genesee Valley eastward through the afternoon hours.

Another round of showers and thunderstorms is expected to move back in from the west tonight with restrictions possible, though this will likely occur after the 06z TAF cycle.

Outlook...

Saturday...Mainly VFR/MVFR. Restrictions likely at times with periodic showers and thunderstorms.

Sunday...Mainly VFR with scattered showers east of KROC.

Monday and Tuesday...Mainly VFR.

MARINE
Generally light winds and waves across the lakes this morning ahead of warm front and a line of showers and thunderstorms moving in from the west. Southwest winds on Lake Erie may increase to near 15kts for a few hours following this activity, then diminish again later this afternoon.

Drier weather expected over the waters this afternoon through early tonight. Another pair of frontal boundaries will then cause showers and thunderstorms to move back in from the southwest, with a drying trend first across Lake Erie late Saturday morning, with Lake Ontario to follow Saturday afternoon through Sunday. Southwest winds on both lakes are expected to increase by Saturday afternoon with SCA conditions likely on both lakes through at least a portion of Sunday, with the east end of Lake Ontario possibly lasting into Sunday night.

BUF WATCHES/WARNINGS/ADVISORIES
NY...None.
MARINE...None.