795 FXUS61 KBUF 132145 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 545 PM EDT Mon Sep 13 2021 .SYNOPSIS... A storm system over the Upper Great Lakes will push a warm front back through our forecast area tonight and early Tuesday. This will be followed by the slow passage of a strong cold front late Tuesday night and Wednesday. While most of the time during the next couple of days will be rain free...these frontal systems will keep at least the potential for more showers and gusty thunderstorms through this period. && .NEAR TERM /THROUGH TUESDAY/... Another MCV will push across parts of our region tonight...thus supporting a possible round of showers and gusty thunderstorms over the western counties. The highest risk for anything significant will be over the Southern Tier where shear values of 50kts will be found along the northern periphery of a marginally unstable environment. The warm front will push through the entirety of our region by midday Tuesday. This will leave us in a pronounced warm sector with Tds jumping into the upper 60s to near 70 and H85 temps hovering in the mid tens. The result will be a warm and humid afternoon...much like what you would experience in July rather than mid September. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... Showers and thunderstorms will increase Tuesday night as the cold front and shortwave trough move into the region. Large scale accent and forcing along this front, in combination with a strong 40+ knot low level jet will likely produce some strong to possibly severe storms. The limiting factor continue to be the unfavorable nighttime arrival time of the front across Western New York, which will mute its potential, but not eliminate the severe weather threat. Wednesday, the cold front slowly progresses from west to east across eastern Great Lakes. Showers and thunderstorms will slowly work east before exiting the entire forecast area late in the day. Drier and cooler air will work in the region as showers end from west to east. Wednesday night and Thursday, a surface ridge to our north will provide dry and quiet weather. && .LONG TERM /FRIDAY THROUGH MONDAY/... A tropical storm may be near the Outer Banks/Mid-Atlantic coast Friday. A plume of tropical moisture will be confined to the east coast however a south-southeast flow Friday will advect some moisture into the region with dewpoints in the mid 60s. Daytime heating will likely lead to showers developing in the afternoon into the evening hours. A weak cold front will approach from the north Saturday. This may produce a few showers, mainly across the North Country Saturday into Saturday evening. Surface high pressure moves across the region Sunday into Monday resulting in mostly dry conditions. Warmer than normal temperatures expected Friday-Monday with highs in the 80s and lows in the 60s. && .AVIATION /22Z MONDAY THROUGH SATURDAY/... MVFR/IFR CIGS from western NY to Finger Lakes tonight...as thunderstorms are expected to pass through the area. Some of the storms may be strong and produce heavy downpours. CIGS gradually improve to mainly VFR in the second half of the night through Tuesday morning. VFR weather expected Tuesday afternoon. Outlook... Wednesday...Mainly MVFR with widespread showers and some thunderstorms. Thursday and Friday...Mainly VFR. Saturday...Mainly VFR. && .MARINE... Light to gentle winds will be found over the Lower Great Lakes tonight in advance of a warm front. Of concern will be the risk for strong thunderstorm activity over Lake Erie. Winds on Tuesday will freshen in the wake of a warm front...becoming southerly on Lake Erie and southeasterly on Lake Ontario. Despite the stronger winds...conditions are expected to remain well below small craft advisory criteria...especially considering the offshore flow into international waters. Moderate to occasionally fresh southwesterlies will then be in place Tuesday night...as a cold front will be in the process of pushing across the western end of Lake Ontario. Strong storms will be possible with this scenario with small craft advisories becoming likely for the east end of Lake Ontario. The front will slowly settle through the Lower Great Lakes on Wednesday...producing widespread thunderstorms in the process. While conditions across the remainder of the region may not necessitate SCA's at that time...there will at lest be a heightened risk for choppy conditions. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...None. && $$ SYNOPSIS...RSH NEAR TERM...RSH SHORT TERM...TMA LONG TERM...HSK AVIATION...RSH/PP MARINE...RSH