983 FXUS61 KBUF 302316 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 716 PM EDT Fri Jul 30 2021 .SYNOPSIS... Fairly cool weather will continue through the first half of the weekend...then Sunday will be quite unsettled with widespread showers and possible thunderstorms. && .NEAR TERM /THROUGH SATURDAY NIGHT/... As drier air from aloft continues to mix into the lower levels this afternoon...self destruct cloud cover will erode to leave plenty of sunshine. This process will become especially efficient as we move past peak heating, so there is likely to be a marked decrease by about 7 PM. Very cool under starlit skies tonight...courtesy of high pressure building across the area from the Upper Mid West. Mins in the 40s in the Srn Tier and parts of North Country...low to mid 50s elsewhere. These readings will average 10 deg below late July normals. High pressure centered over the Upper Ohio Valley will support fair dry weather on Saturday. Remaining cool with temps averaging 10 degrees below normal. Consolidating low pressure will approach from Lake Huron Saturday night. This will encourage thickening cloud cover with some showers expected late...esp near Lake Ontario. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... The low pressure system will continue to push ESE across southern Ontario Province Sunday, initially lifting a warm front from the southwest before swinging a cold front from the northwest through the region. With the passage of these fronts will come widespread showers through the majority of the day, with a few rumbles of thunder not out of the question. Potential for stronger storms currently looks to be limited with this event, as relatively unidirectional flow through the layer will limit overall shear. While instability from diurnal heating will be inhibited by the widespread cloud cover, PWATs nudging close to 1.5" may allow for some some brief heavier downpours. Activity will quickly wind down Sunday Night as the cold front departs to the southeast. Temperatures on Sunday will be unseasonably cool with highs in the 60s, some low 70s on the lower terrain. Lows Sunday night will settle into the 50s areawide. Heights will begin to rise Monday as weak shortwave ridging rounds the base of the longwave trough, allowing for dry conditions to persist right through Monday night. Daytime highs will reach the low to mid 70s, with upper 60s on the higher terrain. Calm winds and clear skies Monday night will allow radiational cooling to bring temperatures down into the mid 50s across the Lake Plains, low 50s and upper 40s elsewhere. && .LONG TERM /TUESDAY THROUGH FRIDAY/... This period will start off with a dry and pleasant day on Tuesday... courtesy of weak surface-based ridging and weak shortwave ridging aloft. With 850 mb temps of +9 to +12 in place and a fair amount of sunshine expected...afternoon highs should reach the mid to upper 70s. After that...a modest upper level low will take shape over the Ohio Valley Tuesday night and Wednesday...before slowly drifting northward to the Central Great Lakes and weakening through the balance of the work week. Weak impulses circulating around this system will combine with slowly increasing warmth and moisture to yield the potential for a few widely scattered to scattered showers/storms each day...mainly in the afternoon and early evening in tandem with peak daytime heating. The above said...much of the time should remain rain free. With respect to temperatures and humidity levels...both will be on a gradual increase through the middle and latter portions of next week...with daytime highs and surface dewpoints respectively reaching the lower 80s and low-mid 60s by next week Friday. && .AVIATION /23Z FRIDAY THROUGH WEDNESDAY/... Generally VFR conditions through Saturday...although valley fog could lead to come MVFR vsbys across parts of the Srn Tier late tonight that may affect KJHW for a period. Outlook... Sunday...MVFR. Showers and possibly a thunderstorm. Monday through Wednesday...VFR. && .MARINE... Winds over the lakes are gradually subsiding. All buoys and nearshores observations are dropping below 15 kts, and waves are summarily decreasing. Small craft advisories have thus been dropped. Colder air coming across the lakes pushing delta Ts to near 18C tonight, but relatively low equilibrium level and less than ideal gradient flow suggest a very low, but non-zero risk for waterspouts. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...Beach Hazards Statement until 2 AM EDT Saturday for NYZ003-004. MARINE...None. && $$ SYNOPSIS...RSH NEAR TERM...Fries/RSH SHORT TERM...PP LONG TERM...JJR AVIATION...Fries/RSH MARINE...Fries/TMA