


Area Forecast Discussion
Issued by NWS Buffalo, NY
Issued by NWS Buffalo, NY
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070 FXUS61 KBUF 300940 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 540 AM EDT Mon Jun 30 2025 .SYNOPSIS... A warm and humid day today ahead of the next approaching cold front. Showers and thunderstorms are expected during the afternoon and into the overnight, with some of the showers and storms capable of producing heavy rainfall at times. Showers and thunderstorms will linger through the day Tuesday, especially for the eastern half of the area. && .NEAR TERM /THROUGH TONIGHT/... A dry morning is expected today as the sfc high over the region pushes to the New England coast this morning. But this will give way to increasing heat and humidity today as a warm front crosses the area ahead of an approaching trough and cold front. Showers and thunderstorms are expected starting this afternoon, as a pre-frontal trough pushes into the region. Today, a weak 500 hPa warm front will push northeast across the area through the afternoon, this may cause a few showers/storms early, but forcing is weak with the front, and the most notable difference with the front will be the increased moisture with only little additional warming aloft. PWat values will increase through the morning and into the afternoon behind the warm front. Values will increase to around 1.50" by late morning and close to 2.00" by mid afternoon for areas south of Lake Ontario. Showers and thunderstorms will start push into the western Southern Tier early this afternoon and expand northeast across all of WNY through the afternoon. Showers and storms will become better organized as well as a pre- frontal trough tracks across the area late in the afternoon through the evening. Lake breeze boundaries will provide additional forcing mechanisms to allow additional showers/storms to develop in the moist and unstable environment. With the high PWats in place and the forcing from the pre-frontal trough, heavy rain will be possible within any showers and storms that develop. WPC has highlighted southwest NY in a `Marginal Risk` area for excessive runoff today. While instability will be 1,000-2,000 J/kg, there will be little to no shear aloft for greater potential for storms to become severe, but a few strong gusts can`t be ruled out if some of the storm cores get high enough. Guidance does indicate some decent DCAPE values for the southwestern portion of NY. There is a `Marginal Risk` for an isolated severe thunderstorm today into this evening. Temperatures today will warm to the low 80s to near 90 for most areas, with the lower elevations between Lake Ontario and I90, along with the northern and western Finger Lakes areas having the warmest temperatures. Combined with increased humidity, apparent (feels like/heat index) temperatures will reach the low to mid 90s for some areas. A limiting factor in the potential for higher apparent temperatures will be increasing clouds, and this airmass in general is a bit cooler than last weeks airmass where temperatures easily hit Heat Advisory levels. Tonight, showers and thunderstorms continue to expand northeast as the pre-frontal trough tracks across the area. Showers and storms should reach the eastern Lake Ontario area by mid-evening, with activity diminishing a fair amount across far western NY soon after. The loss of daytime heating will help to decrease instability as the showers/storms move east later in the evening. Showers/storms associated with the pre-frontal trough will diminish in coverage from west to east through the middle of the night. After a few hours of diminished shower coverage, the cold front will track toward the region by daybreak on Tuesday morning, generally located over SW Ontario. Showers will expand in coverage once again ahead of the front as synoptic forcing increases. While a heavier shower and some thunder will be possible, it should be less than what is expected earlier in the night with the trough. Temperatures tonight will generally remain warm ahead of the approaching cold front with lows in the upper 60s to low 70s for most areas. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... A mid level trough and associated cold front will move east across the eastern Great Lakes Tuesday and into New England Tuesday night. DPVA and height falls ahead of the mid level trough will combine with right entrance region jet dynamics to support large scale ascent along the advancing cold front, with showers and scattered thunderstorms crossing the area from west to east Tuesday. Most of the rain will be in the first half of the day in Western NY, with a drier post-frontal airmass and expanding stable lake shadow northeast of Lake Erie allowing for mainly dry weather later in the afternoon. Any remaining showers and thunderstorms east of Lake Ontario Tuesday evening will end with the passage of the cold front, with clearing skies overnight. Weak high pressure will build into the Ohio Valley and southern Great Lakes Wednesday through Wednesday night, with a return to dry weather and near average temperatures, along with a less humid airmass. && .LONG TERM /THURSDAY THROUGH SUNDAY/... The pattern will briefly amplify across the US later this week as a ridge builds east across the mid section of the nation, and a trough sharpens over southeast Canada. A strong mid level shortwave will dive through the trough from southern Quebec into New England Thursday through Thursday night, which will bring a chance of a few scattered showers and thunderstorms. High pressure will build back into the eastern Great Lakes Friday through Saturday with a return to dry weather and near average temperatures/lower humidity for the Fourth of July Holiday. Another weak cold front will then gradually settle southeast across the Great Lakes and New England later Sunday or Sunday night with increasing chances of a few showers and thunderstorms. && .AVIATION /10Z MONDAY THROUGH FRIDAY/... Mainly VFR conditions today with a few showers/storms possible during the late morning and early afternoon for the Southern Tier. Showers and thunderstorm activity will increase from southwest to the northeast through the afternoon. Heavier showers will bring the potential for lowers VSBYs and CIGs to MVFR and IFR at times. Heavier showers in the afternoon possible for all TAF sites south of Lake Ontario, lower chance for KART. Tonight, showers/storms continue to expand northeast across the entire area, once again, heavier showers will cause reductions to VSBYs and CIGs down to MVFR and possibly IFR. Outside of showers, early VFR CIGs will drop to MVFR for most of the area, with IFR possible for the Southern Tier, including JHW. Heavier showers/storms early for all TAF sites, tapering off through the evening and into the overnight from west to east. Outlook... Tuesday...MVFR/VFR with showers and thunderstorms likely, mainly early. Wednesday...VFR. Thursday...Mainly VFR. Showers and thunderstorms possible. Friday...VFR. && .MARINE... A departing area of high pressure will maintain light winds through this afternoon. Waves are expected to remain below a foot. A warm front will lift across the Lower Great Lakes today, with light winds on Lake Ontario backing to easterly through the day and before the warm front passes through. Behind the warm front a 10 to 15 knot south-southwesterly flow will be found tonight creating a chop on the waters. The winds and waves are expected to remain below small craft criteria through mid week though some choppy conditions will be possible at times. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...None. && $$ SYNOPSIS...SW NEAR TERM...SW SHORT TERM...Hitchcock LONG TERM...Hitchcock AVIATION...SW MARINE...Thomas