


Area Forecast Discussion
Issued by NWS Buffalo, NY
Issued by NWS Buffalo, NY
407 FXUS61 KBUF 071013 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 613 AM EDT Mon Jul 7 2025 .SYNOPSIS... A slow-moving cold front will cross the area this afternoon and evening...while generating showers and thunderstorms capable of producing localized heavy rainfall and gusty winds. In the wake of the front...high pressure and drier/somewhat cooler air will build across the region tonight through Wednesday...before more unsettled conditions return later on in the week. && .NEAR TERM /THROUGH TONIGHT/... During this period broad upper troughing over eastern Canada will gradually amplify as additional shortwave energy ripples eastward through it...which will in turn encourage the rather wavy frontal boundary situated just to our north and west early this morning to our north to slowly push southeast through our area as a cold front. Expect the cold frontal passage itself to take place between later this afternoon and the first half of tonight...with the boundary preceded by a composite prefrontal trough/developing lake breeze boundary that will push east across the area between the midday and afternoon hours. As it has appeared for the past several days...the antecedent airmass out ahead of these boundaries will feature rather high moisture content...with PWATs likely to be in the vicinity of 2 inches. Diurnal heating of this subtropical airmass will quickly lead to the development of moderate amounts of instability through the late morning and early afternoon hours...with this increasingly unstable airmass eventually being lifted by the aforementioned boundaries and resulting in the development of showers and thunderstorms. As is typical...the most widespread activity still appears to be most likely along and ahead of the composite prefrontal trough/lake breeze boundary...and should affect areas from the Southern Tier northeastward across the Finger Lakes and into portions of the North Country. This being said...there may also be a couple secondary maxima in pcpn coverage along the northern fringes of the developing lake breezes...with these potentially affecting portions of the Niagara Frontier and northern Jefferson county/the Upper Saint Lawrence Valley...first during the late morning/early afternoon...and then again late in the day as the cold front itself impinges upon the lingering lake breeze boundaries and briefly enhances low level convergence. With the convection...the biggest forecast concern remains the potential for localized heavy rainfall and flash flooding... especially when given the subtropical airmass...nearly unidirectional flow profiles oriented nearly parallel to the main surface boundaries...short MBE vectors...and rather tall/skinny CAPE profiles. In such an environment...the risk of heavy rain/flooding will be heightened if any training of cells can develop along the aforementioned surface boundaries...with the greatest potential for this still looking to lie from the Southern Tier northeastward across the Finger Lakes/interior of the North Country in association with the composite prefrontal trough/lake breeze boundary. In addition...a secondary (albeit lesser) concern will be the potential for a couple isolated stronger storms to develop and produce localized strong gusty winds. While this potential looks notably lower than that for localized heavy rain/flooding...cannot completely rule this out either given the expected moderate amounts of instability...and the potential for precip loading to lead to some locally strong downdrafts/surface wind gusts. With all this in mind...have continued to mention the heavy rainfall potential in the grids...and have also added a mention of gusty winds in conjunction with surrounding WFOs. Otherwise...it will be very warm to hot again today out ahead of the cold front/prefrontal trough with highs reaching the mid to upper 80s in most places...with a some spots in the Finger Lakes/Oswego county again potentially reaching the lower 90s. Coupled with surface dewpoints in the upper 60s/lower 70s...this will probably result in much of the Finger Lakes region and Oswego county reaching low-end Heat Advisory criteria for at least a few hours prior to the arrival of any convection...and with this in mind have hoisted another Heat Advisory for these areas. These conditions will then improve once the showers and storms arrive. By the time we get to sunset most of the convection will be on the wane with the loss of daytime heating...with just a few more showers/storms possible through midnight or so in tandem with the trailing cold frontal passage. After that...generally dry conditions are expected for the second half of the night as drier and cooler air begins to filter in behind the departing front...though plenty of lower clouds will remain in place in its wake. Where these intersect the higher terrain...some fog will become possible as we push through the night. Otherwise it will be cooler...with lows settling into the lower to mid 60s. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... Cold front through the region by Tuesday, but stalling just to the southeast of the region due to the presence of the remnants of Chantal working up along the east coast. While the impacts of Chantal will not be felt in our region, there could be a chance for a stray shower across far southeastern portions of the area. Otherwise, building high pressure behind the front will bring a dry day for much of western and north central New York. High pressure remaining across the region Wednesday, with dry weather continuing through at least the first half of the day. The frontal boundary to our south will then shift northward as a weak wave travels through the Ohio Valley. Southerly flow sends warmer air into the region bringing the low risk for some diurnally driven summertime convection. && .LONG TERM /THURSDAY THROUGH SUNDAY/... The later half of the week, will feature a longwave trough axis overhead of the central Great Lakes to traverse east into New England by this weekend. This pattern will support several windows of unsettled weather, but no days look to be complete washouts. Otherwise with the troughing pattern overhead, temperatures will be near to slightly above normal. && .AVIATION /10Z MONDAY THROUGH FRIDAY/... Mainly dry/VFR conditions will prevail through early this morning. As we push through the rest of the day and early this evening...a slow-moving surface cold front and leading prefrontal trough will push through our region...with these features and diurnal heating of our very warm and humid airmass helping to generate showers and thunderstorms...some of which could produce locally heavy rainfall and isolated gusty winds. The best convective coverage is expected to focus from the Southern Tier northeastward across the Finger Lakes and interior portions of the North Country this afternoon in association with the prefrontal trough...though secondary maxima in coverage may also occur at times across portions of the Niagara Frontier and Jefferson county...along the northern fringes of developing lake breeze boundaries. Expect the potential for reductions to MVFR or even highly localized IFR (mainly due to reduced visibilities) within any convection...with the risk for this again highest across interior portions of the area. After sunset coverage of showers and storms will be on the wane... though a few more widely scattered showers and storms may still accompany the cold frontal passage through the balance of the evening. In the wake of the front dry weather is expected...though lower stratus will also develop and lower flight conditions to MVFR across the lower elevations and IFR/LIFR across the higher terrain. Where the developing stratus layer intersects the higher terrain of the Southern Tier and North Country...some patchy fog will become possible as we push through the night. Outlook... Tuesday...Improvement to VFR. Tuesday night and Wednesday...Mainly VFR. Thursday and Friday...A chance of showers and thunderstorms with MVFR restrictions possible. && .MARINE... While winds will likely remain below SCA levels today and into this evening...there will be the threat of showers and thunderstorms in association with the approach and passage of a slow-moving cold front. In its wake...winds will become northerly to northwesterly while remaining at light to modest levels into early Tuesday, with generally light winds and sub-advisory conditions then expected to continue through the rest of the week. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...Heat Advisory from 11 AM this morning to 6 PM EDT this evening for NYZ003>006-013-014. MARINE...None. && $$ SYNOPSIS...JJR NEAR TERM...JJR SHORT TERM...TMA LONG TERM...EAJ/TMA AVIATION...JJR MARINE...JJR