Area Forecast Discussion
Issued by NWS Buffalo, NY
Issued by NWS Buffalo, NY
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898 FXUS61 KBUF 262300 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 700 PM EDT Wed Jun 26 2024 .SYNOPSIS... Showers and thunderstorms will end from west to east this evening. Cooler and less humid conditions expected Thursday and Friday. Active weather returns Saturday as a cold front crosses the region. Dry weather return Sunday as high pressure builds in for the start of the new work week. && .NEAR TERM /THROUGH THURSDAY/... A frontal boundary near the NY/PA state line has divided more unstable air to its south from a relatively stable environment to its north. 7 p.m. LAPS CAPE depicts this well with virtually no SB CAPE in Western NY north of the boundary. As a result, a large slug of showers with embedded thunderstorms due to elevated instability is moving across Western NY early this evening. This slug will exit from west to east during this evening. After this,a cold front will move through, and this will generally bring scattered showers and possibly a thunderstorm to Western NY overnight. Northerly flow and residual low-level moisture behind the front should allow for some lower stratus to develop overnight. Some fog is possible for area which sees rainfall through this evening. A secondary cold front will finish crossing the area Thursday morning, bringing a few additional showers. A weak shortwave will dive across southern Ontario and the Saint Lawrence valley Thursday afternoon behind the passage of the front bringing the potential for a few instability showers across the North Country. Otherwise generally dry weather is expected Thursday, with early morning low clouds giving way to increasing amounts of sunshine as high pressure and cooler/drier air builds in. The incoming airmass will also lead to cooler temperatures and lower humidity levels. High temperatures ranging from the upper 60s across the higher terrain to the lower 70s elsewhere with surface dewpoints falling through the 50s. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... Surface high pressure will crest across our region Thursday night through Friday evening, providing comfortable levels of humidity and fair weather. Patchy fog is possible across SW NYS. Behind the surface high deep southerly flow will transport moisture northward, with Pwat values peaking near 2 inches by Saturday afternoon. Showers, first within isentropic lift along a warm front extending across our region Friday night and Saturday morning will become more numerous Saturday afternoon and evening within the deepening moisture and passage of a subtle shortwave. The evening timing of the pre-frontal trough, cloud cover holding instability back to around 750 J/KG or less and poor mid level lapse rates under 6 C/KM are not favorable for strong to severe storms. However, 0-6 km bulk wind shear values 35 to 45 kts could aid in strength to the storm if any taller storms can develop. In addition the very moist atmosphere will allow for localized heavy rainfall to develop. Training cells within a SW flow could bring localized ponding of water through Saturday mid- overnight. Actual cold front will remain off to our west through the night, leaving a still humid, warm atmosphere with prospects for fog in place. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... On Sunday the surface low will slide across east-central Quebec to the Gulf of Saint Lawrence with a mid level shortwave and its associated initial cold front crossing our area during the morning. This will be followed by the passage of the main mid-level trough axis and an associated weaker secondary boundary later Sunday/Sunday night. Of note with the second cold front will be the much cooler airmass that gets ushered in behind it with 850Ts dropping back into the mid single digits C. The passage of these features will support the potential for some additional scattered showers into at least a portion of Sunday night (especially eastern areas), and (during Sunday) a couple more isolated storms. Otherwise high pressure building in from the west will provide drier, cooler, and more comfortable conditions with surface dewpoints falling back into the mid 40s and 50s across the region, lasting through Tuesday. Daytime highs will be in the mid to upper 70s Sunday and the upper 60s to mid 70s on Monday. High pressure slides east of the area on Tuesday with a southerly return flow boosting highs back up into the mid 70s to low 80s, however very tolerable humidity levels will remain in place for one more day. Comfortable overnight lows ranging through the 50s Sunday night and Monday night. Shower and thunderstorm chances start to ramp up again toward mid week as the next frontal system approaches the area with a warm frontal segment crossing the area, followed by another cold front. Exact timing of these features will become better resolved as we get closer in time. Also, expect a return to very warm and humid conditions. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... Steady showers will end from west to east this evening, with some thunderstorms embedded in this large area of rain showers. Mainly VFR outside of areas of MVFR or lower vsby in locally heavy rains. After this, a cold front will move across the area overnight, with increasing low level moisture and a risk for MVFR or lower cigs. Across higher terrain in the Southern Tier, there may be IFR cigs. Fog may also develop there, especially if clouds scatter out at all. Any fog or stratus will lift and scatter during the day Thursday, giving way to widespread VFR flight conditions by mid-day. Outlook... Thursday night and Friday...Mainly VFR. Saturday...Localized restrictions with shower likely and a chance of thunderstorms. Sunday and Monday...Mainly VFR. && .MARINE... A period of light, variable winds across the lakes will precede increasing northwesterly winds behind a cold front tonight, though winds and waves are expected to remain below SCA criteria. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...None. && $$ SYNOPSIS...AR/TMA NEAR TERM...Apffel/TMA SHORT TERM...Thomas LONG TERM...JM AVIATION...AR/Apffel/TMA MARINE...AR/Apffel/TMA