Area Forecast Discussion
Issued by NWS Buffalo, NY
Issued by NWS Buffalo, NY
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405 FXUS61 KBUF 081033 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 633 AM EDT Mon Jul 8 2024 .SYNOPSIS... Surface high pressure over our region to start the day will continue quiescent conditions with summer`s warmth through tonight, with just an isolated lake breeze shower or thunderstorm Tuesday. A few showers along a cold front Tuesday night, with this front stalling over our region and serving as a pathway for tropical rainfall from Beryl Wednesday through early Thursday morning. Copious amounts of rain will likely total multiple inches through Thursday, with hydrologic concerns increasing. && .NEAR TERM /THROUGH TONIGHT/... High pressure is over our region to start the day, with light winds at the surface. A few patches of cirrus aloft, with some well inland Southern Tier valley fog, otherwise it will be a sunny start to the day. Should be dry today, though moisture pooling across the Finger Lakes may yield a spot afternoon shower. Warming aloft will result in surface temperatures well into the 80s today, around 5 degrees warmer than Sunday. Tonight this surface high will slip to the east, with a light southern flow across the region. There may again be some valley fog in the Southern Tier. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... ...Significant Rains from the Remnants of Beryl Possible Wednesday... On Tuesday, the region will be between a mid-level ridge across the mid-Atlantic states and a trough axis near Missouri. For the most part, Tuesday will be rain-free although some widely scattered showers and thunderstorms can`t be ruled out Tuesday afternoon and night. Despite some mid and high level clouds, it`ll be another hot day with highs in the mid 80s to lower 90s. Apparent temperatures will approach the mid 90s in the lower Genesee River valley and western Finger Lakes regions. There`s a risk for heavy rainfall from the remnants of Beryl Wednesday and Wednesday night. The digging trough will pick up moisture from the remnants of Tropical System Beryl and transport them into our area. Precipitable water values surging to 2-2.5" will support the potential for heavy rainfall and a risk for flooding. There will be a diffluent flow aloft combined with a warm front at the surface which can serve as a focus for training storms and heavy rainfall. There are still differences in model guidance, but a consensus has the slug of moisture moving through Wednesday afternoon into Wednesday night. On Wednesday, the area of greatest concern is Western NY where the frontal boundary will be located. During the day Wednesday, there`s a chance of diurnal instability will result in thunderstorms with locally higher rainfall amounts. Wind profiles south of the boundary (Western Southern Tier) show enough shear to support strong thunderstorms with gusty winds. SPC introduced a marginal risk for severe weather for Wednesday. This risk depends on the position of the frontal boundary. By Wednesday evening, the slug of tropical moisture is likely to move across Western NY before exiting across the North Country late Wednesday night. There remains too much uncertainty to issue a Flood Watch yet, but WPC has the entire forecast area in a slight risk for excessive rainfall. In general, expecting over an inch of rain at most locations, with localized amounts of 3 inches possible. Areas most vulnerable to flash flooding are typically areas with steep terrain and urban areas. Otherwise, temperatures on Wednesday will depend on the position of the front, but could see it being much cooler (in the 70s) for much of Western NY due to breezy northeast winds as the surface low moves into Ohio. The remnant surface low will track into southern Ontario province Thursday. There will be some lingering showers and thunderstorms, with the best chances across eastern sections of the forecast area. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... The axis of tropical moisture will be east of the forecast area by Thursday night. Drier air will continue to move into the region, however the mid-level wave will be overhead and diurnally driven showers and thunderstorms will be possible Friday. A mid-level ridge will move across the region Friday night through Sunday and mostly dry conditions are expected across the region. There is a low chance of showers in the afternoon through early evening Saturday and Sunday, mainly inland from the lakes and near lake breeze boundaries. Otherwise, temperatures will be above normal during the period with highs mainly in the 80s. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... For the 12Z TAFS, VFR flight conditions are found at the TAF sites, with inland Southern Tier fog dissipating. Mainly dry through the day today. There will be a little moisture pooling across the Finger Lakes, enough to perhaps form a spot shower. Continued dry tonight with a light southerly flow, with again valley fog formation in the Southern Tier. Outlook... Tuesday..Mainly VFR. A low chance of showers and thunderstorms. Wednesday...MVFR/IFR with tropical rains and chance thunderstorms. Thursday...MVFR/IFR with high chances of showers and thunderstorms. Friday...Mainly VFR with a low chance of showers and thunderstorms. && .MARINE... High pressure is across our region this early morning, producing light winds across the Lower Great Lakes. WIthin the light flow local lake breeze circulations will again form through the afternoon hours. This surface high will drift eastward today, with a light southerly flow across the Lakes tonight, becoming southwesterly on Tuesday. This may bring waves one to two feet on Lake Erie. More unsettled conditions - featuring widespread rain and some embedded thunderstorms - are then expected to develop on Wednesday as an area of low pressure (the remnants of Tropical Cyclone Beryl) track northeastward across the Ohio Valley. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...None. && $$ SYNOPSIS...Thomas NEAR TERM...Thomas SHORT TERM...Apffel/PP LONG TERM...Apffel/HSK AVIATION...Thomas MARINE...Thomas