Area Forecast Discussion
Issued by NWS Buffalo, NY
Issued by NWS Buffalo, NY
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047 FXUS61 KBUF 271816 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 216 PM EDT Mon May 27 2024 .SYNOPSIS... Low pressure will send a cold front east with chances for showers and thunderstorms this afternoon into this evening. Some of the storms may have the potential to generate strong gusty winds...mainly across the Finger Lakes and Eastern Lake Ontario regions. Unsettled weather will persist on Tuesday then a drying trend and cooler conditions will take hold for the rest of the week. && .NEAR TERM /THROUGH TUESDAY/... Svr Wx wise its been quiet so far with just a few embedded stronger cells (low top convection) within the shower activity. The main batch of shower is moving east across the Finger Lakes and eastern Lake Ontario region. However...there is more cells firing in its wake this afternoon and will continue to monitor the situation. Svr Wx details can be found below... A Svr thunderstorm watch has been issued for Wayne, N. Cayuga, Oswego, Jefferson, and Lewis County until 9PM. A potent shortwave will send a cold front east with additional chances for showers and possibly some strong to severe storms this afternoon into early this evening. The greatest threat for severe storms will `likely` be from the Finger Lakes ENE into eastern Lake Ontario region. That said...the `limiting` factor for SVR storms will be the amount of available CAPE. HRRR and various other hi-res guidance only show values around 1100 j/kg this afternoon. Even so...there will be plenty of shear (40 knots 0-6km) to support organized storms. SPC has placed the above mentioned areas in a slight risk for SVR storms. The other thing that needs to be watch is the potential for flash flooding. With a moisture rich environment in place...PW values in the 1.7" to 1.9 range...any of the stronger cells will produce localized torrential downpours. Given this threat...a marginal risk for excessive rainfall blankets our entire CWA. Otherwise...one additional thing to mention outside of the storms today is the gusty winds northeast of the lakes. We will `likely` see breezy conditions with gusts up to 40 mph. Highs will peak in the 70s for most locales. Surface low pressure lifts off into western Quebec by this evening with its trailing cold front entering and crossing the region. We should see a notable down tick in showers activity and storms with its passage for a chunk of the night. This will be courtesy of the mid-level dry slot swinging into the region. However...this dry period doesn`t last very long as a potent mid-level shortwave drops towards the eastern Great Lakes overnight. All indications are that we will once again see increasing chances for showers as we head into Tuesday. Tuesday...A robust shortwave with the cyclonic flow will rotate across the region. This will be accompanied by the next surge of deeper moisture. Again showers and some thunderstorms will be possible...especially during the midday and afternoon hours. Highs on Tuesday will `likely` peak in the 60s to near 70F. It will also be quiet breezy with westerly winds gusting up to 35 mph at times. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... A potent trough and then a cold front will track across the area Tuesday night into early Wednesday morning. As the trough tracks across the area, showers will continue through the first half of the night, before becoming less organized. Forcing from the trough will provide the main focus for showers during the evening and early overnight, while the cold front will move through and continue the potential for showers. Have included sChc of thunder this update as there could be just enough lingering instability early in the night to support a few isolated thunderstorms, though this threat should quickly wane through the night with the absence of diurnal heating. Overall synoptic moisture ahead of the trough will be generally low with PWATs of around an inch, and lowering some to around three quarters of an inch after it crosses the area. With these lower moisture values and weaker forcing from the cold front, showers that do linger into the morning on Wednesday will be less organized. Most areas can expect less than a tenth of an inch of rainfall, with the greatest amounts east of Lake Ontario where forcing and moisture will be slightly better. Temperatures on the night will be in the upper 40s for the higher terrain to the low 50s for the lower elevations. Wednesday, showers will linger across the area, with the best chance for showers southeast of Lake Ontario toward the NY/PA border. Showers will taper off and track out of the area from northwest to southeast. By the afternoon, showers should be limited to a general area from the NY/PA border, to the Finger Lakes & to the western ADKs. Northwest flow over the region will help keep temperatures below normal, with highs in the mid 50s to upper 60s from the higher terrain to lower elevations respectively. Wednesday night, earlier showers should be out of the area, minus a few sprinkles for the Southern Tier and for areas well southeast of Lake Ontario. Clearing skies from northwest to southeast, along with a mostly northerly flow will bring one of the cooler nights the area has seen in a while with overnight lows dropping to the low to upper 40s. The region will remain situated under broad, positively tilted upper level troughing centered over the Canadian Maritimes Thursday. To the west, a strong, progressive ridge of high pressure will be building eastward over the Great Lakes region. The surface high from this feature will "undercut" the initial upper level troughing to a degree, so while it should be another day of cooler than normal weather, it will be drier across the region compared to Wednesday. There remains a very low chance (15-20%) chance of showers across portions of the North Country Thursday afternoon, which will be further removed from the stabilizing effects of the high to the west. Cool, dry and tranquil weather then expected Thursday night as the upper level trough axis quickly pivots away from the eastern Great Lakes and into New England. Temps will again fall back into the 40s overnight. && .LONG TERM /FRIDAY THROUGH MONDAY/... A large area of high pressure and stout ridge will build east into the region during the long term period. The surface high and large ridge will be centered over the region from Friday afternoon through Saturday evening, ensuring fair dry weather. There are some timing issues with the next incoming trough and how quickly the large ridge weakens and/or moves east. Due to this, some guidance is bringing in the potential for showers starting on Sunday morning, but with the lack of certainty, left at most sChc POPs. Rain chances increase some on Monday as another weak shortwave moves across the Great Lakes region on the lee side of the building ridge. Temperatures for the period will start out near normal values in the upper 60s and low 70s Friday, though warm to around 5-10 degrees above normal by Sunday and Monday. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... An area of moderate to heavy showers with embedded thunderstorms will bring MVFR to IFR Cigs and lower Vsbys at KART and KGTB at time this afternoon. Elsewhere...expect VFR to MVFR Cigs with chances for showers and thunderstorms at times. The showers and residual thunderstorms this evening will taper off from west to east...as a cold front will press through the region. Tonight...a cold front will cross the region with showers and thunderstorm diminishing in coverage. However...MVFR to IFR CIGS will develop especially east of the lakes overnight. Outlook... Tuesday...Showers and thunderstorms possible with restrictions. Wednesday...VFR to MVFR cigs with a chance of showers. Thursday through Saturday...VFR. && .MARINE... Southerly winds have strengthen sufficiently enough to issue small craft advisories for all area lakes. There will be thunderstorms throughout the region...some of which could become strong gusty winds. The highest risk for significant convection will be over the eastern half of Lake Ontario this afternoon and evening. Mariners should be extra vigilant to any statements or warnings regarding this activity. Moderate southwest winds will continue into tonight and become westerly with small crafts in place on the lakes through Tuesday. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...Small Craft Advisory until 11 PM EDT this evening for LEZ020. Small Craft Advisory until 8 PM EDT Tuesday for LEZ040-041. && $$ SYNOPSIS...AR NEAR TERM...AR SHORT TERM...PP/SW LONG TERM...PP/SW AVIATION...AR MARINE...AR