Area Forecast Discussion
Issued by NWS Buffalo, NY

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000 FXUS61 KBUF 232010 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 410 PM EDT Thu Mar 23 2023 .SYNOPSIS... Rain will end from northwest to southeast later this afternoon and evening as a cold front moves southeast across the area. High pressure will then build into Ontario and Quebec tonight through Friday with a period of dry and cooler weather. Strong low pressure will then move through the Great Lakes Saturday and Saturday night, bringing another round of rain to the region. The rain may start as snow or a wintry mix across the North Country. Strong winds are possible Saturday night, especially across Western NY. && .NEAR TERM /THROUGH FRIDAY/... Radar imagery showing areas of light to moderate rain crossing the region early this afternoon. A weak baroclinic wave running along an advancing cold front is supporting the areas of steadier rain, but both will quickly start to exit the area through the afternoon. The most widespread rain will be through mid afternoon, with coverage diminishing thereafter. The moist airmass over the cold lakes will produce some patchy fog over Lake Erie and Lake Ontario, with some of this moving into shoreline areas through the rest of the afternoon and early evening. Lowering dewpoints will end this fog potential by mid evening. Rain will taper off from northwest to southeast from mid afternoon through mid evening, with the last of the rain exiting the Southern Tier before midnight as the cold front pushes quickly southeast of the area. High pressure will build east across Ontario and western Quebec overnight. There may be some initial clearing later this evening, but as the airmass grows colder, expect post-frontal lake effect and upslope clouds to expand with low stratus becoming widespread overnight. Cold advection will drop temperatures back into the upper 20s to lower 30s overnight. Friday the frontal zone will stall well south of the area from the Ohio Valley to the Mid Atlantic. High pressure moving east from Ontario into Quebec will bring dry weather to the eastern Great Lakes. Widespread lake effect and upslope stratus in the morning will give way to some partial clearing by afternoon, especially on the lake plains as stable lake shadows expand inland. A colder airmass will keep highs in the upper 30s to lower 40s. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... This period will feature another round of active weather from later Friday night into Sunday. This will come courtesy of a southern stream trough initially over the mid-Mississippi Valley Friday evening...which will deepen and eject northeastward to the central Great Lakes during Saturday...before weakening some and sliding out across Quebec and the Canadian Maritimes Saturday night and Sunday. At the surface...this will spur an initial surface low to rapidly deepen and follow along a similar path through Saturday...with the system then becoming vertically stacked over the central Great Lakes by later Saturday afternoon/Saturday evening. Increasing height falls/DCVA along the front flank of the advancing mid/upper level trough will then force the development of a secondary surface cyclone along the New Jersey coastline Saturday evening...with energy then transferring from the initial primary low to the strengthening coastal system as it lifts northeastward off the New England coastline to Nova Scotia through the rest of Saturday night and Sunday. This system will bring another round of widespread precipitation to our area between later Friday night...Saturday...and Saturday night...with liquid equivalent precipitation amounts through this period expected to range from a half inch to an inch. With respect to precipitation type...the track of the primary low will provide for a substantial enough influx of warm air both at the surface and aloft for the vast majority of the this to fall in the form of plain rain. This said...thermal profiles continue to suggest the potential for a brief wintry mix on the forward flank of this system...though any snow/ice amounts look to be rather limited at this point due to its expected short duration. The greatest potential for such will be across the far eastern Finger Lakes and east of Lake Ontario where thermal profiles will remain colder longer...and where up to a couple inches of snow appear possible. Saturday night...colder air wrapping in behind the primary system`s cold front will result in the rain mixing with/changing back over to snow across the higher terrain as it winds down...though any accumulations should again be very minor. Of greater concern with this system will be the potential for a round of strong winds...especially across far western New York. The initial primary surface low will wrap up rather quickly as it pushes to the central Great Lakes on Saturday...with its central pressure reaching the 980-985 mb range by later Saturday evening...and its associated low level jet increasing to 55-65 knots as it overspreads our region. Initially this will bring a threat of strong south- southeasterly downslope winds during the day Saturday...with this maximized along the Lake Erie shoreline downwind of the Chautauqua Ridge. Following the passage of the surface cold front late Saturday/Saturday evening...the threat will then shift to the typical areas from the Lake Erie shoreline across the Niagara Frontier to Rochester in the west-southwest cold advective regime...which will help to more effectively mix down the higher momentum air from aloft. In both cases model profiles continue to suggest the potential for a period of higher-end advisory to lower- end warning criteria gusts of 50-60 mph...and with this and increasing confidence in this scenario in mind have opted to issue some initial High Wind Watches as outlined below. Elsewhere more in the way of lower-end advisory criteria gusts appear possible both Saturday and Saturday night...and with the more marginal conditions/lower confidence in these areas will opt to address these later on as the event draws closer. On Sunday the primary low will weaken considerably as it translates eastward across Quebec and continues to transfer its energy to the strengthening coastal system...with high pressure and drier air nosing into our area during the afternoon. This will result in still- rather windy conditions Sunday morning giving way to diminishing winds Sunday afternoon...along with lingering scattered rain and snow showers east of Lake Ontario steadily winding down. With good mixing still in place coupled with the return of some partial sunshine and 850 mb temps in the -2C to -7C range...Sunday`s highs should range from the upper 30s to mid 40s east of Lake Ontario to *at least* the mid 40s to lower 50s elsewhere...with the warmest readings found across the Finger Lakes Region. Finally...Sunday night should be mainly dry and quiet as the surface ridge further builds across our region...with lows mainly ranging from the mid 20s to lower 30s. && .LONG TERM /MONDAY THROUGH THURSDAY/...
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Heading into the new work week, subtle upper level ridging will be in the midst of advancing eastward across the eastern Great Lakes. Meanwhile a broad upper level low spanning across northern Canada, will spread a trough southward across the north-central portions of the continental United States. As the ridge pushes eastward, the trough to the west will dig and dive into the upper Great Lakes region, and then continue its eastward pass across the region heading toward the East Coast by Tuesday night. Translating the upper air pattern down to the surface, a surface high over southern Ontario, Canada will be spread across the eastern Great Lakes Monday. This will result in a period of dry weather. Then due to cyclogenesis from the digging trough aloft, a surface low will spawn over the Central Plains before passing east across the Ohio Valley and then into the Atlantic. As of right now model guidance packages differ with the timing of this system, and therefore as a result have low chances for showers Monday night through Tuesday night. The model timing differences continue heading further into the future of the forecast. Overall another upper level trough will dive south across the Great Lakes and Mississippi Valley for later in the week and results in another round of precipitation chances for the end of the work week. Additionally, conditions look to be on the cool side next week with daily highs slightly below average and ranging in the low to mid 40s.
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&& .AVIATION /20Z THURSDAY THROUGH TUESDAY/... A cold front will move southeast and exit the area later this afternoon, with areas of rain tapering off from northwest to southeast. Areas of IFR/MVFR CIGS will continue along and behind the front through the rest of the afternoon before CIGS improve this evening. Rain will produce areas of MVFR/IFR VSBY as well. The moist airmass over the cold lakes will also produce patchy fog over Lake Erie and Lake Ontario, and some of this will impact shoreline areas at times through early this evening with local IFR. Later tonight and Friday morning expect lake effect/upslope stratus to expand, with areas of MVFR CIGS. The stratus will continue through Friday morning before partial clearing by afternoon, especially over and south/southeast of Lake Ontario where stable lake shadows will help to clear out the clouds in the afternoon. Outlook... Saturday...MVFR/IFR with rain, possibly starting as a period of wet snow or mixed precipitation across the North Country. Sunday...Mainly VFR, through MVFR possible across the North Country due to lingering mixed rain/snow showers. Monday...Mainly VFR. Tuesday...VFR/MVFR with a chance of rain/snow showers. && .MARINE... A cold front will move southeast and away from the lower Great Lakes this afternoon and evening. Increasing northwest winds in the wake of the cold front will bring a period of Small Craft conditions to the eastern half of Lake Ontario from early this evening through late tonight. High pressure will build east across Ontario and Quebec late tonight and Friday, with diminishing winds. Strong low pressure will then move from the Ohio Valley into lower Michigan Saturday, then move across Lake Huron into Quebec Saturday night through early Sunday. East to southeast winds will increase in advance of this system, and may briefly approach gale force Saturday. A longer period of southwest to west gale force winds are more likely Saturday night through early Sunday following the passage of the strong cold front. && .BUF WATCHES/WARNINGS/ADVISORIES...
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NY...High Wind Watch from Saturday afternoon through Sunday morning for NYZ001>003-010>012. High Wind Watch from late Friday night through Sunday morning for NYZ019-085. MARINE...Gale Watch from Saturday afternoon through Sunday morning for LEZ040-041. Gale Watch from Saturday afternoon through Sunday afternoon for LOZ042-062. Small Craft Advisory until 5 AM EDT Friday for LOZ043-044. Gale Watch from Saturday evening through Sunday afternoon for LOZ043>045-063>065. Small Craft Advisory from 8 PM this evening to 5 AM EDT Friday for LOZ045.
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&& $$ SYNOPSIS...Hitchcock NEAR TERM...Hitchcock SHORT TERM...JJR/TMA LONG TERM...EAJ AVIATION...Hitchcock MARINE...Hitchcock is the U.S. government's official web portal to all federal, state and local government web resources and services.