208 FXUS61 KBUF 150004 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 704 PM EST Thu Nov 14 2019 .SYNOPSIS... A weak cold front will cross the Lower Great Lakes tonight with snow showers northeast of the lakes that may mix with freezing rain at times. Another cold front will move south across the area later Friday afternoon with a few snow and rain showers. Another fresh batch of cold air will arrive behind this cold front for Saturday. A warming trend will then begin Sunday and last through early next week. && .NEAR TERM /THROUGH FRIDAY/... A peak at the 00z KBUF sounding revealed what was earlier feared... that we would lose our dendritic growth zone. As a result...the nuisance lake induced pcpn northeast of both Lakes Erie and Ontario will fall as a mix of wet snow...rain and or freezing rain tonight. Near surface temps were near freezing as of the writing of this discussion...while most road sensors were suggesting temps in the mid to upper 30s. Have issued a winter weather advisory to cover the potential for freezing rain/drizzle issues...which will initially be on elevated surfaces. As we work our way through the overnight though...lowering temps will chill untreated road surfaces to the point where some icy spots will be possible. As mentioned in previous discussions...the limiting cap is in the vcnty of 7500 ft...so the pcpn will generally be light with nuisance amounts. Outside of the lake enhanced areas, it will be mostly cloudy tonight. Lows will be in the lower 30s on the lake plains beneath cloud cover, and mid to upper 20s farther inland where skies partially clear. Friday will likely start mainly dry in the morning with plumes of lake effect clouds northeast of the lakes, and partly cloudy skies farther inland. A cold front will cross the eastern Great Lakes during the mid to late afternoon. This front will again be moisture starved and largely orphaned from stronger large scale ascent across Quebec. The low level convergence zone may support a few scattered snow showers, and there may be some lake enhanced scattered snow showers as well east and southeast of the lakes. All of this will be light, with any accumulation less than an inch. It will be quite breezy northeast of the lakes, with gusts up to 30-35 mph prior to the arrival of the cold front. Highs will reach the mid 30s in most locations by early afternoon, then begin to drop by late afternoon following the frontal passage. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... Following the passage of Friday's cold front...one more shot of much colder but also rather dry air will build across our region for Friday night and Saturday. The very dry nature of the incoming airmass and veering/short northwesterly to northeasterly fetch will help to confine any lake response to some clouds and scattered snow showers/flurries southeast and south of the lakes Friday night... with these diminishing over time as the low levels dry out and the capping inversion drops to a meager 2-3 kft. Outside of these dry weather will prevail...along with a return to well below average temperatures. Overnight lows will range from the teens south of Lake Ontario to around zero across the North Country...where light winds and clearing skies will allow for excellent radiational cooling...and where we have aimed significantly below forecast guidance for temperatures. The core of the ridge will pass by just to our north on Saturday... then will make its way to the Canadian Maritimes on Sunday...with remnant weaker ridging still extending back southwestward and across our region through Sunday night. This will result in fair dry weather prevailing across our region through the remainder of this period... along with mainly clear/mostly sunny skies. Meanwhile the fresh cold airmass will keep temperatures well below normal through Saturday night...with highs only in the mid to upper 20s Saturday followed by lows again ranging from near zero across the North Country to 10 to 15 south of Lake Ontario Saturday night. Such readings will be a solid 20 to 25 degrees below normal areawide...and could once again threaten record low temperatures at points (particularly at Watertown). For more information on these...please refer to the Climate section below. After that...a developing warm air advection pattern on the backside of the departing ridge will allow readings to notably moderate on Sunday...when highs will recover into the mid to upper 30s east of Lake Ontario and to the upper 30s and lower 40s elsewhere. && .LONG TERM /MONDAY THROUGH THURSDAY/... In the long term portion of the forecast...the guidance has trended a bit faster and more aggressive at breaking down lingering ridging across our region early in the week...with this feature giving way to an initial coastal system making its way northeastward offshore of the east coast...and/or a broad mid-level trough and second surface low/trough approaching from the Upper Great Lakes. Regardless of which of these scenarios you would believe...increasing lift and moisture out ahead of these features should eventually provide the impetus for some scattered rain and snow showers across our region... though the exact timing and coverage of these remains in question given continued notable differences between the various guidance packages...as well as their recent history of favoring drier weather persist longer into early next week. With the above in mind...for now have only increased PoPs a little for the Monday through Wednesday time frame...with broadbrush slight chance to lower-end chance PoPs favored until the forecast picture can become less muddled. Following the passage of these systems...general subsidence and dry/cold air advection should bring about a return to relatively dry weather for Wednesday night and Thursday...before the next system approaches toward the end of the period. As for temperatures...a modest low-level warm air advection pattern early in the week should continue to result in a gradual warming trend with daytime highs rising into the lower to mid 40s through Tuesday...with readings then flatlining and/or falling back a little Wednesday and Thursday as cold advection overspreads our region in the wake of the departing system(s). && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... While VFR conditions will be found across the vast majority of western New York tonight...a chilly southwest flow will support lake induced mixed precipitation for sites like KBUF and KART. These sites will experience MVFR conditions at the very least. The nature of the temperature profile will favor icing below 5k ft...and with the likelihood for icing at the surface...there could be a moderate impact to local ground based operations. The lake response will weaken during the course of the night... although MVFR conditions are likely to persist at KBUF, KIAG and KART. While most areas will pcpn free Friday morning...MVFR cigs will be rather widespread. The exception to the pcpn free weather will be east of Lake Ontario where some lake snow showers will still be in place. As we work deeper into Friday afternoon...MVFR cigs are forecast to lower to IFR levels across the Southern Tier and Finger Lakes region. The lowering cigs ahead of a second cold front will be accompanied by a new round of rain and wet snow showers. Outlook... Saturday and Sunday...Mainly VFR. Monday and Tuesday...Mainly VFR with a chance of showers. && .MARINE... Moderate southwesterlies will continue through tonight and Friday... as a pair of cold fronts will cross the Lower Great Lakes. The strongest winds will occur late tonight through early Friday afternoon...as the pressure gradient will tighten ahead of the second cold front. This will continue to support solid Small Craft Advisory conditions on both lakes. Winds will become north Friday evening behind the cold front, with Small Craft Advisory conditions continuing along the south shores of the lakes. Winds will then diminish Saturday as high pressure builds into the eastern Great Lakes. && .CLIMATE... Another unseasonably cold airmass will settle across our region Friday night through Saturday night. This will not only knock temperatures back to 20 to 25 degrees below typical mid-November averages...but could also lead to some additional new low temperature records. This will especially be the case at Watertown... where it appears that records for all three time periods listed below will likely be broken. At Buffalo and Rochester...new record low temperatures also appear to be a possibility on November 17th. Record Low Minimums for Saturday November 16th... Buffalo..........9F (1967) Rochester........8F (1933) Watertown........5F (1972) Record Low Maximums for Saturday November 16th... Buffalo..........22F (1933) Rochester........23F (1883) Watertown........29F (1980) Record Low Minimums for Sunday November 17th... Buffalo..........13F (1959) Rochester........15F (1959) Watertown........13F (1995) && .BUF WATCHES/WARNINGS/ADVISORIES... NY...Winter Weather Advisory until 9 AM EST Friday for NYZ001-002- 007-010>012-085. MARINE...Small Craft Advisory until 10 PM EST Friday for LEZ040-041. Small Craft Advisory until 7 PM EST Friday for LEZ020. Small Craft Advisory from 7 AM Friday to 10 AM EST Saturday for LOZ043-044. Small Craft Advisory from 3 AM Friday to 10 AM EST Saturday for LOZ042. Small Craft Advisory until 1 AM EST Saturday for LOZ045. && $$ SYNOPSIS...Hitchcock/RSH NEAR TERM...Hitchcock/RSH SHORT TERM...JJR LONG TERM...JJR AVIATION...RSH MARINE...Hitchcock/RSH CLIMATE...JJR