121 FXUS61 KALY 100603 AFDALY AREA FORECAST DISCUSSION National Weather Service Albany NY 103 AM EST Mon Jan 10 2022 .SYNOPSIS... Colder and blustery conditions overnight along with bands of lake effect snow developing. Another, secondary, cold front will usher a frigid air mass into the region Monday night and Tuesday, with well below normal temperatures lasting into the middle of the week. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... Winter Weather Advisory for Lake Effect snow through 1 AM Tuesday morning for Herkimer County... .Update...As of 1:00 AM EST, cold front has cleared our entire region at this time. Winds everywhere are now from the northwest and remain gusty behind the cold front. latest NYS mesonet obs show that cold air and lower dewpoints have been just a tad slower filtering into the region versus previous forecast (especially in the Mohawk Valley), so adjusted both upwards a few degrees over the next several hours to reflect this. Also seeing numerous snow showers across the northern and western half of the region. Snow showers are being driven by combination of lake effect moisture, frontogenesis near 700 mb, and cyclonic vorticity advection aloft. Already seeing a multi- lake connection with a lot of multi bands, but the main lake effect band off of Lake Ontario is beginning to develop in western NY. As this band develops, it is still expected to drop into southern Herkimer County through the early morning hours before lifting back northwards during the day Monday. Other than some minor updates to reflect current trends, previous forecast remains in great shape. Previous near term discussion below offers more details as to the reasoning behind the forecast and expected impacts of the lake effect snow... .Previous [1000 PM EST]...Forecast remains on track. Cold front has moved across most of the local area. It still has to clear the far southeastern portion; winds are still from southwest at KPOU as of 10 pm. With the passage of the boundary winds have shifted to the west and quickly picked up in speed and become gusty in cold air advection. Gusts up to 35 mph have occurred in some locations. 850 mb temperatures are forecast to drop -15 to -18C across the area by daybreak. Temperatures will tumble down into the single across the southern Adirondacks and higher terrain of southern Vermont with lower 20s in the immediate Hudson River Valley from Poughkeepsie northward to Albany with mainly teens elsewhere. Scattered showers are occurring in the wake of the front as the upper trough approaches. As the night progresses a lake effect snowband will develop off of Lake Ontario. PREVIOUS [1626]...Lingering patches of drizzle/freezing drizzle and/or snow grains possible early this evening, mainly across some higher terrain areas of the southern Adirondacks, southern Greens and Berkshires. Then, as a strong cold front approaches and moves through, scattered snow showers are expected, with some brief, localized squalls possible that could produce scattered additional coatings to less than an inch. In the wake of the front, strong west/northwest winds will quickly develop, with gusts of 35-45 mph possible, especially in favored channeled west/northwest flow regime areas such as the Mohawk Valley, Capital Region and Berkshires. These strong winds, combined with any ice lingering in trees, could allow for some downed tree limbs and isolated power outages tonight. A Special Weather Statement (SPS) has been issued through this evening to address this, and also for lingering treacherous conditions on untreated ground surfaces (which may linger even if temps briefly rise above the freezing mark early this evening). Lake Effect snow from Lake Ontario is then expected to develop later this evening, passing southward across northern/central Herkimer County, and eventually settling into southern Herkimer County after midnight. There is some uncertainty regarding whether the band then settles even farther south, out of Herkimer County for a period overnight. As of now, current thinking is that snowband should settle south of the Thruway for a period just before daybreak. Overnight accumulations of 2-4 inches are possible where the band persists longest, which should be south of the Thruway, closest to Oneida County in far southwest Herkimer County. Strong winds will also create areas of blowing/drifting snow within the snowband, and brief, localized whiteout conditions are possible. There is some potential for the eastern extent of the snowband to reach into the Capital Region, Schoharie County, Taconics and Berkshires at times after midnight, producing localized coatings to an inch (except possibly up to 2 inches in far NW Schoharie County). Overnight lows should reach the teens to lower 20s for most areas, except for some single digits in the SW Adirondacks. These min temps may not occur until around, or even shortly after daybreak as cold advection continues through early Monday morning. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... Wind Chill Warning from midnight Monday night through 3 PM Tuesday afternoon for southwest Adirondacks... Wind Chill Advisory from midnight Monday night through 3 PM Tuesday afternoon for the Mohawk Valley, Schoharie County and Helderbergs, eastern Catskills, Washington County, Taconics, southern Vermont and Berkshires... Lake Effect snowband is expected to gradually lift back northward during the day Monday, in response to slightly backing low level wind flow before reinforcing arctic front approaches from the north after sunset. It appears that the band may slow its northward progress during the afternoon, however how far north this occurs remains questionable. At this time, current thinking is that this occurs across central Herkimer County, in the general vicinity of Cold Brook/Mckeever region. This is where greatest snowfall amounts are expected during Monday, especially in the afternoon, with 3-5 inches expected. It is possible that greater amounts may occur, and that a near-term upgrade to a warning is possible. Elsewhere, the LE snowband (in a weakened form) may extend into the northern Mohawk Valley, the Lake George/Saratoga region and southern Vermont, especially in the afternoon. Scattered coatings to an inch are possible, although locally higher amounts can not be ruled out. Scattered snow showers/flurries will be possible in all areas due to general low level instability, and increased forcing ahead of the arctic cold front approaching from the north. High temperatures only in the teens and 20s for most areas, with brisk west winds continuing, especially later in the day ahead of the incoming front, with additional gusts of 25-35 mph possible. Arctic front then settles southward Monday evening. This front may combine with the residual lake effect snowband and/or moisture to produce a thin band of snow showers or even squalls, and radar trends will need to be watched for this possibility. Snow showers should gradually decrease in areal coverage in the wake of the front, and become more confined to the western Mohawk Valley and eastern Catskills as the low level flow veers to a more northerly component. Temps should fall into -5F to -15F range across the SW Adirondacks, and -5F to +10F farther south and east by daybreak Tuesday. Combined with continued brisk winds, wind chills should drop to -25F to -35F within the wind chill warning area, and -15F to -25F for the advisory area, and generally zero to minus 15F elsewhere. It is certainly possible that the advisory area may need to be expanded to include more valley areas. Bitterly cold conditions for Tuesday, with some morning snow showers/flurries possible, especially across the SE Catskills and Mohawk Valley, and perhaps into portions of Washington County and southern VT from Lake Champlain. Temps should struggle to reach the single digits and teens for most areas, with some areas of the southern Adirondacks and southern VT possibly remaining near or below zero. Wind chills will remain between zero and 15 below into afternoon hours for most areas, if not colder. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Frigid airmass will still be in place at the beginning of Tuesday night with a narrow ridge of high pressure overhead, which could result in a quick drop in temperatures. However, the high shifts eastward quickly in response to midlevel height rises. This will induce return flow which should allow temperatures to rise toward morning. However, as the temps will be in the positive and negative single digits at the onset of the winds, the apparent temps will take a dive once the winds kick in before they rise for the remainder of the night. The bottom line is that it will still be quite cold Tuesday night, but likely not headline-worthy. Gusty southerly winds continue Wednesday which will boost highs back toward seasonal normals in the mid-20s to mid-30s. A few upslope snow showers will be possible in the western Adirondacks, otherwise dry mid/low levels should keep precipitation from occurring over the rest of the area. Cold front passes through Wednesday night into Thursday, and there could be a few snow showers along it, although the lack of deep- layer moisture and brief forcing should keep amounts minimal. In the wake of the front, high pressure setting up over western Quebec will funnel cold air back into the region, although likely not as cold as the early-week cold snap. Temperatures look to average below normal Friday into next weekend. Model spread is high for next weekend, but there will be precipitation chances with a positively-tilted trough approaching from the Midwest. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... VFR conditions remain in place tonight along with breezy westerly winds sustained between 10kt and 20kts with gusts to 25kts. Snow showers are tracking through eastern NY and western New England tonight as well and during any snow shower, ceilings could briefly drop to 3000 - 3500ft. While most of tomorrow will remain VFR with breezy west winds still in place, a strong, single lake effect band could track through ALB and PSF in the morning mainly 13 to 16 UTC resulting in IFR visibility and MVFR ceilings. ALB will be closer to the lake effect band than PSF so ALB could even potentially drop to LIFR visibility if the band is particularly strong. During the afternoon, the lake effect band should track northward and could pass through GFL, mainly 18 UTC to 22 UTC resulting in IFR or brief LIFR visibility if the snow is strong enough with MVFR/IFR ceilings. Outside of any lake effect snow, low end VFR ceilings are expected. POU should remain south of the lake effect snow and there maintain VFR conditions. Westerly winds tomorrow will stay breezy sustained 10 to 18kts with gusts to 25kts. Outlook... Monday Night: Moderate Operational Impact. Breezy. Scattered SHSN. Tuesday: No Operational Impact. NO SIG WX. Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Breezy. NO SIG WX. Wednesday Night: No Operational Impact. NO SIG WX. Thursday: No Operational Impact. NO SIG WX. Thursday Night: Low Operational Impact. Slight Chance of SHSN. Friday: No Operational Impact. NO SIG WX. && .HYDROLOGY... Widespread hydrological problems are not expected in the ALY HSA the next several days into late next week. Much colder air will move into the region Sunday night and last through Tuesday night. Temperatures will remain well below normal with some sub-zero minimum temperatures over the high terrain of the southern Adirondacks and southern Greens at night expected. Even valley areas are expected to drop into the single digits overnight, especially Tuesday night. Due to the prolonged period of cold temperatures, ice will form and thicken on most rivers, streams, and shallow bodies of water. In addition, there is a slight chance that localized freeze-up ice jams develop. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...Wind Chill Advisory from midnight tonight to 3 PM EST Tuesday for NYZ038>040-043-047-048-051-054-058-061-063-082-084. Wind Chill Warning from midnight tonight to 3 PM EST Tuesday for NYZ032-033-042. Winter Weather Advisory until 1 AM EST Tuesday for NYZ032-038. MA...Wind Chill Advisory from midnight tonight to 3 PM EST Tuesday for MAZ001-025. VT...Wind Chill Advisory from midnight tonight to 3 PM EST Tuesday for VTZ013>015. && $$ SYNOPSIS...IAA/KL NEAR TERM...IAA/KL/Main SHORT TERM...KL LONG TERM...Thompson AVIATION...Speciale HYDROLOGY...KL/Speciale/Wasula