Area Forecast Discussion
Issued by NWS Albany, NY

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KALY 252117 AFDALY Area Forecast Discussion National Weather Service Albany NY 517 PM EDT Sat Mar 25 2017 .SYNOPSIS... High pressure will briefly build in tonight as the cold front settles well south of the region. However, the front will slowly lift back north tomorrow with light wintry mixed precipitation returning to the region. The best chance of light ice accumulations through Sunday night will be north and west of the Capital Region. A wave of low pressure and its warm front will bring periods of rain to eastern New York and western New England Monday into Monday night. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... As of 515 PM EDT...Latest GOES Water Vapor imagery shows an area of drying quickly pushing southeastward out of Canada and into northern New York. At the surface, visible imagery shows thinning of the clouds north of the Capital District. This dry air clearing corresponds with the precipitation getting cut off to our north and weakening as it moves south of the Capital District, along the the fronal boundary. Per recent trends, and HRRR/RAP13, expect the precipitation to continue its weakening trend this afternoon. The surface front will settle well south of the region tonight. However, a mid-level front (around 850 mb) will be located right on the southwest periphery of the forecast area. Have therefore allowed for slight to chance pops across the Eastern Catskills, the southern Mid-Hudson Valley, southern Taconics, and the Litchfield Hills through the overnight period. The remainder of the area should stay dry but will also cool off quite a bit with skies mostly clearing. Temperatures are expected to drop into the upper teens and 20s north of the Greater Capital District and into the upper 20s/lower 30s south. Towards dawn, the surface frontal boundary will begin to lift north as a warm front. This will bring chances for freezing rain around daybreak to areas south and west of the Greater Capital District. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/... Winter Weather Advisory issued for the eastern Catskills, Helderbergs, and western and central Mohawk Valley from 6 am to 1 pm EDT... Winter Weather Advisory issued for the eastern and southern Adirondacks of northern Fulton, northern Warren, and Hamilton Counties from 2 pm Sunday to 9 am EDT Monday... Winter Weather Advisory issued for southern VT from 6 pm Sunday to 9 am EDT Monday... A challenging and complex forecast continues for the second half of the weekend into Monday morning. A strong canadian anticyclone with anomalously cold air for late March moves southeast across southern Quebec to near eastern Maine, and New Brunswick during the day. A old cold front tries to lift northward from the mid-Atlantic region, but plenty of shallow cold air is dammed into place across the region. Weak isentropic lift with an impulse rotating around the low and mid level ridge may kick off some light sleet and freezing rain south and west of the Capital Region shortly after sunrise. We felt confident to place high chc and likely pops in for a short time frame in the late morning and collaborated with WFO BGM for a winter weather advisory. The main threat should be freezing rain, but there is a chance of sleet. The model soundings do show quite a bit of dry air in place before the clouds rethicken and lower further north and east. Any ice accretions look light on untreated surfaces west of the Capital Region. There is a chance of freezing rain from the Capital Region south and east during the late morning into the early afternoon based on the critical partial thicknesses and the BUFKIT model soundings from the NAM/GFS. The question will be how quick the sfc temps warm despite low level east to northeast winds due to the sfc high downstream. We favored a blend of the GFS/NAM thermal profiles. It should be stressed that if the mixed pcpn threat increases, then the advisories may need to be expanded. The southern Adirondacks are tricky tomorrow as temps may struggle to get above freezing. It is possible a brief period of freezing rain occurs in the early pm, and temps rise slightly above freezing, then fall below prior to nightfall. With the east northeast winds in the boundary layer shifting to east to southeast, some upglide or upslope is possible for freezing rain there. In collaboration with WFO we started one in the afternoon when our POPs increased to likely values. It may take the better part of the day before the pcpn reaches southern VT with the warm advection well ahead of the warm front and the wave approaching from the lower Great Lakes Region. Again, special weather statements may need to be used for light spotty -FZRA too. Highs will generally be in the lower to mid 30s over the mountains, and mid 30s to lower 40s in the valleys. Any ice should melt quickly due to warming temps above freezing and the March sun angle. Sunday night...Some of the guidance continues to show the potential for elevated locations like the southern Adirondacks/southern Greens and perhaps the Berkshires and Litchfield Hills having some elevated freezing rain before warmer air breaks through Monday morning. A brief lull in the pcpn is possible between 00Z-06Z with the mid-level ridge axis sliding downstream. However, low pressure will be churning eastward from the eastern Great Lakes Region, and the QG lift will start to increase for periods of rain and freezing rain especially along the eastern slopes of the Adirondacks, and southern Greens. The low-level ageostrophic winds from the northeast to east in the boundary layer /925 hPa/ are hinting at cold air being dammed into place early on again, especially for the eastern Adirondacks, portions of the Lake George and northern Saratoga Region and southern VT, as well as the northern Berkshires. Some freezing rain is possible again Sunday night into Monday morning. Ice accretions may range from a few hundredths to a quarter of an inch /though a lot could change with these amounts depending on temperatures/.The advisories run overnight for around a tenth of an inch of ice (maybe two tenths in a few spots). Pops were increased to categorical with the increasing isentropic lift and moisture advection into Monday morning. Temps will be rising into the lower to upper 30s across the region. Monday-Monday night...All the mixed pcpn /freezing rain or spotty sleet/ should transition to periods of plain rain. The latest GFS/NAM/ECMWF/CAN GGEM have a stripe of moderate rain ahead of the sfc wave and warm/occluding front moving across the region in the late morning and early afternoon. The cyclonic vorticity advection with the upper level low will keep the rain going into the early pm before diminishing to scattered showers early at night. Temps rebound into the 40s across the region with mid 40s to close to 50F in the valley areas, and lows will be above normal in the mid 30s to around 40F. Tue-Tue night...The latest EC and Can GGEM both build a weak ridge in early TUE with a drier forecast, as a wave passes well to our south. The GFS/NAM continue to have a short-wave pass just to the south of the region with an inverted trough or weak wave bringing some scattered showers or a period of rain back into the region during the afternoon and evening. With all the uncertainty we keep a chance of showers in the forecast with temps actually getting into the upper 40s to mid 50s across the region. Lows in the 30s with a few upper 20s over the southern Dacks. Some snow showers could produce few light accums over the western Dacks at night as cold advection kicks in the wake of the disturbance. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... The period starts out on Wednesday with an upper level low moving eastward across southern Quebec and northern New England. Our region will be under a neutral northwest flow aloft resulting in mainly dry but breezy conditions. There might be a few rain/snow showers over the higher terrain well north of Albany, which will be under a slightly more cyclonic flow. Despite cold advection, the environment should be well mixed, so max temperatures will be close to normal. Dry conditions will prevail Wednesday night, but it will still be breezy as the upper low moves east of New England and into the Canadian Maritimes. Thursday looks to be a pleasant early Spring day across the area with high pressure building in with increasing sunshine and lighter winds. Dry and seasonable conditions should persist through Thursday night with high pressure in control. Friday may end up being dry as well, with models trending slower with a potential upper low approaching from the south-central U.S. Large model spread for the Friday night to Saturday time frame, as guidance having a difficult time resolving what will happen with regards the the upper low. The GFS suppresses the system well to our south, with a dry northern stream flow dominating. However, the ECMWF continues to indicate the low opening into a progressive trough and tracking across the region. For now will mention low chance pops until models are able to better resolve the main features. && .AVIATION /21Z SATURDAY THROUGH THURSDAY/... An area of rain/snow showers is quickly pushing south through the forecast area this afternoon. This has led to variable conditions, with most locations MVFR/IFR. Within the heavier bands of rain/snow, LIFR conditions are possible. Conditions should improve late this afternoon/evening from north to south as high pressure pushes south into the region. This should allow for conditions to improve to MVFR/VFR, except at POU. Some fog development may be possible but the dry air looks to be too strong to allow for fog formation even over a saturated ground. Rain/Freezing rain/snow will begin lifting back north through the area around 12Z/Sun with degrading conditions. Winds are generally light and variable with a tendency to become from the north-northeast through the day with frontal passages. Outlook... Sunday Night: High Operational Impact. Definite RA. Monday: High Operational Impact. Definite RA. Monday Night: Moderate Operational Impact. Chance of SHRA...RA. Tuesday: Moderate Operational Impact. Chance of RA. Tuesday Night: Moderate Operational Impact. Chance of RA. Wednesday: No Operational Impact. NO SIG WX. Wednesday Night: No Operational Impact. NO SIG WX. Thursday: No Operational Impact. NO SIG WX. && .FIRE WEATHER... The snow pack remains in place across much of eastern New York and western New England. The weather pattern will remain unsettled late this weekend into early next week with occasional rain and wintry mixed precipitation. High pressure will build in tonight, but the boundary and a wave of low pressure brings additional rounds of precipitation tomorrow into Monday. && .HYDROLOGY... An unsettled weather pattern will impact the hydro service area the next several days. There is a potential for several rounds of precipitation into early next week. Tonight into Sunday, the front will slowly lift back northward from PA and the Mid Atlantic Region bringing a mixture of mainly sleet, freezing rain, and rain to the region. The front stalls over central NY into eastern PA and Long Island for mix precipitation to occur again Sunday night into early Monday especially north and east of the Capital Region. A wave of low pressure approaches from the eastern Great Lakes Region with the warm front moving through finally with periods of rainfall. The rainfall looks the heaviest late Sunday night into Monday. Temperatures look to be warm enough during the afternoon hours each day that most of the precipitation should fall in the form of rain before changing over to a wintry mix at night for some locations. While there is still some uncertainty with precipitation types and amounts, there is the potential for between half an inch to an inch of rain through Monday. The latest MMEFS forecast indicates a few locations going into action stage by early next week, but confidence is not high for potential of any flooding at this time. Some snow melt is likely the next few days. 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...Winter Weather Advisory from 6 AM to 1 PM EDT Sunday for NYZ038>040-047-048-051-058-063. Winter Weather Advisory from 2 PM Sunday to 9 AM EDT Monday for NYZ033-042-082. MA...None. VT...Winter Weather Advisory from 6 PM Sunday to 9 AM EDT Monday for VTZ013>015. && $$ SYNOPSIS...Wasula NEAR TERM...JVM SHORT TERM...Wasula LONG TERM...JPV AVIATION...BGM/JVM FIRE WEATHER...BGM/Wasula HYDROLOGY...BGM/Wasula is the U.S. government's official web portal to all federal, state and local government web resources and services.