Area Forecast Discussion
Issued by NWS Albany, NY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 160514 AFDALY Area Forecast Discussion National Weather Service Albany NY 1214 AM EST Tue Jan 16 2018 .SYNOPSIS... A low pressure system will approach from the Great Lakes tonight into Tuesday, bringing increasing chances for snow. This system, combined with a developing coastal low pressure area, is expected to bring a moderate snowfall to much of the region Tuesday into Wednesday morning. && .NEAR TERM /THROUGH TODAY/...
-- Changed Discussion --
As of 1214 AM EST...Made some minor adjustments to timing of light snow beginning, as current obs and NYS Mesonet webcams indicating snow reaching the ground across the western Mohawk Valley and southwest Adirondacks. Radar indicating some weak returns in this area too, so increased pops to likely a few hours earlier than the last update. Areas of mid and high level clouds are in place over western portions of the forecast area patches of lower stratus remnants from Atlantic moisture advection in various places as well. Expect an increasing cloud trend after midnight. 00Z KALY sounding shows an ample dry layer in the 850-700 mb layer which should take some time to saturate, so previous forecast idea of gradually increasing PoPs from west to east over the course of the night still looks good. Weak forcing and modest moisture advection should keep any accumulation overnight minimal, outside of favored southwesterly upslope regions of the southern Adirondacks where 1-2 inches may fall in spots by 12Z. Overall, forecast is in good shape without any substantial changes needed. As the upper level low starts to move eastward, it will open up and take on a positive tilt. Ahead of this feature, strong s-sw flow aloft within the mid levels will result in warm air advection for our area, producing some lift. This lift, aided by upslope flow across the southern Adirondacks, will start to produce some areas of light snowfall overnight. This snow looks to mainly impact areas from the Mohawk Valley on north/northeastward, as downsloping and less forcing should help prevent too much from occurring for areas south of Albany. Most areas won`t see much more than just a coating to half inch overnight, as the snowfall will be light and fairly intermittent. As the trough continues to slide eastward, a weak surface low will be moving from the eastern Great Lakes and into upstate New York for during the day Tuesday. With the persistent isentropic lift and approaching upper level energy, light snowfall will gradually expand across the region for during the day. This should allow for a steady light snowfall to develop for most areas from about to mid to late morning onward. Snowfall doesn`t look overly heavy in intensity, but does look fairly continuous throughout the day, especially across the higher terrain. Most areas look to see at least 1 to 3 inches by evening and the evening rush will likely be slow and difficult in many areas, with more snow to come during the late evening into the overnight hours as well. Will include most of the area within a Winter Weather Advisory and continue Winter Storm Watch for far eastern areas. Temperatures through the day will mainly be in the 20s. A few spots in the mid-Hudson Valley may top out around 30. Light winds for tonight look to become southerly for during the day Tuesday at around 5 to 10 mph. Although the snow looks fairly light and fluffy, the relatively light winds should prevent much blowing and drifting from occurring.
-- End Changed Discussion --
&& .SHORT TERM /TONIGHT THROUGH THURSDAY/... By Tuesday night, energy is expected to be transferred from the Clipper type system to an area of low pressure south and east of Long Island. A positive tilt trough aloft will be advancing eastward across the lower Great Lakes and Ohio Valley region. This set up looks to be conducive for some mesoscale banding to develop, and resembles a potential quasi-stationary band pattern from noted CSTAR research. Deterministic and ensemble model QPF has also increased from previous runs, which lends more confidence to a moderate snowfall event, especially for much of the area from the foothills of the southern Adirondacks south and east. Due to the best forecast 850-700mb F-Gen across SE NY into western New England, the most likely area for potential mesoscale banding looks to be across the southern Green Mountains of Vermont and the Berkshires of Massachusetts perhaps as far back as the Taconics in eastern New York based on the CSTAR research. The snow from the coastal low should persist through much of Wednesday morning, especially for areas east of the Hudson Valley. This system will likely impact the morning commute for much of the area. Wednesday afternoon, lake effect snow showers will start to develop downwind of Lake Ontario as westerly wind align with conditional lake-induced instability developing. So scattered snow showers will move back into the western Adirondacks before dark with some light accumulations possible. Lows Tuesday night will be in the upper single digits to upper 20s with highs on Wednesday in the upper teens to around 30. Lake effect snow showers will continue into Wednesday night across the western Adirondacks, but will be light due to lowering inversion heights. Otherwise, it will be mainly dry with near normal temperatures for the rest of the area. Lows will be in the single digits and teens. Mainly dry weather is expected on Thursday as high pressure builds into the region. Temperatures will be seasonable with highs in the upper teens to lower 30s. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
-- Changed Discussion --
Mid-level ridging will be in place for the beginning of the weekend bringing mild temperatures along with it. Apart from the Adirondacks who could see an isolated snow shower on Friday, eastern New York and western New England look to remain dry through Saturday. There will be very weak forcing for ascent on Saturday over the region so there is a possibility some rain/snow showers may have to be added to the forecast as we approach the weekend. On Sunday a deep trough will be in place over the central CONUS. Negative PV advection resulting from the divergent outflow of low over the Midwest will support jet-o-genesis/ridging over the Northeast, further strengthening the WAA regime over our region. There will be increasing clouds during the day Sunday with rain pushing into the region late in the day as the low pressure center progresses northeastward over the Great Lakes region. Global guidance suggests an upper-level cut-off low developing with this system, so many more model runs will be needed to work out the details with this system. Highs will increase from the upper 20s (higher terrain) and low 30s (elsewhere) on Friday into the the low 40s (higher terrain) and high 40s (elsewhere) on Sunday. If the strong WAA regime materializes, temperatures will likely have to be increased. There could be some more snow melt and ice jam flood issues with the warming temperatures and rain next weekend.
-- End Changed Discussion --
&& .AVIATION /05Z TUESDAY THROUGH SATURDAY/... VFR conditions early this evening beneath a lingering ridge of high pressure, although MVFR stratus continues to impact KPSF due to moisture advection off the Atlantic. Some of this stratus is also getting into KALB/KPOU but at around 3.5kft. Expect this stratus to diminish somewhat around 03Z as low-level winds veer. Mid and high level clouds will continue to thicken and lower overnight ahead of an upper level trough tonight. Light snow is expected to begin, spotty at first, around 12Z and become steadier with IFR vsby expected around 14-15Z (except at KPOU where it could be around 3 hours later). Snowfall intensity may vary some during the day allowing vsby to improve to MVFR, but timing on that potential is unclear at this time. Winds tonight will be light and variable, becoming southerly at around 5 kt during the daylight hours on Tuesday. Outlook... Tuesday Night: Moderate Operational Impact. SN likely. Wednesday: No Operational Impact. NO SIG WX. Wednesday Night: No Operational Impact. NO SIG WX. Thursday: No Operational Impact. NO SIG WX. Thursday Night: No Operational Impact. NO SIG WX. Friday: No Operational Impact. NO SIG WX. Friday Night: No Operational Impact. NO SIG WX. Saturday: Low Operational Impact. Slight Chance of SHRA. && .HYDROLOGY... Ongoing flooding due to ice jams will continue to be addressed with areal flood warnings. There could still be some lingering issues as any existing ice jams may tend to become frozen in place due to the very cold temperatures expected over the next few days. Warmer weather is not expected until the weekend. In terms of precipitation, a moderate snowfall is expected for much of the area from Tuesday into Wednesday, with heavy snowfall possible from the northern and central Taconics east through western New England. 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...
-- Changed Discussion --
CT...Winter Storm Watch from noon EST today through Wednesday morning for CTZ001-013. NY...Winter Weather Advisory from 7 AM this morning to 7 AM EST Wednesday for NYZ032-033-038>043-047>053-058>060-063>066- 082>084. Winter Storm Watch from noon EST today through Wednesday morning for NYZ054-061. MA...Winter Storm Watch from noon EST today through Wednesday morning for MAZ001-025. VT...Winter Storm Watch from noon EST today through Wednesday morning for VTZ013>015.
-- End Changed Discussion --
&& $$ SYNOPSIS...11/JPV NEAR TERM...Frugis/Thompson/JPV SHORT TERM...11/JPV LONG TERM...Cebulko AVIATION...Thompson HYDROLOGY...11/JPV

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.