Area Forecast Discussion
Issued by NWS Albany, NY

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 211417 AFDALY Area Forecast Discussion National Weather Service Albany NY 917 AM EST Tue Nov 21 2017 .SYNOPSIS... Fair and mild today with temperatures rising into the upper 40s to mid 50s ahead of an approaching cold front. The front will sweep across the region late tonight into Wednesday bringing some snow and rain showers to the area. A more seasonable air mass will be ushered back in with mainly fair weather then expected through Friday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 917 AM EST...Made some minor adjustments based on current obs/trends. Otherwise, current forecast on track. Mild, fair and breezy today ahead of an approaching cold front. Ridge axis, upper and surface, shifts off the coast and deep southwest flow develops advecting warmer air into the region. Southerly flow will develop this morning and become breezy as the gradient pressure tightens across the region between the approaching cold front and departing ridge. South to southwest winds increasing to 10 to 20 mph with gusts up to around 30 mph. These winds and sunshine will help boost temperatures into the upper 40s to mid 50s; around 10 degrees above normal. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... Fair weather for Thanksgiving. Sharp northern stream short wave trough will approach tonight and move overhead Wednesday as it shears out. In the meantime, a piece of southern stream energy and its associated surface low will remain well off the coast as it quickly heads northeastward off the southeast coast. Clouds will be in the increase in the evening with chances for snow and rain showers increasing mainly after midnight as the cold front moves into the region from the west and some moisture is drawn into the region from the coastal low. Showers will taper off in the afternoon lingering the longest across the higher terrain. QPF amounts are expected to be light with about a quarter of an inch across the western Adirondacks with lesser amounts elsewhere. Light snowfall accumulations of 1-2 inches are expected across the western Adirondacks with less than an inch for areas generally above 1500 feet. With the passage of the cold front a more seasonable air mass will be ushered back in on brisk and gusty west-northwest winds. Areas generally west of the Hudson River Valley will experience little if any rise in temperatures Wednesday while east of the valley temperatures will rise some before dropping off later in the day. Upper flow is expected to go briefly flat Wednesday night across the region between short waves rotating about the upper low over Hudson`s Bay. The next short wave trough will not be as deep and will pass to our north across eastern Canada Thursday night. While at the surface higher pressure builds in. The result will be fair weather with below normal temperatures Wednesday night and Thanksgiving Day. Chances for any snow showers are expected to limited to portions of the western Adirondacks Thanksgiving night with seasonable lows as winds shift to the southwest. && .LONG TERM /FRIDAY THROUGH MONDAY/... Good model agreement that the progressive pattern continues into the long term period with the mean Hudson Bay upper low remaining dominant. Disturbances pinwheeling around the low have favored a storm track along or north of the St. Lawrence Valley recently, at it appears that will continue to be the case. Little evidence at this time that any southern stream energy will phase with the northern stream. Friday appears to be a tranquil and seasonable day. Upper heights will rise in conjunction with shortwave energy tracking across the northern Great Lakes region. Attendant surface low looks to track well north into northern Quebec, dragging its front across the forecast area on Saturday. Midlevel forcing will augment the front and result in shower potential, but it appears to be a low-QPF scenario attm given lack of moisture source and progressive forcing. Given the storm track, a p-type of rain is favored over most areas Saturday, with a tendency to mix with snow with time later Saturday into Saturday night, mainly at elevation. Additional shortwave energy is forecast to carve out a deepening upper trough over the greater Northeast Sunday and Monday. H850 temps progged to fall to - 10 to -15C, or possibly a bit lower as shown by the 00Z ECMWF, by Sunday night. These values are 1 to 2 SD below normal. This will allow for a lake response Sunday into Sunday night, with flow trajectories veering from NW to NNW. Some synoptic forcing with the reinforcing wave could carry some showers further inland than the normal lake effect/upslope favored areas Sunday. It appears height rises build in Monday, allowing lake effect to diminish. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... Aside from a few high clouds, mainly clear skies are expected to prevail throughout the day. An approaching cold front will allow clouds to increase and lower somewhat late tonight, but VFR is expected to prevail throughout the TAF period. Low-level wind shear is likely being seen at the terminals this morning with nearly calm winds at the surface and west-southwest winds around 35 kt at 2000 ft agl. With diurnal mixing, winds may get a bit gusty late this morning into the afternoon, with gusts of 20-30 kt possible, strongest at KALB. Winds will diminish this evening, with low-level wind shear likely once again at the terminals overnight. Outlook... Wednesday Night: No Operational Impact. NO SIG WX. Thanksgiving Day: 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: Moderate Operational Impact. Chance of SHRA. Saturday Night: Moderate Operational Impact. Chance of SHRA...SHSN. Sunday: Moderate Operational Impact. Chance of SHRA...SHSN. && .FIRE WEATHER... South to southwest winds 10 to 20 mph with gusts up to around 30 mph at times today with minimum relative humidity values in the 30s this afternoon. Fair and mild today ahead of an approaching cold front. The front will sweep across the region late tonight into Wednesday bringing some snow and rain showers to the area. A more seasonable air mass will be ushered back in with mainly fair weather then expected through Friday. && .HYDROLOGY... No hydrologic problems are expected this week. Fair and milder weather today with some rain and snow showers late tonight into Wednesday as a cold front crosses the region. QPF amounts are expected to be light with about a quarter of an inch across the western Adirondacks with lesser amounts elsewhere. With the passage of the cold front a more seasonable air mass will be ushered back in with mainly fair weather then expected through Friday. 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...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/JPV SHORT TERM...IAA LONG TERM...Thompson AVIATION...Thompson FIRE WEATHER...IAA HYDROLOGY...IAA

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