Area Forecast Discussion
Issued by NWS Albany, NY

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000 FXUS61 KALY 261935 AFDALY Area Forecast Discussion National Weather Service Albany NY 335 PM EDT MON SEP 26 2016 .SYNOPSIS... Showers along and ahead of a frontal boundary will bring rainfall to the region overnight. A drier pattern returns for Tuesday into Tuesday night before more moisture and the threat for more showers arrives for the second half of the week. Temperatures will moderate with slightly above normal values expected. && .NEAR TERM /THROUGH TONIGHT/... As of 330 PM EDT...H2O vapor loop depicts a deep and nearly vertically stacked low over the upper Great Lakes region with another cutoff broad upper low over the southeast CONUS. Low level moisture transport vectors originate from near the Tennessee Valley where these two upper air circulations converge then transport northeastward as the upstream trough is the most dominant. Regional upstream radar shows a wide area of showers with some embedded thunderstorms across PA, however, atmosphere downstream is a bit more stable and nocturnal timing of the frontal passage should preclude the mention of thunder across our region. As per the last excellent forecast package, little change to the overnight as PoPs increase from west to east with most of the rainfall arriving around midnight and be east of the region toward sunrise. Due to the fast timing of this front, rainfall amounts should be rather light to moderate with intensity. Overnight lows will be milder than last night with mainly 50s expected. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... Tuesday into Tuesday night...Most of the region will be within the dry slot to keep the area mainly rain-free. Thermal column remains rather mild and with a southwest flow the temperatures should climb well into the 60s to lower 70s for valley locations under partly sunny skies. The moisture from the previous rainfall should remain high enough into Tuesday night for patchy fog as winds will be light and variable. Wednesday and Wednesday night...The upper low over the southeast CONUS is forecast to track northeast and off the Atlantic coast as deep upper low over the Ohio Valley continues to slowly migrate southward. These systems will act is tandem to advect in additional moisture back into the region with an increasing east- southeast low level flow. This will allow for clouds and the chance for showers/drizzle to redevelop across the terrain initially then across the remainder of the region Wednesday night. Some model tendencies suggest an inverted trough axis develops but location and convergent signatures remain in low confidence at this time. At least temperatures should remain mild with mainly 60s for highs and lows between 45F and 55F. && .LONG TERM /THURSDAY THROUGH MONDAY/... The one thing that is certain is the there remains considerable uncertainty in the forecast for the latter half of the week and for the weekend. Guidance is in general agreement that the large vertically stacked low which is developing over the upper mid west/western Great Lakes region will linger through the period, however how this exact evolves is in question. Generally speaking, the low is expected to be sinking gradually southward from the Great Lakes region to over the KY-TN-WV-VA-NC area into Friday before beginning to drift back north-northeastward through the weekend. The operational GFS is farther to the east with the low than the ECMWF. However, there is much spread in the GFSensemble members as to the location and movement of the low. With such uncertainty have used a blended model approach to the forecast and have favored guidance from the Weather Prediction Center to maintain forecast consistency. Refer their extended forecast discussion for their insight into the forecast. Overall have an unsettled forecast with chances for showers through the period. As for temperatures, have seasonable daytime temperatures with a bit above normal nighttime readings due to expected cloud cover. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... High pressure will continue to shift eastward off the New England coast through the afternoon, while a trough of low pressure approaches from western NY/PA. Clouds will gradually increase through this evening, with initially high level cirrus clouds moving in then cigs lowering as stratus clouds develop this evening. VFR conditions should hold until late evening, when cigs will likely lower to MVFR levels. Showers will move in from west to east across the terminals starting between 05Z-07Z, with widespread MVFR conditions developing. Best chance for IFR will be at KPSF, although some brief periods of IFR will also be possible at KALB/KPOU/KGFL mainly between 07Z-11Z. Showers will end by 12Z, with VFR conditions returning thereafter. Winds will be southerly around 5-10 kt with some higher gusts near 20 kt at KALB into tonight. Winds will shift to the west Tuesday morning. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA. Wednesday Night: Moderate Operational Impact. Chance of SHRA...FG. Thursday: Moderate Operational Impact. Chance of RA. Thursday Night: Moderate Operational Impact. Chance of RA. Friday: Moderate Operational Impact. Chance of RA. Friday Night: Moderate Operational Impact. Chance of RA. Saturday: Moderate Operational Impact. Chance of RA. && .FIRE WEATHER... A period of showers are expected tonight with the passage of a frontal boundary. Drier weather returns for Tuesday and Tuesday night before additional moisture and shower potential increases for the second half of this week. The RH values have an excellent recovery to 90 to 100 percent with the showers tonight. Expect a lowering of the RH values once again to 35 to 50 percent Tuesday afternoon. The winds will be from the south at 5 to 15 mph into tonight with some gusts in the 20 to 25 mph range early in the evening. The winds will shift to the southwest to west at 5 to 10 mph for Tuesday. && .HYDROLOGY... No widespread hydro issues are expected the next 5 days ending on Friday. A beneficial rainfall arrives tonight as a frontal boundary approaches from the west and moves across the region. Rainfall amounts of about a quarter inch to a half of an inch are expected. Isolated to scattered showers may return Wednesday night into Friday with a cutoff cyclone. Precipitation departures so far this year at our climate sites are: Albany NY: -3.54 inches Glens Falls NY: -6.34 inches Poughkeepsie NY: -11.51 inches Bennington VT: -6.65 inches Pittsfield MA: -8.11 inches The U.S. Drought Monitor released on September 22nd shows drought conditions have changed very little across the region. For details visit: www.drought.gov 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...BGM NEAR TERM...BGM SHORT TERM...BGM LONG TERM...ELH AVIATION...IAA/JPV FIRE WEATHER...BGM/Wasula HYDROLOGY...IAA/BGM/Wasula www.weather.gov/albany

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