Area Forecast Discussion
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FXUS61 KALY 261935
Area Forecast Discussion
National Weather Service Albany NY
335 PM EDT MON SEP 26 2016
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
.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
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
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.
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
No widespread hydro issues are expected the next 5 days ending on
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
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
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