Area Forecast Discussion
Issued by NWS Albany, NY

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000
FXUS61 KALY 140606
AFDALY

Area Forecast Discussion
National Weather Service Albany NY
106 AM EST Wed Nov 14 2018

.SYNOPSIS...
Colder and blustery conditions are expected tonight with
some lake effect snow showers, especially for western parts of the
area. It will be continued cold and breezy on Wednesday with some
additional lake effect snow showers and flurries.  Temperatures will
be frigid Wednesday night into Thursday morning before another storm
system brings widespread snow, rain and sleet to the region for late
Thursday into Friday morning.

&&

.NEAR TERM /THROUGH TODAY/...
As of 1245 am, lake effect activity is becoming more organized
into the Mohawk and Schoharie Valleys per KENX/KTYX 88D and
upstream webcams. SPS was issued highlighting locally slippery
conditions possible. Low-level winds are still expected to
oscillate enough for the band to move around and not result in
advisory-level accumulations in any one area, but locally a
couple of inches are possible especially over the western Mohawk
Valley. A couple of snow showers may make it all the way to the
Capital District/Berkshires per CAMs and CSTAR research/local
inland extent program. CAMs suggest this band may become
oriented more south of our area as we head toward 12Z, but it
some activity may increase again 15-18Z before quickly ending by
21Z as upper level height rises occur and high pressure builds
in. Outside of the lake effect, partly to mostly sunny skies are
expected today, but it will be frigid with high temperatures not
far off from average lows for this time of year. 850 mb temps
will be a very frigid -12 to -16C, or 3 SD below normal per the
NAEFS. It will be blustery as well as 925 mb winds of 25-30 kt
should be in the middle of the mixing layer and represent
frequent gusts. This will produce wind chills as low as the
single digits for the southern Adirondacks/Greens and teens and
low 20s elsewhere.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
Dry and frigid weather is expected for Wed night into Thursday
morning, with mainly clear skies and light to calm winds as high
pressure passes over the region. Good radiational cooling is
expected, especially in areas with snow cover. Lows look to fall
into the teens, and some single digits are possible across the
high terrain of the Adirondacks and southern Greens.

After a cold and clear start, skies will gradually increase
during the day Thursday, as the next storm system approaches.
This will be a large cutoff low over the Mississippi Valley that
will be heading towards the Ohio Valley and mid-Atlantic states.
As this occurs, a rapidly developing surface storm will form
along the eastern seaboard of the mid-Atlantic States and head
northeast for Thursday night into Friday morning.

Plenty of cold air will be in place at the start of this storm.
Despite fighting some dry air at low levels, isentropic lift
should allow for a period of snowfall to move from south to
north after sunset on Thursday and continue into Thursday night.
Depending on the exact track of the developing storm, some
warming temps around 800-850 hpa could allow for precip to
change over to sleet/freezing rain or plain rain by late
Thursday night into Friday morning, although the greatest threat
for this looks to be for areas south and east of the Capital
Region. Steady precip looks to continue into Friday morning
thanks to nearby coastal storm. Have included some mixed precip
or rain for southern/eastern areas, as well as valley areas
towards the end of the storm, as boundary layer temps warm
during the day on Friday.

Although the models show some variability of exact QPF, there is
some consistency amongst the 12z NAM12/ECMWF/FV3-GFS, while the
GFS and some members of the SREF are much lighter with precip
amounts (thanks to a farther east track of the surface storm).
For now, will favor heavier precip solutions. This would results
in a widespread 2 to 6 inches of snow across the area, with
some locally higher totals in the high terrain (especially
across southern VT). We will continue to mention this storm in
our HWO.  Precip should end by early afternoon Friday, with a
few lingering rain or snow showers (especially northern and high
terrain areas). Temps look to mainly be in the 20s to near 30 for
Thurs night and rising into the 30s for Friday.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Friday night and Saturday...Cool and breezy conditions will build
into the region as the cyclone departs to the northeast with some
lake enhanced snow showers over the Adirondacks. WNW flow will favor
some upslope snow showers over the Adirondacks and southern Green
Mountains of Vermont resulting in light snow accumulations under an
inch. Lingering isolated snow showers will persist through Saturday
with moist cyclonic WNW flow overhead. Lows Friday night will be in
the mid 20s to mid 30s and highs on Saturday will be in the mid 30s
to mid 40s.

Sunday through Tuesday...Deterministic guidance begins to deviate
greatly starting Sunday and continuing through the end of the long
term period. The past couple runs of the GFS and Canadian have been
hinting at a clipper-like low progressing through the region on
Sunday while the ECMWF has high pressure building overhead. Subtle
differences within the mean longwave trough seem to be resulting in
large differences in the surface pressure fields and tangible
weather. Regardless, multiple pieces of energy look to break off a
zonally oriented PV streamer, resulting in weak forcing for ascent
in regions of high pressure advection on the 1.5 PVU surface, and
multiple chances for widely scattered rain and snow showers over the
region.

Some guidance suggests the potential for lake-effect snow over the
Adirondacks and western Mohawk Valley Monday into Tuesday as
westerly flow moves in and 850-hPa temps drop to -10 to -13 C. Heat
flux off the Great Lakes is evident in the boundary layer thermal
fields as an inverted thermal trough extending to the NW over the
Great Lakes region. Confidence is very low on the potential for
early week lake effect snow though, given the large discrepancies in
the upper flow patterns between the deterministic models.

Temperatures throughout this period will continue below normal
thresholds with highs in the 20s and 30s and lows in the teens and
20s.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A band of snow effect snow has developed off of Lake Ontario
and will persist through the overnight hours. The band extends
into the western Mohawk Valley with pieces breaking off and
moving eastward across the Schoharie Valley and mid Hudson Valley.
KALB could be impacted by some snow showers and have addressed
this threat with A TEMPO group with MVFR conditions. The lake effect
activity will diminish as high pressure builds in this afternoon.
Otherwise, VFR conditions are expected at the other TAF sites
through the TAF period.

Westerly flow will persist through the night picking up early
Wednesday morning. The pressure gradient between a departing low
and advancing high will tighten resulting in brisk and gusty winds
through much of the day with gusts approaching 30 knots. Winds
are expected to quickly diminish in the evening as the high
takes control.

Outlook...

Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: No Operational Impact. NO SIG WX.
Thursday Night: High Operational Impact. Definite SN.
Friday: High Operational Impact. Definite RA...SN.
Friday Night: Low Operational Impact. Slight Chance of SHRA...SHSN.
Saturday: No Operational Impact. NO SIG WX.
Saturday Night: Low Operational Impact. Slight Chance of SHSN.
Sunday: Low Operational Impact. Slight Chance of SHRA...SHSN.

&&

.FIRE WEATHER...
Drier, colder and breezy conditions are expected tonight into
tomorrow. Some gusts may exceed 30 MPH at times. More widespread
precipitation (mainly in the form of snow) is expected late
Thursday into Friday.

&&

.HYDROLOGY...
No hydrologic issues are anticipated through the rest of the
week.

Aside from some lake effect snow showers over the Mohawk and
Schoharie Valleys, Helderbergs and Catskills, mainly dry
weather is expected tonight into tomorrow. This will allow river
and streams levels to recede from the precipitation that fell
last night into this morning. Temperatures will be turning much
colder and it will rather frigid for Wed night into Thursday,
which could allow for some thin ice to begin to form on shallow
lakes and ponds.

A widespread precipitation event is expected late Thursday
through Friday morning. Precip will mostly be snow, but some
mixed precip or rain is possible for the second half of the
storm, especially for areas south and east of the Capital
Region. There probably won`t be enough liquid precip to have an
immediate impact on rivers and streams.  Drier and continued
chilly weather is expected behind this system for the weekend.

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...Frugis
NEAR TERM...Thompson
SHORT TERM...Frugis
LONG TERM...Cebulko
AVIATION...IAA
FIRE WEATHER...Frugis
HYDROLOGY...Frugis



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