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fxus61 kaly 201121 
afdaly

Area forecast discussion
National Weather Service Albany New York
621 am EST Wed Nov 20 2019

Synopsis...
rather cloudy, cool and damp day is in the forecast today as low
pressure remains in the vicinity. This system will track
eastward tonight as high pressure returns for Thursday with
breaks of sunshine. However, our next weather system approaches
Thursday night into Friday with increasing chances for wintry
weather and breezy conditions.

&&

Near term /through tonight/...
as of 615 am EST...drizzle observed here at the forecast office
as per the 88d rather light reflectivity. The past couple of
0.5 degree scans reveal a slow expansion and a little westward
so we made slight adjustments to those grids. Otherwise, not
much change as temperatures overnight remained nearly stagnate
with lower to middle 30s.

Prev disc...water vapor imagery this early Wednesday morning
depicts moisture continues to advect northward as the center of
the upper low, within the larger scale trough across the
northeast corridor, continues its proximity approach. This in
turn will deepen the moisture profiles across a good portion of
the region, with the deeper moisture along with modest lift
mainly along and east of the Hudson River. Hires and href
reflectivity forecasts suggest the ongoing spotty drizzle/light
snow/light rain will increase a bit in coverage throughout the
day as upper trough amplifies a bit further with approaching
wave. As for precipitation types, cross sections and point
soundings suggest the drizzle or patchy freezing drizzle,
dependent on those critical surface temperatures, will become
light rain/snow as both the moisture profiles thicken above ice
nuclei layers and boundary layer temperatures moderate a bit
today. Further west of the Hudson, a mainly dry day is expected.



Overall, a mostly cloudy, cool day is expected today, with
highs mainly in the 30s to lower 40s.

This aforementioned low tracks off the coast of Cape Cod this
evening as high pressure and subsidence increase. However,
moisture below this inversion will likely get trapped which
makes the cloud and temperature forecast a bit of a challenge.
Per coordination grids, we will begin with clouds and show
improvements for valley and southeast portions of the County Warning Area
overnight as lows will generally fall into the mid and upper
20s.

&&

Short term /Thursday through Friday/...
high pressure will transverse the cwa through the daylight hours
Thursday for a generally a tranquil and party sunny day for most
areas. However, upstream approaching positively tilted trough
axis across the northern plains and upper Mississippi River
valley will increase cloud coverage toward sunset for western
areas. Highs Thursday expected to climb well into the 30s and
upper 40s for Mid-Hudson valley and portions of Litchfield
County.

Thursday night, warm front is expected to move across the region
with best isentropic lift to the northwest and north of Albany.
This is where we will place the higher pops in the forecast
grids. As for precipitation type, a period of wintry mixture
(ra/sn/ip/fzra) is anticipated as temperatures will be generally
30-35f with slowly rising values overnight. Quantitative precipitation forecast appears to
remain light with generally less than one tenth of an inch.

Friday, a strong cold will move across the region during the
morning hours. Rain and snow showers will accompany the frontal
passage with the best chance across the terrain. After fropa, an
abrupt shift of the winds will occur and become west-northwest
with an increase in magnitudes. Forecast mixing layer heights
and momentum Transfer shows potential for wind gusts to approach
40kts Friday afternoon. If this continues to increase with
future guidance, may need wind headlines for portions of the
area. H850 temperatures plunge back toward an average of -10c by
the end of the daylight hours as early highs will range from
around 40f for the dacks to lower 50s for the Mid-Hudson valley
and Litchfield County, CT.

&&

Long term /Friday night through Tuesday/...
main focus in the long term is a low pressure system which could
potentially bring some rain and snow to the forecast area over the
weekend. First, Friday night looks to feature subsidence behind a
strong cold front as midlevel heights rise. Winds are expected to
remain gusty overnight with continued pressure rises. Saturday looks
to be a dry period as the high quickly crosses the area. Saturday
night into Sunday morning look to be the periods where the
approaching low pressure system could impact the forecast area.
There is still considerable uncertainty related to the track of the
low. Recent model trends have been to produce a Miller b type storm,
with the primary low moving northeast to the west of the appalachian
crest giving way to secondary development east of the Appalachians.
Trends within the last 24 hours have been for a track closer to the
coast, which has increased confidence for measurable precipitation.
However, there is still considerable spread among the deterministic
models and ensemble members, so there is not enough confidence for
likely pops yet. Pops were increased relative to the previous
forecast, however. The airmass on the cold side of the low does not
look overly cold, so a variety of precip types are on The Table. For
now, simply went with a mix of rain and snow over most of the area.

Indications are that a period of tranquil weather ensues in the wake
of this system for early next week. Temps during the entire
long term period look to not stray too far from normal.

&&

Aviation /11z Wednesday through Sunday/...
moisture near the surface associated with yesterday morning's
snow never mixed out with light winds in place, so visibility
and ceilings at kalb and kgfl are in IFR/LIFR range. Expect this
to continue through sunrise, with periods of drizzle as well.
Temperatures nearing the freezing level could result in periods
of freezing drizzle, and light accretion on elevated surfaces
cannot be ruled out if a prolonged period of freezing drizzle
occurs. However, confidence in the occurrence of drizzle
coinciding with freezing temperatures is not high enough to
place in the tafs at this point. At kpsf, ceilings remain at
MVFR, but there is some evidence to suggest they will continue
to fall to IFR levels for the remainder of the night. Kpou is
likely to remain mainly VFR, although some periods of MVFR
visibility in mist and MVFR ceilings cannot be ruled out.

After sunrise, north-northwesterly winds increase, which should
allow the IFR/LIFR cigs/vsby to mix out. Some periods of drizzle
or flurries cannot be ruled out at kgfl/kalb/kpsf. Though
overcast skies will likely continue throughout the day, forecast
soundings suggest the low level moisture will mix out such that
ceilings become VFR by the afternoon or evening.

Light winds for the rest of the night will become north-
northwesterly at 5 to 10 kt around sunrise through the rest of
the taf period.

Outlook...

Thursday night: low operational impact. Slight chance of rain.
Friday: moderate operational impact. Windy. Isolated rain showers.
Friday night: moderate operational impact. Windy with gusts to
33.0 no sig weather.
Saturday: low operational impact. Slight chance of rain showers...shsn.
Saturday night: moderate operational impact. Chance of
rain showers...shsn.
Sunday: moderate operational impact. Chance of rain showers...shsn.
Sunday night: no operational impact. No sig weather.
Monday: no operational impact. No sig weather.



&&

Fire weather...
rather cloudy, cool and damp day is in the forecast today as low
pressure remains in the vicinity. This system will track
eastward tonight as high pressure returns for Thursday with
breaks of sunshine. However, our next weather system approaches
Thursday night into Friday with increasing chances for wintry
weather and breezy conditions.

&&

Hydrology...
precipitation amounts will generally be less than a tenth of an
inch through the rest of the week and into the first half of the
weekend. River levels will be steady or slowly falling through
the period. Next chance for more widespread precipitation
arrives for the second half of the weekend.

For details on specific area rivers and lakes, including latest
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.
New York...none.
Massachusetts...none.
Vermont...none.

&&

$$
Synopsis...bgm
near term...bgm
short term...bgm

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