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fxus61 kaly 181129 
afdaly

Area forecast discussion
National Weather Service Albany New York
729 am EDT Wed Oct 18 2017

Synopsis...
high pressure over the mid Atlantic states will drift off the
eastern Seaboard through Thursday, providing dry conditions
with temperatures rising to above seasonal levels. Another high
pressure will build in from the southwest Friday into the
upcoming weekend, allowing dry and mild conditions to continue.

&&

Near term /until 6 PM this evening/...
as of 615 am EDT, just a few patchy clouds across mainly higher
elevations of the Adirondacks/southern Vermont. Otherwise, mainly
clear skies continue. Temperatures are widely varying due to
some wind and earlier clouds, with higher elevations mainly in
the 40s, especially across portions of the Adirondacks. In
valley areas, temperatures are in the upper 30s to mid 40s,
although some lower/mid 30s are noted across some lower spots in
the Berkshires.

For today, expect mostly sunny skies, with just some passing
patches of high/mid level clouds. It should be at least 5-10
degrees warmer than Tuesday due to a surge of warm advection
which occurred overnight, with late day highs reaching 65-70 in
most valley areas, and 60-65 across higher elevations.

&&

Short term /6 PM this evening through Friday night/...
tonight, could be another situation with widely varying
temperatures, as a low level jet and new surge of low/mid level
warm advection approach from the west after midnight. Expect
most lows in the 40s, although some lower elevations could
decouple prior to the increase in wind, allowing for some 30s to
occur, especially across portions of western Massachusetts/southern Vermont.
Also, there is a possibility of some fog/low stratus forming
and/or advecting northward up the Hudson and CT river valleys
toward daybreak, which is depicted most strongly by the higher-
res NAM.

Thursday, some areas of low clouds/fog could linger close to the
Hudson/CT river valleys in the morning, otherwise expect at
least a period of mostly sunny skies, before some mid level
clouds increase from northwest to southeast later in the day ahead of a
weakening cold front. Highs should reach around or slightly over
70 in most valleys, with 60s across higher elevations, although
there is some potential for additional warmth from downsloping
processes, which could allow high temperatures to overachieve
expectations in some areas, perhaps reaching the mid 70s. Since
this is low confidence, have sided closer to the slightly cooler
metmos, which handled a somewhat similar situation last Sunday.
Winds will increase in the afternoon from the south/southwest,
and could gusts up to 25 mph, especially across portions of the
Adirondacks, and within north/south valleys due to channeled
flow, such as the Hudson River valley.

Thursday night-Friday night, the aforementioned weak cold front
should move southeast across the region Thursday night, with
some clouds. Expect partly to mostly sunny skies Friday, with
clear skies for Friday night. Lows Thursday night should be
mainly in the 40s, with mainly 50s to mid 60s for highs Friday
as slightly cooler air settles southward. For Friday night, with
mainly clear skies/light winds, expect min temps to fall into
the 30s for many areas.

&&

Long term /Saturday through Tuesday/...
high pressure builds offshore Saturday and Sunday with gradual
warming over our region. Stronger warm advection occurs Monday into
Tuesday with the development of a highly amplified phased upper
system and associated low level forcing. Good consensus from
sources of guidance for the development of this system but as usual
this far out in time, the details of timing, strength and rainfall
totals very much in question.

The increased low level forcing and deep moisture associated with
the system will result in increasing chances for rain Monday through
Tuesday. There are uncertainties as to the timing of the deeper
moisture and stronger forcing but the onset of cold air advection
and passage of the upper trough axis looks to be generally toward
Tuesday night or later. As usual, this far out in time, changes and
adjustments to the forecast are expected periodically until we get
closer to the event.

Highs Saturday in the mid 60s to around 70. Highs Sunday in the
upper 60s to lower 70s. Highs Monday with rain potentially
spreading into our region in the mid 60s to lower 70s. More clouds
and widespread rain should keep highs Tuesday in the 60s but some
upper 50s northern areas.

&&

Aviation /12z Wednesday through Sunday/...
weak warm front bringing a few mid level clouds to northern areas
but not quite as far south as kgfl. Mainly a clear sky expected
through 12z Thursday.

Persistent light south winds are occurring through the Hudson Valley
and calm at times. The winds are stronger at 2000 feet and above,
which will result in low level wind shear but only through about 14z
when the winds aloft weaken.

Winds will be near calm to south up to 6-8 kt through mid morning.
South to southwest winds will persist at 6-8 kt mid morning through
this afternoon, then trend back to light or calm this evening.
Outlook...

Thursday night: no operational impact. No sig weather.
Friday: no operational impact. No sig weather.
Friday night: no operational impact. No sig weather.
Saturday: no operational impact. No sig weather.
Saturday night: no operational impact. No sig weather.
Sunday: no operational impact. No sig weather.

&&

Fire weather...
high pressure over the mid Atlantic states will drift off the
eastern Seaboard through Thursday, providing dry conditions
with temperatures rising to above seasonal levels. Another high
pressure will build in from the southwest Friday into the
upcoming weekend, allowing dry and mild conditions to continue.

The relative humidity will fall to 40-55 percent this afternoon, then
recover to 80-100 percent tonight, with areas of dew formation
likely. The relative humidity will fall to 35-45 percent Thursday afternoon.

Winds will be mainly south to southwest at 5-10 mph today, then
become light/variable tonight. On Thursday, winds will increase
from the south to southwest at 5-15 mph with some gusts up to
20-25 mph possible, especially across the Adirondacks.

&&

Hydrology...
no precipitation is expected through at least the weekend
thanks to persistent high pressure, with flows remaining at
normal to below normal seasonal levels. The next chance of
rainfall is early next week.

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.
New York...none.
Massachusetts...none.
Vermont...none.

&&

$$
Synopsis...kl/Thompson
near term...kl
short term...kl

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