Albany, NY WFO Forecast Discussion

Forecast Discussion for ALY NWS Office
000
FXUS61 KALY 192038
AFDALY

Area Forecast Discussion
National Weather Service Albany NY
438 PM EDT Thu Jul 19 2018

.SYNOPSIS...
Fair and dry weather will remain across the region
through the remainder of this week and into the start of the weekend.
Unsettled weather conditions are expected to return over the second
half of the weekend, as waves of low pressure along and ahead of a
frontal system slowly approaching from the south and west. Humidity
levels will be on the increase heading into early next week.

&&

.NEAR TERM /THROUGH FRIDAY/...
Very quiet weather with mostly clear skies is expected through
Friday as high pressure moves across the area. Temperatures
early this morning bottomed out a few degrees below MOS blends
and expect a similar bias again late tonight with ideal
radiational cooling conditions expected for late July. Based on
this have gone a few degrees below MOS blends with lows in the
40s in normally cooler locations and mostly lower to mid 50s
elsewhere. Patchy fog will develop once again in cooler
locations especially near a water source. Temperature on Friday
will likely be a few degrees warmer than today with highs in the
mid 80s at lower elevations and upper 70s to lower 80s over
higher terrain.



&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
Quiet weather will continue Friday night through most of
Saturday as high pressure moves off the northeast U.S. coast and
dry weather continues.

Unseasonably deep mid-level low pressure will advance toward
the area from the midwest beginning Saturday night. A jet max
will swing east then northeast around the east side of this
upper low, moving up the east coast Saturday night. This will
initiate surface cyclogenises along the mid-Atlantic coast by
late Saturday with the surface through mid-level cyclone moving
north up the east coast Saturday night into Sunday. There is
some uncertainty as to the exact track of this system, with many
of our operational models now tracking the surface low north
through New Jersey and into central or eastern NY by early
Sunday. However the latest ECMWF is somewhat of an easterly
outlier tracking the surface system north-northeast across New
England. Details on the track of this system will determine
where the heaviest rain falls. This system will have plenty of
moisture and will also be associated with an anomalously strong
low-level east-southeast flow on its east side, so there will
certainly be the potential for a period of very heavy rain late
Saturday night into early Sunday, especially over higher terrain
where the low-level flow will enhance precipitation amounts via
upslope, but where that occurs is still highly uncertain.
Regardless of the details, periods of rain look to be a good bet
Saturday night into early Sunday.


The steadiest rain will move north-northeast of our area
Sunday morning, to be replaced by scattered showers and
thunderstorms by Sunday afternoon as we will be within a warm,
moist and murky southerly flow and lots of moisture. Localized
heavy rain will be a threat from any convection Sunday afternoon
given the uni-directional southerly flow and ample moisture.
Clouds will keep temperatures down to around 80 degrees at most
locations.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A very amplified and stable upper pattern is expected next week with
upper ridging building into the eastern U.S. from the Atlantic and
strong upper energy and troughing approaching from south central
Canada.  The upper low in the OH Valley retrogrades south and west
and weakens but the southwest upper flow between the strong Atlantic
upper ridge and the approaching southern Canada upper energy should
support a continued decent SW/NE oriented low level pressure
gradient across the eastern U.S.

So, from Monday through Thursday, the zone of deep tropical moisture
sets up over the eastern U.S. with above normal southwesterly
boundary layer flow, strongest during the afternoon and evening each
day. The axis of strongest boundary layer winds slowly shifts east
toward New England by Thursday but with all the tropical moisture in
place and approaching upper energy from Canada, coverage of showers
and thunderstorms will continue to be quite noticeable even later in
the week.

Again, tropical moisture, potentially at or above 2 inch PWAT values
in some areas all week, along with the low level forcing/winds
within the pressure gradient, will result in showers and storms
likely Monday afternoon, Tuesday afternoon and Wednesday afternoon,
with the usual decrease in coverage each night with the diurnal
stabilizing that occurs at night.  Scattered showers and storms
Thursday but could be raised to likely as we get closer to the
middle of next week, depending on how the upper and surface features
evolve.

There should be more clouds than sun each day but a few breaks in
the clouds each morning before the afternoon expansion of the
showers and thunderstorms.  The few breaks in the clouds should
allow for enough sun for temperatures to get solidly into the 80s
each day but upper 70s to around 80 in higher terrain. Each night
should be uncomfortable with lows in the upper 60s to lower 70s.

&&

.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
High pressure will continue to be over NY and New England this
afternoon through tonight, and will slowly shift east of the
region tomorrow.

VFR conditions are expected the rest of the afternoon and prior
to midnight due to the strong subsidence with the sfc high. A
few diurnal cumulus will be around, but will dissipate by
sunset.

Ideal radiational cooling conditions are expected, and some
radiational mist/fog is possible at KGFL/KPSF especially between
06Z-12Z. The best chance for IFR/LIFR radiational fog will be at
these two sites. Some patchy shallow fog may form at KALB/KPOU
but vsbys should hold as VFR/high MVFR.

The mist/fog should dissipate quickly between 10Z-12Z/FRI, and
VFR conditions will return with just a few cirrus or cumulus
around.

Light and variable winds of 5 kts or less are likely the rest of
the afternoon. The winds will become calm early this evening
around 00Z. The winds will be light from the southeast at 5 kts
or less towards noontime FRI.

Equipment note...at KPSF electrical work is ongoing on the
field. Power has been cut to ASOS. Therefore TAF is issued as
AMD NOT SKED.

Outlook...

Friday Night: No Operational Impact. NO SIG WX.
Saturday: No Operational Impact. NO SIG WX.
Saturday Night: Moderate Operational Impact. Likely SHRA.
Sunday: High Operational Impact. Likely SHRA...TSRA.
Sunday Night: High Operational Impact. Likely SHRA...TSRA.
Monday: High Operational Impact. Likely SHRA...TSRA.
Monday Night: High Operational Impact. Likely SHRA...TSRA.
Tuesday: High Operational Impact. Likely SHRA...TSRA.

&&

.FIRE WEATHER...
Fair and dry weather will persist through the remainder of this
week and the start of the weekend. Unsettled conditions may
return over the second half of the weekend as a frontal system
slowly approaches from the west.

RH will fall to 30-40 percent this afternoon and recover to
80-100 percent late tonight, with areas of dew formation
possible.

Winds will be from the north to northwest at 10 mph or less today,
then become light/variable tonight. Winds will be mainly from
the southerly direction at 5-10 mph Friday.

&&

.HYDROLOGY...
Dry weather is expected through at least Saturday.

A slow moving frontal system approaching from the west, along
with a several waves of low pressure tracking northward within
a very moist airmass in place, could lead to frequent showers
and thunderstorms, some with locally heavy downpours for Sunday
through at least the middle of 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.
NY...None.
MA...None.
VT...None.

&&

$$
SYNOPSIS...BGM/Wasula
NEAR TERM...MSE/BGM/Wasula
SHORT TERM...MSE/BGM
LONG TERM...NAS
AVIATION...Wasula
FIRE WEATHER...KL/BGM
HYDROLOGY...KL/BGM

NWS ALY Office Area Forecast Discussion