Albany, NY WFO Forecast Discussion

Forecast Discussion for ALY NWS Office
128
FXUS61 KALY 192325
AFDALY

Area Forecast Discussion
National Weather Service Albany NY
725 PM EDT Wed Sep 19 2018

.SYNOPSIS...
High pressure over eastern Canada will bring dry seasonably mild
weather to the area tonight through Thursday. A warm front will
cross the area late Thursday night, possibly accompanied by a
few light showers, then warmer weather will return on Friday.
Showers will accompany a cold front moving across the area
Friday night, followed by a return to cooler weather again on
Saturday.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Boundary layer moisture trapped below dry layers and inversions
aiding in cloud cover development. Clouds are slowly spreading
south and there is a decent consensus in guidance that clouds
will spread across much of the region through the night.
Although, there should be some periods of breaks in some areas.
So, even with light to calm winds, temperatures may not fall
quite as much as they could if it was completely clear. Just
minor adjustments to temperatures and sky cover but also
eliminated the isolated showers from VT this evening as there
seems to be no shower development. The previous AFD has a few
more details and is below...

High pressure will bring clear to partly cloudy skies and near
seasonable temperatures across the area tonight with lows
settling down to the 40s and lower 50s overnight. With clear
skies, light winds and current dew points / cross-over temps in
the mid 50s there will likely be patches of fog developing
around and after midnight as temperatures fall to near the dew
point

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/...
Thursday will be a seasonably mild and dry day as surface high
pressure moves off the east coast and mid-level ridging holds
strong over the southeast and mid-Atlantic states. A warm front
will approach the area late Thursday and will pass east across
the region late Thursday night. Mid-level forcing will be very
limited with this system and low-levels will be rather dry,
however there may be enough lower level overrunning and
frontogentical forcing to produce a few light showers late
Thursday night into early Friday, with pops mainly in the 20 to
40 percent range.

Friday will be breezy and it will turn warmer once again behind
the warm front with temperatures rising well into the 70s in
most places. Dew points will be creeping up back into the lower
and perhaps middle 60s. At this point it does not look like
there will be much forcing for lift and precipitation through
the day Friday and we are keeping pops mainly below 30 percent
until late in the day when a cold front will approach from the
west. This front will cross our area Friday night. Instability
looks to be very limited, partially as a result of the
unfavorable overnight frontal passage timing, however deep
layer winds will be strong. Showers associated with the front
could contain some localized strong gusty winds and maybe a
rumble of thunder if any instability is realized along the
front. SPC currently has our area in a slight risk for severe
weather Friday and this would likely be in association with any
localized convective wind gusts that could develop along the
front. Any convection will be low-topped but fast-moving,
although it will likely be weakening as it moves east into
increasingly less unstable air. At this time it appears that the
best chance of rain will be during the evening Friday moving
rapidly from west to east.

Saturday will feature high pressure building across the area
associated with lowering humidity and near seasonably mild
conditions, which will be several degrees low than Friday.


.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Dry and seasonable Sunday and Monday with highs in the 60s to near
70 but around 60 in higher terrain.  A slow and gradual approach of
a fairly large scale upper trough in central Canada and the U.S.
will result in increasing warm and moisture advection Monday night
and Tuesday.

By Monday night and Tuesday there should be considerable clouds and
some scattered showers as one small upper impulse within the
southwest upper flow tracks through our region and enhances the warm
and moisture advection.  Highs Tuesday in the upper 60s to lower 70s
but some lower to mid 60s higher terrain.

Once the upper impulse exits, southwest upper flow will continue as
the large scale upper trough well to our west just inches east.
Boundary layer temperatures continue to warm as upper ridging
amplifies in the eastern U.S ahead of the upper trough.  There could
still be some scattered showers and possibly some thunderstorms as
the warmth and moisture contribute to some potentially better
instability.  Highs Wednesday in the 70s, maybe near 80 southern
areas and around 70 northern areas.

&&

.AVIATION /23Z WEDNESDAY THROUGH MONDAY/...
Low level moisture trapped under dry layers and inversions is
supporting the development and southward spread of some clouds
through this evening. There is a good consensus that the clouds
will spread to all TAF sites through the night. Ceilings that
will start near or just above 3000 feet will lower later tonight
to below 3000 feet, into the MVFR range. Light winds and periods
of breaks in the clouds could allow for some fog to develop at
KGFL and KPSF after about 07Z but generally MVFR visibilities as
long as the cloud cover dominates.

Ceilings will break up and clouds will become scattered while
rising above 3000 feet after about 13Z Thursday. Once the clouds
become scattered above 3000 feet, those conditions should
prevail through Thursday afternoon.

North to northeast winds at less than 10 Kt this evening will
becoming variable less than 5 kt tonight into Thursday morning.
Winds then become south to southeast at 6 Kt or less Thursday
morning into afternoon.

Outlook...

Thursday Night: Moderate Operational Impact. Chance of SHRA.
Friday: Moderate Operational Impact. Breezy Chance of SHRA...TSRA.
Friday Night: High Operational Impact. Breezy Likely SHRA...TSRA.
Saturday: No Operational Impact. NO SIG WX.
Saturday Night: No Operational Impact. NO SIG WX.
Sunday: No Operational Impact. NO SIG WX.
Sunday Night: No Operational Impact. NO SIG WX.
Monday: No Operational Impact. NO SIG WX.

&&

.FIRE WEATHER...
High pressure will gradually build into the region into tonight,
providing drier, cooler and less humid weather. Seasonable
temperatures are expected through Thursday. An approaching warm
front will bring the next chance of light showers Thursday night
into Friday with the best chance being north and west of the
Capital District. The best chance of rain will be Friday night
with the passage of a cold front, followed by dry weather
Saturday.

RH values will increase to around 90 to 100 percent again tonight, then
decreasing to 50 to 55 percent during the day Thursday.

Winds tonight less than 10 mph, shifting to southeast at 5 to 15 mph on
Thursday.

&&

.HYDROLOGY...
Dry weather is forecast through Thursday. The next chance of
some rainfall will be late Thursday into Friday, as a warm front
advances northward across the region. Best chances look to be
across the northern half of the area.

A cold front will bring additional showers and perhaps some
thunderstorms Friday afternoon and night. Then drier weather is
expected to return for the upcoming weekend into 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.
NY...None.
MA...None.
VT...None.

&&

$$
SYNOPSIS...MSE
NEAR TERM...MSE/NAS
SHORT TERM...Frugis
LONG TERM...NAS
AVIATION...NAS
FIRE WEATHER...BGM/JPV
HYDROLOGY...BGM/JPV

NWS ALY Office Area Forecast Discussion