224
FXUS61 KALY 120555
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
155 AM EDT Mon Aug 12 2024

.SYNOPSIS...
A passing upper level disturbance will continue to allow
for a passing showers and isolated thunderstorms for tonight into
Monday, especially for northern parts of the area.  Temperatures
will continue to run a little below normal for mid August.  Mainly
dry weather is expected for the middle portion of the week, with
temperatures returning close to normal.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Some widely scattered, light showers linger to the north and
west of the Capital District this morning as noted on the KENX
radar with water vapor imagery showing the upper shortwave
trough axis currently located over western New York. As such,
some low stratus have developed over the Southwest Adirondacks
and western Mohawk Valley with mainly clear skies elsewhere
creating an environment supportive of radiational cooling. Some
valley fog has already begun to form, so maintained fog in the
forecast throughout the remainder of the overnight period.
Temperatures primarily span the 50s with low 60s noted in the
lower Mid-Hudson Valley by the NYS Mesonet. With the forecast in
good shape, only minor adjustments were needed with this update
to maintain consistency with the latest obs. Additional details
can be found in the previous discussion below.

PREVIOUS DISCUSSION:
Upper level shortwave trough is currently located over eastern
Ontario and western Quebec and is heading eastward towards the
Northeastern US. Satellite imagery shows clouds have been
increasing across northern areas over the last few hours thanks
to the approaching upper level shortwave. Radar imagery shows
some broken bands of showers and embedded thunderstorms moving
across western and central New York, with some additional
activity also across the Tug Hill and North Country. Based on
radar trends and CAMs, some of this activity will work its way
towards the western Adirondacks and Mohawk Valley for early this
evening and it may also spread towards the Capital Region, Lake
George Saratoga Region and southern Vermont by the late evening
hours.

SPC mesoanalysis shows only limited instability across the area,
with SBCAPE 250-500 J/kg. Some better instability is located
over western New York with closer to 1000 J/kg there. With the
approaching upper level shortwave, there is decent shear in
place, with 0-6 km bulk shear values around 40-50 kts and strong
low-level lapse rates thanks to daytime heating. However, mid
level lapse rates aren`t too high (less than 6 deg C/km) and
moisture is lacking (surface dewpoints only in the 50s and PWATs
under an inch). As a result, there may be some organization to
convection today, but storms aren`t expected to grow too tall or
strong due to the limited instability. While some showers and a
few rumbles are possible across northern areas, severe weather
is not anticipated through this evening. However, a brief burst
of rain, along with some gusty winds and even some small hail
cannot be totally ruled out, but no storms should be strong
enough to produce damage.

With the loss of daytime heating, showers and thunderstorms will
be starting to diminish after sunset and should be mostly gone
by about midnight or so. A stray shower can`t be totally ruled
out for the late night hours over the Adirondacks thanks to the
cool flow aloft over the Great Lakes, but any late night showers
look light and isolated and limited to just the far northwestern
Adirondacks. Otherwise, expect a partly cloudy sky for the
overnight hours with comfortable temps in the 50s.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
Upper level shortwave trough will be moving eastward on Monday
and will be sliding by to the north of the area across northern
New England. With the upper level flow becoming northwesterly, a
few additional diurnally-forced showers or a rumble of thunder
will continue to be possible. Highest coverage will be across
northern areas, although can`t rule out a shower across any part
of the area by afternoon. Again, instability and moisture will
be limited, so no strong/severe weather is expected. Temps will
be a little below normal once again with valley highs only in
the 70s (60s in the high terrain).

Behind this departing shortwave, dry weather is expected through
the rest of the short term period for Monday night through
Tuesday night. A broad trough will still be in place over the
Northeast, so it won`t be too warm, although it start to
moderate somewhat back towards normal. Highs will be in the mid
to upper 70s on Tuesday, with 50s again at night.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Mainly quiet weather looks to continue through the long term
period.

Our area will remain on the backside of a large upper level
trough on Wednesday but moisture remains limited, so will keep
POPs low for Wednesday. Temps looks a little closer to normal
with valley highs reaching into the lower to middle 80s. By
Thursday, some models suggest that the closed upper level
trough may retrograde back towards the area, so there could be
some diurnally-forced showers and thunderstorms, especially for
eastern areas. Will go with slight to low chance POPs for now,
with temps still close to normal.

While Friday should be dry once again, there could be a better
chance for showers and thunderstorms over the weekend as the
next system approaches from the west. With timing still
uncertain, will just keep POPs at chance for now and temps will
continue to be fairly close to normal. At this point, no threat
for any high heat or humidity looks to occur at this time.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
Through 06Z Tuesday...An upper level low will continue to
impact the TAF sites today. Some scattered showers moved through
yesterday. The recent wet ground combined with light to calm
winds allowed IFR/LIFR fog and stratus form at KPSF. We kept the
LIFR/IFR conditions in the TAF until 10Z/Mon, when conditions
should rise back to VFR after sunrise. The rest of the TAF sites
should remain VFR, except KGFL where some MVFR stratus and
patchy mist may form. We used a TEMPO group to address this.
Some mid and high clouds may persist at KALB/KPOU with a south
to southwest breeze to keep conditions VFR.

Expect sct-bkn stratocumulus with some mid and high clouds around in
the late morning into the afternoon at all the TAF sites with VFR
conditions.  Another sfc trough and a short-wave moving around the
upper low will bring some scattered showers and isolated
thunderstorms.  We used PROB30 groups in the 16Z-22Z/MON time frame
with MVFR vsbys/cigs. The limited instability raised enough
uncertainty to keep thunderstorms out of the TAFs so far.  Expect
and improvement to VFR conditions around 00Z/TUE with few-sct
stratocumulus and some mid or high clouds.

The winds will be light to calm at KPSF/KPOU and south to southwest
at 7 KT or less at KALB/KGFL.  The winds will be south to west at 5-
10 KT in the late morning and then increase from the west to
northwest at 8-12 KT in the afternoon with some gusts 15-20 KT.  The
winds will become light and variable after 00Z/TUE.

Outlook...

Monday Night to Wed Night: No Operational Impact. NO SIG WX.
Thursday: Moderate Operational Impact. Chance of SHRA...TSRA.
Thursday Night: No Operational Impact. NO SIG WX.
Friday: No Operational Impact. NO SIG WX.

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.

&&

$$

SYNOPSIS...Frugis
NEAR TERM...Frugis/Gant
SHORT TERM...Frugis
LONG TERM...Frugis
AVIATION...Wasula