597
FXUS61 KALY 070755
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
355 AM EDT Tue May 7 2024

.SYNOPSIS...
High pressure will bring mostly sunny skies and warm
temperatures for today. A storm system will bring some showers
and thunderstorms late tonight into Wednesday, with unsettled
weather and cooler temperatures expected for Thursday and
Friday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 345 AM EDT, high clouds are shifting south/east of the
region, with mainly clear skies and light/calm winds. With low
PWAT`s (around or under 0.50") and clear skies, temps have
dropped into the mid/upper 30s across the SW Adirondacks, and
lower/mid 40s for many areas north of I-90. Temps are warmer to
the south, ranging from the upper 40s to lower/mid 50s. Temps
will likely drop another 2-4 degrees from current levels by
daybreak.

Patchy fog has developed within portions of the mid Hudson
Valley, where boundary layer remains moist. Additional patchy
fog may develop across portions of the upper Hudson Valley prior
to daybreak.

After the chilly start and any fog lifts, expect mostly sunny
skies today with a warm afternoon as mixing depth increases to
at least H800. Expect afternoon temps to reach the lower/mid 70s
for many valley areas, except 75-80 within the Hudson River
Valley from Albany south to Poughkeepsie.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
Clouds increase this evening, with showers/thunderstorms
developing from west to east between 3 and 5 AM ahead of
strengthening low/mid level jet max and warm advection.
Showalter Indices drop to between zero and -2C for areas south
of I-90 by daybreak, so expect some rumbles of thunder within
these areas.

Showers and embedded thunderstorms should continue to move
eastward across the region through mid morning Wednesday before
tapering off from west to east. There should then be a lull in
showers/thunderstorms during the late morning hours.

Low confidence forecast for Wednesday afternoon, as model
guidance offering widely varying possibilities, with some hi-res
guidance suggesting warm front advances north and east before
stalling north of I-90 in the afternoon, while other guidance
suggests warm front shifts through the entire region with gusty
west/southwest winds enveloping many areas and some drying for
the afternoon. Have favored NBM for general evolution of weather
conditions for Wednesday afternoon, with afternoon warming for
areas south of I-90 (max temps in the 70s to perhaps lower 80s) and
remaining cooler to the north (max temps mainly 65-70).

Favoring NBM guidance also would suggest best chance for
additional afternoon showers/thunderstorms would be for areas
south of I-90, where highest probabilities of MU CAPES >500 J/kg
exists. There will be strong 0-6 km shear across the region
(45-55 KT), mainly unidirectional. This would suggest that
should any convection develop, gusty winds and hail could
accompany strongest cells. However, there will be quite a bit of
mid level dry air entraining into the region behind the morning
convection, which could greatly limit overall coverage of any
afternoon convection. At this time, it appears that coverage may
remain isolated to scattered at best, however should any
thunderstorms develop, they could contain damaging wind gusts
and hail. SPC has placed most of eastern NY/western New England
within a Marginal Risk for severe thunderstorms for Wednesday
afternoon.

There could be a few stronger thunderstorms across northern
areas later in the afternoon as well, closer to approaching
shortwave and within an area of steeper mid level lapse rates
(7-8 C/km).

Showers/thunderstorm threat should diminish Wednesday evening,
with patchy fog developing. The next system approaches for
Thursday afternoon and night although there remains uncertainty
in how quickly this system approaches. Some showers may develop
Thursday afternoon, with better chances at night, especially for
areas near and south of I-90. Lows Wednesday and Thursday night
in the 40s to lower 50s, and highs Thursday mainly in the upper
50s to lower/mid 60s.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
The extended forecast continues to feature wet and unsettled weather
into the weekend.  A sfc cyclone and its occluded front will
continue to bring periods of rain to forecast area on Friday.  The
500 hPa low closes off over southeast Ontario and the Great Lakes
Region, as the longwave trough remains positively tilted.  Damp and
cool conditions prevail with max temps running about 10 degrees
below normal with mid 40s to lower 50s over the the higher terrain
and mid and upper 50s in the valleys.  The mid and upper level low
remains near or over eastern NY and New England Friday night into
Saturday.  The rain tapers to scattered showers Fri night. Some
intervals of dry weather are possible on Saturday.  However, the
upstream long wave trough amplifies, as a sfc trough rotates around
the cyclone near Nova Scotia.  We can not rule out a chance of
showers based on the latest medium range and ensemble guidance. Lows
will be chilly with upper 30s to mid 40s over the forecast area
Friday night.  Highs on Saturday with abundant clouds and the chance
of showers will be in the 50s to lower 60s.  Some upper 40s can not
be ruled out over the southern Dacks and southern Greens. Isolated
to scattered showers will continue Saturday night with lows in the
mid 30s to mid 40s.

The 2nd half of the weekend features more inclement weather with a
mid level trough over the Northeast, Ohio Valley and mid Atlantic
States.  A low pressure system and an occluded front will bring some
showers and isolated thunderstorms Sunday afternoon into Sunday
evening.  Temps will continue to run below normal with 50s to lower
60s for highs.  The good news is that the trough begins to lift out
of the forecast area Sunday night into Monday with some ridging
trying to build in from the south Monday afternoon.  Isolated to
scattered showers can not be ruled out, but some sunshine may be
mixed with clouds with temps trending to normal mid May readings.
The latest Day 8-14 Outlook for 14-20 May 2024 from CPC is
forecasting near normal temps with precipitation slightly above
normal.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
Through 06Z Wednesday...Aside for some patchy MVFR/IFR radiational
mist/fog at KPOU/KGFL this morning, expect VFR conditions for all
the TAF sites the next 24 hours.  IFR mist/fog with brief periods of
LIFR are possible at KPOU this morning and a TEMPO group was used to
address this potential prior to 10Z/TUE.  KGFL may have a brief
period of MVFR mist between 08-11Z/TUE where we used a TEMPO. Sct-
bkn cirrus will keep VFR conditions at KALB/KPSF.

Expect mostly clear conditions in the late morning into tonight with
a few cumulus and a few cirrus late in the day as high pressure
builds in.

The winds will vary in direction at 4 KT or less to calm this
morning. They will be northeast to northwest at 4-8 KT in the late
morning through the afternoon...and become light to calm by
00Z/WED.

Outlook...

Wednesday Night: Moderate Operational Impact. Scattered SHRA...TSRA.
Thursday: High Operational Impact. Likely SHRA.
Thursday Night: High Operational Impact. Likely SHRA.
Friday: High Operational Impact. Likely RA.
Friday Night: Moderate Operational Impact. Chance of SHRA.
Saturday: Moderate Operational Impact. Chance of SHRA.

&&

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

&&

$$

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