Albany Office Forecast Discussion

000
FXUS61 KALY 121758
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
158 PM EDT Fri Apr 12 2024

.SYNOPSIS...
Afternoon showers and a few rumbles of thunder exit by
sunset with winds shifting to the southwest and remaining breezy.
Winds stay breezy overnight with much cooler air overspreading the
region in the wake of a cold front. Additional rain and even snow
showers for the higher terrain return tonight and continue into the
day tomorrow. We remain breezy and turn noticeably colder
tomorrow.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1pm EDT...A potent ~978hPa closed low is located in
southern Ontario with strong kinematics continuing over much of
the Northeast with VAD ENX wind profile showing unidirectional
southerly winds ranging 30 - 40kts winds extending through much
of the column. Dew points this afternoon remain quite high in
the upper 50s to around 60 and with some thinning of the clouds,
some surface based instability is present but generally under
1000 J/kg. A boundary continues to track north and east through
the Southern Tier and is now approaching the Catskills and
Central NY this afternoon. With the forcing for ascent generally
parallel to the wind field, precipitation remains oriented in a
north-south line of low topped convection and continues to
track north and eastward through eastern NY this afternoon.
With PWATS still near or slightly over 1", there are pockets of
locally heavy rain that have resulted in a quick 0.25" in an
hour or less. The steadiest rain remains east of the Hudson
River with a few scattered showers in western New England but
this rain will push eastward over the next few hours.

Given the strong wind field, forcing for ascent, and elevated
dew points, SPC introduced a Marginal Risk for severe weather
mainly in areas that have not experience much rain so far today,
namely the Upper Hudson Valley, southern VT and areas
north/east of Albany. These areas have not been worked over yet
and the SPC mesoscale analysis shows 0-3km shear values 30 -
40kts and SB CAPE values ~500J/kg. Thus, as the line of
convection approaches this environment, a few stronger storms or
line segments may develop resulting in locally stronger gusty
winds. Surface winds today have already been gusty with gusts up
to 30mph so it may be hard to differentiate between strong
winds from any storms and the synoptic winds.

The area of rain and storms should gradually track north and
east through the rest of the afternoon exiting into New
England/the North Country by 4-6pm. Besides some brief gusty
winds and lightning, heavy downpours are also likely during any
storms with NYS mesonet observations already showing a quick
0.25 - 0.30" of rain falling in less than an hour from patches
of heavier rain and storms. With some river basins already
running high (especially in the eastern Catskills), the
additional rainfall may push some rivers closer to flood stage.
We will continue to monitor the potential for additional or
renewed river flooding. Total additional QPF amounts expected
to range 0.25 - 0.50" through sunset.

Otherwise, many have already reached their high temperature
for today, reaching into the mid-60s to even close to 70 before
gradually dropping over the past few hours thanks to the rain
and increasing cloud coverage. Once the line of convection and
rain exits later this afternoon, winds shift to the southwest
in its wake and will turn gusty as guidance indicates a period
of quick pressure rises immediately behind the trough axis.
However, given the main cold air advection is delayed until
closer to 06 UTC when the trough axis pushes through, it will
be tough for the strongest winds to mix down to the sfc. Still
expecting a brief window later this afternoon (3 - 7 PM) for
gusts to reach 30 - 40mph as the winds shift to the southwest,
especially in western New England and the Taconics.

We will have a brief dry yet breezy period this evening before
the trough axis and upper level closed low moves overhead
towards or after Midnight ushering in a much cooler air mass
and wrap around precipitation thanks to moist, cyclonic flow.
Winds shift from the southwest to west overnight in the wake of
the trough axis, resulting in cold air advection. Temperatures
trend into the 40s in the valley with 30s in the higher
terrain. Rain showers may mix with or even turn to mainly wet
snow showers in the higher terrain of the southern Adirondacks
as temperatures drop into the low to mid 30s by the pre-dawn
hours. Additional rain amounts overnight are still expected to
be much lower compared to the daytime with just around or under
0.10" expected. With breezy westerly winds continuing overnight
and froude numbers remaining under 1 suggesting blocked flow,
some upslope showers should lead to enhanced precip amounts on
the west facing slopes of the Taconics and southern Greens.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Low pressure will continue to lift northward across Ontario and
into western Quebec for tonight into Saturday. The upper level
trough axis will be moving across the region during this time as
well. The combination of wraparound precip around the low
pressure area and the cyclonic flow with the upper level trough
will allow for some additional showers to develop and spread
across the area for late tonight into Saturday. While most areas
will start off dry this evening, the threat for showers will
increase through the overnight, especially northern, western and
high terrain areas. With some colder air moving in aloft, there
could be some wet snow that mixes in for the western
Adirondacks, but any light accumulation will be limited to the
highest terrain. Most of these showers should be fairly light in
intensity and additional QPF will generally be under a quarter
of an inch with this activity.

While some partial clearing is possible this evening (mainly
southern areas), clouds will return for late tonight and skies
should stay fairly cloudy through the entire day on Saturday.
Temps will fall into the mid 30s to mid 40s for tonight and will
only rise into the 40s to near 50 for Saturday (only upper 30s
in the highest terrain).

Clearing looks to finally return on Saturday night as the storm
system moves away from the area and high pressure tries nosing
in from the south. Temps should fall into the 30s.

The dry and quiet weather will be short-lived, as another
northern stream disturbance will rotate towards the area for
Sunday into Sunday night. Clouds will return and there will be
the threat for additional light rain showers, mainly Sunday
afternoon into Sunday evening. A rumble of thunder is possible
for southern areas as well. Temps will be milder than Saturday
with 50s for most areas. Some clearing will return again by late
Sunday night with temps falling into the mid 30s to mid 40s
behind the departing system.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Long term period begins at 12z Monday with upper troughing or an
upper low centered north of the region. With the core of the cold
air centered north of our area, northwest winds will result in
neutral to cold advection, and winds could be breezy with high
pressure to the west and a surface low off to our northeast. Skies
will likely be partly cloudy. This pattern will support deep mixing,
so bumped up daytime highs a few degrees above NBM guidance.
Temperatures will likely top out in the low to mid 60s for valleys
with 50s for the high terrain. Surface high pressure moves overhead
Monday night and Tuesday, with ridging building in aloft. Monday
night and Tuesday remain mainly dry, with lows in the 30s to
around 40 Monday night. Tuesday will be a few degrees warmer with
highs in the 60s to around 70 for the valleys and upper 50s to low
60s in the higher elevations.

Tuesday night through Thursday night...Lower forecast confidence for
this period, as our weather will depend on the complex evolution of
an upper low that gets sheared out by the flow as it tracks near the
Great Lakes and a second upper low located further to the west that
eventually tracks eastwards towards our area by the end of the
forecast period. Guidance suggests that as a surface low tracks into
the Great Lakes in association with the first upper low, its warm
front lifts northward across the region sometime Wednesday or
Wednesday night, although the exact timing is still uncertain. This
warm front will result in some showers and possibly a rumble of
thunder. We will be in the warm sector Wednesday night into
Thursday. Above normal temperatures are expected for this timeframe
with a few showers around. Then, rain chances increase towards the
end of the long term period as the system`s cold front tracks
through the region. Behind the cold front, temperatures look to
remain near to slightly below normal with near to slightly above
normal precipitation for days 8-14 per the CPC`s latest
forecast.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
Through 18z Saturday...A cold front will pass through the area from
SW to NE this afternoon between 19z to 22z. SHRA with occasional
downpours and isolated thunder are expected to accompany the passage
of the front. Coverage of TSRA not anticipated to be expansive
enough to mention in TAFs, but will monitor trends closely for
possible amendments. Mainly MVFR conditions are expected through
the rest of the afternoon, with brief periods of VFR at KALB/KGFL
and IFR possible at KPSF.

After the cold front passage mainly VFR conditions are expected into
this evening, with MVFR cigs then developing later this evening and
especially overnight. Scattered showers will occur as an upper level
low pressure system moves over the region. There may be some periods
of more widespread showers on Saturday, with the best potential at
KPSF where prevailing showers have been mentioned. For now will
mention VCSH at the other sites. Mainly MVFR conditions should occur
on Saturday.

Winds will initially be southerly at 10-15 kt with gusts of 20-25 kt
ahead of the cold front, then shifting to the southwest by later
this afternoon behind the cold front with similar speeds/gusts.

Outlook...

Saturday Night: Moderate Operational Impact. Breezy. NO SIG WX.
Sunday: High Operational Impact. Likely SHRA.
Sunday Night: Moderate Operational Impact. Chance of SHRA.
Monday: Low Operational Impact. Breezy. NO SIG WX.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.
Tuesday Night: Low Operational Impact. Slight Chance of SHRA.
Wednesday: Moderate Operational Impact. Chance of SHRA.

&&

.HYDROLOGY...
Rain from last night has lifted north of
eastern NY and western New England and resulted in about 0.25 to
1.25 inches of rain with the highest amounts in the eastern
Catskills. River rises have occurred this morning with a few
points along the Schoharie Creek, Esopus Creek and Williams
River reaching flood stage.

Periods of rain showers have been ongoing across the region
since the evening hours on Thursday. Although most areas have
only see light amounts so far (under a half of an inch), some
isolated areas of the Catskills and Adirondacks have locally
seen over an inch of rainfall since yesterday. Additional
showers are expected through the morning hours, with showers
gradually tapering off for this afternoon into this evening,
before more showers move back in for late tonight into Saturday.
While most areas will only see an additional quarter to half
inch of rainfall, some high terrain areas could see an another
inch or two of rainfall, especially the Catskills.

Based on this rainfall forecast, rises on area rivers and
streams are likely. While the current river forecasts keep main
stem rivers within their banks, there may be some near bankfull
rises (action stage), especially across the Catskills and the
Adirondacks. Within the bursts of heavier rainfall, some
ponding of water on roadways or nuisance flooding of urban, low-
lying, or other flood-prone areas is also expected.

In addition, the strong southerly flow, combined with tidal
effects, is allowing for a period of minor flooding on the
Hudson River during the time of high tide early this morning.
This could cause some localized flooding near Kingston and
Poughkeepsie for a few hours early this morning.

River observations and forecasts can be monitored using the
National Water Prediction Service located at water.noaa.gov.

&&

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

&&

$$

SYNOPSIS...Speciale
NEAR TERM...Speciale
SHORT TERM...Speciale
LONG TERM...Main
AVIATION...Main
HYDROLOGY...Frugis/Speciale

NWS ALY Office Area Forecast Discussion