Area Forecast Discussion Issued by NWS Albany, NY
000
FXUS61 KALY 141034
AFDALY
AREA FORECAST DISCUSSION
National Weather Service Albany NY
634 AM EDT Sun Apr 14 2024
.SYNOPSIS...
After a dry start to the morning, showers are expected
to overspread the area today, with a few thunderstorms for areas
along and south of I-90. Drier weather returns Monday and Tuesday
with temperatures running a few degrees above normal. Cooler weather
is expected for the second half of the week with increasing rain
chances.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
.Update...As of 6:30 AM EDT...Mainly clear skies and diminishing
winds have allowed for a couple hours of favorable radiational
cooling conditions, and as a result temperatures have dropped
into the upper 20s to low 30s for many of the high terrain
areas. Knocked temperatures down a couple degrees through the
next few hours to better reflect this trend. We should warm up
before precip moves into the region around mid-morning, but with
the cool temperatures and low dew points this morning we could
see some wet snow mix in across the highest terrain of the
Adirondacks as precip begins. Little to no snow accumulation
expected, however.
Otherwise, main focus today will be on the potential for severe
weather south and west of Albany. 06z HRRR and NAMNEST
indicating possibility of some showers out ahead of the main
line of storms this afternoon, and if this were to happen it
would likely reduce the overall severe threat. Not completely
sold on this solution, but something to monitor nonetheless.
Otherwise, previous forecast remains on track, with more details
about the severe threat this afternoon in the previous
discussion below...
.Previous...Skies have become partly to mostly clear as the
upper trough and associated deeper moisture move off to our east
into New England. Dry conditions are expected through early
this morning, but today is shaping up to be a potentially
active weather day. A weak surface low forms near the Great
Lakes and tracks near the I-90 corridor today in response to an
upper shortwave disturbance. The surface low will help to lift a
warm front northwards into our region, but it appears that the
front will stall near or just south of I-90. For areas north of
the front, today will be mostly cloudy and cool with periods of
rain due to fairly strong isentropic lift. An isolated rumble of
thunder can`t completely be ruled out due to some pockets of
elevated instability, but no severe weather is expected for
areas north of I-90.
For areas to the south, most of today, at least through the
early afternoon, should remain on the dry side with partly to
mostly cloudy skies. It will be much warmer here, with highs
well into the 60s for the valley areas. However, a round of
thunderstorms is possible this afternoon and evening as the
surface low and its attendant cold front track through the
region. Some of these storm could be strong to severe, mainly
for the southeastern Catskills and perhaps the Mid Hudson
Valley...
The big question regarding thunderstorm potential today is the
amount of surface-based instability that will be available. CAM
and HREF guidance suggests a tongue of up to a couple hundred
J/kg of SBCAPE will extend into western Ulster County, with just
some elevated instability for areas to the east. Mid-level lapse
rates are fairly impressive across the souther portion of our
CWA at over 7C/km, but a capping inversion will help to stifle
convection through at least mid-afternoon. The cap may erode as
heights fall aloft and lift increases ahead of the cold front
this afternoon. If the cap erodes and there is enough
instability, then we could see a line of storms develop.
If any storms do develop, then severe weather is possible across
the southeastern Catskills and perhaps the Mid Hudson Valley.
Low-level and deep-layer shear are both extremely impressive,
with a southwesterly LLJ increasing to 45-50 kt this afternoon
and 500 mb winds at around 60 kt from the west. The main risk is
for damaging winds, but large (1"+ diameter) hail also cannot be
ruled out. While hodographs are quite elongated and curved,
especially in the low-levels, LCLs look to be on the high side,
so the tornado threat appears low in our CWA. We collaborated
with SPC on the overnight D1 convective outlook to keep the
slight risk across the southeastern Catskills and Mid Hudson
Valley where the severe threat is highest, but the northern
extent of the slight and marginal risk were trimmed back due to
lack of instability further north and east. Timing of storms
looks to be mainly from mid to late afternoon through this
evening. A few storms may make it into western CT as well, but
less instability here combined with the loss of daytime heating
by the time storms arrive should limit the severe threat for
Litchfield County.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
Tonight, the surface low tracks off to our east and its cold
front tracks through the region. Showers and storms come to and
end this evening behind the cold front, and we dry out
overnight. There will be some breaks of clearing overnight, but
winds should remain elevated enough to keep temperatures mainly
in the mid 30s (terrain) to mid 40s (valleys).
Monday, we will have an upper trough located to our north with
an associated cold pool aloft over our region. Recent guidance
has trended slightly further south with the upper trough,
resulting in slightly cooler weather for Monday compared to
previous forecasts. However, deep mixing should help to offset
the cooler airmass, so temperatures should still reach the low
60s for valley areas with 40s to 50s across the higher
elevations. Instability as a result of the cold pool aloft
combined with daytime heating will likely lead to increasing
afternoon clouds, and a couple showers are possible for the high
terrain areas north of I-90. It will also be breezy with a
relatively tight pressure gradient between the departing low to
our east/northeast and high pressure building in from the west.
The surface high gets closer to our area Monday night, which
should allow winds to diminish. Lows will drop into the 30s for
most areas.
Tuesday and Tuesday night...We will still be influenced by the
relatively cool airmass aloft, although the upper trough moves
off to our east and surface high pressure builds overhead. It
will be a few degrees warmer than Monday, and while some daytime
cumulus clouds will likely develop in the afternoon there should
be more sun compared to Monday. Not really expecting and showers
Tuesday either. We remain under the influence of the surface
high and upper ridging Tuesday night. Temperatures should drop
off quickly after sunset with favorable radiational cooling
conditions, although a few more clouds are possible after
midnight with increasing mid-level warm advection. Lows will
generally be in the 30s with some low 40s near the I-84
corridor.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Models have trended slower with next incoming system, with some
possibility for approaching upper level trough to shear out south
and west of the region as downstream upper troughing lingers over
the NW Atlantic Ocean, resulting in an upper level confluent flow
across the northeast states and slower arrival of precipitation. As
of now, expect dry conditions Tuesday night, with showers slowly
expanding northeast across the region Wednesday into Wednesday night.
There may be a break in any precipitation Thursday into early
Friday, before a cold front approaches from the west with a possible
wave of low pressure tracking along it. This should increase chances
for showers or a period of steady rain Friday into a portion of
Saturday.
Seasonable temperatures are expected Wednesday through Friday, with
highs mainly in the 50s and overnight lows in the upper 30s to mid
40s. Turning cooler Saturday, with highs in the 40s to lower 50s,
and overnight lows in the 30s to around 40.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
A fast moving low pressure system will track across the region this
afternoon, then move east of the region tonight.
Mainly VFR conditions are expected through around 15Z/Sun, although
can not completely rule out some patchy ground fog forming at KGFL
between 08Z-11Z/Sun resulting in MVFR/IFR Vsbys.
Rain showers will then develop between 15Z-18Z/Sun at KGFL, KALB and
KPSF associated with approaching low pressure system and warm front.
There could be intermittent MVFR Cigs/Vsbys developing within any
heavier rain showers, especially later this afternoon. There also
could be a few rumbles of thunder at KALB and KPSF later this
afternoon, however overall chances are too low to mention in current
TAFs.
At KPOU, most of the showers should remain to the north/east until
late afternoon. As a cold front moves southward, there is a chance
of showers and thunderstorms between roughly 22Z/Sun and 02Z/Mon.
Strong wind gusts could accompany any thunderstorms.
Showers should taper off after 02Z/Sun, however MVFR Cigs may linger
well into Sunday night, with pockets of IFR Cigs possible,
especially at KPSF.
West to northwest winds 8-14 KT with some gusts of 25-30 KT will
diminish to 5-10 KT after 08Z/Sun. Winds will then back into the
southwest at 5-10 KT Sunday morning, then become light/variable at
KGFL and KALB this afternoon, while remaining south to southwest and
increasing to 10-15 KT with some gusts up to 25 KT at KPOU and KPSF.
Winds will then become west to northwest at 5-10 KT Sunday evening.
Winds will be stronger, and variable in direction in and near any
thunderstorms.
Outlook...
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.
Tuesday Night: No Operational Impact. NO SIG WX.
Wednesday: Moderate Operational Impact. Chance of SHRA.
Wednesday Night: High Operational Impact. Likely SHRA.
Thursday: Moderate Operational Impact. Chance of SHRA.
Thursday Night: Moderate Operational Impact. Chance of SHRA.
Friday: Moderate Operational Impact. Chance of SHRA.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...Main
NEAR TERM...Main
SHORT TERM...Main
LONG TERM...KL
AVIATION...KL