Area Forecast Discussion Issued by NWS Albany, NY
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000
FXUS61 KALY 251426
AFDALY
AREA FORECAST DISCUSSION
National Weather Service Albany NY
1026 AM EDT Mon Mar 25 2024
.SYNOPSIS...
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Amplifying high pressure in southeast Canada will make for dry,
mostly sunny conditions today. Tranquil weather will persist
into Tuesday, though clouds will begin to stream into the region
in advance of a series of disturbances. Scattered showers are
then expected for the middle portion of the week before dry
conditions return for the beginning of the weekend.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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.UPDATE...As of 1025 AM EDT, surface high pressure, centered
over Atlantic Canada, continues to nose southward across the
region. A vertically stacked upper-level low is located across
the western Atlantic Ocean. Some high cirrus along the western
periphery of the ocean low have moved into portions of far
eastern New York and western New England. Subsidence with the
high overhead will prevent these high clouds from expanding much
more westward today. Therefore, sunny conditions are expected
across most of the region today with mostly sunny conditions for
areas east of the Hudson River.
A well-mixed environment and plenty of radiation underneath a
strong, late-March sun angle will allow temperatures to rise
into the 40s across most of the region with lower 50s across
portions of the mid-Hudson Valley and upper 30s across the
higher elevations. Rapid melting of snow/ice will continue
throughout the day.-- End Changed Discussion --
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.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
Atmospheric heights continue to decrease across the area Monday
night into Tuesday as the aforementioned high pressure pushes
further into the Canadian Maritimes and the low still well to
our west in the Midwest continues its slow crawl north and east.
Dry, mainly clear conditions will, however, persist tonight
into Tuesday morning with low temperatures falling into the 20s
to 30.
Tuesday morning will see clouds begin to increase as an inverted
trough forms and nears the Long Island and New England Coasts in
response to the cycling low in the Atlantic. Easterly to
southeasterly flow will advect moisture into the region and
clouds will increase from the southeast to northwest to start.
However, clouds will also begin to stream into the region from
west to east in response to the nearing upper-level trough
associated with the aforementioned Midwest low. Conditions will
remain mostly dry Tuesday despite the increasing clouds, though
some light, scattered showers are possible in western New
England due to the influence of the adjacent inverted trough off
the Atlantic. High temperatures were a bit of a challenge for
Tuesday as there is some uncertainty as to just how fast clouds
will overspread the region. However, with breaks of sun likely
through Tuesday afternoon, temperatures look to reach the mid
40s to low 50s outside of western New England where a faster
obstruction to solar radiation will only allow temperatures to
rise into the upper 30s to low/mid 40s.
Scattered showers in response to the nearing upper-level trough
and cold front associated with the northeast-propagating low
will begin overnight Tuesday and last through Wednesday night.
All showers look to be relatively light and scattered in nature
as moisture transport and forcing looks to be relatively weak.
Though precipitation type should primarily be rain across the
region due to warm antecedent temperatures, it is possible that
showers beginning in the Southern Greens and Berkshires late
Tuesday evening/Tuesday night could begin as freezing drizzle.
Model soundings show a broad warm nose that would be favorable
for such an outcome. However, with precipitation expected to be
light, and temperatures moderating quickly after daybreak
Wednesday leading to a brief window of duration, little
accretion is expected.Showers will gradually taper off by early
Thursday morning as the front begins to exit the region.
High temperatures Wednesday will reach the upper 40s to mid 50s
with lows in the mid 30s to low 40s Wednesday night.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
Main focus for the long term period remains on the Thursday - Friday
period when a maturing northern stream closed low from the Upper
Midwest escapes into Ontario with its associated cold front slowly
progressing eastward. Broad ridging extending from the East Coast
into the western Atlantic will maintain southwest flow and a milder
air mass over the Northeast a head of the boundary into Thursday.
Meanwhile, a southern stream shortwave digging into the Gulf Coast
States could start to phase with the northern stream closed low
Thursday into Thursday night. The general model consensus is in good
agreement on this general evolution but guidance differs on the
amplification of the southern stream shortwave and resulting
cyclogenesis that may ensue along the slow moving cold front. Should
the southern stream shortwave strengthen quickly, it may take on a
negative tilt and thus result in rather rapid cyclogenesis along the
front just off the East Coast. Given that the front is slow moving,
it may be close enough to the coast that the precipitation shield
associated with the developing coastal low may extent into part of
eastern NY and western New England. On the other hand, if
cyclogenesis is slower to occur, the front would have more time to
escape off the coast and the ensuing coastal low would be farther
off shore and thus mainly impact New England.
While there are differences on the overall track and areas that may
be impacted by any coastal development, guidance is in good
agreement that the strong southwesterly flow ahead of the boundary
would provide a strong moisture fetch from the Gulf of Mexico. Thus,
the coastal low would focus and direct this reservoir of moisture
northward along the boundary and thus present yet another
opportunity for widespread precipitation. Luckily, latest trends
show precipitation occurring on the warm side of the boundary,
favoring mainly rain. Latest ensemble trends have wobbled back and
forth on the western extent of the precipitation shield with the 00
UTC runs trending back west compared to the 18 UTC runs. Even still,
the highest probabilities for greater than 0.10" of precipitation
reside south and east of the Capital District and favor western New
England. Therefore, we maintain likely POPs in Berkshire and
Litchfield County as well as parts of southern VT, the
central/southern Taconics and the mid-Hudson Valley and trended POPs
downward heading north and west on Thursday. The moisture gradient
along the boundary would likely tighten from the coastal low leading
to a tight west to east QPF gradient. The ensembles are picking up
on this showing a tight gradient along the probability contours.
This would make for a challenging POP and QPF forecast.
By Friday, the majority of the precipitation from the coastal low
should escape mainly to our east with a northwest wind shift
supporting cold air advection with the true cold air mass
overspreading the Northeast. Latest guidance suggests the coastal
low could deepen rapidly off the New England coast, leading to a
tightening sfc pressure gradient over the Northeast resulting in
breezy conditions. Within this pattern change, temperatures should
trend cooler compared to Thursday with the breezy winds making it
feel even cooler.
We will then monitor an approaching warm front for the weekend that
may reside mainly to our south over the mid-Atlantic as a much
warmer air mass builds over the southern tier of the country. Weak
shortwaves riding along this warm front and the northern periphery
of broad ridging would support additional opportunities for
precipitation. Still much uncertainty on the exact position and
timing of any shortwave so maintained slight chance POPs for the
weekend forecast. Temperatures generally remain near normal.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
High pressure dominating the Northeast today will support VFR
conditions at all TAF sites through 06 UTC Tuesday with SKC
conditions at ALB, GFL and POU today. Just some innocuous
cirrus clouds spilling into PSF. For tonight, low stratus clouds
from the Atlantic will likely push inland towards 06 - 12 UTC
TUE for PSF and POU and thus introduced MVFR ceilings in the
next TAF update.
Light and variable winds early this morning will shift out of
the east by 13 - 16 UTC at all TAF sites with sustained winds
reaching 5-9kts and gusts up to 15kts. Winds will subside once
we lose daytime heating towards 01 - 04 UTC Tuesday with winds
likely lingering at PSF the latest.
Outlook...
Tuesday Night: Moderate Operational Impact. Chance of SHRA.
Wednesday: Moderate Operational Impact. Chance of SHRA.
Wednesday Night: Moderate Operational Impact. Chance of SHRA.
Thursday: Moderate Operational Impact. Chance of SHRA.
Thursday Night: Moderate Operational Impact. Chance of SHRA.
Friday: Low Operational Impact. Breezy. Slight Chance of SHRA.
Friday Night: Low Operational Impact. Breezy. NO SIG WX.
Saturday: Low Operational Impact. Breezy. NO SIG WX.
&&
.HYDROLOGY...
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River flows will continue to recede throughout the day. Flood
Warnings for minor flooding continue only for Falls Village and
Stevenson Dam on the Housatonic as of 10 AM EDT.
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.-- End Changed Discussion --
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...Gant
NEAR TERM...Gant/Rathbun
SHORT TERM...Gant
LONG TERM...Speciale
AVIATION...Speciale
HYDROLOGY...Rathbun