[Cambium]

Non stop rain here. And barely moving

Almost 1 inch past 36hrs

[Cambium]

NAM model says Friday we get historic Tulip crushing snowstorm. Goodbye blooms too

No thanks!!

[Cambium]

While no extreme cold pattern coming, no torch warm pattern either.


Here's why.... See that Big Circle? That's a cold pool of air. Below freezing above 3000 feet. That will keep the surface in check and chilly at times.


Litchfield County Snow Friday???

[Cambium]

NWS NY

Area Forecast Discussion
National Weather Service New York NY
356 AM EDT Wed Apr 14 2021

In response to the massive Upper low approaching from the west, low
pressure develops south of LI on Thurs. The low is broad and weak,
but winds up a bit more Thu ngt. The models are in pretty good
agreement with the low track Thu ngt, taking it thru the Cape
and Islands by 12Z Fri. With the h85 low tracking across LI,
the sfc low should stay n of the benchmark, supporting this
consensus. This would tend to dryslot most of the area by late
Thu ngt. It would also keep snow accums north as well. Followed WPC
for QPF for the event, which is still around an inch and a half.
Some rasn was added for interior portions of CT, as well as
parts of the Lower Hudson Valley for Thu ngt. The NBM was used
for temps Thu, but the fcst is weighted heavily towards the NAM
2m data for Thu ngt

NWS Albany with an impressive technical discussion!

AREA FORECAST DISCUSSION
National Weather Service Albany NY
652 AM EDT Wed Apr 14 2021

...A Winter Storm Watch has been issued for Northern Berkshire,
Southern Berkshire, Bennington, Western and Eastern Windham
Counties from Thursday evening to Friday night...

Volatile, fitting for this time of year (transition season, prime
shoulder season), is a great way to describe the weather pattern
during this timeframe. After experiencing May-like temperatures on
both Tuesday and Wednesday, in a 36-48 hours period, the weather
pattern pendulum just like that swings back into winter mode.

Key Takeaways:
* Winter weather returns Thursday night into Friday
* Rainfall Thursday-Friday could be moderate to heavy at times.
* Precipitation type will mostly be in the form of rain in the
valleys. Could change over to a rain/snow mix late Thursday night
into Friday. Any snow accumulation will be very light (less than
one inch). Any snow accumulations will occur on unpaved surfaces.
* Preliminary snow amounts Thursday night-Friday: 1-3 inches over
the eastern Catskills, 2-6 inches over the SW Adirondacks, 3-8
inches over the Berkshires, and 5-10 inches over southern VT with
locally higher amounts up to 12 inches
* Snow could be moderate to heavy at times
* Snow to liquid ratios will be on the order of 5-9:1 (wet snow
maker)

Concerns/uncertainties include:
1) the amount of cold air supply coming from the closed low
(this will dictate snow ratios and thus snow amounts).

2) the exact track of the storm system (this will dictate how
much atmospheric/dynamic forcing will be in play which will also
impact snow amounts).

Technical Discussion:
All eyes are on an anomalously strong and elongated closed 500 mb
low from the Great Lakes that is progged to merge with a moisture
rich storm system (Gulf of Mexico and Atlantic source regions) to
our south resulting in a compacted, yet vigorous coastal storm
system. Ultimately, this will bring the combination of a much needed
soaking rain and accumulating wet *snow*, some of which could be
moderate to heavy Thursday-Friday.

We begin the short-term period Wednesday evening/night with clouds
increasing in coverage and lowering in elevation ahead of this
potentially dynamic storm system.

As mentioned, this storm system is coming rich of moisture with feed
from both the Gulf of Mexico and the Atlantic Ocean. QPF values are
running between 1-2 inches. So, regardless of the type of
precipitation, the values will be a healthy amount and something we
certainly need given the fact that much of the forecast area is
under a D0 (Abnormally dry) category.

As far as snow potential for the valleys, not overly impressed with
the amount of cold air associated with the closed low with 850 mb
temperatures ranging between -3C to -5C. This type of cool airmass
may not be strong enough to translate snow to the surface. Most
places in the valley, surface temperatures are expected to hold
above freezing. A mix is certainly possible. That said, am thinking
up to a coating in the valleys with accumulation occurring over the
unpaved surfaces and not the paved surfaces.

Higher elevations above 1500 feet will have a better chance to
convert over to snow. Mid-level lapse rates sampled between 5C/km-
7C/km over the area supports modest lift. The best H850-H700 FGEN
lines up over western New England and points northeast. Lift over
western New England (Berkshires and southern VT) are sufficient
below the DGZ and at times within the DGZ with omega values between
minus -1 to -2 Pa/s. Snowfall will also be enhanced through some
upsloping with east winds between 15-20 kts at the surface and
between 20-30 kts at 850 mb. These prospects support the potential
for moderate to heavy burst of wet snow at times over these locales
(Berkshires and southern VT). Snow to liquid ratios between 5-9:1
will not only support heavy wet snow variety, but more conservative
snow amounts. After collaboration with neighboring WFOs and WPC,
preliminary amounts of 1-3 inches over the eastern Catskills, 2-6
inches over the SW Adirondacks, 3-8 inches over the Berkshires, and
5-10 inches over southern VT with locally higher amounts up to 12
inches is reasonable at this stage.

Forecast models slow the coastal storm down. So, it`s possible that
precipitation lingers through Friday night before coming to an end
Saturday morning. The system finally pulls away Saturday bringing a
return to quiet weather.

[htfdcolt]

Looks like the classic "elevation" storm on Friday. Still, pretty unusual to have a cold rain this late in April. Will be welcome for the drought watchers on this forum!

[Cambium]

Blues..............SNOWSTORM

Coastal storm. Upper Low catches it. Stalls it. Makes it loop around. Cold air filters in. Snow falls.


Should be mostly high elevation event but should see some at surface. Not here though. Northern CT might see an inch or so?

[middletownbmxer]

glad we didn't have another April fools prank from grandfather winter because ohhhh boy i would've been pissed. already packed my coats away.

[Cambium]

Forecast changes within 24hrs because models trended wetter and some snow down in Fairfield county

National Weather Service New York NY
1037 PM EDT Wed Apr 14 2021

Model guidance has trended wetter with the system impacting the
area during this time. An inverted trough extending N of the
intensifying sfc low, with low level WAA to its east, should
result in at least a moderate rainfall. Rain should become
heavy at times from late day Thu into Thu evening across S CT
and Long Island, during peak low level WAA/destabilization. Any
elevated CAPE should be shallow so do not expect thunder, but
with TT nearing 50 cannot totally rule it out either.

With most of the precip along and E of the inverted trough, NYC
and points west may not see much precip late Thu night, but CAA
on the back side of the intensifying low as it passes between
Montauk and the 40/70 benchmark should pull down enough cold air
to allow precip to mix with or change to wet snow across
interior S CT and the lower Hudson Valley, with a coating of
accumulation possible on grassy surfaces especially in the
higher elevations of northern Fairfield/New Haven

[Cambium]

Interesting setup. Upper Low about to cross the region with a surface low off the coast. #NewEnglandSnowstorm in Mid April.

It's near 0°F at 10,000' under the ULL and will be below freezing at 2500' over New England tonight





From KBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
448 AM EDT Thu Apr 15 2021

Deep closed upper level across the eastern Great Lakes will slowly
move east today and be located in southwest NY by early evening.

THIS EVENING THROUGH 6 PM FRIDAY/...

* Significant Elevation Snow Expected in the Berkshires and
possibly the northern Worcester Hills

* A small/slushy accumulation is possible in some lower elevations

This is a text book meteorological setup for a late season snowstorm
across the high terrain of southern New England tonight and Friday.
However, given very marginal thermal profiles and a high dependence
on intensity/track specific snow accumulations are uncertain. We
will break things down a bit more below.

A deepening closed mid level low will approach from the west tonight
and track across the region on Friday. This is a classic setup for
heavy precipitation with a deep moisture plume and very strong
forcing. The strong omega will result in dynamic cooling with
thermal profiles becoming isothermal tonight into Friday across the
high terrain. Rain should flip to snow this evening across the
Berkshires and a bit later tonight across the northern Worcester
Hills. 925T dropping below 0C in this region give us confidence in
ptype changing to wet snow, which will fall heavy at times. Some wet
snow is even possible in the lower elevations of interior southern
New England very late tonight and Friday during the heaviest
precipitation. Total precipitation should be on the order of 1 to
2.50 inches, which will continue through Friday afternoon.

The guidance has trended a bit further southeast with the mid level
low track over the past 24 hours. Therefore, we upgraded to a Winter
Storm Warning for a good portion of the east slopes of the
Berkshires. Heavy Wet snow of 4 to 8 inches is anticipated with
localized amounts up to 10 inches possible at elevations near and
above 1500 feet. Given the southeast trend; we opted to issue a
Winter Storm Watch for the northern Worcester Hills. This will give
the next shift a look at the 12z guidance and either upgrade to a
warning or replace with a Winter Weather Advisory. This should be a
classic wet snow event with surface temperatures in the 32-33 degree
range. Therefore, some power outages will be possible where snow
amounts reach or exceed 6 inches. Despite the recent mild weather;
roads will become snow covered in the high terrain given the
intensity expected.

A few inches of snow are also possible in the CT Hills and possibly
even some small/slushy accumulations in some lower elevations of
interior southern New England. Heavy precipitation intensity may be
enough to flip some lower elevations to a period of wet snow. This
will be highly dependent on the track of the mid level low and its
associated dryslot. We still are favoring mainly heavy rain across
eastern MA/RI. However, some of our latest guidance indicates that
there could even be a burst of wet snow for a time on Friday if the
system tracks as far southeast as the NAM indicates. This is
certainly something that later shifts will have to watch closely.

So to sum up...significant wet snow accumulations are anticipated for
portions of the high terrain. Amounts are highly dependent on
banding and precipitation intensity with very marginal temperatures.
SNOW LIQUID RATIOS will be on the order of 7-9:1 in the higher elevations and
even less if any accumulations down in the lower elevations. Later
shifts will certainly need to fine tune snow accumulations and
Ptype given this very fragile setup.

Friday night and Saturday...

The mid level blocking pattern continues, meaning a slow exit of the
low overhead during this time period.

"localized amounts up to 10 inches possible at elevations near and above 1500 feet."

Litchfield hills??!

[Cambium]

I like this snow map from the HiRes NAM model. Makes sense


https://twitter.com/gilsimmons/statu...36684022530049