Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 04/04/24
Area Forecast Discussion
National Weather Service Burlington VT
1012 PM EDT Wed Apr 3 2024
.SYNOPSIS...
A late season winter storm will bring widespread snow and mixed
precipitation to North Country. Strong to damaging winds will
develop along the favored downslope areas of the Green Mountains
this evening into overnight tonight, leading to power outages
and localized whiteout conditions along mountain passes. Scattered
snow showers can be expected through Saturday before dry
weather returns for the early portion of next week.
&&
.NEAR TERM /THROUGH THURSDAY NIGHT/...
As of 1006 PM EDT Wednesday...Winds continue to be gusty
along/west of the central and southern Greens late this evening,
with gusts of 40-60 mph having been reported so far. Power
outages continue to slowly increase, with the most outages now
being reported in Rutland County (over 3300 as of 10 pm). Steady
precipitation has spread back over the region, with a band of
heavier rates now lifting into Adirondacks/central Greens.
There has been lightning reported with this band, and expect
there could be additional thunder as it continues to push
northward through midnight/1 AM. Webcams/RWIS sites indicate
roads are now becoming snow covered, especially at higher
elevations, where precipitation is now mostly snow with some
sleet. Here in the Champlain Valley, currently a mix of rain,
sleet, and snow falling, but not seeing much in the way of
accumulation just yet. This will likely change as the
aforementioned band lifts northward.
Travel is becoming difficult in mountain passes, with periods
of blizzard- like conditions expected overnight. Winds will
remain gusty much of the night, especially as any breaks in
precipitation move overhead. Lower elevations should start
seeing snow accumulation shortly, and low visibility and snow-
covered roads will make travel hazardous. Please use caution if
you are out and about tonight.
Previous discussion...We`re in the phase where we`re watching
how this winter storm plays out. There`s plenty of bust
potential on either end for this event given the presence of
sleet and entrained mid- level dry air, like what is heading
towards us right now. Model radar depictions are not impressive,
but guidance continues to insist that there`s plenty of QPF
likely with this event and the potential for locally heavy
snowfall means there is likely to be a large amount of
variability within miles of any given point. So today has been
tweaking sleet further north, trying to account for more dry air
in the face of what`s lifting north, and how warm surface
temperatures have been.
This first batch of a wintry mix and some rain will lift north
followed by some drying. In this area of drying, wind gusts are
expected to notably ramp up. The inversion layer is somewhat lower
in the latest forecast guidance, but an ACARs sounding into ALY
suggests the inversion layer is right about where it needs to be
to produce strong downslope winds. Across eastern Vermont, the
Adirondacks, across Chittenden and Addison this should produce
wind gusts of 40 to 50 mph this evening. Across the southern
Greens, particularly Rutland County, wind gusts of 50 to 60 mph
should develop over the next few hours. If the inversion layer
holds and 800hPa flow is stronger than expected, it is not out
of the realm of possible a gust just under or at hurricane
force gust is observed in Rutland County, as North Adams,
Massachusetts observed a 67 mph gust. Scattered to numerous
power outages are possible, supported by the uptick in power
outages across New York within this area of drying.
The coastal low is on track to develop this evening into the
overnight hours, lofting plenty of moisture back in the area. The
easterly jet will help to maintain the warm layer aloft, with a
pocket of potentially heavy sleet, rain, and snow for part of the
night. It could be quite messy. Snowfall rates along the
international border are most likely to approach 1 inch per hour.
Predawn and early morning, the warm nose should collapse, but
snowfall rates will be on the decline. But with the sun coming out
and temperatures warming into the mid to upper 30s, additional
accumulations will be mainly confined to grassy, elevated surfaces.
It`s at this time the snow characteristic becomes wetter, but with
the overall rates decreasing on Thursday, it`s hard to say how much
this impacts power outages. The main impact from snow will be the
slippery travel likely on Thursday morning. Heading into Thursday
night, additional light accumulations are possible. Overall, the
totals are not the primary thing to focus on, because the bust
potential on this event is higher than normal. The main focus is the
difficult travel from downslope winds and heavy snow heading into
Thursday morning, and then the power outage potential from those
strong winds.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
As of 354 PM EDT Wednesday...A slow-moving upper level low will
continue to meander eastward across the region, bringing additional
chances of showery precipitation throughout the day. Daytime high
temperatures will climb into the 30s to low 40s, however brisk
northerly winds will make it feel a bit cooler. Snow showers will be
limited to the higher terrain as lower elevations see primarily rain
showers with a mix of rain and snow in between given the
temperatures throughout the day. Snow will become the more
widespread precipitation type heading into the evening as overnight
lows drop into the upper 20s to above freezing, although
accumulations will still be minor. Additional snowfall accumulations
throughout the day will be fairly minor, with a inch or two possible
on the mountain peaks.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 354 PM EDT Wednesday...A large upper level low will continue to
depart to the east, with the coverage of showers diminishing on
Saturday into Sunday. Temperatures will continue to warm up
throughout the weekend as upper-level ridging moves in behind the
departing the low, with seasonable daytime high temperatures in the
40s to low 50s and overnight lows will
Upper-level ridging and surface high pressure will continue to build
into the region Sunday into Monday, bringing dry and mild weather.
Dry conditions and mostly sunny skies in the Northeast will make for
favorable conditions for viewing the total solar eclipse, although
these trends will continue to be monitored as we get closer.
Temperatures will be continue to warm as we head into next week,
with highs in the low to upper 50s and overnight lows generally in
the 30s. Although these temperatures will be quite pleasant, bodies
of water across the region remain dangerously cold so use additional
caution near any lakes or rivers. Dry weather is expected to
continue into Tuesday before clouds and precipitation chances begin
to increase late Tuesday as another low pressure system tracks
toward the Northeast.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
Through 00Z Friday...A tough stretch for aviation is in store during
the TAF period with issues from low ceilings, low visibility, LLWS
and strong winds. The mixed precipitation over the region will
gradually change to snow this evening and northern terminals should
be all snow by midnight. Sleet may remain in the southern terminals
for a few hours into Thursday. Snow prevails into the day Thursday
but should begin to lighten up a little in the afternoon. Once the
precipitation transitions to snow, visibilities will drop to IFR at
that terminal. The snowfall rates will not be steady so the
visibilities will likely fluctuate between IFR and LIFR as the
intensities change. Ceilings will drop slightly tonight but they
should generally remain VFR and MVFR for much of the night and into
the day Thursday. LLWS will be a concern all night, some of which
may approach extreme conditions at RUT with strong downsloping
winds. LLWS should weaken by mid-morning Thursday. Mountain wave
breaking is possible along the western slopes of the Greens and
will likely cause strong turbulence. Winds will also be quiet strong
all night, with gusts up to 50 kts at any terminal. At RUT, the
strongest gusts will approach 60kts. The winds should generally be
southeasterly this evening, slowly transition to northeasterly
during the night and into day on Thursday. Winds will remain strong
for much of the night but lighten significantly during the day
Thursday, with gusts likely not exceeding 30 kts at any terminal.
Outlook...
Thursday Night: Mainly IFR, with areas MVFR possible. Likely
SHSN.
Friday: Mainly MVFR, with local IFR possible. Likely SHRA,
Definite SHSN.
Friday Night: Mainly MVFR, with areas IFR possible. Chance SHSN,
Chance SHRA.
Saturday: MVFR. Chance SHRA, Slight chance SHSN.
Saturday Night: Mainly MVFR, with local IFR possible. NO SIG WX.
Sunday: Mainly MVFR, with areas VFR possible. NO SIG WX.
Sunday Night: Mainly VFR, with local MVFR possible. NO SIG WX.
Monday: VFR. NO SIG WX.
&&
.CLIMATE...
Some record precipitation amounts are possible during this
event. Below are some of the records under threat.
April 3:
KMSS: 1.12/1990
April 4:
KMPV: 1.19/2006
KPBG: 0.86/2007
KMSS: 1.03/1990
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Winter Storm Warning until 6 AM EDT Friday for VTZ003-004-
006>008-010-016>021.
Wind Advisory until 10 AM EDT Thursday for VTZ003>010-016-020.
Winter Weather Advisory until 6 AM EDT Friday for VTZ001-002-
005-009-011.
High Wind Warning until 10 AM EDT Thursday for VTZ011-017>019.
NY...Winter Storm Warning until 6 AM EDT Friday for NYZ026>028-030-
031-034-035.
Wind Advisory until 10 AM EDT Thursday for NYZ029>031-034.
Winter Weather Advisory until 6 AM EDT Friday for NYZ029-087.
&&
$$
SYNOPSIS...Haynes
NEAR TERM...Hastings/Haynes
SHORT TERM...Kremer
LONG TERM...Kremer
AVIATION...Myskowski
CLIMATE...Team BTV
Area Forecast Discussion
National Weather Service Louisville KY
938 PM EDT Wed Apr 3 2024
.KEY MESSAGES...
* Windy conditions continue into the evening. Low chance of small
hail until sunset.
* Scattered rain and snow showers are possible tonight into tomorrow
morning. A localized dusting of snow is possible on elevated
surfaces, but will not be impactful.
* High confidence in frost/freeze potential Saturday morning
with decreasing confidence Sunday morning.
* Cloud cover and rain potential are still trending down for Eclipse
Day, with above normal temperatures likely.
&&
.UPDATE...
Issued at 937 PM EDT Wed Apr 3 2024
Current forecast remains in great shape so no changes are planned
this evening. With the sfc low located to our north, we continue to
see light precip stream across the forecast area. Plenty of
vorticity lobes cyclonically swinging around the upper low will
continue to provide forcing for additional precip chances through
the overnight. As mentioned in the afternoon discussion, still
expecting to see overall precip coverage and intensity wane some,
which we are already seeing and will continue in the coming hours.
Will keep mention of light rain/snow mix in the weather grids for
tonight, as sufficient moisture remains in place. Forecast remains
in good shape for tomorrow too, so refer to the discussion below for
more details.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 347 PM EDT Wed Apr 3 2024
Rest of the Afternoon...Current satellite imagery depicts scattered
convective cells across the region as a cold airmass is being
destabilize from the bottom by surface daytime heating. As a result,
showers are currently driven by steep low-level lapse rates with the
coldest cloud top temperatures around -27 degC which corresponds
fairly well with the top of the moist layer of 3 km, as shown in
latest SDF ACARS soundings. Although such showers are low topped,
fairly low freezing levels, steep 0-3 km lapse rates, and SBCAPE
above 250 J/kg are are supportive of sporadic lightning as well as
small hail and gusty winds above 40 mph. Expect such showery
activity to diminish west to east later this afternoon as a solid
overcast mid-level cloud layer approaches from the north, blocking
solar radiation and any chance of further destabilization.
Tonight...Upper low and attendant surface low pressure will start
moving south-southeast from the lower Great Lakes through Indiana and
into southern Ohio. The associated cyclonic vorticity advection will
allow the necessary forcing for a continuous stream of intermittent
showers, but coverage and intensity will decrease compared to the
afternoon activity with forecast soundings showing some drying in
the core of the DGZ layer. That being said, lowering temperatures
and sufficient moisture slightly above the -10 degC isotherm will
allow a transition to snow showers, especially with heavier activity
overnight. most of the snow showers should be light and based on
ground temperatures accumulations should remain light and mostly
focused on elevated surfaces. No impactful accumulations are
expected at the moment.
Thursday...Low-topped convective showers are very likely to
continue tomorrow as the upper low and attendant surface low pressure
will be closest to the area. However, GFS forecast soundings and
also CAM guidance are indicating a lull in the heaviest convective
activity during the morning hours as DGZ layer remains somewhat sub-
saturated and the mid to upper clouds block substantial solar
radiation. Meanwhile, breeze westerly winds and below normal
temperatures are anticipated with throughout the day as highs barely
make it to the 50 degree mark. By the afternoon, moistening of the
mid-levels and steepening 700-500 mb lapse rates will favor a
renewed chance of cellular convective showers with isolated
lightning, frozen hydrometeors, and gusty winds around 30 to 40 mph.
Best coverage for such activity will be focusing aorund the
Bluegrass region.
&&
.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
Issued at 347 PM EDT Wed Apr 3 2024
Thu Night - Sunday...Warmer and clearer conditions are anticipated
this weekend as the slow-moving upper low over the East Conus tracks
to the Atlantic and upper ridging moves in from the Central US. At
the surface, high pressure over southern Canada/Upper Great Lakes
starts descending to the Ohio Valley. As a result, broken cloud
layer will slowly break as it slowly retreats to the northeast.
Furthermore, winds will be lighter on Friday compared to previous
days with light NW winds in place. Models have been showing a small
chance of showers for the easternmost areas, but it should mostly be
light rain with no frozen hydrometeors expected given dry air in the
DGZ and warming boundary layer temperatures. Still advertising
frost/freeze headlines for the Friday night/Saturday morning
timeframe due to the possibility of good radiational cooling and
decoupling surface winds. Lowest temperatures (upper 20s to low 30s)
still expected for southern Indiana and north-central Kentucky.
Temperatures will continue an upward trend through Saturday and
Sunday as winds veer to the east and southeast, respectively. One
thing to notice in recent model trends is the earlier onset of
showers as models are pushing the next shortwave trough/upper low
farther east (more in line with the GFS solution) with a warm front
lifting through the lower Ohio Valley. As a result, rain chances has
started to increase on Sunday along with breeze southerly winds.
Next Week...Based on the aforementioned model trends, southern
Indiana and north-central Kentucky should be on the edge of the warm
sector by Monday with warm front to the north and cold front across
the Mid Plains and drier air, aka lowering precip chances, giving a
better viewing chance of the solar eclipse.
&&
.AVIATION /00Z TAFS THROUGH 06Z SATURDAY/...
Issued at 738 PM EDT Wed Apr 3 2024
Surface low pressure just to the north of our area will continue to
promote periods of light precip and low ceilings for this TAF
package. Expect ceilings to lower to MVFR tonight, with VCSH ongoing
for most sites. LEX and RGA have the best chance for seeing some
light RASN mix, but impacts are not anticipated. Ceilings should
continue to lower below fuel alternate (below 2k ft) by early
tomorrow morning. Ceilings could be bouncing between IFR and MVFR, so
confidence does become somewhat limited by tomorrow morning. Winds
will remain quite breezy at all terminals, with a west wind and
gusts up to 25 kts.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...None.
IN...None.
&&
$$
UPDATE...CJP
SHORT TERM...ALL
LONG TERM...ALL
AVIATION...CJP