Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/05/23
AREA FORECAST DISCUSSION
National Weather Service Albany NY
1029 PM EST Wed Jan 4 2023
A low pressure system and a frontal boundary will bring
some light showers, drizzle patchy fog overnight lingering into
Thursday afternoon with mild temperatures over most areas. Portions
of southern Vermont could see some light freezing rain closer to the
southern Green Mountains. A few rain and high terrain showers
continue Friday amid mostly cloudy skies. The weekend should be
mostly dry and a bit cooler.
.NEAR TERM /THROUGH THURSDAY/...
Winter Weather Advisory remains in effect for southern
Vermont from 1 am to 1 pm Thursday...
.UPDATE as of 1029 pm EST...The rainfall has tapered to
scattered to numerous showers north of the Capital Region ahead
of the low pressure system and warm front. The weak sfc low is
over west-central NY according to the latest RAP. Further south
the showers are isolated to scattered with patchy drizzle. We
reduced the PoPs substantially south of the Capital Region, and
followed close to the latest 3-km HRRR trends. The ARW-WRF and
3-km NAM continue to show some spotty freezing rain/drizzle
forming closer to 4-6 am along the southern Greens. Temps are
struggling to cool with the high situated further to the north
over southern Quebec. Some consideration pulling the Winter WX
Advisory for southern VT, but will hold on to it into morning to
make sure no freezing rain/freezing drizzle materializes.
Temps are generally in the 40s to lower 50s south of the
Berkshires/Capital Region. The exception is west of the southern
Greens where Bennington has warmed to 50F! From the Capital
Region northward mainly mid and upper 30s, but some warmer air
is sweeping in with the wave and front to the west with
Woodgate up to 44F just west of Old Forge in the NYS Mesonet
this hour. We may see temps steady or slowly rise into the early
morning hours before becoming steady or slowly falling off.
Lows will generally be in the 30s to lower/mid 40s. Again, any
light ice may be confined closer to the southern Greens close
to 4-6 am, and thereafter if at all. Patchy to localized areas
of fog will also continue overnight into the dank air mass.
.PREV DISCUSSION ...
The latest water vapor loop nicely shows the short-wave moving
across Lake Ontario and western NY with rainfall overspreading
the region from the west/southwest. The low pressure system is
approaching from the west riding along the frontal boundary, as
the isentropic lift increases. We used the latest radar and 3-km
HRRR trends to re-trend the PoPs into the categorical values
with the highest values north and west of the mid Hudson Valley.
Temps remain in the lower 40s to lower 50s south/southwest of
Albany with mainly 35-40F readings to the north and east. Dover
Plains remains the warmest in the southern Taconics this hour in
the NYS Mesonet at 53F. We also expanded the patchy fog
coverage and made it cloudy everywhere overnight. This fast
moving wave should move towards northern NY by midnight or so,
and the rain should taper to showers. We will have to see if
colder subfreezing air begins to drain southward between 4-7 am
east of the southern Greens for some patchy freezing rain. The
WSW remains in effect starting 1 am for southern VT. Lows
tonight are expected in the lower 30s to lower 40s.
The best potential for some freezing rain/drizzle appears to be
along and east of the Green Mountain spine with colder air
making an entrance from the northeast very late tonight into
Thursday morning. This likely won`t occur until the steadier
precipitation has exited, so any icing amounts should be very
light. Lows tonight will be very mild in the mid-30s to mid-40s.
Patchy fog and drizzle will likely continue during the rain and
after the steadier rain exits.
Thursday, most if not all areas likely remain socked in with a
stagnant low level pressure pattern. Slight hint of shortwave
ridging in the wake of Wednesday night`s wave will mean steady
precip isn`t expected, but patchy drizzle/fog could continue. Some
areas along and east of the Green Mountain spine could remain below
freezing with light icing possible. Catskills/Taconics/NW CT will be
not as warm as Thursday as 925 mb temps cool, but the remainder of
the area should see fairly similar temps to Wednesday with a small
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
Thursday night into Friday morning, forcing for ascent will increase
with time ahead of a shortwave trough. This will keep showers around
at times, particularly during the 12-18Z Friday (morning) period.
The airmass is not particularly cold for this time of year, but
cooler than Wed/Thu, so some light snow could occur over the higher
terrain. Little to no impacts expected due to marginal surface temps
around freezing and light nature of the precip. Temps will still
average quite a bit above normal during this period. Clouds may
clear in the valleys somewhat Friday evening into Friday night on
the back side of the shortwave trough. However, they will likely
remain widespread over the higher terrain, particularly over the
lake effect belts of the western Adirondacks where some light lake
effect snow is expected to linger.
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
The extended forecast begins with an upper level trough over
southeast Canada and the Northeast to open the weekend. A cold front
and the upper level trough axis will bring some isolated to
scattered lake effect snow and upslope snow showers for the western
Adirondacks, eastern Catskills, n-central Taconics, and southern
Greens with light snow accums. In the cold advection, 850 hPa temps
fall into the -7C to -10C range based on the 12Z GFS which is close
to normal based on the latest 12Z NAEFS. Highs will be in the mid
30s to around 40F in the valley elevations, and mid 20s to lower 30s
over the mtns. In the northwest flow aloft, a seasonably cold night
is expected with lows in the teens to mid 20s with high pressure
building in to close the weekend.
High pressure remains in control Sunday with seasonably cold and dry
weather, but clouds increase Sunday night, as most of the medium
range and the ensembles have a short-wave trough and a sfc low
moving from near the central MS River Valley to off the Mid
Atlantic/NJ Coast Sunday night into Monday. The northern extent of
any light snow/snow showers is uncertain. We did carry slight or
low chance PoPs late Sunday night into Monday. The 12Z CMC/GFS
remain further north with the wave compared to the ECMWF/Ensembles.
Lows will be mainly in the 20s with highs in the 30s with a few
upper 20s over the mtns.
Monday night into the mid week, another period of normal to slightly
above normal temperatures is possible Monday night through Tuesday
with high pressure building back. Mid and upper level heights
increase along the East Coast with ridging building in. However,
Tuesday night into Wednesday a northern stream trough will be
approaching, while a southern stream trough will be ejecting from
the lower Mid Atlantic States/Southeast for the mid week. If the
disturbances phase an oceanic or coastal storm would form. Right
now, it appears most of the guidance would favor an unphased system
with the northern stream disturbance bringing a slight chance of
light rain or snow and limited impacts for the ALY forecast area.
Temps continue to trend seasonable for the mid week.
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
Through 00z Friday...MVFR to LIFR conditions are expected at all of
the ALY terminals through at least Thursday morning. The worst of
conditions are expected over the next 6-9 hours as of this update
due to a combination of rain, drizzle, low stratus, mist, and/or
The latest radar reflectivity shows the second batch of rain
moving into the forecast area. This batch of rain is associated with
a double barreled low pressure system and quasi-stationary frontal
boundary. Expect for rain showers to persist through this evening
into tonight as this storm system continues to shift east-northeast
over the area. With MVFR to LIFR cigs and visibilities already
ongoing, any rain showers will further decrease flying conditons.
Overnight tonight, expect for rain showers to decrease in coverage
and intensity over the area. There could be some lingering rain
showers or drizzle during the overnight period into Thursday
morning. Have VCSH headlines during this time to reflect this. MVFR
to LIFR conditions overnight into Thursday morning are expected to
Drier trends could develop Thursday afternoon with the
chance for some intermittent showers developing Thursday evening.
The expectation is that cigs will try to improve on Thursday from
sub 1,000 feet AGL to 1-2.5 kft AGL once the rain ends. Visibilities
could also improve in the 3 or more statute miles range.
Winds by and large will be light and variable if not calm during the
00z TAF cycle.
Thursday Night: Moderate Operational Impact. Chance of SHRA.
Friday: Moderate Operational Impact. Chance of SHRA.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: Low Operational Impact. NO SIG WX.
Saturday Night: No Operational Impact. NO SIG WX.
Sunday: No Operational Impact. NO SIG WX.
Sunday Night: Low Operational Impact. Slight Chance of SHSN.
Monday: Low Operational Impact. Slight Chance of SHSN.
VT...Winter Weather Advisory until 1 PM EST Thursday for VTZ013>015.
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
947 PM CST Wed Jan 4 2023
Issued at 947 PM CST Wed Jan 4 2023
No significant changes are needed for this update. Fog is not yet
becoming as widespread as the previous two nights and has actually
shown some improvement in northwest North Dakota. Satellite
trends suggest the fog has mostly exited McKenzie County, but will
wait a few more hours before removing it from the advisory to
make sure that no redevelopment occurs. Ward and McLean Counties
may need to be added to the advisory if current trends persist.
UPDATE Issued at 622 PM CST Wed Jan 4 2023
Visibility has lowered below a half mile across much of northwest
North Dakota, with near-zero being reported at times. A Dense Fog
Advisory has been issued for Divide, Burk, Williams, Mountrail,
and McKenzie Counties through tomorrow morning. The advisory will
likely need to be expanded, but will wait to get a better sense of
where else the most concentrated dense fog will develop. The
mention of fog in the forecast was expanded across most of western
and central North Dakota, in line with HRRR/RAP guidance.
Southwest North Dakota may be spared from the dense fog tonight,
but extended runs of the HRRR and RAP show fog becoming widespread
across western North Dakota once again tomorrow night.
.SHORT TERM...(This Evening through Thursday)
Issued at 225 PM CST Wed Jan 4 2023
Like the previous days...it`s all about the fog. The dense fog
from this morning has almost fully burned off, except for patchy
spots along the Missouri River and the northwest. The Fog Advisory
has been cancelled, but will probably have to be issued again
tonight along and east of the river. Light and variable winds and
small dew point depressions are the leading cause. Thursday the
fog will hang around until the surface high pressure pushes it
east and burns off. Patchy fog is possible once again Thursday
evening through the overnight.
.LONG TERM...(Thursday Night through Wednesday)
Issued at 225 PM CST Wed Jan 4 2023
Friday temperatures will be slightly cooler from an incoming
ridge, then through the weekend under the ridge temperatures will
warm into the 20s and 30s. Temperatures nearing or exceeding 40 in
the southwest is possible with warmer air aloft pushing in. The
NBM 90th percentile has highs in the 30s in the central and
nearing 40 in Bowman county. These above average temperatures will
continue through Wednesday, with no precipitation.
.AVIATION...(For the 00Z TAFS through 00Z Thursday Evening)
Issued at 622 PM CST Wed Jan 4 2023
Dense fog is possible once again at most terminals through
tomorrow morning, though KDIK has lower chances at seeing fog.
Visibility may vary between VLIFR and MVFR categories. No other
aviation concerns are expected through the forecast period.
Dense Fog Advisory until noon CST /11 AM MST/ Thursday for
Area Forecast Discussion
National Weather Service Burlington VT
1031 PM EST Wed Jan 4 2023
A period of rain is expected this evening. A strip of freezing
rain will be possible along the international border, followed
by some drizzle or freezing drizzle, mainly east of the Greens.
Across far northern New York, some difficult travel is expected,
and the Thursday morning commutes for far northern New York and
east of the Greens could be impacted. Precipitation will wind
down to scattered snow showers by late Thursday afternoon.
Quieter weather, though with several chances for light
precipitation, is expected for the weekend into the new week.
.NEAR TERM /THROUGH THURSDAY NIGHT/...
As of 1031 PM EST Wednesday...A challenging forecast continues
for the overnight hours as cold air continues to take it`s sweet
time sagging southward across the international border. As of
10 PM, subfreezing air has only made it into the hollows of the
eastern Adirondacks, the northern St. Lawrence Valley and the
far northern Greens around Jay Peak. Elsewhere, surface temps
range from the low 30s just above freezing, to near 40 degrees
in Rutland and Montpelier. Model guidance continues to struggle
with this airmass with most cooling the low levels way too fast.
For this update, heavily relied on the 00Z NAM3 and HRRR which
continue cooling where subfreezing air is already in place,
continuing the ice threat there, while bringing other areas
close to freezing but not quite. Additionally, looking at water
vapor, a mid-level dry slot is quickly advancing into the
region, and radar returns are rapidly diminishing so widespread
precipitation will likely be done in the next few hours. With
all this in mind, feel most of the advisory area in
central/southern Vermont won`t see any impacts below 1500 feet,
while above 2500 feet up to a quarter inch of ice is possible,
especially at the summit peaks. Areas of fog and drizzle will
likely continue through the night, but the next shift may need
to adjust the advisory timing if warm trends and ending precip
Previous Discussion...The theme continues to be the observation
of continued warmth and dewpoints above freezing and cold air
only slowly shifting south. Below freezing area remains north of
Hawkesbury and Ottawa. It has barely budged all day. We`re
finally starting to see dewpoints sinking into the upper 20s,
but it will take some more time for mixed precipitation to get
going. Even the usually cold NAM12 came in with toasty
temperatures. Overall, the consensus of 12z guidance and what
we`re observing indicates a continued need to thin the freezing
rain line, as well as adjust it further north.
After taking a closer look at Massena, we are still concerned due to
favorable northeast winds at 15 to 25 mph sustained and 30 mph
gusts, but the preceding warm conditions and moderate rate of
precipitation will hinder ice from accumulating most effectively.
The temperatures even then remain marginal, about 30 to 32, which
appear likely to keep temperatures at bay. Still, if there`s a place
to watch closely, it will be the area in and around Massena, and
perhaps a few spots that set north of Lyon Mountain, like Ellenburg.
As such, we`ve continued trimming parts of the advisory out. The
best chances for freezing rain will be between 8 PM and 5 AM in
northern New York. In Vermont, the best opportunity for icy weather
will be as surface high pressure moves north of Montreal and brings
cold winds from northeasterly flow. However, with deeper moisture
moving north as the high does so, it seems mostly confined to
freezing drizzle, which should mainly impact elevated surfaces.
Vermont`s ice totals have been trimmed further, with mostly a glaze
to a few hundredths. It could be quite spotty, and tied to higher
terrain. The trend to lesser impacts continues across Vermont,
Onto the weather beyond this system. The region should largely dry
on Thursday afternoon, with temperatures warming into the 30s across
the area, with some lower 40s in the Champlain Valley and parts of
St. Lawrence County. Towards evening, a small vort max will round
the upper low, and combined with the positioning at the left exit
region of an upper jet, should provide at least some forcing for a
bit of rain/snow showers. Still warm overnight, with upper 20s to
lower 30s Thursday night and into Friday.
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
As of 355 PM EST Wednesday...Approaching low pressure Friday will
bring isolated to scattered snow showers to the North Country.
However, upper level support will become rapidly absorbed into
broader cyclonic flow over northern Canada resulting in opening of
the low level circulation. This will effectively weaken forcing
keeping chances lower than recent systems. Overall flow remains
cooler with 0C 925-850mb remaining south of Vermont keeping
precipitation mode as snow. Best chances for snow and light
accumulation up to an inch or so will be in southern Saint Lawrence
County where flow regime favors some lake enhanced showers off of
Lake Ontario. Elsewhere, snow showers will only produce token
amounts given their more scattered nature with a dusting to less
than an inch possible. Upsloping along the Green Mountains could
produce an inch mainly towards the higher elevations. Surface flow
will be turning from southwest to west and northwest with slight
cold air advection. Still temperatures start warmer than average
Friday with highs in the mid/upper 30s trending slowly cooler
overnight into the mid/upper 20s.
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 355 PM EST Wednesday...Ensemble and deterministic solutions
favor a zonal pattern across the central tier of the country
resulting in several waves ejecting off the Rocky Mountains. These
waves will have trouble phasing with moisture out of the lower
latitudes while arctic airmass will likely be locked more towards
northern Canada due to a massive blocking high extending the length
of the Rocky Mountains from the southwestern United States through
northwestern Canada. Without being able to phase with moisture out
of the Gulf or with colder airmasses of continental Canada, the next
series of waves will remain weak and lack depth of moisture. After
some isolated, lingering upslope snow showers Saturday, high
pressure will transit the region Saturday night through Sunday.
Models then trend marginal wetter as a fast moving, weaker variety
low passes south of Vermont. Kept slight chances of showers rather
than increasing pops since drier air will remain over the region and
could keep shower chances lower. Another quick migratory high will
pause precipitation chances behind the wave before the potential for
a deeper trough swings out northern Canada bringing more chances of
The verdict is still out for what happens after the mid week wave
passes. The main question is whether the polar vortex will drop
southward enough to increase the amplitude of the longwave trough
over the eastern seaboard supporting development of a stronger
offshore low over the western Atlantic baroclinic zone, or if it
will end up being too progressive becoming more of an issue for
eastern Canada/Maine. Ensembles favor a larger amplitude, but
deterministic models are split on where the axis of the wave ends up.
Temperatures will continue to run slightly warmer than average
through the beginning of the week until the longwave begins to
deepen and pool colder, more seasonal air over the Northeast around
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
Through 00Z Friday...Challenging aviation forecast with a
variety of ceiling heights as rain overspreads our region. Will
also have different precipitation types as colder air sinks down
into our region from the north associated with a stationary
front which has been situated to our north most of the day.
Currently all sites are IFR or lower except for KPBG and KMSS
which are MVFR. Expect widespread precipitation overnight, and
then precipitation will come to an end after 12z. Freezing rain
will impact KMSS for the longest, while other sites should
mainly see rain. KSLK will also briefly have some freezing rain
or sleet. Precipitation will become more scattered after about
10z, and then ceilings should start to improve after 15z. North
to northeast winds around 5 to 10 knots, except closer to 12 to
15 knots at KMSS, are expected, which will then trend light and
variable about 09z, and then southeast. KMSS will remain
northeasterly, though, and will experience notable direction
shear from northeast surface winds at 10 to 15 knots, and
southeast to southerly winds around 30 knots at 2000 ft agl
between 08z and 15z Thursday.
Thursday Night: Mainly MVFR, with local IFR possible. Chance
SHSN, Chance SHRA.
Friday: Mainly MVFR, with local VFR possible. Chance SHSN, Chance
Friday Night: Mainly MVFR, with local IFR possible. Slight chance
Saturday: Mainly MVFR, with local VFR possible. Slight chance
Saturday Night: Mainly VFR, with areas MVFR possible. NO SIG WX.
Sunday: VFR. NO SIG WX.
Sunday Night: VFR. NO SIG WX.
Monday: Mainly VFR, with local MVFR possible. Slight chance SHSN.
VT...Winter Weather Advisory until 10 AM EST Thursday for VTZ003-
NY...Winter Weather Advisory until 10 AM EST Thursday for
Area Forecast Discussion
National Weather Service Cheyenne WY
538 PM MST Wed Jan 4 2023
Issued at 533 PM MST Wed Jan 4 2023
Quick update for this evening. Let the High Wind Warning expire
for central Laramie County and eastern Platte County this evening
since winds have continue to subside. Also, webcam and visibility
observations across Carbon and northern Albany counties have
improved today even with the gusty westerly winds in the afternoon.
Decided to cancel the Winter Weather Advisory for blowing and
drifting snow with improving road conditions and visibilities.
.SHORT TERM...(This evening through Friday)
Issued at 230 PM MST Wed Jan 4 2023
Mostly sunny conditions have spread across the area this afternoon
as temperatures hover near or slightly above the freezing mark for
portions of SE WY and the NE Panhandle. Along and west of the
Laramie Range, particularly the I-80 Summit and Arlington/ELk
Mountain areas, blowing snow continues to impact the region thanks
to continued gusty winds. Observations from early this morning
through 21Z have highlighted westerly wind gusts of 45-65+ mph.
The strong winds have created travel impacts for roads and the
Interstates today. Observations through this morning to the early
afternoon hours have reported visibility of less than 1 mile in
the Interstate 80 corridor. GOES-16 visible satellite imagery
depicts the mountain and gravity wave signature over our western
forecast zones this afternoon. Water vapor imagery analysis
highlights the stacked ULL to our east across the Upper Midwest
and Mississippi valley, a building upper level ridge over the
Great Basin, and another weather system sweeping across the
Pacific Northwest. The mid-levels of the atmosphere look to be
drying as surface high pressure and subsidence move into the
Intermountain West, which includes WY.
The remainder of the day will see elevated to strong wind gusts
across the higher terrain. The eastern Platte County and Central
Laramie County forecast zones are anticipated to see decreased
wind gusts by 0Z this evening. Blowing snow will remain a hazard
for the higher terrain where the elevated wind gusts and recent
snowfall make areas slick. Temperatures will decrease quickly
after dark due to mostly clear skies and the recent snowfall. The
CWA will see several locations with single digits to the teens for
overnight lows, with a couple locations east of the Central
Laramie Valley being slightly warmer due to elevated winds mixing
the warmer temperatures from the nocturnal inversion down to the
The upper level ridge axis will propagate from the Great Basin
toward our cwa on Thursday. Mostly sunny conditions and warmer
temperatures will make a return as well. Daytime highs in the 30s
to low 40s are expected. The steering flow aloft will arrive from
the northwest, thus the mountain zones will see orographic uplift
enhancement. This should lead to isolated snow showers in the
higher terrain, but other areas will remain mostly sunny and near
seasonal averages for temperatures.
Thursday night into Friday will see the upper level ridge axis
propagate quickly to the east as the upper level flow becomes
progressive. As this occurs, the steering flow will shift to the
southwest from an approaching upper level shortwave disturbance
making a trek toward the Intermountain West. The bulk of the
energy appears to remain along and west of the Laramie Range on
Friday, but mostly cloudy conditions can be expected for the cwa.
Light snowfall over a prolonged period may result in accumulations
for the Snowy/Sierra Madre near winter headline criteria. The
NamNest is the most aggressive, with this feature, but the HRRR
has begun to pick up on snowfall for several locations in Carbon
County as well.
.LONG TERM...(Friday night through Wednesday)
Issued at 230 PM MST Wed Jan 4 2023
Quasi-zonal flow expected across the area this weekend into early
next week with brief periods of shortwave passages that could lead
to light mountain snowfall and strong winds across southeast WY.
Snowfall will mainly be focused along the Sierra Madres Saturday
morning with remaining mid-level moisture from a compact upper level
trough moving through the central Rockies. Saturday will be the
coolest day of the extended period as 700mb temps sit between 5 and
10 degrees C below zero, but afternoon temperatures still look to be
in the upper 20s and 30s. Lee side troughing with a passing
shortwave to the north Saturday night into Sunday will tighten
pressure gradients across the Laramie Range and increase flow aloft.
This could lead to the next period of high winds for wind-prone
locations across southeast WY. Could see elevated winds extend
across the NE Panhandle as well so blended in NBM 90th percentile
for winds Sunday into Monday. Most models show a more amplified wave
passing through the central Rockies Wednesday that could provide a
better chance for precipitation across the area. Highest PoPs were
spread across Carbon Co, mainly around the Sierra Madres with
orographic forcing. However, this system will be fairly progressive
and latest Euro is farther south than the GFS keeping most of the
precipitation in CO. Expecting to see a gradual warm up with an
upper level ridge building across the western CONUS through late
next week before the next Pacific wave approaches from the west.
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 436 PM MST Wed Jan 4 2023
Mostly VFR expected, with the exception of MVFR CIGs possible at
KRWL. Otherwise, largely a wind forecast tonight into tomorrow.
Some LLWS is expected to develop at KCYS overnight as strong winds
decouple from the surface. Marginal LLWS is possible at other
terminals through the night. Lighter surface winds expected
overnight, which will become stronger again late Thursday
Issued at 230 PM MST Wed Jan 4 2023
Fire weather concerns will remain low as recent cold temperatures
and snowfall across the area minimize the threat for any potential
conditions of fire spread. Breezy to gusty west winds will remain
across SE WY FWZs for today and Thursday. A chance of additional
snowfall for the area exists on Friday.
WY...Winter Weather Advisory until 5 AM MST Thursday for WYZ103-106-
High Wind Warning until 5 AM MST Thursday for WYZ106-110-116-117.
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
925 PM CST Wed Jan 4 2023
Issued at 924 PM CST Wed Jan 4 2023
We did remove a few counties from the Winter Weather Advisory for the
rest of tonight.
Douglas and Todd counties in central MN were dropped as snow has
ended in these counties. More counties in western MN may be able to
be dropped through the night as the back edge of the snow slowly
At the other end of the CWA, we dropped Pepin, Dunn, Barron, Rusk,
Chippewa, and Eau Claire counties. Here, temperatures are expected to
remain between 31 and 34 through the night, with maybe a half inch of
snow at best expected the rest of the night, there isn`t much support
for continuing the advisory in those counties the rest of the night.
For the rest of the forecast, the main change we`ve made was to
greatly increase the PoPs through the night in eastern MN and into
Thursday morning in western WI to account for the fact that it will
be lightly snowing much of the time. It won`t accumulate to much, but
when you look out the window, you will likely shoot a sarcastic "hey
look, it`s still snowing" to whomever is within earshot.
.SHORT TERM...(This evening through Thursday night)
Issued at 230 PM CST Wed Jan 4 2023
- Light to moderate snow continues through tonight. Snow ends from
west to east by Thursday morning.
Snow will continue for nearly all of the CWA into tonight as the
precipitation shield continues to rotate counter-clockwise around
the stalled surface low in southeast MN. In fact, the closed
circulation of the low is quite visible within both the radar
reflectivity and clouds on satellite. Snowfall is generally light
but small bands of moderate snow are scattered within the
precipitation shield. These are mainly across south-central MN where
patches of 2-3" (to even nearing 4") is expected by Thursday
morning. (Most of it falling Wednesday afternoon.) Elsewhere, 1-2"
inches is likely. When breaks in the snow do occur due to the drying
of the DGZ, freezing drizzle is likely given the still saturated low-
level thermal profiles.
The low will finally push east towards Lake Michigan by Thursday
afternoon, dragging the snow with it. Snow should taper off from
west to east, exiting our eastern WI counties also by Thursday
afternoon. For the rest of the period, the weather looks pretty
quiet. Colder temperatures have already worked their way into
western MN where upper teens to lower 20s are this afternoon. The
northwesterly flow proceeding the low will continue to slowly cool
us down over the next few days. Tonight`s lows will range from the
mid to upper 20s across southeast MN and west-central WI to mid
teens in western MN. Thursday`s highs should occur in the morning as
temperatures will warm a couple of degrees but then cool the into
Thursday night. Lows Thursday night will be in the single digits.
.LONG TERM...(Friday through Wednesday)
Issued at 230 PM CST Wed Jan 4 2023
- Slightly below normal temperatures Friday through Sunday before
gradual warm up early next week.
Friday through Wednesday... Friday morning, a 1030mb Canadian high
pressure drops south into the Upper Midwest and remains over the
region through the weekend. This sfc high will suppress the jet and
any shortwaves in the midlevel flow to our south. So we`ll see
little to no precipitation and cooler than normal temperatures
through the weekend. High temperatures will range in the mid to
upper teens and low temperatures will be a few degrees either side
of zero. Early next week, the surface high moves off to the east,
setting up return flow over the region. Temperatures gradually warm
up toward normal to slightly above normal.
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 530 PM CST Wed Jan 4 2023
Surface low down by LSE will only slowly drift east this period, with
light snow continuing through the night for all by AXN, which should
see snow end by 6z. Followed a RAP/GFS timing for ending the snow and
the HREF/GFS for showing some clearing skies slowly moving southeast
across MN on Thursday, though confidence is somewhat low on just how
quickly. Another thing to watch with the clearing tonight is the HRRR
shows this filling in with dense fog, so if it gets to AXN early
enough, AXN could have fog in the morning. That fog theme then shifts
our direction for Thursday night...
KMSP...Conditions will be somewhat variable through the night. Vsby
between 1sm and 5sm in snow can be expected through the night, with
cigs bouncing between 008 and 016. Improvements in cigs will be slow
on Thursday, but by the time we get to 24 hours from now, we should
either see mostly clear skies or a clearing on the doorstep.
/OUTLOOK FOR KMSP/
Fri...VFR. Chc mrng fg. Wind lgt & vrb.
Sat...VFR. Chc mrng fg. Wind SE 5 kts.
Sun...VFR. Chc mrng MVFR/IFR cigs. Wind lgt & vrb.
MN...Winter Weather Advisory until 6 AM CST Thursday for Anoka-Benton-
Parle-Le Sueur-Martin-McLeod-Meeker-Mille Lacs-Morrison-
WI...Winter Weather Advisory until 6 AM CST Thursday for Pierce-Polk-St.
Area Forecast Discussion
National Weather Service Reno NV
229 PM PST Wed Jan 4 2023
A series of winter storms will impact the region through early next
week. Rain and snow with strong gusty winds are expected through
Thursday morning, with a break in the weather for Friday. The next
storm will bring mainly light snow Saturday into Sunday, before a
stronger and warmer atmospheric river could bring rain and low
elevation flooding concerns along with heavy mountain snow.
.Short Term (through 12z/Friday)...
Next and more substantial wave of this current storm is slated to
impact our region tonight through Thursday.
* I really want to emphasize how complex the precip types will be
for W Nevada especially areas below 5500 feet. Increasing winds
and warm air aloft have mixed down in some areas lifting
temperatures well into the 30s at RNO or even above 40 at TRK/TVL,
while the Carson Valley is mired in low 20s as of this writing.
With surge of warm air aloft associated with the precip tonight,
we could easily be looking at a situation where some valleys have
snow and freezing rain while other areas are just rain. Things may
get really interesting 10-13z/Thurs when remnants of NCFR work
into the area and that could switch things to all snow for a brief
period. Winter weather advisory has been posted for the Sierra
Front to account for this scenario, which will impact the Thursday
morning commute. Be ready for anything...
* In the mountains, this looks to be a slam dunk 9-12 hour period of
heavy wet snow from mid-evening into Thursday morning. Significant
travel disruptions should be expected along with increasing
avalanche risks. Strong winds aloft could also mix down resulting
in tree damage and power outages, especially in areas with heavy
snow caked to trees already. Additional convective heavy snow
showers look likely for tomorrow afternoon/evening in an unstable
airmass, so winter storm warning will continue through at least
* Elsewhere in the region including the Highway 95 corridor, strong
winds are expected to surface this evening and tonight per the
latest HRRR guidance. Wind advisories will continue for Mineral
and parts of Lyon Counties. Rain and snow showers are likely in
these areas as well Thursday morning but wind will probably be the
main weather issue.
The march of winter storms will continue through the longer range
forecast period with periods of valley rain, heavy mountain snow,
and enhanced breezes. Friday looks to be relatively quiet as a
short wave ridge briefly builds over the western US ahead of the
first in the series of active Pacific storms to affect the region
this coming weekend. Subsequent systems will bring a mixture of
impacts to the region into next week.
Friday will start off on the chilly side with lows in the 20s for
lower valley locations, and single teens for most Sierra Valleys
under a cover of partly to mostly cloudy conditions across the
region. Daytime highs will rise into 40s for most valley areas with
mountain locations remaining below freezing. Remote at best, some
Sierra valleys such as the Martis or Sierra valleys may have the
potential for patchy freezing fog during the early hours due to
lighter winds and higher RH’s in those areas. Some lingering
showers will continue pushing across northeast CA close to the CA/OR
border and the Sierra Crest with only a minimal impact to the more
highly traveled mountain passes. But these relatively quieter
conditions won’t last long, as the first in a series of upcoming
storm systems drives east into the West Coast later Friday.
The weekend storm will still take advantage of a moderate level tap
of sub-tropical moisture as incoming cold front brings a period
heavy to the Sierra crest Saturday afternoon and evening and a
shorter period of overnight light snow into western NV through
Sunday morning. Timing remains, however, an issue as to the onset of
precipitation into western NV. Most current blended model guidance
is leaning towards a rain shadowing scenario Saturday. But snow
levels will make only modest rises to 4500’-5500’ during the day
with far western NV valley locations initially seeing a wintry mix
of rain-snow Saturday evening that gives way to light snow as snow
levels drop to valley floors after midnight. Light snow will
eventually spread east into the western NV Sunday morning before
transitioning to mostly showers later Sunday morning. Areas across
the Sierra crest above 7000’ should see 1-2 feet of additional
accumulated snow with a few more inches of snow around the eastern
Sierra foothills. Blended guidance continues to foretell up to a
foot of new snow for some areas of eastern CA west of US-395.
Not to leave out the more important elements, wind gusts Saturday
across Sierra ridges could top out at 80 mph as well.
The next system in line to affect the area later Monday into Tuesday
will tap into a deeper more moist conduit of sub-tropical moisture.
Current expectations continue to project this system to be the
strongest Pacific winter system moving into the region. With that
said, the potential for flooding is a very real possibility seeing
the various complexities and upcoming impacts associated with this
upcoming system. Forecast precipitation values from current ensemble
guidance continues to project several inches of precipitation higher
elevation areas of the Sierra. Before venturing into into the
mountains, it’s advised to consult the latest forecast avoid the
days with the most significant impacts across the region.
* S/SE winds will increase as we see a break in precipitation late
afternoon and this evening. Gusts on the order of 20-30 knots are
possible, with some appreciable low level wind shear with winds 50
knots just above the surface.
* Precipitation rates increase rapidly this evening in the Sierra
and into W Nevada overnight as narrow cold frontal rain band moves
into the region. Heavy wet IFR/LIFR snow is likely for Sierra
airports including TRK, TVL, and MMH with mainly light to moderate
MVFR rain at RNO, CXP, and MEV. With cold ground, don`t be
surprised to see some of this rain freeze to paved or elevated
surfaces. Also can`t rule out a changeover to snow in at these
lower elevation airfields around 10-13z/Thurs as period of more
intense lift moves across the region.
* Precip becomes more showery after 18z/Thursday with periods of
MVFR-IFR snow in the Sierra and MVFR rain/snow showers in W Nevada.
NV...Winter Storm Warning until 4 AM PST Friday NVZ002.
Wind Advisory until 10 AM PST Thursday NVZ001.
Winter Weather Advisory from 1 AM to 10 AM PST Thursday NVZ003.
Lake Wind Advisory until 10 AM PST Thursday for Pyramid Lake in
CA...Winter Storm Warning until 4 AM PST Friday CAZ071.
Winter Storm Warning until 4 AM PST Friday CAZ072.
Winter Storm Warning until 4 AM PST Friday CAZ073.