Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/02/22
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
601 PM CST Thu Dec 1 2022
.UPDATE...
Issued at 601 PM CST Thu Dec 1 2022
A few radar returns are being observed in the northwestern corner
of the state, but so far, neither obs nor webcams have shown any
snow reaching the ground. A little light snow should start
reaching the ground over the next few hours as the lower levels
continue to saturate. Otherwise, no major updates at this time.
&&
.SHORT TERM...(This Evening through Friday)
Issued at 358 PM CST Thu Dec 1 2022
An Arctic cold front will bring a period of light snow, strong
northwest winds, areas of blowing snow, and bitterly cold
temperatures and wind chills to much of western and central North
Dakota late tonight through Friday evening. A Winter Weather
Advisory for blowing snow has been issued for portions of south
central North Dakota into the James River Valley.
Water vapor imagery shows a strong mid to upper level trough digging
into the Pacific Northwest this afternoon. The trough is expected to
cross the Northern Rockies by Friday morning, reaching the Northern
Plains Friday afternoon. It will be preceded in time by an Arctic
cold front that is forecast to enter northwest North Dakota late
tonight and sweep across the state by Friday afternoon. A burst of
gusty winds is possible with the initial frontal passage, but the
nocturnal temperature inversion may help mitigate the momentum
transfer. However, stronger pressure rises trailing the front and a
tightening pressure gradient will drive sustained northwest winds
near 30 mph with gusts as high as 50 mph late Friday morning
through the afternoon, especially from south central into eastern
North Dakota.
Strong synoptic scale forcing from Q-vector convergence and DCVA is
likely to bring a period of light snow to most, if not all of
western and central North Dakota tonight through Friday afternoon.
Divide County may see a longer period of light snow beginning as
early as this evening as a baroclinic zone temporarily stalls over
that area. Ensemble systems show varying degrees of confidence in
snow accumulations around 1 inch, but are generally at least 50
percent for this threshold across a majority of the forecast area.
We are generally discounting earlier CAM guidance that produced no
snow at all, though a light dusting is still a plausible low-end
outcome for all areas. The progressive nature of the snow and short
residence time of saturation within the DGZ should prevent
significantly higher totals, but localized amounts as high as 2
inches appear possible. Some runs of the RAP have shown a banding
potential in the 850 mb frontogenesis field, but it is very
transient and seems unlikely to be a larger factor than the
background synoptic forcing.
Existing snowpack is well crusted over, but any fresh snowfall will
easily be blown around by the strengthening northwest winds on
Friday. Ensembles are consistent in painting the strongest winds and
highest QPF potential from south central North Dakota into the James
River Valley, and blowing snow guidance suggests moderate to high
confidence (50 to 70 percent) in visibility reductions as low as
half a mile in rural areas. A Winter Weather Advisory has been
issued to account for this hazard, in effect from 8 AM to midnight
CST on Friday.
After the arrival of the cold front overnight/Friday morning, near
steady or falling temperatures are forecast for the remainder of the
day, ranging from around zero northwest to 15 above southeast.
Daytime wind chills colder than 10 below will be common, with 20s
below becoming widespread Friday evening across the north.
.LONG TERM...(Friday Night through Thursday)
Issued at 358 PM CST Thu Dec 1 2022
Well below normal temperatures highlight the long term period.
Low temperatures Friday night into Saturday morning are forecast to
fall into the 5 to 15 below range, with resulting wind chills as low
as 30 below. A Wind Chill Advisory will likely be needed, but
exact location and timing details still need to be worked out.
A general northwest flow pattern is advertised through the weekend,
with moderating temperatures especially to the south and west.
Ensembles then point toward another surge of Arctic air entering
the region by late Monday and remaining in place through
Wednesday. Some light snow may be possible over this timeframe,
but predictability remains quite low. Southwest North Dakota would
be slightly more favored for light snow in this pattern given the
location of the baroclinic zone at the edge of the Arctic air
mass, and NBM PoP guidance confirms this thinking. Dangerous wind
chills in the 20s and perhaps 30s below zero will be possible
during the overnight and morning hours Monday night through
Wednesday morning. It should be noted that while global ensemble
systems show significant cold anomalies at 850 mb, there is still
a large spread in NBM surface temperature guidance. The warmer end
of the NBM temperature spread is still below normal, but the
spread suggests lower confidence in the intensity of the potential
Arctic outbreak.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
Issued at 601 PM CST Thu Dec 1 2022
Starting the period, VFR ceilings and visibilities, along with
light and variable winds, are present. A cold front will move
west to east across the state late tonight through Friday morning.
This will result in deteriorating conditions as gusty northwest
winds, light snow, blowing snow, and MVFR/IFR ceilings develop.
Conditions will begin to improve from west to east through the day
Friday.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 8 AM Friday to midnight CST Friday
night for NDZ022-023-025-034>037-042-045>048-050-051.
&&
$$
UPDATE...Telken
SHORT TERM...Hollan
LONG TERM...Hollan
AVIATION...Telken
Area Forecast Discussion
National Weather Service Denver/Boulder CO
526 PM MST Thu Dec 1 2022
.SHORT TERM...(This evening through Friday)
Issued at 250 PM MST Thu Dec 1 2022
...STRONG WINDS MOST AREAS...
...SNOW, BLOWING SNOW, AND DIFFICULT TRAVEL FOR THE COLORADO HIGH
COUNTRY LATE TONIGHT AND FRIDAY...
A potent, quick hitting shortwave will produce strong winds over
the entire forecast area, and difficult travel with snow and
blowing snow in the Colorado high country. This shortwave is
currently located along the west coast of the U.S. and will begin
to advance rather quickly eastward as it opens slightly and a
130-140 knot jet races eastward across the northern Rockies and
Great Basin tonight and early Friday. The 130-140 knot jet core
will then settle across the forecast area Friday afternoon. Mid
level winds will also be strengthening through tonight and early
Friday, while low level gradients also sharpen with lee troughing
ahead of the upper level trough.
Regarding the wind threat: While the gradients are strong, the
stability profile is not all that great for high winds with only a
marginal mountain top stable layer. There is one window for
mountain wave enhancement for a few hours late this evening into
the early morning hours. Then snow develops in the mountains which
typically breaks down the mountain wave. At the same time,
however, the brute force aspect of this event will really get
underway with 50-60 knot cross mountain flow, so any reflection
would bring high winds into the foothills and Palmer Divide.
Interesting the HRRR is still advertising 70 knot gusts onto the
Palmer Divide into early Friday morning. Still think that`s a bit
overdone, but wow - that`s a rare event. The existing High Wind
Warnings for the foothills and Palmer Divide area remain
unchanged.
Meanwhile, most of the plains including the I-25 Corridor will get
howling Friday morning with increased prefrontal heating/mixing,
and then large scale subsidence building in by afternoon with
passage of the cold front. Given the mid level flow and expected
daytime mixing, high winds look like a good bet over most of the
plains with gusts peaking at 55-60 mph in most locations.
Therefore, we did upgrade the existing High Wind Watch for most of
the plains to a High Wind Warning. Will mention some blowing dust
in areas that saw lighter snow earlier this week as the ground
quickly dries.
We`re also concerned about the northern I-25 Corridor. While the
winds are a bit too westerly to bring High Winds (>58 mph) to Fort
Collins, points to the north of Wellington will likely exceed
that criteria for a few hours late Friday morning into at least
mid afternoon, making it hazardous to travel for high profile
vehicles (e.g. semi trucks) and other lightweight vehicles. Thus,
we added Zone 38 (eastern Larimer/NW Weld County) to the High Wind
Warning.
With regard to snow: Satellite is showing mid/high clouds
thickening into Utah ahead of the trough, although most if not
all of this is virga so far. The column will gradually moisten
overnight with continued synoptic scale lift and thus snow is
still expected to develop late tonight - first in the northern
Gore and Park Ranges, and then eventually into the Medicine Bow
Range and Summit County late tonight or early Friday morning. The
heaviest snow will likely occur with the passage of the mid level
cold front by late morning when orographics improve (WNW flow).
Even ahead of that, light snow combined with the very strong winds
will produce travel headaches with snow, blowing snow, and snow
covered roads. But travel will be quite hazardous if not difficult
once the heavier snow arrives mid/late morning into early
afternoon. Fortunately, this is a fairly quick shot as drier air
and some subsidence eventually weakens the orographically forced
snow. In fact, by late afternoon there should even be a few breaks
in the sky cover, but there will still be lingering snow showers
and of course blowing snow in open areas and over the higher
passes. Overall totals still look to be sitting in the 4-8 inch
range due to the relative short duration of this potent
snow/blowing snow event, while 10-12 inches likely in the Park
Range as that is more favored by the initial WSW flow. Winter
Storm Warning will remain in effect due to the expected travel
impacts in snow, blowing snow, and significantly reduced
visibility/occasional whiteouts.
.LONG TERM...(Friday night through Thursday)
Issued at 210 PM MST Thu Dec 1 2022
Zonal flow will dominate the long term forecast, with a few brief
shots of mountain snow mixed in through the week.
Winds will wane Friday night as our upper level system quickly
ejects into the upper Midwest. Some blowing snow will still be
possible across the mountains overnight as a few gusts up to 50
mph will still be possible overnight. Any snow Friday evening
should come to an end by midnight.
Saturday will be quiet initially, but snow will redevelop across
the high country as moisture works back into the region. Light
snow will continue through most of the weekend... favoring the
Park Range... through most of the weekend. A more potent shortwave
arrives sometime or Monday or Tuesday which will bring better
chances of snow across most of the mountains. Can`t rule out some
rain or snow making it out onto the plains Monday night or
Tuesday, though chances still seem fairly low. Temperatures should
be a little above average across the urban corridor given some
downslope flow.
Guidance tries to get another weak system into the region during
the latter half of the week, which would bring additional light
snow amounts to the high country. Still to early to talk many
details about this, but it does look like the progressive and
fairly active pattern will continue into next weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 454 PM MST Thu Dec 1 2022
VFR conditions will persist through the TAF period but winds will
create problems on Friday. Light winds at DEN will increase this
evening with their usual drainage direction. As a pressure
gradient along the I-25 corridor increases, winds will increase
later tonight. Some high resolution models have gusts up to 45
knots at DEN during the early morning hours. This seems to be a
bit over-done but gusts up to 35 knots are possible. By the mid
to late morning, winds will increase in strength again. This is
when gusts up to 50 knots will be possible. A cold front will move
across DEN around 17Z or so shifting winds more to the west-
northwest. Winds will continue to veer in the afternoon towards
the north-northwest as speeds will slowly come down as well.
Tomorrow evening, winds will return to weaker levels.
&&
.FIRE WEATHER...
Issued at 250 PM MST Thu Dec 1 2022
Fire weather conditions will be elevated over Lincoln County
through early this evening. Then winds will diminish a little.
Friday will see more widespread elevated fire weather conditions
as strong, gusty winds develop in all areas. Locations that saw
only light snow (e.g. northern and eastern Lincoln County into
Washington County) will see the greatest threat. At least
temperatures turn cooler in the afternoon with gradual improvement
in humidity. However, grass fires will still be a concern.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning from midnight tonight to 5 PM MST Friday
for COZ031-033-034.
High Wind Warning from 8 PM this evening to 5 PM MST Friday for
COZ035-036.
High Wind Warning from 9 AM to 5 PM MST Friday for COZ038-042-
044>051.
High Wind Warning from midnight tonight to noon MST Friday for
COZ041.
&&
$$
SHORT TERM...Barjenbruch
LONG TERM...Hiris
AVIATION...Danielson
FIRE WEATHER...Barjenbruch
Area Forecast Discussion
National Weather Service Columbia SC
715 PM EST Thu Dec 1 2022
.SYNOPSIS...
Cooler and dry conditions are expected to finish out the work
week. Saturday is the warmer of the two weekend days ahead of
the next cold front. Scattered showers possible with the front,
but the next chance for significant rainfall is not expected
until early next week.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Fair and seasonably cool. Surface ridge axis over the region
with a dry atmosphere in place, with only some high thin cloud
cover streaming across initially. Coastal trough to develop late
tonight in response to approaching upper disturbance. Guidance
indicating some isentropic lift developing with some lower
cloud cover developing and possibly shifting north into our
southern FA by daybreak. Lows mid 20s north to low 30s south.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
General consensus as the surface high pressure shifts offshore
of an increase in low level moisture with onshore flow
developing. Bit more of a discrepancy in models in the timing
and degree of moisture increase but generally expect at least
some scattered low level clouds during the day Friday with at
least weak isentropic lift. Fairly significant spread in model
guidance for temperatures tomorrow but cooler guidance seems to
be overdoing the low level moisture increase (fairly significant
moist bias for today already). Highs may be a degree or two
below normal in the upper 50s to low 60s. Deeper moisture will
move into the area Friday night as a cold front approaches the
Appalachians. HiRes guidance keeps the area dry through Friday
night but increasing clouds will keep lows in the mid to upper
40s.
Front moves into the area Saturday, although best lift remains
north of the area with somewhat weak convergence along the front
in our forecast area. With PWATs rising to near the 90th
percentile in the NW forecast area, have included chance for
showers mainly in the northern and western forecast area for
Saturday. Warm advection ahead of the front will lead to
temperatures in the mid 60s to the NW to low 70s to the SE.
Front will continue to work through the area into Saturday
night, although there is some uncertainty as to how far south
the front moves but widespread clouds will keep lows in the mid
40s to low 50s in the south.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Uncertainty remains a bit higher in the long term period as the
front remains hung up somewhere in the southeastern US. As a
result, blended guidance shows a fairly large spread in
temperatures, especially as we move into next week. Anomalously
high moisture beginning next week will lead to chances for rain
with the passing of weak shortwaves over the area which with
generally WSW flow aloft. Generally temperatures should remain
above normal, especially around the middle of next week when the
front will lift northward as a warm front. Blended guidance has
shown a bit of variability from run to run with pops as well so
a bit less confidence in the details but generally, expect
unsettled conditions into next week.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
High confidence in VFR conditions through the overnight period
with a low chance of some MVFR cigs developing on Friday.
Strong high pressure resides over the region while westerly
upper level flow is allowing cirrus clouds to stream over the
region tonight. The surface high will shift to the coast by 12z
with low level flow shifting to the southeast allowing moisture
to return and some scattered stratocumulus clouds expected to
advect into the region from the coast on Friday. HRRR hinting at
some possible MVFR cigs by mid morning with some support from
the SREF but MOS guidance is not showing this as much.
Therefore, decided to include a tempo group for MVFR cigs around
the 13-17z time frame. Winds will be calm to light and variable
overnight before picking up from the east to southeast on Friday
around 5 knots.
EXTENDED AVIATION OUTLOOK...Restrictions possible Saturday
associated with a cold front moving through the area with
scattered showers. Restrictions possible Monday as the front
moves back north as a warm front.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
Area Forecast Discussion
National Weather Service Duluth MN
802 PM CST Thu Dec 1 2022
.UPDATE...
Issued at 733 PM CST Thu Dec 1 2022
A Winter Weather Advisory will be issued for portions of northern
Minnesota Friday into Friday night for the quick moving area of
low pressure and strong cold front that will produce snow, blowing
snow, and strong wind. There may be a wintry mix as well prior to and
just after frontal passage, including freezing drizzle/freezing
rain. The RAP is forecasting a low level moist layer increasing in
depth from 1000 feet to around 3000 feet ahead of the front. This
may be enough to produce some freezing drizzle ahead of the front
and prior to the cold air moving in. This low pressure system
won`t produce heavy snowfall, but rather amounts from around a
half inch to near 3 inches in spots. Far northern Minnesota will
have the best chance at seeing the higher snowfall totals. What
will be significant is the combination of snow and increasing
northwest wind behind the front which will cause reduced
visibility. The HREF has 60-90 percent probabilities of the
visibility dropping to a half mile or less over northern
Minnesota, generally north of US Highway 2, from mid- afternoon
Friday into Friday evening. Areas further south and east may also
see a period of lower visibility in snow and blowing snow but
confidence isn`t quite there to issue a Winter Weather Advisory at
this time. Another concern for the Douglas/Bayfield and possibly
eastern Carlton Counties is enhanced snowfall from a gravity wave.
The RAP is showing a good signal for gravity wave development
after 00Z Saturday through 06Z Saturday. It`s possible a Winter
Weather Advisory may be issued for the rest of the Northland with
later updates depending on the latest model trends.
&&
.DISCUSSION...(This evening through Wednesday)
Issued at 457 PM CST Thu Dec 1 2022
Summary...A messy and windy winter system is due through the area
on Friday, Friday night and Saturday which is the most
significant system in the forecast. After that moves through, we
should have a quiet and cold day on Sunday. Small precipitation
chances return for the Monday through Wednesday time frame.
An inverted trough along with a fairly potent shortwave and upper
level trough that moves across the area during the day on Friday.
A weak surface low within that moves across the forecast area
Friday afternoon and evening. Frontogenesis with this system on
the west side of the surface feature will produce a band of
precipitation that moves into northern MN late Friday morning and
afternoon, continuing into WI Friday night. This precipitation
should begin as a period of mixed freezing rain, snow and sleet,
with some decent signals for freezing rain in model soundings for
at least a short period of time. However, the moisture is lacking
aloft, and we may either not have any precipitation, or low
stratus will sneak in ahead of the trough and we will find
ourselves with freezing drizzle instead. Either way, Friday we
still have high uncertainty in just how things are going to
evolve. We may need a winter weather advisory for mainly the
northwestern portions of the forecast area for Friday and Friday
night, but due to concerns over precipitation type during the
daytime, have held off for now and we can take another look at the
low level thermal parameters this evening and tonight and make
that final call. The cold air advection, tight pressure gradient
and downslope flow will produce strong winds, especially along the
North Shore Friday night and early Saturday, and we should be
gusting 40 to 50 mph in some locations overnight. Have issued a
Wind Advisory for the overnight and early Saturday time range.
Once that system begins to pull out late Friday night and
Saturday, we should get a brief period of lake effect along the
South Shore, but then these should dry up by late morning.
Early next week we have deep cyclonic flow with cold air aloft,
and the models run some shortwaves through the upper level flow
across the area. However, they all have different timing and
track, so there is rather poor agreement in this time range. We
are carrying small pops for portions of the area all three days,
and we will have to wait and see how these resolve in the next few
days. Temperatures will be on the cold side, with high
temperatures potentially in the single digits on Tuesday and
Wednesday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 536 PM CST Thu Dec 1 2022
VFR conditions will occur across most of the Northland tonight
with a southerly low level jet creating low level wind shear over
much of the area. The low level wind shear will last longest at
KHYR, until about 16Z. The southerly low level jet will be
advecting warmer air into the region tonight into Friday morning.
Then an area of low pressure and cold front will move through the
region Friday into Friday night bringing in much cold air.
Ceilings will lower ahead of the front to MVFR or even IFR
with precipitation with the system occurring mostly post frontal.
However, some patchy drizzle or freezing drizzle is possible
ahead of the front. Any mixed precipitation will become all snow
after frontal passage and the cold air moves in. Winds will also
increase after frontal passage and they will get strong. This will
occur mainly after 00Z for the TAFs.
&&
.MARINE...
Issued at 457 PM CST Thu Dec 1 2022
South winds have not been increasing as expected this afternoon,
and have had to delay the onset of stronger winds into early
evening. These winds should develop over the course of the
evening, producing Small Craft Advisory conditions along the south
shore for wind, and along parts of the North shore for both wind
and waves. If the stronger winds do materialize, the Advisory we
have out now may need to be expanded. Conditions should improve
during the day on Friday. Friday night northwest winds develop and
become strong, especially along the North Shore and into the open
waters. For now we have a Gale Watch out, which is looking likely
to be converted over to a Gale Warning. However, there is a small
chance of needing to upgrade the more exposed zones to a Storm
Warning, so have left things as a Watch for now.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 22 34 1 13 / 0 90 90 0
INL 18 27 -5 10 / 0 100 80 0
BRD 24 34 1 16 / 0 90 100 0
HYR 22 37 1 14 / 0 20 90 10
ASX 23 38 6 16 / 0 20 80 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...Wind Advisory from 10 PM Friday to 8 AM CST Saturday for MNZ020-
021-037.
LS...Small Craft Advisory until midnight CST tonight for LSZ121-146-
147.
Gale Watch from Friday evening through Saturday morning for
LSZ121-140>148-150.
Small Craft Advisory until noon CST Friday for LSZ140-141.
Small Craft Advisory until 8 AM CST Friday for LSZ148-150.
&&
$$
UPDATE...Melde
DISCUSSION...LE
AVIATION...Melde
MARINE...LE
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
538 PM CST Thu Dec 1 2022
...Aviation Update...
.DISCUSSION...(This evening through Thursday)
Issued at 325 PM CST Thu Dec 1 2022
Key Messages:
*Breezy winds continue through tonight and pick up tomorrow
*Strong winds tomorrow both ahead of and and behind the cold front
*A Red Flag Warning has been issued for tomorrow afternoon
*Quiet weather through mid week next week
Breezy south and southwest winds continue today with little reprieve
expected in the overnight hours. Satellite showing mostly clear
skies with just a few high clouds to the north. Temperatures are on
track for this afternoon to be in the 50s just about everywhere.
Winds will continue to be breezy overnight with a tight sfc pressure
gradient as the sfc trof approaches from the west. Overnight lows
are expected to be mainly in the 30s with a few 20s further north
and west.
Tomorrow looks to be jampacked weather wise. A cold front is set to
move through the area mid to late afternoon tomorrow. Winds will be
strong both ahead of and behind the front with gusts to around 45-50
mph initially out of the southwest, then turning westerly, then
abruptly shifting to the northwest behind the front. Went with a
mixture of NBM 4.1 and HRRR for wind gusts since the HRRR seems to
have the strongest possible gusts. Should things look like they are
going more the way of the HRRR, a High Wind Warning might be
warranted. The strong winds coupled with low RH values will lead to
increased fire weather concerns. A Red Flag Warning has been issued
for critical fire weather conditions tomorrow afternoon from noon to
6 PM for north central Kansas. Though anywhere south of HWY 6 in
Nebraska could be subject to at least near critical conditions
tomorrow afternoon. There is also the potential for some blowing
dust as well, though the area looks to be mainly limited to south of
HWY 6 as areas further north have recently had snowfall. Regarding
tomorrow`s highs, model spread has narrowed some and so there is a
little better confidence that highs will range from upper 40s up
north, to 60s even 70s! across north central Kansas.
After the trof aloft passes through we will be mainly in zonal flow,
so temperatures won`t dip nearly as much behind this particular cold
front. Saturday`s highs are expected to be in the 30s and 40s with
high pressure moving through at the sfc and bringing back southerly
winds. Sunday`s highs are expected to be in the 40s as a weakening
ridge aloft approaches from the west. Monday afternoon another sfc
trof moves through with a cold front in tow. Models keep us mostly
dry, though there is a small chance we could be clipped by some snow
with this front. Around 30% of EPS members have some QPF, though
amounts look to be a trace to 0.02" at best. Tuesday temps come
down behind the front into the 30s. Highs on Wednesday will be
similar though maybe just as touch warmer as we continue in mainly
zonal flow aloft.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Saturday)
Issued at 526 PM CST Thu Dec 1 2022
LLWS is expected tonight into Friday morning.
Southerly surface winds then pick up Friday morning, gradually
turning to the west in the late morning and afternoon.
A cold front moves through Friday afternoon (20-23Z timeframe),
leading to strong northwesterly winds. Gusts of at least 40kts are
possible through the early evening on Friday.
Sky conditions are expected to remain VFR through the period, with
only SCT-BKN high clouds tonight into Friday morning.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...Red Flag Warning from noon to 6 PM CST Friday for KSZ005>007-
017>019.
&&
$$
DISCUSSION...Shawkey
AVIATION...Mangels
Area Forecast Discussion
National Weather Service Grand Rapids MI
912 PM EST Thu Dec 1 2022
LATEST UPDATE...
Update
.UPDATE...
Issued at 912 PM EST Thu Dec 1 2022
Will be adding more cloud cover to the fcst tonight as a mid
level cloud deck has recently poured in from the west/southwest.
These clouds could impact our low temp fcst (warmer) but will
leave that as is for now since the thicker clouds may depart
after 3-4 am from west to east, per the latest RAP RH progs.
Will also push off the start time of the Gale Warning on Lk MI
based on latest 00Z run of the HRRR. A few gale gusts could flirt
with Big Sable Point for a time overnight, but the more
widespread/persistent gales do not begin in the nearshore area
until after Noon on Friday.
&&
.DISCUSSION...(This evening through next Thursday)
Issued at 343 PM EST Thu Dec 1 2022
-- 1st order of business is the wind potential Friday/Saturday --
The higher wind potential exists from roughly Friday afternoon
through Saturday morning. The first burst will come Friday
afternoon and evening centered roughly on 7pm in the evening. This
first burst of wind will be warm air advection but the gradient is
strong and 40+ knot winds are in the mixed layer along the
lakeshore. The lakeshore may be the favored area with this first
burst of wind in the warm air advection. The next time frame of
concern will be late tonight and Saturday morning in the cold air
advection right behind the cold front. This time frame has the
potential to see the most widespread gusts, but they could be just
a tad lower then Friday evening. Confidence is high in stronger
wind gusts occurring but location is still a bit of a question
mark. We feel the lakeshore is probably the most slam dunk area with
a Wind Advisory most likely needed. Later forecast shifts will
decide where wind headlines are needed.
-- Precipitation with the cold front Fri night/Saturday --
Rain is expected to break out Friday night along and ahead of the
cold front. Heavy rain is not expected. Rain will mix with and
change over to snow with the passage of the cold front as wet bulb
zero heights crash to zero. We could see some light accumulations
of snow across the area after the transition over to snow. At this
point we think most areas will be in the zero snow to a dusting
category. A few locations especially up towards U.S. 10 could see
a half inch or so.
-- Rest of the forecast fairly uneventful --
We have a couple of weak systems to deal with in the rest of the
forecast period, one being Monday into Monday night and the other
on Wednesday. The first system early in the week looks to bring a
mix of rain and snow given marginal surface temperatures.
Precipitation amounts look to be light. Mid week system also looks
to be light in terms of precipitation and should be more of the
snow variety with colder temperatures.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 650 PM EST Thu Dec 1 2022
VFR weather prevailing through 00Z Friday evening. SCT-BKN cloud
deck around 10,000 ft tonight, lowering to 5000-7000 ft Friday
and becmg BKN-OVC. South winds 8-12 kts tonight increasing Friday
to 15-25 kts with gusts to 35 kts possible at times in the
afternoon.
&&
.MARINE...
Issued at 343 PM EST Thu Dec 1 2022
Earlier today we issued a long duration Gale Warning which extends
from 10pm this evening through Saturday afternoon at 4pm. We ran
the ongoing Small Craft Advisory (SCA) up to the start time of
the Gale to account for building winds and waves this evening.
20-30 knots of wind is in the mixed layer this evening, which is
high end SCA conditions.
Winds tonight and Friday morning may end up under performing just
a bit as the setup will be one of warm air advection. This could
limit mixing just a tad, but we felt confident enough to go ahead
and match neighboring offices which have a Gale Warning.
The highest winds in this gale event will likely come Friday
evening, centered around 7pm in the evening. BUFKIT overviews show
40+ knots in the mixed layer. The other solid time frame for wind
will be late Friday night and Saturday morning in the burst of
wind just behind the cold front. Winds around 35 knots are solidly
in the mixed layer.
Waves look to peak in the Saturday morning time frame in the 8-13
foot range.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...Small Craft Advisory until noon EST Friday for LMZ844>849.
Gale Warning from noon Friday to 4 PM EST Saturday for
LMZ844>849.
&&
$$
UPDATE...Meade
DISCUSSION...Duke
AVIATION...Meade
MARINE...Duke
Area Forecast Discussion
National Weather Service Lincoln IL
730 PM CST Thu Dec 1 2022
.SYNOPSIS...
Issued at 303 PM CST Thu Dec 1 2022
Tomorrow will be the last hill on the roller coaster ride as
strong southerly winds bring temperatures back into the 50s
Friday. However, a sharp cooldown is expected for the weekend as
highs return to the 30s on Saturday. It will be quite gusty
tomorrow, with southerly winds gusting to 45 to 50 mph. Scattered
light showers are possible late tomorrow afternoon into tomorrow night
along and ahead of a cold front that will move through tomorrow
night.
&&
.UPDATE...
Issued at 730 PM CST Thu Dec 1 2022
An area of altocumulus around 700 mb has been working its way east
across the forecast area this evening. Latest runs of the RAP and
NAM suggest this continuing to move through the CWA over the next
few hours, before the next surge of clouds comes in from the west
and southwest overnight. Forecast was updated to hit the clouds
harder this evening.
&&
.SHORT TERM...(This evening through Friday night)
ISSUED AT 303 PM CST Thu Dec 1 2022
As high pressure continues to quickly shift east southwest flow
will return to the area and bring warmer temps back into the
region. This evening, conditions will be dry but clouds will be on
the increase tonight and especially tomorrow. The southerly wind
will bring waa into the area and temps will rise into the 50s
across the CWA. This could be tempered depending on the cloud
cover tomorrow, but hoping the southerly winds will compensate for
the clouds. Northern areas of the CWA could see some lower clouds
in the afternoon and this could bring some very light precip for
the late afternoon. Will have slight chance of light rain for now.
As a weak mid level trough moves into the area for tomorrow night,
a better chance of precip is expected tomorrow evening through
late tomorrow night. This will move through quickly and should be
out of the CWA before any temps drop back down to below freezing.
So, all precip should be liquid, but there could be a slight
chance of a mix of rain and snow as the precip is ending late
tomorrow night in the east near I-57. The best chances of precip
tomorrow will be in the east of I-55, however, a slight chance
will be seen back to the west and around the IL river.
The other issue tomorrow is the trough and associated sfc system
will have a very tight gradient, which will result in very strong
sfc winds from tomorrow afternoon through tomorrow evening.
Southerly sfc winds will be 20-30 mph with gusts of 45 to 50
possible. A wind advisory has been issued to cover this with most
of the area being in the advisory from noon til 9pm. Areas in the
central and northeast...including the cities of
Bloomington/Normal, Lincoln, Decatur, Charleston/Mattoon, Paris,
Champaign/Urbana, and Danville...will remain in the advisory
until midnight tomorrow night. High profile vehicles, especially
on east to west roads should drive with caution.
&&
.LONG TERM...(Saturday through Thursday)
ISSUED AT 303 PM CST Thu Dec 1 2022
Models and ensembles continue to show some differences in the
extended forecast. Deterministic models are trending south with
the next systems while the ensembles continue with precip chances.
So current forecast will maintain some form of pops from last
Sunday night through Thur. However, the better chances will be
from Mon through Tue evening across the central and southeastern
parts of the CWA. Precip type will be tricky during the period
since part of the setup during this time will favor over-running.
If the precip over-running the front to the south is rain, there
will be a chance that some scattered light freezing rain is
possible. HOWEVER, there remains too much uncertainty in the model
solutions to go with any freezing type precip. So, for now will
keep it simple with just rain and/or snow until models show better
consistency and agreement.
Temps in the extended will start out cold, in the 30s, but then
warm in the 40s for Sun through Tue. This wont last long as max
temps will drop into the 30s to lower 40s again for Wed and Thur.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 526 PM CST Thu Dec 1 2022
Main aviation concern will be with the winds the next 24 hours. In
the shorter term, a low level jet is expected to develop across
western Missouri this evening, extending into northern Illinois
overnight. Have introduced LLWS at all sites except KCMI,
beginning around 02-03Z at KSPI/KPIA and by 06Z at KDEC/KBMI.
Strong south surface winds then ramp up during the morning across
central Illinois, with gusts over 30 knots likely by late morning.
Latest guidance shows the highest potential of 40+ knot gusts at
KCMI/KDEC late in the forecast period, extending a short time
after 00Z.
A period of ceilings near 8-10kft will occur tonight, then will
gradually lower during the late morning and especially the
afternoon. Have kept all sites VFR, though latest NBM shows about
a 30-40% chance of ceilings below 3,000 feet by 00Z from KBMI-
KSPI west.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from noon to 9 PM CST Friday for ILZ029-031-037-
041-047>052-061-066>068-071>073.
Wind Advisory from noon Friday to midnight CST Friday night for
ILZ038-042>046-053>057-062-063.
&&
$$
UPDATE...Geelhart
SYNOPSIS...Auten
SHORT TERM...Auten
LONG TERM...Auten
AVIATION...Geelhart
...Updated Aviation Forecast Discussion...
.DISCUSSION...
Issued at 342 PM CST Thu Dec 1 2022
Key Messages:
- Wind Advisory Friday into Friday evening for gusts up to 45
MPH.
- Small chances of light rain/snow across northeast Nebraska
Friday afternoon.
- Saturday morning wind chills -10 to 5.
Tonight and Friday:
Latest water vapor imagery shows a trough moving onto the Pacific
northwest coast this afternoon with largely weak southwesterly flow
across the western and central US. The above mentioned trough is
expected to move into the northern Plains over the next 24-hrs,
pushing a strong cold front into the region. This will come through
much of the forecast area during or just after peak heating,
allowing highs to top out in the mid 40s across our north to the
low 60s in our south. There are small chances for light rain/snow
across far northeast Nebraska Friday afternoon in association
with this boundary with steepening mid-level lapse rates behind
the front. We are not anticipating much in the way, if any,
accumulation due to the dry nature of the forecast soundings. The
main story for Friday will be the strong post-frontal winds.
Strong mixing should produce gusts up toward 45 mph with some HRRR
runs pushing wind gusts up toward 50 mph. Did hoist a wind
advisory for much of the afternoon/evening hours of Friday behind
the front.
Saturday and Sunday:
Gusty northwest winds will continue into early Saturday with strong
cold advection. With temperatures dropping into the single digits to
mid-teens, wind chill values Saturday morning could approach -10 in
far northeast Nebraska. Highs for Saturday should warm into mid to
upper 30s as cool northwesterly winds turn to warming southerly
winds by Saturday afternoon. Much lighter winds are expected Sunday
with highs in the 40s.
Monday through Thursday:
Most signals point to a continued dry forecast with temperatures
ranging in the 30s and 40s for highs with lows generally in the
teens.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 535 PM CST Thu Dec 1 2022
Wind is the primary concern over this 24 hour period. Quick
southerly winds continue overnight with 50 knot winds at about
FL015 through Friday morning.
Surface winds pick up the pace and become northwesterly Friday
afternoon. Gusts of 35-45 knots are expected by 23Z. Gusts will
taper through Friday evening.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Wind Advisory from 3 PM to 10 PM CST Friday for NEZ015-030>034-
042>045-050>053-065-066-078.
Wind Advisory from 3 PM Friday to midnight CST Friday night for
NEZ067-068-088>093.
Wind Advisory from 1 PM to 8 PM CST Friday for NEZ011-012-
016>018.
IA...Wind Advisory from 3 PM to 10 PM CST Friday for IAZ043-055-056-
069.
Wind Advisory from 3 PM Friday to midnight CST Friday night for
IAZ079-080-090-091.
&&
$$
DISCUSSION...Kern
AVIATION...Nicolaisen
Area Forecast Discussion
National Weather Service Reno NV
115 PM PST Thu Dec 1 2022
...WINTER WEATHER IMPACTS CONTINUE ACROSS THE REGION...
.SYNOPSIS...
The current winter storm will continue to bring major impacts to
the Sierra and portions of western Nevada through tonight. Cold
temperatures arrive Friday during a brief break in activity.
Another potent winter storm will bring additional heavy snow with
travel impacts to the Sierra as early as the overnight hours
Friday into early Saturday. Snowfall impacts will likely then
spread into western Nevada through the day on Saturday.
&&
.SHORT TERM...(Through Friday Night)
Our current winter storm is well underway across the Sierra and
western Nevada. As of this writing, precipitation is just now
beginning to spillover into the leeside of the mountain ranges. We
have already seen impressive snowfall rates in Lassen and portions
of Plumas through the morning hours. Expect rates to tick up into
the afternoon as a NCFR brings in rates that may exceed roadway
plowing capabilities at times (along with very low visibility) and
result in even messier conditions as we head into the evening
commute... The greatest chance for snowfall accumulation across
western NV valleys will also be during this time. Rates could also
be impressive for a brief period of time in the valleys as well;
supported by forecast soundings at RNO suggesting a well saturated
isothermal layer in the ideal snow growth region (-18C to -12C).
Heavier snow will abruptly end this evening from north to south
and hi-res guidance looks to push the main precipitation south of
Tahoe by sunset and Mono county by midnight. Nevertheless, a few
showers here and there will still be possible; to account for
these lingering showers and allow time for roadway conditions to
improve - a 4am Fri end time to the winter weather headlines still
seems reasonable.
As far as temperatures go for Friday? It`ll be really cold. ENS
meteograms still indicate that the skies will quickly clear late
overnight, along with winds becoming much lighter. Couple that
with a fresh coat of snow on the ground and we`ll have the recipe
for rapid cooling. The timing of clear skies, however, will
dictate "how much" cooling we`ll see. But, expect single digit to
sub-zero morning lows in Sierra valleys and solid teens elsewhere
in western NV (but isolated single digits can`t be ruled out under
ideal conditions for some western NV communities). Highs will be
chilly, with everywhere only topping out in the upper 30s or
colder.
Enjoy the very brief break in weather as our next system will
work its way into the Sierra and NE California early Saturday. Hi-
resolution models have started to pick up on this system, and
snowfall may arrive into Mono county as early as midnight tomorrow
(Friday night), spreading north during the overnight and early
morning hours. Winter Storm Watches have been hoisted for this 2nd
storm - details will be highlighted more in the long term
discussion below.
-Dustin
.LONG TERM...(Saturday onward)
Our next storm is still on track to be colder, slower, and wetter
than today`s storm. However, the timing of the system looks to be
slightly earlier than expected, with impacts to the Sierra
now arriving as early as Friday night.
A closed low developing off the coast of southern California will
provide a moisture tap for the initial surge of moisture on Friday
night. High-resolution models, including the HRRR and NAM, suggest
snow showers will intiate along the southern Sierra crest into Mono
county late Friday night. Showers will spread northward along the
Sierra through the morning, with impacts to the Tahoe Basin by late
morning. Snowfall intensity looks to remain relatively lower than
the first storm, and generally continuous through Monday morning.
However, higher snowfall rates are expected Saturday afternoon into
Sunday morning for the Sierra as the main upper-level closed low
system that has been tracking southward off the Pacific coast swings
into northern California. This system will provide additional lift
and moisture Saturday afternoon across the Sierra, consequently
leading to some periods of heavier snowfall and potentially allowing
snow showers to spill over into northeastern California and western
Nevada. The ECMWF Extreme Forecast Index notes a widespread area
of enhanced CAPE across the Sierra into western Nevada on Sunday,
suggesting showers may become convective, potentially even
producing thunder and lightning through the afternoon. The main
storm should taper off through Monday morning, though some
lingering showers may persist as the long wave trough hangs over
the western US through the first half of next week.
While the weekend storm will see relatively lower snowfall rates in
comparison to the first storm, it will hang around our region for a
longer period of time. Therefore, storm snow totals will likely be
similar or even higher than those observed from today`s storm.
Blended guidance suggests a nearly certain (97-99%) chance for at
least a foot of snow, a 80-90% chance for at least 2 feet, and a
30-50% chance for at least 3 feet along the Sierra crest. Chances
for snow across far Western Nevada has increased slightly to a
50-60% chance for at least an inch of snow and a 20-30% chance for
at least 2 inches.
South-southwest winds are expected to increase along the Sierra
on Saturday morning ahead of the main closed low system. Gusts as
high as 80+ mph are possible along the Sierra crest through Sunday
morning. Gusty winds will once again raise concerns for
backcountry recreation and aviation. Visit
sierraavalanchecenter.org for more information on avalanche danger
if you plan to head into the backcountry this weekend.
-Whitlam
&&
.AVIATION...
A winter storm will continue to bring heavy snow accumulations to
the Sierra with accumulations possible for lower elevations through
the evening as snow levels fall. There will be a brief break Friday
into Saturday AM, and then another potent winter storm will approach
the area with more snowfall for the Sierra and western NV.
* Winds have gradually lessened as snow pushes into the region this
afternoon. The LLWS along with brisk northwest winds will persist
a bit longer (06-09Z Friday) in the eastern Sierra of Mono County
including KMMH.
* Snow is producing IFR/LIFR conditions for the Sierra terminals
this afternoon. Heaviest snowfall rates with substantial runway
accumulations look to be in the will continue through 0Z Friday
for KTVL/KTRK and 22Z-06Z at KMMH as a heavier band of snowfall
migrates southward; rates of 2" per hour will be common with a
peak of 3-4" per hour possible along the front. For western NV
terminals, a rain/snow mix will transition to all snow around 22z-
0z with periods of MVFR/IFR conditions. Snow totals for western NV
will be around 0.5-1" for lower valley airports, but there is a
25% chance for 2" at RNO and 50% chance for 2" at MEV/CXP.
Edan
&&
.REV Watches/Warnings/Advisories...
NV...Winter Weather Advisory until 4 AM PST Friday NVZ005.
Winter Storm Warning until 4 AM PST Friday NVZ002.
Winter Storm Watch from late Friday night through late Sunday
night NVZ002.
Wind Advisory until 7 PM PST this evening NVZ001-004.
Wind Advisory until 1 PM PST this afternoon NVZ003.
Winter Weather Advisory until 4 AM PST Friday NVZ003.
CA...Winter Weather Advisory until 4 AM PST Friday CAZ070.
Winter Storm Warning until 4 AM PST Friday CAZ071.
Winter Storm Watch from late Friday night through late Sunday
night CAZ071.
Winter Storm Warning until 4 AM PST Friday CAZ072.
Winter Storm Watch from late Friday night through late Sunday
night CAZ072.
Winter Storm Warning until 4 AM PST Friday CAZ073.
Winter Storm Watch from Friday evening through late Sunday night
CAZ073.
&&
$$