Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/16/24
Area Forecast Discussion
National Weather Service Columbia SC
737 PM EST Mon Jan 15 2024
.SYNOPSIS...
Weak low pressure will bring chances for light rain on Tuesday
with a colder airmass settling over the area for the middle of
the week. Temperatures moderate towards the end of the week
before a strong cold front crosses the region and ushers in a
much colder airmass for Friday Night through the weekend.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Satellite this evening shows passing mid to high level clouds
streaming across the region with an area of clearing off to the
west. A short period of clearing is possible tonight before the
clouds build back in ahead of an approaching cold front and this
will determine how quickly temperatures fall during the
overnight. Much of the region should remain dry tonight with a
few passing showers possible towards daybreak, mainly north and
west of I-20. Lows tonight range from the upper 30s to lower
40s northwest to the lower to mid 40s in the southeast.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Synoptic setup continues to look similar to what has been
forecast the past few days, with precip chances slightly
higher than previously forecast. Deep, longwave upper level
trough will finally begin to shift eastward by 12z Tuesday, with
a secondary shortwave digging into the base of the trough and
helping translate it eastward. HREF guidance is pointing towards
increasing moisture in the sfc to 700 hPa layer, with PWs
approaching 1" along and south of the I-20 corridor by midday.
Given increasing lift, despite the primary surface low forming
off the coast, light rain is now expected across much of the
central and southern FA where moisture will be greatest. This
will likely be associated with primary arctic cold front pushing
eastward out of the OH and TN Valleys but behind the
aformentioned coastal low. Light rain is the correct way to put
it, as this looks to be the ultimate high PoP/low QPF event with
rain totals generally expected to be between 0.01" and 0.05".
HREF probabilities of >0.1" are less than 10% across the entire
FA. Best probabilities for measurable rainfall are across the
southern FA. Given widespread cloud cover and increased rain
chances, bumped high temps down a bit into the lower 50s for
many.
Cold air advection looks to commence quickly Tuesday evening,
with the Arctic high translating eastward across the area.
Lows will likely be in the mid 20s for many, with some low 20s
in our cooler spots. The NBM has been consistently trying to
show upper teens in the western FA, but remain skeptical of this
given strong cold air advection allowing surface winds to
remain 4 to 8 mph much of the night. HREF probabilities reflect
this well, showing very low probabilities of lows Wednesday
morning being less than 20F. Wednesday looks cold and beautiful,
with sunny skies, dry air, and well below normal temperatures
expected. Look for highs in the low to mid 40s. Ideal
radiational cooling conditions likely set up on Wednesday night,
with very low PW air & the surface high directly over the
region. This should allow temps to get into the lower 20s in
many areas.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
Forecaster confidence remains high in this period concerning the
pattern evolution and the subsequent sensible impacts. Deep
upper level trough looks to remain largely stationary, moving
slightly by Thursday while remaining anchored across
southeastern Canada and the Great Lakes region. However, a
series of shortwaves are expected to push southeastward out of
the NW CONUS as a strong ridge looks to build across the west
coast. This will help to shift the strong surface high eastward
on Thursday and offshore by Thursday night. Southerly flow will
increase moisture across the FA quickly as the shortwave
approaches from the northwest, increasing clouds and rain
chances on Thursday night. Generally, LREF members and grand
ensemble probabilities indicate another high PoP/low QPF event,
with high (>70%) chances of measurable rain, but low
probabilities of >0.1". This is likely owing to how dry the air
is preceding this, in addition to the speed of the system. Most
of the rain looks to be to our east by midday on Friday.
Behind the cold front on Friday, the coldest airmass of the
season awaits. Temps on Thursday/Friday will be seasonal, in
the low to mid 50s. But Saturday through Monday is likely to be
the coldest period of the season thus far. Upper level trough
will propagate eastward as the ridging across the western CONUS
shifts eastward. Between the two, intense upper level
convergence and subsidence will foster an intense surface high
pressure system that will only feature moderate modification as
it translates eastward. The EFI, NAEFS, and LREF signals for
this are strong and consistent, raising forecaster confidence to
high levels. As a result, very cold days and nights are likely
this weekend, fostered by the surface high being nearby and dry
air in place. Expect highs in the upper 30s on Saturday and low
40s on Sunday, with mid-upper 40s by Monday. Overnight lows look
frigid. EFI values of 0.8-0.9 suggest lows likely in the teens
in many places on Saturday night, with lows only a few degrees
warmer on Sunday night. If you haven`t it would be a good idea
to winter-proof exterior water spigots to help prevent issues
with pipes.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
VFR conditions expected through most of the forecast period but
there could be a period of MVFR cigs on Tuesday as a cold front
crosses the region.
A cold front remains to our west with satellite imagery showing
higher clouds streaming over the area with some lower
stratocumulus moving into the region from the south. Expect
patchy lower clouds to continue to develop and move over the
area as a weak coastal low develops, although cigs expected to
remain VFR. The cold front will move into the region on Tuesday
crossing the area during the afternoon with some lower cigs
expected and possible light rain showers. Mixed signals in the
guidance on cig restrictions but NBM and HRRR show some MVFR
cigs in the CSRA so included a prevailing group from 14-18z at
AGS/DNL while lower confidence at CAE/CUB/OGB results in tempo
groups there during the 14z-19z time frame. Winds overnight will
be light and from the southwest then pick up to around 5 to 10
knots mid morning and begin shifting to the west as the front
approaches and increasing to around 10 to 12 knots.
EXTENDED AVIATION OUTLOOK...Restrictions possible Thursday
night and Friday as another weak low pressure system crosses the
region.
&&
.HYDROLOGY...
Many local rivers remain in flood from heavy rains last week, but
are generally receding. Expect rivers will continue gradually
falling, however several will remain above flood stage into early
this week.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
524 PM CST Mon Jan 15 2024
.Discussion...
Issued at 327 PM CST MON JAN 15 2024
Key Messages:
- Light Snow Ends This Evening
- One More Morning of Bitter Cold; Brief Break
- Snow Chances Return, Another Cold Blast End of Week
Previous 1147 AM Discussion on Snow:
Snow showers continue to move across Kansas along leading edge of
vort max with approaching jet streak. H75 thermal boundary currently
sits along the Interstate 70 corridor providing extra lift through a
DGZ that is saturated from about 700mb to 600mb. Through this zone
RAP/HRRR have been showing enhanced lift in the omega fields with
values around -10 microbars. Since 12z, RAP and HRRR have shown an
upward trend in liquid equivalent QPF of around 0.03 to 0.06
inches, which up from ranges of 0.01 to 0.02 early depicted in their
output. 12z HREF mean QPF is also in this range. With the Arctic
Airmass still in place, snow ratios are shaping up to be in the 16:1
to 18:1 range. As this moves through, this is increasing potential
for at least one-half inch of snowfall, and perhaps closer to 1.0
inch. At 13z, NBM probabilities for at least 0.25 inches of snowfall
was around 70 percent, with 30 percent for exceeding 0.50 inches.
Currently thinking amounts of 1.0 inch would be the top end of
amounts, and likely would be very localized. HREF mean snowfall maps
appear rather low, but the main concern is the QPF field increase
along with higher snow ratios. Kuchera snowfall maps from the HRRR
are around 2 inches. Current trends with the snowfall do not support
these totals using Kuchera ratios, thus expectations remains between
0.5 to 1.0 inches from eastern Kansas into Central Missouri.
The main concern will be the timing, as this enters the area around
2pm and could continue through the evening commute, including the
Kansas City Metro. Visibilities throughout central Kansas this
morning have been around 1/2 of a mile to 1 mile. The main challenge
right now is despite an uptick in QPF, CAMs and other models are not
showing any substantial FGEN signals, and static stability is not
overly low, and the EPV fields do not scream classic banded snowfall
signals. With that being said though, concentrated convergence can
still make for a period where snowfall rates are close to 1.0 inch
per hour. With cold road temperatures, this likely stays on the
roads and could make for slick spots. So far, amounts in Central
Kansas have been on the lower end, with just a few tenths, but
convergence may increase as this moves eastward. For now, will hold
off any short-fused headline decisions. While snow accumulations
remain rather light, the the concentrated snowfall rates over a
short period of time may still make for travel impacts.
Discussion Created at 327 PM For Remainder of Forecast:
Tuesday, H5 short-wave trough axis that brought Monday`s snowfall
will exit the area but continues to provide CAA to the area. This
will result in another overnight of Wind Chills between -15 to -30
across the forecast area. The stronger mid-level northwesterly flow
will direct the surface anticyclone toward the southeast away from
the area. Drier air comes in and should help to remove most of the
cloud cover for Tuesday afternoon. A weak short-wave trough moves
across the Intermountain West later Tuesday into Wednesday that will
promote stronger dCVA into southwestern CONUS and attempt to promote
surface cyclogenesis. This promotes lower-level southerly flow from
the Plains into the mid-Mississippi River Valley early Wednesday and
also promotes H5 height rises across the region for a brief period.
A nose of a relatively warmer airmass (though temperatures still
well below normal) is currently progged to make it at least Hwy. 36,
with few solutions and ensemble members pushing it to the Iowa
border. Through early Wednesday morning, Wind Chills between -15 and
-20 expected so have issued a Wind Chill Advisory for our northern
counties that continues into Wednesday morning. Temperatures
Wednesday afternoon will be in the lower to mid 20 north, and
steadily increase to the lower to mid 30s south of Interstate 70.
Light snow flurries are possible in far northeast Missouri. The
relief on Wednesday though is short lived. Once this short-wave
passes through the area, medium-range synoptic models depict an
amplified H5 ridge axis over the Pacific Coast. For our area though
this promotes stronger northwesterly flow in the mid-levels and
sends strong high pressure southward forcing a polar/arctic airmass
back into our area, which will send temperatures into the single
digits with wind chills once again well below freezing. Ensemble
probabilities for temperatures less than 10F Friday through Sunday
is over 90 percent for most of our forecast area, and over 90
percent for air temperatures less than 0F across our far northern
counties. Prior to the coldest temperatures over the weekend, during
Wednesday`s warm push and with the arrival of the cold front,
additional snow is expected. Current ensemble members are spread on
the exact track of favorable forcing for precipitation, but overall
probabilities for measurable precipitation within the CWA is above
70 percent for the middle end of this week. We will continue to
monitor the track of the system to determine how impactful it may
become.
&&
.Climate...
Issued at 230 AM CST MON JAN 15 2024
----------------------MONDAY (1/15)----------------------
RECORD LOW FORECAST LOW
Kansas City (MCI): -10 (1979)** -13
KC Downtown: -9 (1972) -9
St. Joseph: -16 (1979) -16
Kirksville: -18 (1972) -20
Sedalia: -3 (2009)** -8
RECORD COLD HIGH FORECAST HIGH
Kansas City (MCI): 6 (1972) 2
KC Downtown: 6 (1972) 3
St. Joseph: 4 (1972) 1
Kirksville: -3 (1972) -1
Sedalia: 12 (2009) 3
**Record low has already been broken for today (1/15/2024)
----------------------TUESDAY (1/16)----------------------
RECORD LOW FORECAST LOW
Kansas City (MCI): -13 (1977) -9
KC Downtown: -1 (2018) -6
St. Joseph: -12 (1977) -12
Kirksville: -9 (2009) -13
Sedalia: -3 (2018) -5
RECORD COLD HIGH FORECAST HIGH
Kansas City (MCI): 1 (1977) 13
KC Downtown: 9 (1982) 15
St. Joseph: -1 (1982) 12
Kirksville: 8 (1957) 7
Sedalia: 10 (2018) 14
&&
.Aviation...(For the 00Z TAFS through 00Z Tuesday Evening)
Issued at 523 PM CST MON JAN 15 2024
As the area of snow shifts east, VFR conditions are expected to
develop and continue into Tuesday with NW winds transitioning to
W.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...Wind Chill Warning until noon CST Tuesday for KSZ025-057-060-
102>105.
MO...Wind Chill Warning until noon CST Tuesday for MOZ001>008-011>017-
020>025-028>033-037>040-043>046-053-054.
Wind Chill Advisory from noon Tuesday to 6 AM CST Wednesday for
MOZ001>008-015>017.
&&
$$
Discussion...Krull
Aviation...BT
Climate...HB
Area Forecast Discussion
National Weather Service Grand Forks ND
935 PM CST Mon Jan 15 2024
.KEY MESSAGES...
- Hazardous wind chills down into the -25 to -40 below range
continue across the forecast area through tomorrow morning.
- Light snow tonight and Tuesday for northwestern MN.
Probabilities of 60 to 70 percent of seeing at least a half an
inch.
- Periodic wind chills as low as -30 during the morning hours
through the end of the week as the Arctic air mass slowly
moderates. Warmer temperatures on the horizon after this week
as the weather pattern shifts.
&&
.UPDATE...
Issued at 935 PM CST Mon Jan 15 2024
Cancelled the winter weather advisory in the Devils Lake Basin
as visibilities are improving across the area. Some reductions
in visibility are still possible, but they shouldn`t be advisory
level. Lows tonight expected to get into the teens below zero.
Otherwise, forecast remains on track.
Issued at 652 PM CST Mon Jan 15 2024
Light snow showers are moving south in the Red River Valley this
evening. No accumulation expected out of these, outside of some
flurries. More snow showers will be possible starting tonight
around Lake of The Woods, with accumulations under 2 inches when
all is said and done Tuesday night. Forecast remains on track.
&&
.DISCUSSION...
Issued at 256 PM CST Mon Jan 15 2024
Broad and deep upper trough with several embedded shortwaves
continues across central and eastern portions of North America.
One reinforcing shortwave currently digging through the northern
Plains has helped tighten the pressure gradient and bring some
cold air advection to northeastern ND, along with some scattered
flurries. Winds have been ramping up through this afternoon, and
visibility in portions of the Devils Lake Basin have dropped to
a half mile or even quarter of a mile at times. Web cams show
coverage is pretty spotty, but Cavalier county sheriff`s office
reported some low visibility and more of the ND DOT map is
showing some scattered snow drifts. Put out a winter weather
advisory through midnight, and should see some improvement after
winds start to decrease later tonight.
The winds will also bring wind chills in the -30 to -40 range
overnight into tomorrow morning. As expected, the temperatures
have moderated enough so only a few stray NDAWN sites are
reporting less than -40. Most other spots are above warning
criteria and should remain so through tomorrow morning.
Along with the current weak shortwave moving through, models
bring another weak wave/vort down into northwestern MN Tuesday.
There doesn`t seem to be much in the way of frontogenesis to
enhance light snow, but Q vector convergence has a fairly
extended period of synoptic lift over the Lake of the Woods
area. Some of the models are trending in a higher direction with
snow totals, with the HRRR putting some 1 to 1.5 inches of
accumulation by tomorrow evening. The ensemble probabilities
show around 60 to 70 percent chances of at least a half an inch
of accumulation, but probs for over an inch are in the 20 to 40
percent range. An inch or so over a 36 hour period seems
possible, but impacts look fairly minor at this point as there
will be a lot less wind to blow the snow around in that area.
Wednesday, The low pressure system over the Hudson Bay start to move
south as it retrogrades towards the Great Lakes region. Thursday
evening into Friday a shortwave moves over the Northern Plains to
give a slight chance of flurries to a dusting to our Minnesota
counties. Cluster Analysis shows some uncertainty with how far west
and south the low pressure system will move over the Great Lakes
region. This creates some uncertainty with how far west or south to
expect this light snowfall. If the system stays North in Central
Ontario (20% chance) then only the LOW area may see a dusting.
However, if the system moves further south and west closer to the
arrowhead of Minnesota (60%) then a dusting of snow could be seen as
far west as the Devils Lake Basin and portions of SE ND. Friday
evening into Saturday, we start to see the trough move eastward
towards Greenland and an upper level ridge begins to push its
way into the Northern Plains. This weekend we could start to see
above average temperatures ranging between the teens and
twenties. The uncertainty with these temperatures are going to
how amplified to ridge will be over the North Plains and the
effects of our snowpack on temperatures. A less amplified ridge
combined with our snowpack will cool the temperatures into the
single digits and a more amplified trough will increase our warm
air advection over the region to propel our temperatures into
the twenties. Looking past these weekend, model guidance shows a
westerly flow over the Northern Plains to keep us above average
through next week. Ensemble guidance does forecast a phase
change in the Arctic Oscillation and Eastern Pacific
Oscillation. The ensembles show phase shifting from a negative
phase to a strong positive phase starting this weekend and
continuing into next week. This shift in influence would support
an above average warming pattern for the Northern Plains giving
more confidence for warmer than normal temperatures.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 528 PM CST Mon Jan 15 2024
Main concerns this TAF period are winds around 20 - 25kts
sustained with gusts up to 35kts at times (mainly in the DVL
Basin, gusts elsewhere up to 30kts). These will continue
unrelenting overnight into Wednesday. SN showers should move
south and end before midnight tonight, but with higher winds,
BLSN will continue to limit visibility at least a little bit
into Wednesday. Ceilings will remain mainly VFR, but could at
times drop to MVFR especially at MN TAF sites.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Wind Chill Advisory until noon CST Tuesday for NDZ006>008-
014>016-024-026>030-038-039-049-052>054.
MN...Wind Chill Advisory until noon CST Tuesday for MNZ001>009-
013>017-022>024-027>032-040.
&&
$$
UPDATE...AK
DISCUSSION...MM/JR
AVIATION...AK
Area Forecast Discussion
National Weather Service Green Bay WI
505 PM CST Mon Jan 15 2024
Updated aviation portion for 00Z TAF issuance
.DISCUSSION...
Issued at 239 PM CST Mon Jan 15 2024
Short Term...Tonight and Tuesday
The latest RAP analysis and satellite/radar imagery show a beefy
1044mb centered over Montana with a ridge axis extending southeast
into the mid-Mississippi Valley. Further north, a polar vortex is
spinning over Hudson Bay. Westerly low level winds continue to
push a bitterly cold arctic airmass into the region, with wind
chill values remaining near 20 below over parts of central to
north-central Wisconsin early this afternoon. Meanwhile, shortwave
energy is dropping southeast across central Canada with plenty of
clouds and flurries upstream. Forecast concerns continue to
revolve around wind chill headlines and light snow chances.
Clouds and Snow Chances: Behind shortwave energy, which will be
moving across the northern Great Lakes tonight, models continue to
show deep layer of near saturation after midnight through Tuesday
morning, and lingering across far northern WI on Tuesday
afternoon. In general, models seem overdone in their low level
moisture fields, which leads to doubt whether there will be
sufficient saturation for light snow or flurries. But considering
the obs upstream, decided to add the flurries mention, and time
the chance with the arrival of the higher humidity fields in the
mid levels. Low levels dry out again over central and east-
central WI on Tuesday afternoon, which should lead to partial
clearing.
Temperatures and Wind Chills: Trended low temperatures towards
persistence tonight. With incoming clouds and wind, don`t think
temps can get much colder than last night. Highs on Tuesday will
likely only reach from 0 to 5 above.
In terms of wind chills, they start to reach 20 below around 6 pm
over north-central WI, but may not reach 20 below until after 9 pm
over northeast WI. Don`t prefer to get picky with wind chills when
they are that close to advisory criteria (northeast WI), so will
let the start time of the advisory continue as planned. The end
time also looks reasonably close.
Long Term...Tuesday Night Through Monday
Cold will remain the focus of the extended period. The pattern
will begin to shift over the weekend again, bringing back some
relatively warmer weather for early next week.
Temperatures...Very cold temperatures will remain the focus of the
extended forecast throughout the week, as arctic air remains
trapped in our area thanks to an upper low to our northwest. That
said, the coldest days are today and tomorrow, so some mild
warming is expected for the extended period. High temperatures
from the midweek through Saturday will make it into the upper
single digits to low teens, taking the edge off the coldest
daytime wind chills. That said, overnight temperatures will likely
remain cold enough to produce additional wind chill headlines in
some areas. Finally, the warm up is starting to come into sight
as well, with temperatures rising back towards the upper 20s to
lower 30s over the end of the weekend into early next week.
Precipitation...The cold air will remain favorable for lake
effect through the extended, bringing fairly consistent chances
for some light snow to far north-central Wisconsin, near the
Upper Peninsula border. Outside of this relatively small area
however, the rest of the region should be fairly dry until Friday,
when an area of diffluence could produce some brief flurries or
light snow for the region.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 504 PM CST Mon Jan 15 2024
VFR conditions should continue through at least midnight. An upper
level disturbance and surface trough will likely produce some scattered
to broken low clouds late tonight through Tuesday afternoon. There
could also be some brief snow showers or flurries. Cloud bases will
likely be between 1500 and 2500 feet but the clouds should be quite
shallow. Visibility outside of any snow showers will be excellent.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
Wind Chill Advisory until noon CST Tuesday for WIZ005-010>013-
018>022-030-031-035>040-045-048>050-073-074.
&&
$$
DISCUSSION.....MPC/Uhlmann
AVIATION.......RDM
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
804 PM CST Mon Jan 15 2024
.KEY MESSAGES...
* Dangerously cold temperatures and wind chills will continue
tonight through Tuesday morning. Minimum wind chills will range
from -15 to -35 tonight and Tuesday morning. Wind chills of 10
to 20 below are expected Tuesday night north of I-70.
* There is a 50-70% chance for light snow late this afternoon into
tonight. Snow accumulations of a half to 1 inch are probable
southeast of the Illinois River, with the best chances of 1 inch
from I-72 south to I-70. Another clipper system will likely
bring more snow Thursday and Thu night with 40-60% chance of 1
to 2 inches of snow.
* Temperatures rebound back to near normal values by midweek
before another brief surge of bitterly cold temperatures returns
Friday into Saturday with wind chills likely 15 to 25 below
north of I-70 Friday night.
&&
.UPDATE...
Issued at 804 PM CST Mon Jan 15 2024
Updated forecast this evening to increase PoPs to likely (55-70%)
for measurable snow overnight, focused near and north of the I-70
corridor into east central IL. Latest analysis showed a band of
strengthening frontogenesis in the 800-700 mb layer, which is
shown by increased radar reflectivity from near St. Louis
northeast toward Effingham, and corresponding surface
obs/visibilities around 1 mile. RAP forecast soundings over
southeast IL show a deeply saturated isothermal layer
overspreading the region this evening, favorable for snow growth.
Even through moisture is quite limited, QPF of 0.05-0.10" in the
higher band would result in 1-2" accumulations given SLRs near
20:1 in the Arctic airmass. Given the very cold temperatures all
snow will accumulate on roads creating slick travel. They system
is tracking a good 50-100 miles farther south than previous
forecasts so removed accumulations for the Peoria and Bloomington
areas, pushing the light accumulations closer to the I-72
corridor. Another update was to expand the Wind Chill Advisory for
our remaining 3 southeast counties in coordination with the
Paducah office. Here wind chills will drop as low as -10 to -15F.
The remaining wind chill headlines remain in place farther north,
with wind chills dropping as low as -35 over the far northern CWA.
25
&&
.DISCUSSION...
Issued at 300 PM CST Mon Jan 15 2024
Continued wind chill warning for nw half of CWA through noon Tue
with wind chills down to 25 to 35 below. Have wind chill advisory
se half CWA (except Lawrence, Richland and Crawford counties) for
wind chills of 15 to 25 below zero tonight into Tue morning.
Issued a new wind chill advisory for northern CWA from Fulton to
Tazewell to McLean counties north from Tue afternoon thru 9 am Wed
for wind chills as cold as 15 to 20 below especially Tue night.
Mid afternoon surface map shows strong 1045 mb arctic high
pressure over the southern Canadian Rockies and ridging into the
central plains and sw IL. Strong 986 mb low pressure remained
over sw Hudson Bay Canada. Pressure gradient over central IL is
weaker today than yesterday so west to nw winds have weakened to
5-15 mph. Temps were mostly in the single digits above zero except
1 below in Galesburg and Lacon and 2 below in Macomb over deeper
snow pack. Wind chills were mostly in the 5 to 15 below zero range
except 15 to 20 below zero nw of the IL river where deeper snow
pack. Had a fair amount of sunshine today over central IL but
broken mid/high clouds starting to spread ne into central IL at
mid afternoon. Snow was south of the Ohio river and also over
central and sw MO and back into KS.
A clipper system aided by a strong 130 kt or stronger polar jet
will track eastward over central/southern IL and toward the Ohio
river valley tonight, spreading light snow east over areas from
IL river southeast and then diminish from the west during
overnight. Not too much qpf but the high snow ratios (17-20:1)
will support half to 1 inch of snow form Lincoln south to along
I-70. WNW picking up tonight to cause some blowing snow too and we
will likely issue a SPS to address this similar to what happened
Saturday afternoon into Sat night, though not as strong of winds.
Wind chills to drop back to 25 to 35 below zero from I-55 nw and
15-25 below zero se of I-55 overnight into Tue morning. Far
southeast IL near Lawrence county has lowest wind chills of 10 to
15 below zero and will need to watch this area if needed in wind
chill advisory too. Lows overnight mostly in the single digits
below zero, but range from zero to 4 above se of I-70 to 10-15
below zero nw of the IL river over deep snow pack.
A chunk of 1030-1032 mb high pressure breaks off and settles into
the southern plains on Tue afternoon with clouds decreasing Tue
over central IL though brisk/gusty WSW winds prevail of the day
Tue. Another bitter cold day Tue with highs in the single digits
north of I-70 and lower teens from I-70 south. Wind chills of 15
below or a bit colder north of Lincoln for Tue night to support
another wind advisory northern 8 counties from Tue afternoon thru
early Wed morning.
High pressure over the southeast states Wed gives breezy sw winds
over central/se IL with temps modifying. Highs Wed around 20F
north of Peoria to upper 20s to around 30F sw CWA and southeast
IL. Clouds to increase north of I-70 on Wed ahead of next clipper
system. This system ejects from the northern Rockies into central
plains and eventually bring more snow chances to central IL
overnight Thu and Thu night, with 40-60% chance of 1-2 inches of
snow over central IL as snow ratios will be high in cold air mass.
Reinforcing arctic air on strong nw winds arrives later Thu night
into Sat morning on back side of slipper system, and will likely
need wind chill headlines Fri night into Sat morning especially
north of I-70 where wind chills likely reach colder than 15 below
zero. Lows Fri night actually look similar to tonight`s low
temperatures with areas nw of the IL river possibly getting to
8-15 below zero.
The core of the arctic high pressure (1040 mb or stronger) moves
into IL during during next weekend and should bring fair weather
with winds diminishing. Temps to also start modifying with highs
in the 20s next Sunday and 30s on Mon/Jan 22.
Good news for those who are tired of winter bitter cold. The
Climate Prediction Center (CPC) 8-14 Day Outlook for Jan 22-28 has
much of country trending above normal temperatures with IL having
60-70% chance of above normal temperatures. There is also a
40-50% chance of above normal precipitation over central IL with
greater than 50% chance of above normal pcpn in southern IL. So a
milder and more active pattern looks to return to IL the end of
the month.
07
&&
.AVIATION... (For the 00z TAFs through 00z Tuesday Evening)
Issued at 527 PM CST Mon Jan 15 2024
An upper level disturbance will spread -SN and lowering VFR
ceilings across the central IL terminals this evening. Ceilings
should drop to MVFR for a few hours, accompanied by MVFR
visibility which may briefly drop to IFR levels at KSPI-KDEC-KCMI.
Farther north, periods of light snow will affect KPIA-KBMI with
conditions primarily remaining VFR. The system departs the area
later tonight with VFR then dominating the remainder of the
forecast. West winds near 10 kt will be common overnight, with
gustiness developing around midday Tuesday while direction backs
slightly to west-southwest.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
Wind Chill Warning until noon CST Tuesday for ILZ027>031-036>038-
040>043-047>051.
Wind Chill Advisory from noon Tuesday to 9 AM CST Wednesday for
ILZ027>031-036>038.
Wind Chill Advisory until noon CST Tuesday for ILZ044>046-
052>057-061>063-066>068-071>073.
&&
$$
Area Forecast Discussion
National Weather Service Northern Indiana
751 PM EST Mon Jan 15 2024
.SYNOPSIS...
Issued at 221 PM EST Mon Jan 15 2024
Bitterly cold temperatures will continue through midweek. A period
of light snow is expected late this evening into early Tuesday
morning with a coating to 1 inch for most locations. Otherwise,
light lake effect snow continues through the week for largely west-
wind favored areas.
&&
.SHORT TERM...(This Evening through Wednesday Night)
Issued at 221 PM EST Mon Jan 15 2024
Key Messages:
* Dangerous cold will continue through Wednesday morning.
* Lake effect snow showers continue for mainly far northern/western
Berrien County with light additional accumulations and impacts.
* Light system snow is expected away from the Lake late this evening
into early Tuesday morning with a coating to 1 inch expected.
Bitterly cold cyclonic flow will persist under a large Ontario/James
Bay centered negative height anomaly. This will allow for times of
headline level wind chills (< -15F) through Wed AM, especially for
locations north of US 24 where values could briefly reach into
the -25F to -30F range Tue AM.
A light synoptic snow event remains likely later this evening into
early Tuesday morning as a potent shortwave pivots through.
Favorable left exit upper jet support and a developing mid level
frontogenetic circulation expected with this wave, though moisture
quality is definitely the limiting factor for much more than a half
inch to inch of light fluffy snow during this time. Roads could be
slick in time for the Tue AM commute, though the system snow is
expected to tapper off by 11z.
As for the LES in Berrien Ct, light snow and reduced visby`s have
held on so far today thanks to a 20C Lake-850 mb temp differential
and the shallow convective layer conveniently within the dendritic
growth zone. See no reason why this doesn`t continue into this
evening, with a boost overnight into Tuesday AM as the
aforementioned mid level shortwave tracks through. Opted to extend
the WW.Y as a result in Berrien CT through 18z Wed as at least minor
impacts to travel will persist.
&&
.LONG TERM...(Thursday through Monday)
Issued at 221 PM EST Mon Jan 15 2024
Key Messages:
* Another shot of arctic air and sub-zero wind chills Friday night
through Sunday morning.
* Periodic chances for lake effect snow continue, with areas away
from the lake potentially receiving light snow Thursday into
Friday.
Model guidance continues to suggest a weaker low amplitude shortwave
tracking through on Thursday with a chance for light snow. The
Ontario pv lobe then finally releases southeast through the Great
Lakes around Friday with additional snow chances, followed by LES
and and one more shot of arctic air. Snow accums through these
periods appear light, though a combination of wind, cold and light
snow accums can create hazardous travel. The pattern then flips
Sunday into next week with warming temperatures.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening)
Issued at 742 PM EST Mon Jan 15 2024
A weak upper level system will bring a narrow band of snow to
northern Indiana. Updated the TAFs with the latest expectations
derived from obs/trends + HRRR model data. Went with about a 4
hour window of IFR conditions at FWA; otherwise, favor VFR
conditions for most the TAF period.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Wind Chill Advisory until 11 AM EST /10 AM CST/ Wednesday for
INZ005>009-012>015-017-018-020-022>025-103-104-116-203-204-
216.
Wind Chill Advisory from 1 AM Tuesday to 11 AM EST Wednesday for
INZ026-027-032>034.
MI...Wind Chill Advisory until 11 AM EST Wednesday for MIZ078>081-177-
277.
Winter Weather Advisory until 11 AM EST Wednesday for MIZ177-277.
OH...Wind Chill Advisory until 11 AM EST Wednesday for OHZ001.
Wind Chill Advisory from 1 AM Tuesday to 11 AM EST Wednesday for
OHZ002-004-005-015-016-024-025.
LM...Small Craft Advisory until 1 PM EST Tuesday for LMZ043-046.
&&
$$
SYNOPSIS...Steinwedel
SHORT TERM...Steinwedel
LONG TERM...Steinwedel
AVIATION...Skipper
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