Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/04/24
AREA FORECAST DISCUSSION
National Weather Service Albany NY
1027 PM EST Wed Jan 3 2024
.SYNOPSIS...
A cold front will track through the region tomorrow leading to
scattered snow showers followed by colder temperatures for the
end of the week. A storm system passing off the coast will
likely bring accumulating snowfall to portions of the region
late Saturday into Sunday.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
.UPDATE...As of 10PM, GOES16 water vapor shows our northern
stream trough tracking across southern Canada and approaching
the international border. Southwesterly flow ahead of the trough
has led to lake effect off Lake Erie and Ontario but given the
flow direction, snow showers have remained mainly north and
west of our western Adirondack zones. As the night progresses
and the trough approaches, winds should back to the west
allowing snow showers to extend into the chimney of Herkimer
County. Trimmed back the south and eastward extend of POPs
overnight as most snow showers should be in the western
Adirondacks.
Forecast soundings show deep boundary layer so lake effect snow
can be steady at times but the residence time is quite limited
as the trough axis arrives by 12 UTC or so, transitioning the
primary lake band into multiple bands.
Further south, we increased POPs to slight chance in Dutchess
and Litchfield County mainly 09 - 12 UTC Thursday as the high
res guidance including the RAP indicate a narrow corridor of
snow showers that develop as increased CVA ahead of the incoming
trough becomes coincident with the coastal front. Any snow
showers that develop here should be light but a quick coating
cannot be ruled out just in time of the morning commute.
Otherwise, increased temperature a bit from the previous
forecast thanks to extensive cloud coverage overnight that will
prevent radiational cooling and the fact that the colder air
mass lags behind the initial sfc front arriving early Thursday
morning. Overnight lows mainly in the upper 20s to around 30.
.PREVIOUS DISCUSSION [349 PM]...
Low level flow off the Great Lakes and an inversion at the
boundary layer is supporting widespread clouds across the
region. There is some scattered lake effect snow shower activity
into the southern Adirondacks. A weak upper disturbance and
cold front will support continued widespread clouds over our
region through the night.
The clouds will prevent good radiational cooling conditions, so
a slow cooling of the temperatures will occur, as any scattered
to isolated snow shower activity in the southern Adirondacks
will diminish through daybreak. Lows in the 20s to lower 30s.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
Stronger reinforcing cold front tracks through our region
Thursday morning into midday. Scattered snow showers will
accompany the front as an upper impulse and better low level
forcing along the temperature gradient at the leading edge of
the cold advection. There could be 1 to 3 inches of snow in some
parts of the southern Adirondacks with some snow shower activity
that transitions to lake effect. Otherwise, some dustings are
possible elsewhere. Clearing once the front exits and flow turns
more north and northwest and any lake effect turns to more
multibands west of our region Thursday afternoon and night.
Highs Thursday in the mid 30s to around 40 with around 30 higher
terrain, and temperatures falling in the afternoon.
Colder airmass with sun on Friday and high clouds beginning to
move into our region later in the afternoon. Highs in the lower
to mid 30s with 20s higher terrain.
High clouds thicken through Friday night and upper energy and
low level jet forcing begin to approach through the day
Saturday. the leading edge of an area of snow could reach the
eastern Catskills, mid Hudson Valley, Schoharie Valley and NW CT
late Saturday afternoon. Highs Saturday in the lower to mid 30s
with upper 20s higher terrain.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
An active pattern lies ahead for the long term period with two storm
systems looking to impact eastern New York and western New England
with winter precipitation. Though details remain uncertain, the
first system is expected to first show influence over the
region by Saturday night, likely bringing light to moderate
amounts of accumulating snow. The second, more complex system
whose details contain even more ambiguity, looks to grace the
region Tuesday evening. This storm could also inflict measurable
snow across the region, but based on recent guidance, could be
more of a wintry mix type of event. Read on for details...
Saturday night through Monday...High pressure ridging over eastern
Canada begins to push eastward as an open wave with numerous pulses
begins to take shape over the northern Midwest, Great Lakes and Ohio
Valley region. Simultaneously, a low pressure system, having
originated in the Southeast, finds itself centered in the Carolinas
along its northeasterly track up the Atlantic Coast. Throughout
Saturday night into Sunday morning, the low will progress further
into the Delmarva, becoming situated just off the NJ/Long Island
coastlines after midnight. Of course, being several days out at this
point, there remains a decent amount of uncertainty surrounding the
orientation of this track as well as the timing, but model guidance
seems to be in fair agreement in this solution at this time.
With cold air having been ushered into the region in response to the
prior passage of a cold front, upper-level jet dynamics and
increased confluence at the surface to support lift and southerly
flow aloft to support plenty of moisture advection, light to
moderate snow is becoming an increasingly likely result of the
passage of this system. In addition to the temporal and evolutionary
uncertainties of this system, there remains a fair amount of
uncertainty in the amount of snow that will be accumulated and which
areas can expect the most. At this time, the axis of heavier snow
appears to be south and east of the Capital District. However, based
on the latest guidance and ensembles, it would seem that much of our
area will see measurable snow that could meet at least Advisory
criteria. Will continue to monitor the situation closely.
This will be a relatively fast moving system. Most of the snow looks
to fall overnight Saturday into Sunday morning. With the coastal low
still within reach of influence, however, snow could linger
throughout the day Sunday especially in western New England. Snow
from this coastal low will taper off by Sunday afternoon, however, a
secondary low pressure system beginning in the northern Midwest
Saturday night will slowly track north and east into southeastern
Canada through Monday which could help to generate some lake-induced
snow showers especially in the SW Adirondacks. Minimal additional
accumulations are expected.
Tuesday through Wednesday...The second system of interest for the
long term comes potentially Tuesday evening through Wednesday. A
fairly potent low pressure system looks to track toward the region
from the Southern Plains after becoming closed off from originating
as an open wave in the southwest CONUS. The main low looks to weaken
along its northeast track through the central U.S. while a secondary
low looks to form near the eastern Great Lakes. While antecedent
cold air could certainly allow snow to be the preliminary
precipitation type, but an influx of warm air could force the change
over to rain or additional wintry precipitation types. These details
are still very ambiguous at this point being a week out. However,
this will be another system that will monitor closely going
forward.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
VFR conditions expected to prevail through 06 UTC but with snow
showers developing upstream, ceilings are expected to lower tonight
with MVFR ceilings developing at PSF, ALB, and GFL by 08 - 12 UTC.
POU likely remains VFR. As our cold front approaches tomorrow
morning, chances for snow showers increases at these sites mainly
from 15 - 18 UTC with potentially MVFR visibilities, should a
stronger snow shower track overhead. Given the uncertainty if a snow
shower will impact any one of the sites, we used a TEMPO group to
highlight the window where snow showers are most likely. Additional
snow showers are possible by 18 - 20 UTC at GFL, ALB, PSF but given
more uncertainty, did not include this update.
By 18-19 UTC, the cold front should push through the terminals with
winds shifting to the northwest and turning windy in the wake of the
front. Ceilings should luckily improve back to VFR by or shortly
after 19-20 UTC.
South-southeasterly winds tonight remain around 5kts but increase to
5-10kts and shift to the west by 12 - 18 UTC before the cold front
arrives from northwest to southeast and leads to a wind shift to the
northwest. Winds will also increase to 8-15kts with gusts to 20kts.
Outlook...
Thursday Night: Low Operational Impact. Breezy. NO SIG WX.
Friday: No Operational Impact. NO SIG WX.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: Low Operational Impact. Slight Chance of SN.
Saturday Night: High Operational Impact. Likely SN.
Sunday: High Operational Impact. Likely SN.
Sunday Night: Low Operational Impact. Slight Chance of SN.
Monday: No Operational Impact. NO SIG WX.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...NAS
NEAR TERM...NAS/Speciale
SHORT TERM...NAS
LONG TERM...Gant
AVIATION...Speciale
Area Forecast Discussion
National Weather Service La Crosse WI
509 PM CST Wed Jan 3 2024
.KEY MESSAGES...
- Flurries or patchy freezing drizzle ending this evening
- Light snow possible this weekend with less than an inch for
most (70 to 95%).
- Winter storm to affect parts of the central U.S. early next
week (Mon/Tue). Northeast Iowa into southwest WI have a 10-30%
chance of impacts snow accumulations (3" or more). Gusty winds
will also attend the system. This is a long ways out, however
if traveling, check back for forecast updates
&&
.DISCUSSION...
Issued at 228 PM CST Wed Jan 3 2024
Tonight - Thursday:
Water vapor satellite imagery this early afternoon shows well the
shortwave trough moving across the region, with latest surface
analysis showing the surface cold front draped northeast to
southwest through the forecast area. Observations have shown light
snow/flurries across portions of Minnesota and Wisconsin, with light
radar returns over the past few hours starting to increase across
the local area. A few reports of freezing drizzle have been noted by
surrounding offices, but reports have been fairly patchy so far.
Chances for flurries/light snow continue across the forecast area
into the afternoon and early evening before gradually dissipating
tonight.
The challenge then turns to how long cloud cover may hang across the
area. GOES-16 satellite imagery shows quite a large area of stratus
stretching down from Canada and across the region. There has been
quite a bit of variability among model guidance on clearing out
these clouds, with some of the hi-res guidance leaning towards
keeping the current stratus around longer tonight. Trends will
continue to be monitored through the evening as this will impact the
overnight temperatures tonight. Have leaned towards the blend for
temperatures for now, but any clearing could send temps a bit cooler
and vice versa. Surface high pressure looks to slide across the
region for Thursday bringing drier conditions with highs looking to
be mostly in the 20s to near low 30s.
Friday night through Sunday Snow Chances:
The closed 500mb low over the Four Corners regions Friday night is
forecast to become negatively tilted with the brunt of the storm
system advancing eastward into the OH Valley/TN Valley/Southeast
U.S. Meanwhile, the open wave lifts northeast into the Mid
Mississippi Valley and leads an approaching trough advancing across
Manitoba and the Northern Plains. The trough is better organized
over Minnesota Saturday. The northern part of this trough lifts
into Canada with the southern portion lags, but pushes across
Iowa Saturday night and Sunday. The 03.12Z EC ensembles at LSE
are around 50% with some trace or light QPF amounts with at
least 60% of the members having light QPF at MDZ. Expected snow
amounts remain light with a trace to around an inch or so of
snow.
Accumulating snow and strong wind chances early next week:
We continue to monitor the storm system for early next week. The
storm system is over the West Coast Saturday and forecast to close
off over the Four Corners area Sunday night...tracks across
TX/southern OK Monday and toward Indiana Tuesday. We continue to
remain on the northwest side of the storm system. This track takes
the main swath of snow southeast of the area. We continue to see 10-30%
probabilities of 0.25" liquid across parts of northeast Iowa
into southwest WI and the temperatures support snow. The EC
Extreme Forecast Index current has 70 to 80 percent higher than
climate maximum from parts of Missouri across Illinois into
northern Indiana with the shift of tails of 1 and 2 in this area
indicating an anomalously snowy event for them. Gusty northwest
winds would be across this area as well.Gusty northwest winds
would be across this area as well.The storm system still has
several days before it makes it to the West Coast and the track
and attendant weather can still shift. For now, the strong winds
are in the 25 to 30kt range. If traveling across the region
early next week, you`ll want to monitor updates to the forecast.
Temperatures will generally be at or above normal into early next
week.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 458 PM CST Wed Jan 3 2024
Models have been too optimistic too clear out the stratocumulus
deck that remains across much of the Upper Mississippi River
Valley and this trend is expected to continue tonight. Have
slowed down the improvement from MVFR to VFR at RST given the
upstream trends. Models typically struggle with clearing
stratocumulus decks in the cold season but the latest rapid
refresh models have begun to catch on to this trend; however,
latest RAP may be too pessimistic, keeping MVFR cigs through
tomorrow afternoon. Tonight, expect low-end VFR (with occasional
MVFR) to continue east of the Mississippi...and high-end MVFR
(with occasional VFR) to continue west of the Mississippi. By
Thursday, VFR conditions are expected to return, but there is a
30% chance high-end MVFR cigs remain at RST through the day.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
DISCUSSION...EMS/Zapotocny
AVIATION...JAW
Area Forecast Discussion
National Weather Service Dodge City KS
547 PM CST Wed Jan 3 2024
.KEY MESSAGES...
- Dense Fog Advisory in effect for late tonight into Thursday
morning ahead of Storm #1. Dense Fog expected to be fairly
widespread from sunrise through late morning.
- Winter Weather Advisory issued for Storm #1 late tomorrow
afternoon through early Friday. Widespread 2-3" snowfall is
expected (greater than 50% chance of occurrence) across much
of southwest, west central, and south central Kansas. Minor
impacts likely with at least partially snow covered roads
early in the morning.
- A High-impact winter storm is more concerning (30+% chance of
occurrence) Monday into early Tuesday due to the combination
of 25-35 mph winds and moderate to heavy snowfall during the
height of the storm. This will likely be a large storm
covering much of Kansas with models zoning in on a very
intense cyclone center track across Oklahoma.
&&
.SHORT TERM /THROUGH FRIDAY/...
Issued at 353 PM CST Wed Jan 3 2024
This Short Term discussion will focus on Storm #1 which will impact
southwest and portions of south central and west central KS late
tomorrow afternoon through early Friday.
The mid-afternoon water vapor loop and RAP analysis showed our
incoming storm quite well with the center of the mid level cyclone
along the NV-CA border between Las Vegas and Reno. A few lightning
flashes were evident on the ENTLN plot near the -30C cold core
center of the 500mb low. All models have locked in on a high-
confidence track from near ABQ 18z Thursday to around Canadian-
Perryton in the TX Panhandle 12z Friday. Ahead of the low, a weak
backdoor cold front will ooze south late tonight with winds both
behind and ahead of the front becoming increasingly upslope
component overnight. As temperatures fall to the lower 30s and
perhaps upper 20s, dewpoints will be around the same. The upslope
surface wind component will support dense fog development, which the
NAM12 and HRRR models both have been in agreement with. Latest 12Z
HREF model shows 50 to near 70% probabilities of 1/4 mile or less
visibility from Scott City to Hays down to Dodge City to Stafford,
so we have enough confidence both from numerical models and
conceptual models to run with a Dense Fog Advisory from roughly
Midnight to 10 AM. Dense fog may persist beyond 10 AM, but this is a
start.
Next question will be the inception of accumulating snow. Short term
hourly resolution models are in pretty good agreement with leading
wave of rain/snow moving into Elkhart-Liberal mid to late afternoon
Thursday. The time window of any rain will likely be short until the
entire lower-mid tropospheric column saturates and wet bulbs down to
below 0C. Snowfall rates of 1/4" to 3/4" per hour rates will be
common from mid-evening through around midnight or shortly there
after with the initial warm conveyor axis when upward vertical
motion will be strongest. Most areas will see the bulk of their
snowfall accumulation in the mid-late evening through 09Z (3 AM CST)
time frame for most areas. The stronger snowfall rates overnight
will obviously be timed with nocturnal time of day such that this
will aid in at least some light, slushy accumulation on roads that
are not traveled much. For this reason, we will issue a Winter
Weather Advisory to cover Thursday Night into early Friday time
frame. Winds will remain easterly during much of the event at speeds
of 10 to 15 mph, so we do not expect blowing and drifting of snow to
be an issue. As far as snowfall totals go, higher amounts will be in
the far southwest areas up towards Dodge City with 2-3". Some of the
latest models are showing total QPF with this storm in the 0.30 to
0.45" range, which would support some 4 to perhaps 5" amounts in
localized spots where/if a deformation axis sets up (most likely
between Dodge City and the Oklahoma border). Latest 100-member Super
Ensemble is showing a 10-20% probability of exceedance of 5" mainly
along the Oklahoma line from Elkhart to Englewood.
Accumulating snow is expected to come to a quick end from southwest
to northeast from mid to late morning Friday. The expected new snow
cover is likely to prevent temperatures remainder of the day Friday
to exceed much above 32F for most of the area.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 353 PM CST Wed Jan 3 2024
This Long Term discussion will focus on Storm #2 Monday into early
Tuesday. It certainly appears now that yesterday`s phantom 12Z run
of the deterministic ECMWF was just that: A Phantom Run. The Super
Ensemble means held serve and sure enough, today`s ECMWF 12Z run now
shows a very robust mid-latitude cyclone taking the "Golden Path"
for potential major winter weather impacts for much of our southwest
Kansas region. This development in the ECMWF reverting back to its
ensemble system (no longer an outlier) and the other two ensemble
systems (GEFS and Canadian GEPS) lends higher confidence now in a
high impact winter storm for southwest Kansas. Today`s latest 12Z
run of the EPS now has a tightening of clustered MSLP lows focused
on the southern Texas Panhandle with many member MSLP lows in the
996-999mb range valid 12Z Monday. 12 hours later (valid 00Z
Tuesday), the MSLP membership still remains fairly clustered from
near Childress, TX on the southwest portion of the envelope to
around Ponca City, OK on the northeast portion of the envelope. Many
of the member centers of MSLP surface lows off the EPS 12Z, 18Z, 00Z
fall along or very near the "Golden Path" for significant
accumulating snow across southwest Kansas.
The anomalous magnitude of moisture influx into such a large
cyclone, the anomalously high wind field all around the cyclone once
it fully deepens across Oklahoma, and the classic track from the
southern Texas Panhandle across central Oklahoma, tied to the time
of year and strong low level cold advection driving south at the
onset of heavy precipitation...all these elements are very
concerning for a widespread high impact winter storm. New snowfall
in excess of 3" (currently at 60-75% probability of exceedance off
the 12Z 100-member Super Ensemble, AND sustained wind speeds likely
(60%+) to be well in excess of 25 mph at times would combine to
create near blizzard or blizzard conditions for a minimum of 6 hours
during the height of the storm. Based on forecast experience of
winter storms on the High Plains along with very good model
agreement to this point, there is at least a 1-in-10 chance of major
blizzard impacts including Southwest Kansas.
This is certainly a storm we are very concerned about Monday into
Tuesday because of the wind aspect. The end user needs to be
reminded that 50+ mph wind gusts (which is definitely on the table!)
only requires just one inch of new snowfall or established snow
depth to create very dangerous whiteout or near whiteout blizzard
conditions. Please keep checking back for updates concerning Storm
#2 early next week.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 502 PM CST Wed Jan 3 2024
HREF and CAMS were in good agreement this afternoon with low
clouds and fog spreading into southwest Kansas overnight behind
a backdoor cold front. Latest CAMS were verifying well with the
stratus/fog located in southern Nebraska at 23z Wed and
therefore will follow the general trend of these latest models
with this area of IFR/LIFR ceilings and visibilities spreading
across the Hays area between 05z and 07z Thursday. These low
clouds/visibilities will be in/near the Garden City, Dodge City
and even briefly near Liberal areas after 10z Thursday. Based
on observations with this area of clouds and fog in Nebraska
along with HREF probabilities and the latest CAMS there is a
high probability (>80%) for ceilings to fall below 1000ft and a
60-80% chance for visibilities 3/4mile or less at Hays, Garden
City and Dodge City between 06z and 12z Thursday. The
visibilities and ceilings will improve some after 14z but based
on the latest HREF there is a 60-80% chance that ceilings will
stay below 2000ft AGL through Thursday evening.
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory from midnight tonight to 10 AM CST Thursday
for KSZ030-031-043>046-063>066-077>079.
Winter Weather Advisory from 8 PM Thursday to noon CST Friday
for KSZ030-031-044>046-064>066-077>081-087>090.
Winter Weather Advisory from 3 PM CST /2 PM MST/ Thursday to 9
AM CST /8 AM MST/ Friday for KSZ043-061>063-074>076-084>086.
&&
$$
SHORT TERM...Umscheid
LONG TERM...Umscheid
AVIATION...Burgert
Area Forecast Discussion
National Weather Service Green Bay WI
603 PM CST Wed Jan 3 2024
Updated aviation portion for 00Z TAF issuance
.KEY MESSAGES...
- Lake effect snow may bring up to an inch of additional
accumulations to Vilas County tonight.
- Minor snow accumulations are possible throughout the weekend,
with a 15 to 30% chance of up to 1 inch of snow.
- Watching next Tuesday and Wednesday for the potential of a
more organized system which could bring snow and wind.
&&
.DISCUSSION...
Issued at 219 PM CST Wed Jan 3 2024
Short Term...Tonight and Thursday
The latest RAP analysis and satellite radar imagery show a cold
front moving southeast across southern Wisconsin and northern
Lower Michigan early this afternoon. Behind the front, a surface
trough is diving across northeast and central Wisconsin with
winds shifting to the north behind the trough. The trough led to
an uptick in relatively stronger snow showers across the snow
belt of north- central Wisconsin, briefly dropping visibilities
below 1sm. With wind directions remaining 350-360 degrees, snow
showers should continue to impact the lake effect snow belt of
north- central WI into the evening. Elsewhere, overcast conditions
prevail with scattered light snow showers and flurries which are
more focused along the trough. Temperatures were holding steady
in the middle 20s to middle 30s across the region.
Sky and Precipitation: Lake effect snow showers in the snow belt
should continue into the evening hours. As low level winds back with
incoming high pressure after midnight, the snow showers should
come to an end. The surface trough, on the other hand, should be
exiting central and east-central WI early in the evening, with the
more focused snow shower activity departing with the trough. Some
flurries will likely stick around behind the trough and through
the evening, however. Additional accumulations around a half inch
will be possible along the Vilas County-U.P. border.
Cloud cover is more tricky as winds will remain out of the north
though late tonight, but very dry air with dewpoints near zero
are dropping into the Arrowhead of Minnesota. Arrival of this dry
air combined with backing low level winds should lead to clearing
skies in the downsloping areas late tonight, followed by the rest
of the area Thursday morning. That should lead to ample sunshine
for most of Thursday with only some high clouds moving overhead.
Temperatures: Not an easy min temp forecast tonight due to the
cloud cover. Because of the slower clearing trend, trended warmer
for low temps. But there is a large spread in min temp forecast
thanks to the incoming high pressure and diminishing winds. If
skies clear, good radiational conditions will exist that could
lead to temperatures falling well below the forecast. Highs on
Thursday will be colder than today`s readings, and range from the
middle to the upper 20s.
Long Term...Thursday Night Through Wednesday
Quiet conditions are expected to end the work week as high
pressure moves over the region. The next chance for snow comes
this weekend with an unorganized system. Chance for accumulations
over 1" are 10-30%, mainly across the Northwoods. As the light
snow shifts out of the area towards the end of the weekend
attentions then shift to a more robust and well organized system
that is forecast to impact Wisconsin Tuesday and Wednesday.
Moderate to heavy snow and gusty winds look like the primary
hazards with that system.
Friday...High pressure is expected to continue moving eastward
over the area keeping conditions calm and dry Friday. Temperatures
trend slightly above seasonal to end the week and into the
weekend.
Saturday and Sunday...Forecast confidence is increasing for areas
of snow across the CWA this weekend as a disorganized noisy
pattern sets up over the area. A surface cold front is expected to
stall over WI coincident with a series of upper-level shortwave
impulses passing over the area. Snowfall is forecast to be more
widespread Saturday and become more scatted Sunday as the WAA
forcing becomes weaker. Best chance (20-30%) for over 1" is across
north-central WI, while the chance for over 1" is 5-20%
elsewhere. While impacts this weekend should remain minimal it is
important to remember that even small amounts of snow can create
slippery roads, especially on untreated roads, secondary roads,
and bridges.
Monday through Wednesday...Lingering snow active should come to
an end late this weekend leaving Monday dry as a brief period of
high pressure slides over the area. Model guidance has been
consistent over the past several days regarding a well organized
system ejecting out of the southern Rockies early next week and
impacting the upper Midwest next Tuesday and Wednesday. The
primary hazards with this system are expected to be moderate to
heavy snow and gusty winds. The specific details with this system
regarding timing, snow amounts, and exact location will need to be
refined over the coming days. One import aspect to monitor is how
this organized low interacts with a northern jet stream that is
progged to set up over central Canada next week. This interaction
will be important for determining the track of this system.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 603 PM CST Wed Jan 3 2024
High-end MVFR and low-end VFR clouds are expected to continue
this evening, then drier air should allow this cloud deck to
erode. Some minor clearing already noted across parts of central
and east-central WI as of 6pm. Still some concern the strong
inversion will trap enough moisture to keep clouds all night and
even into Thursday, especially closer to Lake Superior. Will keep
similar timing for the clearing as the previous TAFs for now and
monitor cloud trends. Mid and high clouds are expected for much of
Thursday as well. Can`t rule out a few flurries through the
evening, especially over northern WI, but they will not amount to
much and not impact flying conditions. Light north winds will
gradually shift to the west/southwest on Thursday.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....MPC/GK
AVIATION.......Bersch
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1026 PM EST Wed Jan 3 2024
.SYNOPSIS...
Low pressure brings a chance of light snow to the mountains early
tonight. Another system could produce a wintry mix to parts of the
region Friday night and Saturday morning. Heavy rainfall is possible
with a third system at the beginning of next week.
&&
.NEAR TERM /THROUGH THURSDAY/...
As of 10:20pm EST Wednesday: Radar still showing mostly virga over
the area, with coverage decreasing over time. Some light rain has
been reported at a few places with stronger radar echoes from
Greenwood to Monroe and southward. Temperatures are in slow decline
and should reach sub-freezing levels over the mountains by morning.
MRX radar does show echoes reaching closer to the ground as they
cross the TN/NC state line area, and have kept in some rain becoming
snow tonight and tomorrow morning for that area. No significant
accumulations are anticipated at this time, however. Outside of the
mountains, lows will be at or below freezing with clouds
substantially clearing by daybreak.
Starting off the forecast period with a broad swath of shortwaves
and DPVA aloft traversing across the region from the SW. As the
waves move through, moisture is becoming more limited. Guidance from
the HRRR and NAM show a drier boundary layer this afternoon. PWATS
from the GFS and EURO indicate a brief uptick in values, up to 0.5
inches, mainly concentrated to the southern counties of the CWA.
Winds will veer N/NW overnight and provide the opportunity for
mechanical lift along the TN/NC border. The limiting factor will be
available moisture, which continues to decrease. Any snow in the
mountains will be dependent on the amount of moisture available,
which could be slightly more or less than models are suggesting.
Either way, Guidance from the HRRR and NAM show almost zero
accumulations. Once the shortwaves move out of the area, a brief
stint of high pressure returns to round out Thursday and spills into
the beginning of the next forecast period. Temperatures overnight
should hover near freezing in the Piedmont as cloud cover will help
to insulate. Thursday highs should warm into the 50s.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
As of 207 PM EST Wednesday: Quiet conditions on Friday ahead of
an approaching potent trough which will dig across the central
Great Plains, to arrive in the Deep South by evening. As the
system slides into the Carolinas on Friday evening, deep-layer
synoptic forcing will ramp up from west to east beginning around
00z, and profiles will quickly become saturated as generally S
winds develop and begin bringing moisture in from the south.
It still looks like it`ll be a good case for winter weather during
the predawn hours Saturday and into the first part of the day.
Meteorologically, it`s about as straightforward as these types of
systems ever are: we`ll find ourselves ensconced in a stable surface
wedge, with low-level WAA ramping up through the overnight hours
and likely producing a warm nose before daybreak. Well-saturated
profiles will produce lots of precipitation, and it will boil
down to a p-type issue. Models aren`t in great agreement just
yet on exactly how deep the warm nose will be (the NAM is the
most aggressive, producing a robust warm nose over most of the
Piedmont and even parts of the eastern Upstate / I-77 corridor)
or on how cold the surface layer will get (the NBM`s mean surface
temp is 32 degrees for many locations across the Upstate, though
there`s a little bit of a skew toward colder temps in the ensemble
distribution). What passes for a consensus at this point seems
to be that the farther east you go, the more reliably cold the
surface will be and thus the more freezing rain will be favored
over other p-types; the farther west you go into the Foothills,
the weaker the warm nose becomes and thus the more sleet or even
sleet-snow mix will favored. The mountains, as usual, will see
snow as the dominant p-type...although some sleet may still be
possible in some of the mountain valleys.
In general, QPF has trended downward this cycle, and the snow totals
reflect this. However, with a more aggressive warm nose depicted in
the 12z suite of guidance, ice totals have jumped a tad upward for
many NC locations as more of the overall QPF is now expected to fall
as ice. Over SC...temperatures are still expected to widely remain
just a degree or two too high to produce ice; only areas near the
SC-NC state line are advertised to receive measurable freezing rain
(which isn`t much of a change from the previous forecast). The good
news is that ice will be primarily restricted to elevated surfaces
- think power lines and tree branches. Although a few patches
of ice aren`t impossible on roadways, sub-freezing temperatures
should be brief enough to preclude widespread road ice.
We`ll transition back to all-rain conditions by late morning
Saturday as temperatures rise, and by evening a punch of dry air
will cut precipitation off from south to north. Models are split
on how quickly rain will end, but no further winter precip is
expected going into Saturday night.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 140 PM Wednesday: As the weekend storm pulls away on Saturday
night and Sunday, some lingering upslope mixed precipitation will be
possible along the NC-TN border but not much impact is expected.
Otherwise, conditions will dry out with near normal temperatures
Saturday night through Sunday night.
A powerhouse storm system will begin to take shape across the south-
central part of the country on Monday. A deepening upper low will
move out of the southern plains toward the Great Lakes states by
Monday night and Tuesday with an associated anomalously strong
surface low rapidly developing and moving toward the Ohio Valley.
This system looks to have a variety of impacts across the area from
Monday night through Wednesday.
Precipitation will rapidly spread across the forecast area on Monday
night. Most of this will be rain, but there may be some high
elevation snow with some light accumulations through early Tuesday
before a changeover to rain. Very strong forcing and an enhanced low
level focus along an eroding wedge boundary, along with upslope flow
and anomalous precipitable water will create a scenario with very
heavy rainfall possible on Tuesday. WPC is forecasting 3-4 inches of
rain across a large portion of the forecast area Monday night and
Tuesday and that seems reasonable with this setup.
Models project the warm sector of this system to spread into the
lower Piedmont of the Carolinas and Georgia Tuesday, so there may be
some severe weather threat as well roughly along and southeast of
Interstate 85.
Winds may also be a concern with the strength of the surface
gradient, low level jet and cold air advection on the backside of
the system.
Expect an improvement in conditions, but with some wind and cooler
temperatures on Wednesday.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
At KCLT and elsewhere: An upper shortwave is crossing the area this
evening, carrying across an area of light showers with it that look
on radar to be virga. Some showers may eventually reach the surface
after very dry low-levels of the atmosphere gradually moisten, but
rain chances are slim and this is carried in the TAFs as VCSH. At
higher elevations, cooling will be enough for light snow in any
places showers manage to reach the surface. As upper wave passes
through tonight/Thurs. morning, concurrent passage of weak surface
boundary will cause the surface winds to go from generally
southwesterly to becoming northerly early Thursday morning.
Northerly flow will also cause the current OVC100 with the virga to
become SCT to CLR Thursday morning. 850mb winds behind the front of
20 to 30kts, along with decent surface mixing in the clearing skies
after dawn, is expected to give some gusts on Thursday at the 20 to
25kts level, especially at KAVL, before relaxing later in the
afternoon/evening.
Outlook: VFR through Friday with restrictions likely over the
weekend as a storm system crosses the area. Heavy rain is possible
at all the TAF terminals Saturday, along with a brief wintry mix at
KAVL and KHKY.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...CP/DEO
NEAR TERM...CP/WJM
SHORT TERM...MPR
LONG TERM...SCW
AVIATION...WJM
Area Forecast Discussion
National Weather Service Jackson MS
959 PM CST Wed Jan 3 2024
...New MESOSCALE UPDATE...
.MESOSCALE UPDATE...
Issued at 959 PM CST Wed Jan 3 2024
Rest of tonight...
A quiet & cold night is on tap across the region. Water vapor, RAP
& evening 00Z upper air analysis indicate shortwave swinging
through the southeast states while ridging centered across the lee
side of the Rockies into the Plains. RAP indicates 1030mb sfc
high over the northern Plains that will continue to build
southeast, with sfc ridging continue to build in the Gulf Coast
states. As mean ridging continues to filter in, CAA will persist
overnight but gradient & sfc winds will relax. This favors
efficient radiational cooling & lows some 5-10 degrees below
normal in the mid-upper 20s. Areas of frost are likely overnight.
With some areas in the east remaining under cool stratus through a
good portion of the day, there is some decent crossover temps
>3-5 degrees. There have been some indications of some sparse
areas of patchy ground fog possible overnight but not dense
enough for it to add anything in the HWO graphics. Have a few
areas of patchy fog in overnight but nothing impactful. Updates
are out. /DC/
&&
.DISCUSSION...
Issued at 326 PM CST Wed Jan 3 2024
Tonight and Thursday:
With the departing area of low pressure that brought clouds and
showers earlier today, clouds thin and most areas will be partly
cloudy tonight. Light, generally northerly winds combined with
clearing skies and a drying airmass will allow for decent
radiational cooling tonight. This will allow lows to dip to below
freezing across the area with frosty conditions areawide by dawn.
Sun with only a few scattered high clouds on Thursday will allow for
temperatures to warm a bit more than we saw today under the
influence of building high pressure. Highs top out in the middle 50s
F by tomorrow afternoon with winds remaining light and northerly.
/86/
Friday through Wednesday:
A progressive flow pattern across the CONUS will continue the parade
of weather systems into the middle of next week. An upper-level low
pressure system opening into a wave as it passes Friday will usher a
surface low along the Gulf Coast Friday into Friday night, with best
chances for heavier rain and some thunderstorms south of Interstate
20 Friday afternoon and evening. A faster, less amplified wave on
its heels Saturday into Sunday is not expected to produce precip in
our area.
Then Sunday into Monday, attention turns to a sharper shortwave
trough expected to dive and deepen from the Pacific Northwest toward
Texas/Oklahoma by Monday afternoon with heights falling 2 standard
deviations below normal. In response to the rapidly deepening
system, a developing surface low over the Southern High Plains will
lift a warm front northwards from the Gulf Coast. A more unstable
air mass will possibly advect far enough north into our forecast
area to bring a brief window for severe storms Monday night. It`s
anticipated that rain falling north of the warm front may help the
surface boundary lock in at some point along its northward
trajectory, but very strong flow around the system should still set
up favorable wind profiles for supercell storms capable of producing
tornadoes where storms can become surface based. There is a Slight
Risk for severe storms along the Gulf Coast Friday and Friday night,
and the best estimate for timing this far out is Monday night in our
forecast area to see the favorable overlap of surface-based
instability reaching into the US Highway 84 corridor as winds become
more southerly. If the front advances farther north toward the I-20
corridor, the threat for severe storms with wind and tornado
potential would also likely encompass a fast-moving squall line
along the Pacific cold front punching east.
In addition to severe thunderstorm hazards, an increasing pressure
gradient around this potent low pressure system will drive a
gradient wind threat mainly on the back side Tuesday. Steep low-
level lapse rates associated with the Pacific cold front will aid in
deeper mixing during the day Tuesday. This should help sustained
winds get to around 20-30 mph and some gusts over 40 mph through
peak mixing. Right now it appears the best wind potential will be
through northeast LA/southeast AR and the MS Delta/areas north of I-
20. /NF/
&&
.AVIATION...
(00Z TAFS)
Issued at 518 PM CST Wed Jan 3 2024
VFR conditions with light northerly winds up to 10mph, are psbl
through the TAF period. Areas of frost are psbl overnight at all
TAF sites & there could be a brief spotty areas of patchy
freezing fog, but not dense enough to become a concern to mention
in the 00Z TAF cycle. /DC/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 55 29 56 32 / 70 0 0 0
Meridian 50 24 55 28 / 80 0 0 0
Vicksburg 55 28 56 32 / 60 0 0 0
Hattiesburg 55 29 57 31 / 100 0 0 0
Natchez 56 30 57 34 / 70 0 0 0
Greenville 53 31 51 31 / 20 0 0 0
Greenwood 52 28 53 32 / 40 0 0 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
DC/NF/DC
Area Forecast Discussion
National Weather Service Memphis TN
823 PM CST Wed Jan 3 2024
...New UPDATE...
.UPDATE...
Issued at 817 PM CST Wed Jan 3 2024
Clouds have begun to move into portions of northwest Tennessee
while mostly clear skies remain over the remainder of the Mid-
South. Temperatures across the region range from the upper 20s to
the mid 30s. Clouds will continue to slowly drop south into the
region overnight which will help keep temperatures from dropping
as much. Made some minor tweaks to low temperatures for Thursday
morning.
ARS
&&
.SYNOPSIS...
Issued at 201 PM CST Wed Jan 3 2024
A series of upper level low pressure systems will bring
precipitation chances to the Mid-South for the end of the week
and the beginning of next week. Temperatures will be near normal
for this time of year.
&&
.DISCUSSION...
(This evening through next Tuesday)
Issued at 201 PM CST Wed Jan 3 2024
Currently, a SFC low pressure system continues to track eastward
across the northern Gulf of Mexico. Patchy areas of rain continue
to occur across Northeast Mississippi. Have been getting reports
of sleet occurring within the heavier bands. Any sleet that occurs
will be short-lived and not accumulate. Meanwhile, clouds have
cleared across much of eastern Arkansas and the Missouri Bootheel.
Temperatures are in the 40s with the warmest temperatures
occurring across Northeast Arkansas where more sunshine has
occurred.
Clearing will continue to take place this evening as the SFC low
continues to move east. However, the clear skies will be short-lived
as the HRRR and RAP models shows the low clouds currently located
over Eastern Missouri and Illinois moving into the Mid-South by
late this evening. The cloud cover will likely hang around much of
the day. The HRRR shows some clearing occurring near the
Tennessee River, but looking at what occurred today and given
this time of year, not really expecting it to happen. Thus, have
adjusted highs slightly downward across areas north of I-40.
SFC high pressure will build in over the area from the Upper
Mississippi Valley with some upper ridging occurring aloft
Wednesday Night through Thursday Night.
By Friday Morning, the first in a series of upper level low
pressure systems will move into the Southern Plains. A SFC low
will develop along the Gulf Coast allowing for precipitation to
begin to spread into Eastern Arkansas. Looking at a sounding from
the 3KM NAM, precipitation could begin as snow as it moves in.
However, the model is quicker with precipitation onset and is the
outlier at this time. Something to keep an eye on as the time
frame comes into the time window of more of the CAMS.
The SFC low will track northeastward from the Louisiana Gulf Coast
northeastward into the SW Georgia by Saturday afternoon. Rain will
spread across the area Friday through Saturday Morning. Meanwhile,
the upper level low will move northeastward from the Southern
Plains into the Upper Mississippi Valley Friday into Saturday
Night. A shortwave will then rotate around the upper low and move
into the Mid-South Saturday Night. Would not be surprised to see
some light precipitation as it moves in. Left forecast dry for
now, but would not be surprised to see only a brief lull in
precipitation chances Saturday afternoon occurring between the two
systems.
Sunday will be tranquil before another more potent upper level low
system moves into the region. This system takes a slightly more
northerly track and will be nearly vertically stacked with the
SFC low. Models are showing the current track to be from the
Southern Plains into the Ohio Valley Monday into Tuesday Night. A
second SFC low will likely develop along ARKLAMISS region as the
system becomes occluded. This will keep severe weather chances to
the south of the CWA as instability is pinched off. To the north,
a potential winter storm could occur along the I-44 corridor near
the track of the upper level low. Based on the expected track
right now, the Mid-South will see just rain. However, can`t rule
out some elevated thunderstorms occurring across North
Mississippi. This system bears watching as any deviation north or
south of the low track could dramatically change the forecast.
However, the biggest concern from this system could be the
gradient wind as a tight pressure gradient will occur across the
entire region during the Monday through Tuesday time frame. Winds
on Tuesday could be 20-30 MPH sustained with higher gusts.
Some light snow or flurries could occur on the backside of the
departing low pressure system Tuesday Night. Otherwise, high
pressure will begin to build into the region for Wednesday.
KRM
&&
.AVIATION...
(00Z TAFS)
Issued at 518 PM CST Wed Jan 3 2024
MVFR CIGs will move into the Mid-South overnight with some
guidance suggesting pockets of IFR developing by sunrise. However,
confidence for IFR CIGs remains low so did not include in TAFs at
this time. By the end of the period, expect a return to VFR
conditions areawide.
Winds will veer to the northeast through the period, becoming
sustained at 8-10 kts by midmorning.
ANS
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
PUBLIC FORECAST...KRM
AVIATION...ANS
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
532 PM CST Wed Jan 3 2024
.KEY MESSAGES...
- Chances for snow increasing for the weekend. Strong system
early next week looking increasingly likely to miss us to the
southeast.
- Much colder air moving in mid to late next week.
&&
.DISCUSSION...
Issued at 133 PM CST Wed Jan 3 2024
Primary forecast concerns are with the widespread light snow
that is expected to move through the region late Friday night
through Saturday, and colder (but likely still slightly above
normal) temperatures next week. The significant storm system
expected to impact the central US during the first half of the
week continues to look like it will mainly impact locations to
our southeast (with some light snow on its periphery possible
over the southeast half or so of our area late Monday into
Tuesday).
Stratus has had little success in breaking up today, with only
some occasional breaks over the far west and southwest portion
of the area. Stuck with the more pessimistic guidance given
current observations/trends and a tendency for much of the
guidance to be too optimistic of late. This keeps mostly
cloudy/cloudy conditions in place for most of the area through
Thursday, with some improvement possible Thursday night into
Friday ahead of the weekend system. An upper trough with a weak
surface reflection will track from the northern plains on Friday
and across Minnesota Saturday before exiting into the Great
Lakes on Sunday. The majority of the warm advection
precipitation from the system looks to stay mostly to our north
Friday night into Saturday, but we should get into sufficient
forcing from differential PVA, upper divergence, and some post-
frontal system relative upglide to see widespread light snow
move through from west to east late Friday night and Saturday.
The best chance will be across the north, where some measurable
(1-2") snow looks possible. Chances for measurable snow are less
toward the Minnesota Valley, but some light accumulations still
seem possible. At this point the metro area could see around an
inch, give or take. As the system gets into the time range of
the CAMS and HREF we should better be able to refine the
precipitation and derivative snowfall amounts. In a winter with
so little snowfall so far, even an inch or two could catch some
folks by surprise if traveling.
Light snow chances will return Monday night and Tuesday as a
strong surface low tracks through Missouri and Illinois. The
best chance for any measurable snow in our area will be
southeast of the Twin Cities metro area, and any amounts in our
southeast forecast area would still look be an inch or less.
Cooler temperatures will be seen from Sunday through the middle
of next week, but readings will still be a bit above normal with
highs generally in the 20s and lows in the teens. Another quick
moving system could impact the area Wednesday night and
Thursday, but there is far too much spread in the guidance at
this point to include anything more than chance PoPs.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 519 PM CST Wed Jan 3 2024
Continued the trend of the previous forecast with keeping the
MVFR stratus at the TAF sites longer then the forecast guidance
suggests. Winds are light, and a few sounding such as the RAP
keep MVFR skies overhead. Clouds could start to break up on
Thursday as high pressure moves across the region.
KMSP...
MVFR clouds remain across the region, and should linger into
Thursday afternoon. Light northerly winds will become more
south/southwesterly on Thursday.
/OUTLOOK FOR KMSP/
FRI...MVFR. Chc IFR/-SN late. Wind S 10-15 kts.
SAT...MVFR/-SN with IFR possible. Wind SW 5-10 kts.
SUN...MVFR with -SN possible early. Wind NW 05 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...WFO MPX
AVIATION...JRB
Area Forecast Discussion
National Weather Service Marquette MI
711 PM EST Wed Jan 3 2024
.SHORT TERM...(The rest of this afternoon through tonight)
Issued at 238 PM EST WED JAN 3 2024
Key Messages:
-Lake effect flurries and snow showers continue across much of the
UP this afternoon amid chilly NNW flow.
-Lingering LES becomes confined mainly to the NW snowbelts of the
eastern UP through tonight.
-Another 1-3 inches of snow is possible from western Alger to
eastern Luce counties, with lighter totals up to a half an inch in
the western and north-central UP the rest of today through Thursday
morning.
The midlevel trough continues to exit eastward this afternoon while
ridging slowly builds in from the Plains, and water vapor shows
drier air working into the Great Lakes. Amid chilly NW flow aloft,
850mb temperatures are falling to around -16C this afternoon, and
with lake temperatures at around 4C, widely scattered lake effect
flurries and snow showers continue across much of the UP. A few
flakes have even been reported as far south as Escanaba and Iron
Mountain. A swath of higher reflectivity is currently directed into
eastern Marquette and western Alger counties, and the Day Cloud
Phase Distinction RGB does show a stronger convergent band extending
from the tip of the Keweenaw into that area, perhaps with a Lake
Nipigon connection. Occasionally, some heavier snowfall rates are
also evident into eastern Alger county into northern Schoolcraft
county, with lighter snowfall rates elsewhere. With snow ratios
around 20:1 (as observed here at the office) and a couple bullseyes
of QPF around 0.5in likely (50-80%) from eastern Marquette through
Alger and northern Schoolcraft counties, another inch or so of snow
will be possible there before 00Z with totals below an inch
elsewhere.
Into the evening and overnight hours, northerly winds at the surface
slowly back more to the NW and eventually west as the ridge builds
into the Great Lakes. This should help to bring an end to lingering
LES in the western and north-central UP later tonight while snow
continues mainly across Alger, northern Schoolcraft, and western
Luce counties. Heavy snowfall rates are not expected, with soundings
continuing to show dry lower levels beneath an increasingly drier
DGZ as inversion heights lower. Still, with persistent banding and
that potential Lake Nipigon connection, another couple of inches
will not be ruled out overnight in the snowbelts of the eastern UP.
Otherwise, look for temperatures to turn much colder. Currently we
hover in the mid and upper 20s across most of the area, but
temperatures should fall well into the teens overnight. Where we can
experience clearing skies (most likely across the central UP),
temperatures may even flirt with the single digits in some spots.
.LONG TERM...(Thursday through Wednesday)
Issued at 328 PM EST WED JAN 3 2024
Key Messages:
-Only light lingering NW to W`rly lake-effect snow Thursday. A
stronger band from Munising eastward may bring up to an inch or two.
-More light lake-effect snow is possible (50% chance) over the
Keweenaw late Thursday night through Friday. May see a fluffy inch
or two.
-Light system snowfall expected across the area Friday night through
Saturday. Expect an additional 1 to 2 inches, with the Keweenaw
possibly (50% chance) seeing up to 3 inches.
-Developing and deepening storm system over the Southern Plains next
week tracks through central Lower Michigan Tuesday night. Will be
monitoring for potentially significant system/lake enhanced snowfall
and wind impacts late Tuesday through Wednesday next week.
The lake-effect snowfall ends over Upper Michigan Thursday as high
pressure ridging across the area backs winds from the northwest in
the morning to the southwest by the evening. Given the ridging,
short-inversion tops, and dry air near the surface, thinking
snowfall will remain light in most of the lake-effect snow showers,
especially over the western U.P. where there will be lower relative
humidities. That being said, some of the CAMs such as the NAMNest,
NSSL-WRF, FV3-WRF, and ARF-WRF all hint at a Lake Nipigon connection
in one of the snow bands over the eastern U.P. Thursday. It`s
possible underneath this band that there may be some locally
moderate snowfall rates (1/2 per half) at times; should you get
caught in this band in the eastern U.P., you could see visibilities
sharply decrease down to a half mile, so you should still drive with
some extra caution over the east on Thursday. Outside of the
stronger band that will move from around Munising eastward
throughout the day, the snowfall totals are predicted to be an inch
or less. Where the strongest band moves through Thursday could see
one to two inches of fluff. As the winds back with time, expect the
snow bands to slowly lift away from Upper Michigan, with the last of
the lake-effect snow ending over us by Thursday evening.
The lake-effect action won`t be away for that long though, as a
`Bayfield Bomber` setup looks to bring the white stuff back over the
Keweenaw late Thursday night through Friday morning. With CAMs
showing the winds veering ever-so-slightly to the west-southwest
late Thursday night, lake-effect snow over the open waters of Lake
Superior looks to come back onshore over the Keweenaw Peninsula.
While CAMs such as the 12z HRRR show a single, modest convergent
band moving over the Keweenaw very late Thursday night/early Friday
morning, with delta-Ts only getting to around 13C, inversion heights
only getting up to 4 kft, all of the CBL below the DGZ, and dry air
still remaining near the surface, the snowfall associated with this
`Bayfield Bomber` only looks to be a fluffy inch or two late
Thursday night through Friday. However, it is possible (30 to 40%
chance) that the convergent winds with this `Bayfield Bomber` could
cause overachieving snowfall rates/totals. Therefore, this may need
to be monitored just in case models pick up on improving
environmental conditions for this lake-effect snow band.
As we head towards Friday evening, a low pressure deepening over the
Northern Plains brings some light snowfall across the U.P., mainly
over the northern half. While the snowfall totals are still fairly
light (mainly 1 to 2 inches, with the Keweenaw possibly (50% chance)
seeing up to 3), model guidance has trended the warm frontogenesis
of the low further south than before. In addition, we may (30%
chance) get a shot of some energy traveling north from Lake
Michigan, which would ever-so-slightly increase the strength of the
frontogenesis over our area. With delta-Ts near 10C off of Lake
Michigan, there may also be some slight lake-enhancement over the
south to southeast wind snow belts. In addition, south to
southeasterly upslope flow may slightly increase the forcing too
across the central and east Friday night into Saturday. Therefore,
while it is currently not expected as of this time, there is a small
chance (10 to 20%) that we may see snowfall amounts and rates
increase enough in the future to warrant a low-end Winter Weather
Advisory across portions of Upper Michigan; the Keweenaw currently
has the best chance of receiving one as of right now (around 20%).
As the low pressure moves along the northern border of Lake Superior
Saturday and Saturday night, the warm front lifts off to our north
with the snowfall. However, the cold front of the low looks to
possibly (50 to 60% chance) bring some light snow back across our
area Saturday night into Sunday, with the greatest chances for
seeing snowfall in the north half.
Attention turns to the much-talked about low pressure system that`s
expected to develop over the Southern Plains and lift into central
Lower Michigan next week. It seems as if the model guidance has
converged quite a bit since earlier this morning, with the GFS,
Canadian, and Euro deterministic suites now all bringing the low
through central Lower Michigan. While there is still some nuance
among the differing guidances, this should cause us to see some lake-
enhanced snowfall over the northeast snow belts in the north central
and east. This in turn could bring some significant snowfall across
these aforementioned portions of the U.P. for the middle of next
week. We may (50% chance) have to hoist up a winter weather product
for our north central and east in the future for this, especially if
the northwestward trend of the low continues in subsequent forecast
packages and we receive more system moisture than previously
expected.
Overall, while temperatures will feel much closer to normal from now
to the end of next week, we still will likely (70% chance) remain
above normal even past next weekend. I`m thinking for highs we will
range from the mid 20s to mid 30s; as for the lows, I`m thinking
they will range from the mid teens to mid 20s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 711 PM EST WED JAN 3 2024
MVFR conditions will linger into tonight at all TAF sites until NNW
lake effect snow showers taper off. Drier air should filter into
the TAF sites overnight with a return to VFR at IWD and SAW
somewhere in the Thu 05-07Z time frame. CMX, on the other hand,
will fluctuate around the MVFR/VFR mark where lake clouds will be a
bit more persistent. Breezy northwest winds to 14 kts at SAW will
subside by Thu 06Z.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 342 PM EST WED JAN 3 2024
North-northwesterly winds of 20 to 30 knots across the eastern half
of the lake this afternoon die down to 20 knots or less tonight as
ridging builds in from the west. Winds remain calm until Thursday
evening, when a low pressure moving through northern Ontario
interacts with the high pressure ridging over us, tightening the
pressure gradient over the lake. This brings west-southwest to
westerly winds of 20 to 30 knots back across Lake Superior Thursday
night into Friday. As the gradient slackens Friday with ridging
developing to our west, the winds decrease to 20 knots or less again
by the mid-afternoon hours. Come Friday night, a low pressure
developing over the Northern Plains lifts into north central
Minnesota. As it does so, it`s warm front developing over the U.P.
and the lake allows east to southeasterly winds of 20 to 25 knots to
develop along the Canadian border. Winds die back down to 20 knots
or less again as the low lifts into northern Ontario and skirts the
northern Lake Superior shoreline Saturday through Saturday night. On
Sunday behind the cold front of the low, northwest to northerly
winds of 20 to 25 knots look to move back across the lake Sunday
through Sunday night. As we look to the middle of next week, we may
see some strong northeasterly winds return to Lake Superior as a
robust, vertically-stacked low moves from the Southern Plains
through central Lower Michigan.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...LC
LONG TERM...TAP
AVIATION...TDUD
MARINE...TAP
Area Forecast Discussion
National Weather Service Paducah KY
523 PM CST Wed Jan 3 2024
.KEY MESSAGES...
- Calm weather will last through Friday with rain likely into
Saturday. A few snowflakes are possible our northwestern
counties.
- The system for next Tuesday (January 9th) looks like it could
be more impactful for the area with the surface low
approaching the all time record low, with respect to low
pressure systems. This may result in widespread significant
wind (50 - 60 mph) for much of the Quad State.
&&
.UPDATE...
Issued at 520 PM CST Wed Jan 3 2024
Updated aviation discussion for 18z TAFs.
&&
.DISCUSSION...
Issued at 207 PM CST Wed Jan 3 2024
Calm and cool weather is expected to continue through the end of the
work-week as weak mid-level ridging continues to move through the
region. The next day should see the return of some clouds as a weak
frontal passage from the north overnight tonight. This might promote
somewhat warmer minimum temperatures closer to 30 than the past few
nights given sufficient insulation from radiative cooling. That
being said, expect highs in the mid 40s and lows into the 20s
through Friday.
The real knuckle-cracking starts for us on Friday with the arrival
of the first of two systems that will be the main show for weather
over the CONUS through next week. On Thursday, a potent upper level
trough will begin to dig into the western TX Panhandle and with a
90+ knot jet streak rounding its base. With time, this momentum tugs
the trough eastward into the central Plains with a developing lee
surface cyclone over the Red River in OK. However, recent guidance
has sped and flattened out the upper level wind fields to a point
where the lee cyclone that could have tracked into our region will
be superseded by a new area of near-surface deepening on the
Gulf Coast. In response, our higher POPs and QPF have shifted to
the south and east, with max QPF in the Pennyrile being around
.4" - .5" with lowering amounts moving northwest. Some
inconsistency still remains as to the true P-type with our
northern counties still having a non-zero chance at some
snowflakes as temperatures cool just enough overnight Friday for
some flakes to make it to the ground with rain. No snow
accumulation is expected, but a very small potential still
exists in our far northwestern counties.
Saturday and into Sunday will see the departure of the first wave to
our east where it will promptly speed off into the North
Atlantic. High pressure will build in through Sunday, keeping us
dry and mild but likely overcast.
Beginning Monday confidence continues to increase with regards to a
significant system to make its run on the central CONUS early
next week. A textbook synoptic setup will take shape starting
Monday night with a powerful jet streak digging into the
southern plains at 700 - 200 mb. The associated DCVA and height
falls will be more than enough for a powerful sub-990 mb low to
track from OK through MO and into the Rust Belt in S IL/IN with
near-record or record low pressure possible in our region. Run-
to-run consistency continues to be remarkably high in the
GFS/ECMWF/Canadian Ensembles. There is still some shuffling
around with regards to the exact track of the center of low
pressure and the magnitude to which it will deepen. The EPS has
produced a slowing trend will simultaneously pulling the system
south, with around 40% of members displaying a track east of our
area. However, the GFS and Canadian Ensembles are much faster
and keep the low through our region almost an entire 12-24 hours
earlier. These complications in track confidence shine a light
into the difficulties of pinning down exact precipitation types
out to this range, but the scenario of no significant ice or
snow accumulation appears most likely. Storm total QPF amounts
are still subject forecast uncertainty, but anywhere from 1" -
1.5" of rain are possible with a small potential for snow in the
northwest yet again. Track shifts to the south and east would
bring higher chances for snow accumulation, but again that still
appears unlikely.
One impact for all portions of the region that has become much
clearer is the potential for strong winds on the back side.
Overnight Tue into Wed strong pressure gradient forces will
combine with 925 - 850 mb CAA to create an environment conducive
for strong vertical momentum fluxes, irregardless of sunshine.
Ensemble guidance shows good agreement on sustained winds around
20 - 30 mph, with todays NBM guidance continuing is trend of
increasing sustained and gusting winds to around 40 mph.
Looking at higher percentile wind gusts in conjunction with a
trend towards higher winds reveals a very real possibility for
wind gusts well above 40 mph overnight Tuesday and Wednesday
morning. However, it is yet to be seen if future guidance will
continue this trend.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 520 PM CST Wed Jan 3 2024
MVFR stratus deck over our northern terminals (KMVN/KEVV) is
expected to slowly sag southward across the rest of the region
this evening and overnight. HRRR seems to have a decent handle
on it and suggests it eroding from the north during the morning.
However, the SREF probabilities of MVFR cigs is still around
30-40% by 18z tomorrow, so not totally confident it`ll be
completely gone by afternoon. For now have a SCT deck in and
will assess with later packages. Winds will be primarily out of
the N/NE through the period.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
UPDATE...SP
DISCUSSION...JGG
AVIATION...SP
Area Forecast Discussion
National Weather Service Shreveport LA
934 PM CST Wed Jan 3 2024
...New UPDATE...
.UPDATE...
Issued at 923 PM CST Wed Jan 3 2024
Skies have cleared across the forecast area allowing temperatures
to rapidly cool into the mid 30s to lower 40s. Several locations
have already cooled to near their dewpoints. Combined with wet
soils from the recent rains, conditions should be quite supportive
for patchy fog during the early to mid morning hours of Thursday.
Where temperatures have fallen below freezing, this will likely
materialize as freezing fog and areas of frost. It is worth noting
that the latest HRRR is considerably less aggressive in terms of
fog coverage. Visibilities are generally expected to remain above
a mile in most locations.
Overall, the forecast appears to be on track for the remainder of
the night. No updates are anticipated.
CN
&&
.SHORT TERM...
(This evening through Thursday Night)
Issued at 109 PM CST Wed Jan 3 2024
Mostly clear skies expected overnight allowing for temperatures to
fall to slightly below freezing across much of the region with the
exception of possibly Deep East Texas. Surface high responsible
for the colder air across the ArkLaTex remains centered across
the Northern Plains, ridging into the midwest, and will be quick
to shift east allowing for light east winds to return across the
ArkLaTex by daybreak. There may be a short window of time near
daybreak where moisture return within a layer of slightly
subfreezing temperatures could allow for frost and possibly
freezing fog conditions across mainly south Arkansas, northeast
Texas and north Louisiana. Model guidance has been fairly
inconsistent in handling fog potential with the HRRR being one of
the more aggressive models. Therefore, for this forecast, went
ahead and maintained patchy fog and frost wording in all areas
where temperatures could dip below freezing. No major impacts are
expected at this time.
A surface and upper-low moving out of the Four Corners region into
Texas on Thursday will be the next weather maker that will bring
widespread showers to the region on Thursday night. Near
subfreezing temperatures associated with the departing surface
high could linger across south Arkansas as convergence increases
in response to a surface low across north Texas. Thus, there is
the possibility for a rain/freezing rain mix across northern
McCurtain, Sevier, Howard, Hempstead, and Nevada counties near
daybreak Friday morning. No accumulations are expected.
Otherwise, highs on Thursday will average in the 50s with lows on
Thursday night ranging from near freezing near I-30 to the lower
40s across Deep East Texas. /05/
&&
.LONG TERM...
(Friday through next Tuesday)
Issued at 109 PM CST Wed Jan 3 2024
An active weather pattern will continue through the end of the first
week of 2024 across the Four State Region. This is due to the mostly
zonal orientation of the subtropical jet stream that will generally
steer a parade of Pacific troughs across the Sun Belt states over
the next week and beyond. These troughs will proceed across the
Rocky Mountains to create corresponding chances of precipitation
through most of Friday and next Monday into Tuesday. Day 1-5 WPC QPF
totals range from 0.5-inch to 2+ inches, while Day 1-7 totals add at
least another inch to that with next week`s disturbance. A day 3
Marginal ERO has been issued for our southern zones as a result with
otherwise seasonable temperatures expected through the period.
Long range guidance continues to suggest the increasing potential
for wintry precipitation along or north of the I-30 corridor on
Monday. This potential will vary depending on the trajectory of this
trough, and while its intensity is more certain to be robust
(pulling more sub-540 decameter thicknesses across the area), small
variances in variables like moisture and trajectory add up and
ultimately add more uncertainty to resolve in the next few days. /16/
&&
.AVIATION...
(00Z TAFS)
Issued at 534 PM CST Wed Jan 3 2024
VFR flight conditions will prevail initially. While some scattered
instances of clouds between 3500 and 6000 feet have developed over
the last few hours, these clouds should also dissipate somewhat
prior to midnight local time. After 04/06z, patchy fog may develop
at most of the TAF sites. This may actually occur as freezing fog
at KTXK, KELD, KSHV, and KMLU. Visibilities may decrease enough to
result in IFR conditions across portions of East Texas and Central
Louisiana. Flight conditions should improve back into the VFR
range by 04/15z as the fog lifts and scatters.
CN
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 35 58 40 47 / 0 0 30 90
MLU 31 56 33 47 / 0 0 10 100
DEQ 29 53 33 45 / 0 0 50 60
TXK 31 53 36 44 / 0 0 40 80
ELD 29 54 33 44 / 0 0 10 90
TYR 36 58 41 53 / 0 0 70 50
GGG 34 58 39 49 / 0 0 60 70
LFK 35 59 41 53 / 0 0 50 80
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
SHORT TERM...09
LONG TERM....33
AVIATION...09