Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/23/22
Area Forecast Discussion
National Weather Service Boston/Norton MA
1023 PM EST Thu Dec 22 2022
.SYNOPSIS...
A high impact storm brings multiple hazards, including high
winds, coastal flooding, and heavy rainfall tonight into
Friday, followed by plummeting temperatures Friday evening. A
chilly holiday weekend ahead, while majority of the region
remains dry, areas along the immediate south coast, Cape Cod,
and Islands likely to see ocean-effect snow showers Saturday,
and possibly Sunday. Looking ahead to next week, dry with
temperatures moderating to near average.
&&
.NEAR TERM /THROUGH FRIDAY/...
Mainly tweaked the forecast tor reflect observed trends this
evening, especially temperatures and rainfall timing. Will
continue to monitor timing of winds across southern New England,
and transition to rainfall across the Berkshires.
630 PM update...
Forecast is unfolding as expected so far, on the front end of
this prolonged storm system. Radar shows returns having
overspread most all of southern New England, with snow being
reported in the Worcester Hills and Berkshires as of 6PM.
Previous Discussion...
Synoptic pattern remains little changed tonight through Fri, as
a powerful primary low pressure area with associated well
developed 500 mb cyclone pinwheels and occludes tonight into Fri
across the Gt Lakes, which will swing a powerful cold front
through Southern New England Fri aftn. This system will bring a
multitude of potential hazards tonight into Friday.
Each of these hazards will be touched upon in turn, described
below roughly in order of timing:
-- Winter Weather --
While precipitation begins as all rain, temps will be marginally
cold enough at onset to begin as light accumulating snow across the
eastern slopes of the Berkshires.
Winter Weather Advisory for the eastern slopes of the Berkshires was
maintained for tonight thru early Fri AM. However current temps in
an area from Blandford to Rowe are marginal at around 30 to 32
degrees, and with temperatures standing to rise in a non-diurnal
fashion, snow amounts were reduced in the Advisory area. Think the
risk for accumulating snow will probably cease before the Advisory
expiration due to the rising temps and this is also the indication
in the latest HREF hourly p-type guidance. 2 to 4 inches of new snow
should be common in the east slopes of the Berks where the Advisory
is in effect with local amts up to 5 inches possible.
Warming temperatures however will likely melt whatever snow develops
(as well as some additional melt where snowpack existed previously
in these same areas, to be discussed below).
-- Strong to Potentially Damaging Winds (Main Storm Impact) --
12z guidance today reflected no major change to the forecast and/or
messaging regarding strong to damaging wind gusts. Thus no changes
were made to high wind warning/wind advisory areas either in space
or in valid times.
SE winds will continue tonight, steadily increasing in sustained
wind speed and gust magnitude. Period of strongest SE wind gusts
early Fri morning to early aftn, associated with passage of a 65-80
kt 925 mb SE jet in conjunction with a strong to extreme isallobaric
pressure fall-to-rise couplet tied to the strong cold front. The
strongest wind gusts are still anticipated across RI and
eastern/southeast MA where local gusts could be as much as 65 mph;
further inland more removed from the stronger jet, peak gusts up to
50 mph.
Upon passage of the strong cold front Fri aftn, winds will shift
abruptly to SW; intense cold air advection will steepen lapse rates
considerably and lead to more frequent albeit somewhat lower gust
speeds to around 45-55 mph through remainder the aftn.
Nonetheless the potential exists for wind-related damage,
with possible power outages.
-- Heavy Rain, Possible T-Storms and Flooding Potential --
Rain is already near our southern coastal waters associated with
warm front. Other than early tonight in the Berkshires, rain will
continue to advance and become steady tonight into the overnight.
Locally heavy rain is possible by early Fri AM. Combination of
strong mid to upper level divergence, surge in PWAT values to near
or just over 1 inch, along with some elevated instability above the
frontal inversion (showalter indices 0 to -1) could favor a period
of at least heavy downpours Fri AM with a lower probability risk for
thunderstorms across eastern MA and RI. HREF calibrated 1-hourly
thunder progs show some t-storm chances between 12-16z. Rain comes
to an end rapidly by Fri aftn.
Storm total rainfall around 1 to 2 inches, with 2-3 inches possible
in the upslope-enhanced areas in the eastern slopes of the
Berkshires and Litchfield Hills. Possibility exists for urban and
poor drainage hydrologic problems Fri. While generally modest rises
are anticipated on most rivers, the combination of rainfall and
added water due to snowmelt along creeks, rivers and tributaries
along the Connecticut and Merrimack basins. See latest river
forecasts from the NERFC for more information.
-- Rapid Temperature Drop Fri Aftn --
Heavily utilized a mix of the HRRR and the NAM-3km for temperatures.
For tonight, expect non-diurnal temperature trends with early lows
in the 30s to low 40s, with temperatures rising into the mid 40s to
mid 50s by daybreak Fri. Temperatures may rise a few degrees more
into the morning on Fri with highs in the mid to upper 50s.
But the real notable change will be the rapid fall in hourly
temperatures as the potent cold front surges through Southern New
England. And this is from the surge of modified Arctic air which is
surging through much of the central part of the nation currently.
While we are not expecting anything as extreme as the temperature
falls experienced in those areas, significant hourly temperature
falls with rapid drying remain anticipated once the front clears our
area starting Fri Aftn. By sundown, temps will have fallen into the
mid to upper 20s west of Worcester, around freezing from central MA
into western RI, and upper 30s to low 40s eastern MA and RI.
The combo of continued gusty WSW winds and rapid post-frontal drying
should enhance evaporative potential and mitigate significant flash
freeze issues across interior New England. However icy spots could
still be possible.
-- Coastal Flooding --
See the coastal flooding section for more detail.
&&
.SHORT TERM /FRIDAY NIGHT/...
400 PM Update:
Similar to Fri aftn, temps were heavily based on the 12z
NAM-3km to better show the rapid fall in hourly temps, versus a
model- blended approach. Because the very cold air mass is
extremely dry and that winds will still be quite gusty from the
W, that should help enhance evaporation; icy spots possible in
shaded areas but we`re not looking at a flash freeze attm
despite the falling temps. Lows range upper single digits to the
upper teens, around low 20s Cape and Islands. Sub-zero wind
chills anticipated in western/central MA and northern CT by
Christmas Eve morning, with values around 10 below across the
Berkshires. If wind speeds stay stronger for a longer period of
time (viewed as unlikely), potential for wind chill advisories
exists for the eastern slopes of the Berkshires but too
uncertain attm.
Also looking at a rare WSW wind-driven ocean effect snow shower
scenario in the southern waters Fri night, given the much
colder air and the relatively mild ocean waters. Have snow
amounts up to a couple inches in the Islands with a coating
across Cape Cod.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Highlights...
* Gusty winds linger through Saturday
* Dry and chilly through Christmas, then remaining dry with
moderating temperatures next week.
Details...
Saturday starts out quite chilly (in the single digits and teens)
compared to 24 hours before (30s and 40s). What will make conditions
even more harsh will be lingering gusty winds on cold SW flow. This
cold advection pattern makes for a very well mixed boundary layer,
efficiently mixing down gusts of 30 to 40 mph from a 30 to 45 kt 925
mb jet. Wind chills will be in the single digits and teens on
Saturday afternoon, and things remain dry for the vast majority of
the area. The only exception will be for portions of Cape Cod
(especially the southern coast) and the islands where the SW
trajectory of the wind may direct light ocean effect snow showers
overhead Saturday into early Sunday. Anywhere from a dusting further
north to an inch or two further south toward Nantucket is possible.
Sunday the low lifts further into northern Quebec and the pressure
gradient relaxes, allowing winds to finally diminish appreciably.
Christmas Day will be quiet and dry, with plenty of sun under
approaching high pressure. As we move into the week between
Christmas and New Years` we`re looking at more of the same with dry
and quiet weather beneath a sprawling area of high pressure that
builds in from the south and east. The main change of note will be
slowly moderating temperatures, into the 30s and even 40s by
Thursday.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Tonight: High confidence in trends, moderate on timing.
Deterioration all sites this period with MVFR-IFR ceilings,
advancing precip (largely -RA/RA, but higher elev -SN thru 06z in
the Berkshires and northern hills in Worcester County), and
increased E/SE gusts.
Winds increase to become ESE sustained 15-25 kt/gusts 35-45 kt
with areas of low-level shear/turbulence.
Friday: High confidence in trends, moderate on timing.
**Significant aviation impacts probable this period.**
Through the morning...IFR-possible LIFR ceilings with VFR/MVFR
with steady rain, some heavy at times (low prob T/TS
eastern/southeast airports 12-16z). Strong SE winds, gusts 40-50
kt strongest eastern/southeast MA and the Cape. Areas of LLWS
still possible.
After 16z...a powerful cold front then moves through the TAFs
with a rapid decrease in rain coverage, ceilings improving to
MVFR- VFR levels and a gusty wind shift from SE to SW/WSW, gusts
35-45 kt. Lower probability for the western airports (mainly
BDL-BAF) that any wet pavement could freeze and become icy as
temperatures fall into the upper 20s between 21-00z Sat.
Friday Night: High confidence.
MVFR to VFR with gusty W to SW winds gusts up to 45 kt.
Generally dry but ocean effect SHSN possible at ACK and perhaps
HYA/FMH. Rapid temperature fall likely Fri night that may cause
icy spots on runways.
KBOS Terminal...Moderate confidence.
KBDL Terminal...Moderate confidence.
Outlook /Saturday through Tuesday/...
Saturday: VFR. Windy with gusts up to 35 kt. Slight chance SN.
Saturday Night: VFR. Windy with gusts up to 35 kt.
Christmas Day: VFR. Windy with areas of gusts up to 30 kt.
Sunday Night through Monday: VFR. Breezy.
Monday Night through Tuesday: VFR.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Tonight through Friday night...High confidence.
Increasing easterly flow this afternoon, becoming southeast and
ramping up during the evening and overnight hours. Winds will
reach Storm force by sunrise on Friday. Seas increase to 11-17 ft
across the outer coastal waters by sunrise Friday, and continue into
Friday night.
Outlook /Saturday through Tuesday/...
Saturday: Strong winds with gusts up to 35 kt. Rough seas up to
16 ft. Chance of snow, chance of freezing spray.
Saturday Night: Strong winds with gusts up to 35 kt. Rough seas
up to 13 ft. Chance of snow, chance of freezing spray.
Christmas Day: Strong winds with gusts up to 30 kt. Rough seas
up to 12 ft. Slight chance of snow.
Sunday Night: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Rough seas up to 9 ft.
Monday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Seas up to 5 ft.
Monday Night: Winds less than 25 kt. Seas locally approaching
5 ft.
Tuesday: Winds less than 25 kt.
&&
.TIDES/COASTAL FLOODING...
400 PM Update:
Overall there were no significant changes noted regarding the
concerns for coastal flooding and beach erosion. Prior forecast
thinking remains valid for this update and is below:
* Coastal Flood Warning for both the east and south coasts Fri
morning
We continue to expect widespread minor coastal flooding with
pockets of moderate coastal flooding, along with beach erosion.
It is rather unusual to have coastal flooding on an east to
southeast wind, and for it to impact both coasts, but this is a
highly anomalous system.
The magnitude of coastal flooding will be determined by how
quickly the winds/seas ramp up. Guidance still looking like an
earlier onset is most likely. This means a greater risk of
moderate flooding along the south coast for places like
Narragansett Bay.
The high tides occur around 7-9 AM Friday along the south
coasts, and in the 10 AM to noon timeframe across the eastern MA
Coast. Given an ESE wind direction and support from the various
guidance, we are expecting a 1.5 to 3.5 foot storm surge.
Typically vulnerable shoreline roads may become flooded and
impassable within a few hours of high tide. In addition, there
may be significant beach erosion on the south coast, including
ocean-exposed beaches of Rhode Island and Westport. Significant
beach erosion may also occur on the south side of Marthas
Vineyard and Nantucket.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Wind Advisory until 7 PM EST Friday for CTZ002>004.
MA...Wind Advisory until 7 PM EST Friday for MAZ002>004-008>012-026.
Winter Weather Advisory until 7 AM EST Friday for MAZ002-008-
009.
High Wind Warning until 7 AM EST Saturday for MAZ005>007-
013>024.
Coastal Flood Warning from 5 AM to 2 PM EST Friday for MAZ007-
015-016-019>024.
RI...High Wind Warning until 7 AM EST Saturday for RIZ001>008.
Coastal Flood Warning from 5 AM to 2 PM EST Friday for RIZ002-
004>008.
MARINE...Storm Warning until 7 PM EST Friday for ANZ230>237-254>256.
Storm Warning until 1 AM EST Saturday for ANZ250-251.
&&
$$
SYNOPSIS...Loconto/BW
NEAR TERM...Belk/Loconto/BW
SHORT TERM...Loconto
LONG TERM...BW
AVIATION...Belk/Loconto/BW
MARINE...Loconto/BW
TIDES/COASTAL FLOODING...Staff
Area Forecast Discussion
National Weather Service Corpus Christi TX
610 PM CST Thu Dec 22 2022
...New AVIATION...
.SHORT TERM...
(Tonight through Friday night)
Issued at 158 PM CST Thu Dec 22 2022
Key Messages
- Very cold temperatures and single digit wind chills tonight and
tomorrow
- Strong winds over the coastal region and Gulf waters
The strong cold front we have been talking about over the last
several days is right on our doorstep. MSAS analysis and surface
observations place the front across the Hill Country.
Temperatures are currently in the 30s across the Austin-San
Antonio area while we are still sitting around 60 degrees across
South Texas. Temperatures will fall very quickly behind the front
with temps in the upper 20s to low 30s by early this evening.
Overnight, lows will fall into the upper teens to mid 20s. Strong
CAA will keep temperatures below freezing for much of the day
tomorrow. The current forecast has temps rising in the mid to
upper 30s. However, there is still a chance that some spots remain
below freezing all day. Another cold night is in store Friday with
lows falling back into the low to mid 20s. In addition to the
brutally cold temps, winds will be packing quite the punch.
Strong northerly winds will develop this evening and persist
through the night before finally subsiding through the day Friday.
Winds will be strongest along the coast and over the waters.
Lastly, there is a low end chance for precip over the waters on
Friday as an upper shortwave rotates through the region as a plume
of low level moisture lifts out of Deep South Texas. Temperatures
will be warmer over the waters so not expecting any wintry
precip. However, if this moisture shifts a bit closer to the
coast, we can`t completely rule it out.
Now for the hazards:
Hard Freeze Warning: The Hard Freeze Warning has been extended
through noon on Saturday. Temps may briefly rise above freezing
for a couple of hours Friday afternoon but will quickly fall back
into the low 20s.
Wind Chill Warning: The Wind Chill Warning has been extended
through noon on Saturday. Similar to the Hard Freeze Warning, we
will climb above criteria during the day Friday but will quickly
fall back Friday night. We likely won`t see the single digit wind
chills, generally in the 10-15 degree range.
Wind Advisory: The Wind Advisory has been expanded to include
inland Kleberg and Jim Wells counties. Recent runs of the HRRR
(it`s been handling this front very well) continue to hint at
frequent gusts to around 40 MPH overnight. The Advisory remains in
effect through noon Friday.
Fire Weather: Low RH values and strong winds across the Coastal
Bend tomorrow may result in a brief period of elevated fire
weather conditions.
See the Marine section below for the Gale Warning.
&&
.LONG TERM...
(Saturday through next Wednesday)
Issued at 158 PM CST Thu Dec 22 2022
Key Messages:
- Cold freezing nights through Sunday night
- No significant precipitation chances with a warm up next week
A trough axis will move over the region Saturday and Sunday around
the SW periphery of the broad deep trough over the NE CONUS,
maintaining the surface ridge and cold temperatures over South
Texas through the weekend. Will see some moderation of
temperatures into the upper 30s on Saturday with abundant
sunshine. Expect another hard freeze Saturday Night/Sunday morning
due to the aforementioned conditions and strong radiational
cooling. Highs will be a bit warmer Sunday as the surface ridge
begins to erode but still only in the mid 40s (25 degrees below
normal).
Yet another trough swings through the area on Monday sending a
weaker reinforcing surface ridge into South Texas Monday Night.
However the flow becomes onshore again on Tuesday allowing for more
warming into the mid 60s as the next trough enters the northern
Rockies.
&&
.AVIATION...
(00Z TAFS)
Issued at 602 PM CST Thu Dec 22 2022
Expect a mixture of MVFR and VFR ceilings this evening, followed
by predominate VFR conditions after 06z Friday. Expect VFR to then
continue for the remainder of the TAF period. Strong to very
strong north surface wind expected this evening/early tonight,
followed by a gradual decrease in wind speeds during the 06-12z
Friday period. Afterward, generally moderate to breezy north wind
during the mid/late morning hours Friday, becoming weak to
moderate toward the end of the TAF period.
&&
.MARINE...
Issued at 158 PM CST Thu Dec 22 2022
A strong cold front will push offshore early this evening leading
to very strong northerly winds. A Gale Warning is in effect
through Friday evening as winds gust up to 45 knots at time. It`s
possible we see a few gusts to storm force overnight. In addition,
seas will elevated to 15-18 feet. Conditions will slowly subside
Friday afternoon with a few gusts to gale possible through the
evening hours. Moderate to strong offshore flow Saturday through
Sunday afternoon will subside to weak to moderate on Monday as
high pressure settles over the NW gulf. Small Craft Advisory
conditions likely persist for the gulf waters through Sunday
morning. Moderate to strong onshore flow returns by Tuesday night.
A weak cold front is forecast to move off the coast Monday Night
resulting in moderate offshore winds. Onshore winds return Tuesday
becoming moderate to strong by Wednesday and will likely result
in Small Craft Advisory Conditions.
&&
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 22 36 25 38 / 0 0 0 10
Victoria 19 34 23 39 / 0 0 0 0
Laredo 26 38 25 40 / 0 0 0 0
Alice 21 36 23 38 / 0 0 0 0
Rockport 22 37 25 37 / 0 0 10 10
Cotulla 23 38 22 41 / 0 0 0 0
Kingsville 23 36 24 37 / 0 0 0 10
Navy Corpus 26 37 30 38 / 0 0 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...Hard Freeze Warning until noon CST Saturday for TXZ229>234-
239>247-342>347-442-443-447.
Wind Chill Warning until noon CST Saturday for TXZ229>234-
239>247-342>347-442-443-447.
Wind Advisory until noon CST Friday for TXZ231>234-241>247-
342>347-442-443-447.
GM...Gale Warning until 6 PM CST Friday for GMZ231-232-236-237-250-
255-270-275.
&&
$$
SHORT TERM...TC
LONG TERM....JM
AVIATION...WC/87
Area Forecast Discussion
National Weather Service Dodge City KS
441 PM CST Thu Dec 22 2022
...Updated Aviation Discussion...
.SHORT TERM...(This evening through Friday night)
Issued at 141 PM CST Thu Dec 22 2022
A little warming this afternoon on the HRRR shows temps
increasing to the mid single digits above zero along the southern
tier of counties, to around 0 degrees along the Interstate 70
corridor. The momentum transfer weakens through late afternoon,
and a marginal decrease in wind speed should be realized, noted in
the HRRR 2m wind fields as well as the LAV guidance which ramps
sustained wind speeds down to around 20kts by this evening.
The bulk of the cold air advection has already occurred, so
temperatures are not anticipated to fall that much more overnight.
That said, the ark valley west across GCK into eastern Colorado
is favored by the models for the coldest air which NAM takes
temperatures into the -10 to -15 deg F range, while the rest of
the forecast area falls into the the 0 to 10 below range, with
sustained 20 mph winds gusting to 30. The Wind Chill Warning
remains in effect through noon Friday. Model consensus warms temp
in to the teens over the bulk of the area Friday afternoon, as
winds significantly weaken to around 10 to 15 knots. Wind chills
will still be dangerous Friday morning, although not quite as
extreme, probably struggling to reach warning criteria along the
Oklahoma state line. Look for wind chills Friday morning
approaching 30 below zero north of highway 400.
.LONG TERM...(Saturday through Thursday)
Issued at 141 PM CST Thu Dec 22 2022
Significant airmass modification is seen going into the weekend.
Light westerly winds return with weak downslope warming as the
main arctic airmass continues to retreat into the Midwest. While
still a cold and dry airmass, the NBM forecast warms overnight
lows into the single digits above zero by Sunday morning while
highs in the 20s on the lower Plains and the 30s on the High
Plains modify to the 30s to low 50s west by Sunday afternoon.
This overall trend looks to carry into the workweek as an
amplified upper ridge develops into the Rockies region with
potential for better downslope trajectories in the boundary layer.
The ECMWF ensemble mean at Liberal on Wednesday is 63 degrees.
The next major synoptic scale trough appears to develop around
Day 7 late Thursday into Friday. Canadian/GFS and ECMWF all show a
sharp synoptic scale trough moving into the Plains, as pressure
falls develop a typical Elkhart low that ejects eastward ahead of
what appears to be a rather insignificant cold front.
ECMWF ensemble members produce anywhere from nothing - to a range
of 0.01 to 0.06 inches of precipitation on a 6 hour basis, and a
trace to just under an inch of snow. In those same timescales. The
NBM is accounting for a lot of this already with about a 20
percent chance of snow or fzra/mixed phase on Thursday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 435 PM CST Thu Dec 22 2022
VFR conditions for the entirety of the period for all TAF sites.
Gusty north to northwest winds up to 30kts to start diminishing
after sunset around 02Z to around 15kts due to clearing skies and
weakening gradient. A few lingering lower level clouds present
will clear after this point as well remaining mainly clear through
the end of the period. Northwest winds will continue to diminish
to less than 10kts as high pressure builds in towards sunset near
the end of the period with no other weather elements expected at
this time.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC -14 18 0 30 / 0 0 0 0
GCK -15 16 -1 30 / 0 0 0 0
EHA -11 20 4 35 / 0 0 0 0
LBL -11 18 0 33 / 0 0 0 0
HYS -12 14 -4 23 / 0 0 0 0
P28 -7 18 3 26 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
Wind Chill Warning until noon CST /11 AM MST/ Friday for KSZ030-
031-043>046-061>066-074>081-084>090.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Lowe
Area Forecast Discussion
National Weather Service Des Moines IA
551 PM CST Thu Dec 22 2022
...Updated for the 00z Aviation Discussion...
.DISCUSSION.../Tonight through Thursday/
Issued at 305 PM CST Thu Dec 22 2022
Key Messages:
- Blizzard conditions combined with dangerous wind chills will
create life threatening conditions for anyone that ventures out
tonight through Friday, particularly over northern/central Iowa
- Bitter cold through Saturday morning, then gradual upward
temperature trend
- Light snow chances parts of Iowa Christmas Day
Details: The snow has pushed into eastern Iowa as of early this
afternoon with COOP and spotter reports showing snowfall was between
2 to 4 inches in most places. Several reports between 4 and 5 inches
came were received from around the Webster, Hamilton, and Boone
county area. The arctic front that brought this snowfall is over
eastern Lake Michigan and stretches to near Little Rock to near San
Antonio. The parent trough of this front is digging southeastward
toward the western Great Lakes while surface low pressure develops
over the Ohio Valley. As this surface front pulls away, the clouds
are also departing to the east leaving behind a clear sky over
western into central Iowa. Winds in the wake of the front have been
increasing with gusts between 25 and 35 mph this morning and that
has increased into the 30 to 40 mph range now. Temperatures continue
to fall and with the increasing winds, the entire area is solidly in
Wind Chill Warning criteria with most places at or below -35F.
With the fresh snow and these winds, GOES-East day snow fog RGB
show a widespread field of blowing snow, which has a bit of milky
appearance to it over western/central Iowa, eastern/central South
Dakota, eastern/central Nebraska, and Minnesota. Frankly, it is
amazing to see such a large area of blowing snow. Visibilities thus
far this afternoon in Iowa have generally bottomed out around a half
a mile with KEST (ASOS), KEBS (AWOS), and KCIN (AWOS) reporting
such. Recently, KCAV (AWOS) reached a quarter of a mile. We`ve also
seen social media reports around Pocahontas of quarter mile
visibility, drifting snow, and county plows being pulled off the
roadways. As the surface low moves into the eastern Great Lakes,
explosive deepening of this low will occur, which will increase the
pressure field between the eastern Great Lakes and a ~1050mb high
moving down the eastern spine of the northern Rockies. For Iowa,
this means winds will be stronger tonight and Friday then they have
been so far. Current forecast for wind gusts is toward the BUFKIT
mean mixed layer wind versus the top of the mixed layer, which are
impressive around 50 knots over northern Iowa and also shown in HRRR
runs. For now, peak gusts were kept between 40 and 50 mph after
midnight tonight into Friday evening, but will monitor trends in
case we need to trend towards the top of the mixed layer. With these
stronger winds continuing to loft snow, we continue to forecast
blizzard conditions tonight into Friday and the headlines are in
good shape. Those blizzard conditions will be most likely in rural,
open areas so if you are in a sheltered, city/urban location and it
doesn`t look bad, do not be deceived.
While the blizzard conditions alone are a concern for personal
safety, the bitterly cold air with these winds will create wind
chills of -35F or lower across all of Iowa. Stealing from the
midshift`s discussion, wind chills this low are uncommon and happen
on average maybe a few hours per year (10hr/yr at Estherville to
2hr/yr at Des Moines), so this is a somewhat rare, prolonged cold
scenario for Iowa. If you were to venture out tonight or Friday and
become stranded due to a vehicle break down, stopped in traffic due
to an accident, or go off the roadway due to poor visibility, these
wind chills would be dangerous and life threatening if exposed for a
short period. We don`t use those words lightly or often, but that is
the current scenario that we see unfolding, particularly over
northern and central Iowa. Wind chills will generally be below -25
if not -30F or lower across the state through Saturday morning.
While the Wind Chill Warning conditions are currently included in
the Blizzard Warning and Winter Storm Warning, will need to issue a
separate wind chill headline once the other warnings end.
While the forecast is dry through Friday and Friday night, the RAP
shows a thin layer of saturation dropping into northern Iowa in the
afternoon and evening with little lift noted in cross sections. The
RAP and HRRR BUFKIT soundings show that the not fully saturated
profile warms (yes, warms) to near the lower end of the
-18 to -12F dendritic growth zone while at the same time further
drying. There is no ice introduction so we could see freezing
drizzle or perhaps flurries briefly over northern Iowa, but
confidence was too low to include it at this time.
It will remain blustery through Saturday as the trough and surface
low wrap up and move northeast into the Quebec province. With around
36 hours of blowing snow, crystals will have been fragmented down
and the relatively lighter winds should result in blowing snow being
not be as prevalent. There could still be streamers across roadways,
which could pose a travel risk. After Saturday morning, the coldest
period will be in the past with temperatures forecast to rise
gradually into next week.
The next chance for light snow will come from a clipper system that
looks to track through the region later this weekend. Moisture will
be limited and it will take top down saturation to overcome the dry
low levels. Cross sections do not show robust lift, but sufficient
for light snow. Compared to yesterday, the 100 member grand ensemble
is slower with the arrival of snow holding off until later in the
afternoon with it more tracking through southern Minnesota,
northeast half of Iowa, and southwest half of Wisconsin. So, a bit
of light snow with amounts around an inch possible in parts of the
state are possible Christmas Day.
&&
.AVIATION.../For the 00Z TAFS through 00Z Friday evening/
Issued at 543 PM CST Thu Dec 22 2022
Main concern for terminals remains visby reductions from blowing
snow which will last for the TAF period and beyond. Visby will be
largely IFR and LIFR. Winds will increase around 06z tonight and
may exceed 45kts at times, especially for eastern terminals. MVFR
and IFR cigs will prevail through the period.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
Blizzard Warning until 6 AM CST Saturday for IAZ004>007-015>017-
023>028-033>039-044>050-057>062.
Winter Storm Warning until 6 AM CST Saturday for IAZ070>075-
081>086-092>097.
&&
$$
DISCUSSION...Ansorge
AVIATION...Jimenez/Fowle
Area Forecast Discussion
National Weather Service Grand Rapids MI
1107 PM EST Thu Dec 22 2022
LATEST UPDATE...
Update
.UPDATE...
Issued at 1107 PM EST Thu Dec 22 2022
Synoptic portion of the event is still ongoing in eastern sections
of the forecast area towards U.S. Highway 127 from Mt. Pleasant to
Jackson. Snowfall from this portion of the event has been on the
order of 2 to 4 inches for the most part.
We are currently shifting into the lake effect portion of the
event. The surface low is located near Oscoda with a trailing
Arctic front stretching south into Southeast Lower Michigan just
west of Ann Arbor. The front has now cleared the entire forecast
area with much colder air flowing in on westerly winds.
Temperatures have already plunged to 14 at Fremont and Ludington.
To the west across the lake, it is in the teens below zero already
west of Madison WI.
Lake effect has begun with 25+ dbz echoes already occurring in a
sheared environment (which is not good for lake snow). Once wind
direction consolidates a bit more in the vertical which happens
towards daybreak, the lake effect should really increase in
coverage and intensity. The wind in the vertical is completely
linked up or more uniform in direction by midday tomorrow. We
expect the worst of the conditions to occur Friday and Friday
night. Forecast winds in the mixed layer remain above 40 knots.
Conditions that are already not great with 2-4 inches of new snow
and winds gusting to 30 knots should become much worse as snow
becomes heavier, more powdery with time and wind gusts that may
exceed 40 knots. Obviously, the Blizzard Warning and Winter Storm
Warnings remain in place and unchanged.
The areas that will see the least snow from this entire event will
be interior portions of the state from Mt Pleasant south to St.
Johns and in far southeast Jackson County towards Brooklyn.
Otherwise, major impacts are expected along the spine of Highway
131 and points to the west.
850-925mb layer omega really tells the story of the next 24-36
hours. We will see a major convergence zone near/in between I-96
and I-94 over Southwest Lower Michigan. This converence zone is
driven by the cold air wrapping around the bottom of the lake. The
thermal gradient that will be in place between air flowing off a
lake surface that is 42 degrees and air flowing into far Southern
Lower Michigan that will be in the single digits will create a
frontal zone essentially that will drive a dominant lake band.
Snowfall rates in this zone (Muskegon to Grand Rapids to Eaton
Rapids to Battle Creek to South Haven) will approach and exceed an
inch an hour at times. Suffice it to say given the snow, wind and
powdery nature of the snow travel will be life threatening much
of the time. Keep in mind salt loses much of its effectiveness as
temperatures fall towards 10 degrees.
&&
.DISCUSSION...(This evening through next Thursday)
Issued at 346 PM EST Thu Dec 22 2022
-- Blizzard Conditions Friday / Snow showers into Sunday
- 4 pm Thursday till 1 am Friday
We have been writing about this event for over a week now. The
bottom line is nothing much has changed in terms of the actual
forecast through the weekend. We have the snow from the warm
advection part of the system moving through the area from now
until late this evening. Since the 1000/850 moisture transport
vectors are aimed at eastern part of lower Michigan with this
event (late afternoon into early evening), it is that part of the
state that will likely have the greatest snowfall from this part
of the event. Based on HREF, NAMNEST, HRRR, RAP and just simple I
have been forecasting for 46 years, I am thinking 3 to 6 inches
from this part of the storm. This part of the system should
largely be done by early Friday morning.
- 1 am till 7 am Friday
The second part of the system will be the dangerous part of the
system for us. This is when the arctic air surges in we are
expecting an 5 to 10 degree temperature drop in one hour. This has
happened upstream, MKE fell from 28F to 19F in one hour (for
example). This is when the lake effect snow kicks in. So, there
may be a break in the snow near and east of US-131 after midnight
as a result of that. However for areas west of US-131 the snow
showers should follow the front quickly. In fact the area between
Holland and South Haven get into a strong convergence band after 1
am. This band will be aimed toward Kalamazoo. So in the period
between 1 am and 7 am, there could be another 2 to 4 inches in
that area. Here is the glitch through, this is behind the arctic
front, so winds will be kicking up with this part of the event. So
south of a line from Muskegon to Grand Rapids to Battle Creek
between 1 am an 7 am, there may already be near blizzard to
blizzard conditions in that area. Outside of that I would expect
mostly and inch of less after midnight.
- 7 am Friday through 7 pm Saturday
The boundary layer wind turns more westerly by mid morning Friday.
Inversion heights rise from around 5000 ft at sunrise to near 7000
by midday. The DGZ is nearly on the ground and there is strong
lift in the cloud bearing layer. There is also the I-94 and I-96
convergence bands wiggling around some but not much through this
time period. Winds in between 1000 ft and 5000 ft will be in the
40 to 50 knot range from the west. Air temperatures will be near
10F. All of this leads to mostly small be densely falling
snowflakes on very strong winds. Hence a blizzard (3 hours or more
with visibilities near or under 1/4 mile and frequent wind gusts
to 35 mph our more). This will lead to two bands of heaver snow
accumulations, one near I-94 and one near I-96. As for where the
heaviest snowfall will be remember we have 40 to 50 knot winds in
the cloud bearing layer. During the event in mid November we had
20 to 30 knot winds in the cloud bearing layer, that resulted in
the heaviest snowfall near US-131. With winds 10 to 20 knots
stronger, I would have to believe the heaviest snow will be EAST
of US-131. Seems a good 6 to 12 inches could fall during this time
in the heaver snow bands.
Outside this area we will have snow showers but not all that
heavy. There will still be winds gusting to 40 to 50 mph and
temperatures near 10F. So wind chill values will be near -10F most
of the time from mid morning Friday into the day on Saturday.
So I do not believe that area will have real blizzard conditions
but being outside for any lenght of time will still be dangerous.
That is why to keep the Winter Storm Warning.
One large scale through on all of this, we have a 170 knot polar
jet core crossing a baroclinic zone with a strong shortwave today.
That happens well south of us. This does lead to a surface wave on
the cold front that runs into very difluent winds aloft over
southeastern Canada (Ontario and Quebec) tonight into Friday.
This causes rapid deepening of the surface low. It is that
deepening of the surface low with an upstream 1050+ mb high that
leads to the strong winds Friday into Saturday.
- Warm up and melting snow follow for mid to late next week
While all this is happening we have one of those 170 to 180 knot
east Asia jet features crossing the mid Pacific by early next
week. That will do what it always does, create a deep trough over
the western CONUS and large upstream ridge over the eastern CONUS.
That means by mid week we get booted out of the cold air and go
back into warm air. This is one more system that takes southeast
from MN to KT early next week. Currently we expect that to miss us
to the south Mon/Tue but if it shifts a touch north we could see
a little light snow from that Mon/Tue.
The ridge building gives milder by dry weather mid week, but
toward the weekend (New Years) we get that western trough to move
east into the central CONUS. That will kick out a series of
southern stream system so we likely will see rain from that or
rain to snow if one of those systems can pull down Just enough
cold air as it scoots by us. We will have to watch how this plays
out for possible ice jams etc..
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 739 PM EST Thu Dec 22 2022
The synoptic (system) snow is moving through Southwest Lower
Michigan at this time (00z). The arctic front that is driving much
of this snow is situated just east of GRR (frontal passage
occurred right at 00z) and just to the west of AZO at this time.
The system related snow will continue off to the east with the
front so a tapering of the snow as was expected this evening
is on schedule. Flake size will get smaller tonight as the Arctic
air pours in and winds increase out of the west and northwest.
Lake effect snow will begin this evening and become more steady
state towards and especially after midnight. Non stop lake effect
snow is then expected through Saturday night. Bottom
line...system snow is shifting east...slight lull in the snow in
the late evening hours...then lake effect snow ramps up after
midnight.
What this means for aviation is a continuation of very poor
conditions for the next 24 hours. Widespread IFR and LIFR are in
place at 00z and this will not change much as the system snow is
replaced by lake effect snow and blowing snow (as the wind
increases). Visibilities as we head into the day on Friday will
frequently be at or below one mile. KMKG, KGRR and KAZO will see
the worst of the conditions with visibilities at 1/4 and 1/2 a
mile. Winds from the west and northwest tonight and Friday will be
increasing into the 20-30 knot range with gusts towards and above
40 knots. Whiteout conditions are expected at times at all of our
TAF sites late tonight and especially in the daylight hours of
Friday. Given the magnitude of the winds from a westerly
direction, north/south runways will likely drift shut Friday.
&&
.MARINE...
Issued at 346 PM EST Thu Dec 22 2022
Given the rapidly deepening storm that heads into central Ontario
and becomes a 970 mb low while we have a 1055 mb high to our west,
it surly makes sense to have STORM WARNING in our Near Shore. We
have a gale warning in front of it to allow a time for winds to
ramp up. Also we have a freezing spray warning since winds of 40
knots and temperatures in the teens will lead to rapid ice buildup
on any ships on Lake Michigan.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Blizzard Warning until 7 PM EST Saturday for MIZ037-038-043-044-
050-056-057-064-065-071-072.
Winter Storm Warning until 1 AM EST Saturday for MIZ039-040-045-
046-051-052-058-059-066-067-073-074.
LM...Heavy Freezing Spray Warning until 7 PM EST Saturday for
LMZ844>849.
Storm Warning until 1 PM EST Saturday for LMZ844>849.
&&
$$
UPDATE...Duke
DISCUSSION...WDM
AVIATION...Duke
MARINE...WDM
Area Forecast Discussion
National Weather Service Gray ME
1035 PM EST Thu Dec 22 2022
.SYNOPSIS...
A large low pressure system impacts New England tonight through
Friday night. This system will bring wintry precipitation at
first, and then heavy rain, possible flooding, strong winds, and
significant coastal impacts as we enter a period of high
astronomical tides. Drier and breezy conditions are expected
over the holiday weekend as high pressure builds towards the
region.
&&
.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
725 PM Update... Little change to the forecast right now,
except to load in latest temperatures which are a couple degrees
cooler than previously advertised. This has little bearing on
the going forecast logic.
Previously...
Peaceful evening in store with high impact storm on the
doorstep. Make final preparations this evening!
Cirrus continues to flood into northern New England this
afternoon as this system comes together across the Ohio Valley.
Low level stratus has become thicker across much of the interior
over the past few hours. Expect this trend to continue,
particularly across southern NH as precip is quickly filling in
through eastern NY state.
Precip overspreads mainly approaching midnight. This will likely
be in the form of snow or some patchy freezing drizzle. Low
levels have visibility been saturating (clouds mentioned above)
and now to start precip off, just need that deeper moisture.
Winds remain light and variable through midnight, but will trend
SE afterwards.
&&
.SHORT TERM /MIDNIGHT TONIGHT THROUGH FRIDAY NIGHT/...
1035 PM Update... Refreshed temperature trends through the
overnight and morning hours with latest hires guidance, namely
the HRRR which seems to be handling current observed trends well
with wet-bulb processes cooling surface temperatures through the
southern half of the area. Which this in mind, re-ran the
weather/accumulation forecast with a wet-bulb adjustment for
snowfall which resulted in higher totals by a couple inches
through the mountains. It also resulted in light accumulations
through the foothills and toward the coastal plain; but these
shouldn`t be of much consequence. Another adjustment made was to
the wind gust forecast Friday evening with steep lapse rates
through the mid-levels tapping into a strong southwesterly jet.
This prolongs damaging wind threat, but fits well within the
existing High Wind Warning.
Previously...
A high impact storm blasts through northern New England Friday.
Primary change was accentuating a period of strong, damaging
winds NW of the Whites and western ME mountains. Some temp
trends also brought in the chance of more wet snow accumulation
to the north where a Winter Weather Advisory has been issued.
- Winds: Increasing pres gradient along a lifting jet will
arrive late tonight. This will stream over the Whites and be
swept to lower elevations NW of the mountains. Have pushed
some gusts to 70 mph here, as well as increased winds/gusts at
the higher summits of the White mountains where upwards of 150
mph will be possible through at least the early morning hours.
The other wind max will fall along the ME coast. This is where
onshore flow will slowly track north through the day. GEFS
wind probs of > 50 kt gusts do increase as the jet lifts
north, and there is a possibility stronger winds do penetrate
further inland across the ME capitol region into some of the
central foothills. Still, think the chance of 70 kt gusts here
is maximized at some of the elevated ocean platforms or along
the Midcoast. Local guidance also has a wide spread of peak
wind gusts for Rockland.
- Coastal Flooding: See Tides/Coastal Flooding section. Of
discussion today was the freshwater runoff factor for
locations that will be susceptible to moderate/major coastal
flooding. Once site in particular is Portland where heavy rain
will have been underway prior to the rising high tide Fri AM.
Additional runoff from some of the hilly urban environment
will be slow to drain due to elevated tides/surge. Thus, some
calculated surge impacts may be enhanced due to heavy runoff.
- Winter Weather: A chilly day today, and increasing clouds
through the day will help lock in some cold air tonight. This
should set the stage for a bulk of the area to begin as snow
late tonight. The exception may be the southern ME coast and
southern NH. Snowfall rates increase into the foothills and
mountains through Fri morning, with a transition to rain
expected towards noontime through Jackman. Snow ratios will
again be low with warm temps and obliterating dendrites amid
the high winds incoming. So, wet snow accumulation will again
be possible for the Winter Weather Advisory area. In addition,
a brief period of freezing drizzle will be possible through
the early morning hours in the foothills and parts of the
interior, but should transition to rain quickly.
- Heavy Rainfall: Not much change in QPF forecast at this time.
Although some high res guidance and HREF forecasts are
indicative of some enhanced rainfall rates Friday morning.
Would expect some flash flooding concerns, especially where
previous hard snowpack has covered drains or created channels
where rain can initially pool. Rain tapers quickly late in the
afternoon, with a change back to snow showers...but
accumulations here are not expected.
- Flash Freeze: Still on the table for Friday night. With such a
short period of warm temps...this should be enough to soften
top of snowpack, add more snow/rain content, and then quickly
refreeze overnight. This will create the potential for some
loading issues as well as freezing areas of standing water.
Any damp surfaces that are not dried out by brisk SW winds
will be slick come Saturday morning.
- River Flooding: See Hydrology section.
Breezy conditions continue Friday night, but the highest should
be behind us. Will continue to watch some hires solutions
depict showers/squalls Fri evening before winds start a very
slow decrease through the weekend. It will be quite different to
have cooler temps arriving from the SW.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Overview: Deep trof and below normal temps will be the rule for much
of the week before the pattern flips back to warmer than normal very
late in the period. Below normal precip expected as well.
Impacts: Besides the colder weather there are no significant weather
impacts anticipated in the extended.
Forecast Details: With very active weather in the short term the
extended is primarily using the NBM. Trof will dominate the pattern
with cold and dry offshore flow prevailing for much of the period.
Some mtn snow showers are likely...but widespread precip threat
looks low. By the middle of next week a strong Pacific jet stream
will flood much of the CONUS with warmer than normal temps and that
will eventually work its way into the local area beyond the forecast
range. The next coherent signal for widespread precip will be early
in the new year.
&&
.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
Short Term...Trending MVFR this evening, becoming IFR tonight
through Friday. LIFR will be possible in BR/+RA/SHSN. Very gusty
winds, up to around 50 kts, will be possible at coastal TAF
sites and towards KHIE where locally strong downslope winds will
impact. Expect LLWS through Friday morning and afternoon for all
sites. Winds shift SW overnight Friday, slowly decreasing.
Long Term...Widespread VFR conditions expected. Surface wind gusts
near 25 kt for all terminals both Sat and Sun afternoons.
&&
.MARINE...
Short Term...SE winds build towards Storm force tonight as a
large storm arrives from the south. Winds shift S Friday
evening, and then SW overnight...slowly slackening to Gale
force. Seas will also quickly increase towards 20 ft tonight
through Friday, remaining around 15 ft through Fri night.
Long Term...Strong SCA conditions expected to be ongoing with
potentially gale force gusts near 25 nm from shore. Those winds will
linger into Sun night before gradually diminishing. An end to the
SCA conditions looks likely by Mon night.
&&
.HYDROLOGY...
Confidence continues to grow for widespread flooding Friday
into early Saturday with significant impacts to travel. Moderate
to heavy rainfall (1 - 3") along with snowmelt will lead to the
potential for flash, urban, and small stream flooding impacts,
as well as scattered minor and isolated moderate river flooding.
There are a few adjustments to the latest forecast that could
help limit the runoff and subsequent magnitude of flood impacts.
First is the faster storm movement which reduces the melting
window from 12 hrs to 6-9hrs, and secondly is the amount of snow
at the onset of the event. Despite these favorable trends, the
region will still experience widespread flooding from the
moderate to heavy rainfall over frozen ground. The area snowpack
will work to both dampen and exasperate the area flooding in
the course of this event.
South of the foothills to the coast the SWE is 0.5-1.5”. Here
the snowpack is likely to ripen, and for the immediate coast we
can expect a nearly complete melt out. At the coast runoff will
be slowed by rising tides with peak rainfall rates forecast to
simultaneously occur with high tide. Poor drainage flooding is
expected at the usual coastal hot spots.
From the foothills northward the SWE is 2-4”. This deeper and
colder snowpack has a lower density and is not expected to ripen
and melt out in this event. On the contrary, much of the
rainfall will be held in the snowpack where it will be slowly
released into the waterways. There will still be sufficient
runoff for flooding in the mountain areas due to the rapid
runoff in the hills and the small storage capacity of the
streams and creeks.
&&
.TIDES/COASTAL FLOODING...
Storm surge guidance continues its trend with the rapid onset
of storm force winds late tonight and Friday morning. ESTOFS
continues to be the most conservative storm surge guidance
available however even this model brings Portland to 13.8 feet
at high tide Friday morning. Other guidance is even higher such
as the Snap-X and ETSS solutions topping at around 14.1 feet in
Portland which would be one of the highest tides of all time.
There is some uncertainty with this forecast as there has been
large changes with guidance in a short period of time as the
core of the strongest winds appears to be advancing slightly
faster than progged a couple days ago.
In any case, moderate coastal flooding can be expected with
pockets of major flooding possible. Have continued a Coastal
Flood Warning for the entire coastline of western Maine and the
Seacoast of New Hampshire. Ran this product through the early
afternoon hours as the storm force southeasterly winds will be
slow to allow the tide out during the midday hours Friday.
Communities that have a southeast exposure such as Hampton, New
Hampshire may be particularly hard hit with the potential for up
the three feet of water in some locations.
Large, battering waves will continue to impact the region
through Friday night and potentially into Saturday.
All-time storm tide records for Portland, Maine all in MLLW
(1912-Present).
#1. 14.17` set on 2/7/1978 (Blizzard of `78)
#2. 13.98` set on 1/9/1978
#3. 13.79` set on 1/4/2018
#4. 13.40` set on 1/4/1990
#5. 13.31` set on 3/16/1976
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Winter Weather Advisory until noon EST Friday for MEZ007>009.
High Wind Warning until 2 AM EST Saturday for MEZ007>009-014-
018>028.
Flood Watch from 7 AM EST Friday through Saturday morning for
MEZ007>009-012>014-018>028-033.
Wind Advisory until 2 AM EST Saturday for MEZ012-013-033.
Coastal Flood Warning from 7 AM to 2 PM EST Friday for
MEZ023>028.
NH...Winter Weather Advisory until noon EST Friday for NHZ001>003.
High Wind Warning until 2 AM EST Saturday for NHZ001>003-010-
013-014.
Flood Watch from 7 AM EST Friday through Saturday morning for
NHZ002>015.
Wind Advisory until 2 AM EST Saturday for NHZ004>009-011-012-
015.
Coastal Flood Warning from 7 AM to 2 PM EST Friday for NHZ014.
MARINE...Storm Warning from 4 AM Friday to 3 AM EST Saturday for
ANZ150>154.
&&
$$
UPDATE...Casey
NEAR/SHORT TERM...Cornwell
LONG TERM...Legro
HYDROLOGY...Jamison
TIDES/COASTAL FLOODING...Cannon
Area Forecast Discussion
National Weather Service Houston/Galveston TX
537 PM CST Thu Dec 22 2022
...New AVIATION...
.SHORT TERM...
(This evening through Friday Night)
Issued at 308 PM CST Thu Dec 22 2022
The Arctic cold front has just passed Houston metro area this
afternoon. Temperatures have already fall below freezing across our
northernmost counties with strong winds of around 20-25 mph and
gusts upwards of 30-40 mph, warranting a wind advisory across our
area. Strong CAA and clear skies should bring lows in the teens for
all of SE Texas and lower 20s along the immediate coast. Frigid
temperatures and strong winds should put minimum wind chill indicies
near or below zero overnight/early Friday morning. Therefore, all of
SE Texas will be under Wind Chill Warning from 6 PM today until noon
Friday.
HRRR continues to out perform other guidance, such as the NBM, when
it comes to handling the FROPA. Therefore, I have opted to lean
closer towards that solution and other high resolution guidance
heading into Friday. With that being said, much of SE Texas, outside
of the immediate coastline, will likely stay below freezing all day
tomorrow. HREF probabilities further confirm this suspicion,
depicting a firm 80% probability of sub freezing conditions for
areas along and north of I-10 during peak solar heating. This means
that many locations across the region may remain below freezing for
36 hours or more. Therefore, a Hard Freeze warning will be in effect
from 6 PM today through noon on Saturday.
These frigid conditions may result in hypothermia or frostbite if
precautions are not taken. Avoid outdoor activities and dress
appropriately for the weather. Frost and freeze conditions will kill
sensitive plant life, so take steps now to protect them while you
still can. Water pipes should be wrapped, drained, or allowed to
drop slowly to prevent freezing and possible bursting.
03
&&
.LONG TERM...
(Saturday through next Wednesday)
Issued at 308 PM CST Thu Dec 22 2022
Did not make a lot of changes from the previous package with the
cold arctic air mass in place across SE TX on Sat. Despite weak-
ening CAA (as the surface high slowly drifts east), highs on Sat
will be in the mid and upper 30s for most of the CWA...around 40
closer to the coast. The light to moderate north winds will keep
wind chills in the teens in the morning and in the 30s to 40s in
the afternoon. With mostly clear skies (and light north winds) a
return of sub-freezing temperatures is expected the night of the
25th (Christmas night). Overnight lows will dip into the low/mid
20s. Hard Freeze Warnings will likely be issued during this time-
frame. Highs for Christmas day could climb into the mid to upper
40s with wind chills in the upper 30s (so, progress!).
A weak cold front late Mon will just help to reinforce this cold
dry air mass for Mon night with lows back to freezing and/or sub-
freezing for northern parts of the FA. But, with the upper ridge
building over the region and onshore winds returning by Tues, we
should see warmer temperatures through mid week. 41
&&
.AVIATION...
(00Z TAF Issuance)
Issued at 537 PM CST Thu Dec 22 2022
With the strong cold front now off the coast, the area will be seeing
decreasing clouds this evening while N to NW winds remain strong and
gusty on through the overnight hours. TAF sites have possible MVFR
ceilings for a couple more hours (maybe until around 03Z) followed by
SCT250 or SKC for the remainder of the 23/00Z TAFs. Gusty N to NW winds
(around 22ish with gusts to around 30 inland and around 30ish with gusts
around 40 or higher at the coast) can be expected with a gradual decrease
as the day progresses tomorrow.
42
&&
.MARINE...
Issued at 308 PM CST Thu Dec 22 2022
With the cold front finally off the coast, strong north to north-
west winds will be strengthening this evening and tonight. A Gale
Warning remains in place for our bays and Gulf waters through 3PM
tomorrow afternoon. (The expiration time was extended earlier to-
day to match neighboring offices.) Gusts up to 50kt are expected.
Elevated seas with wave heights from 7-14ft, occasional seas near
17ft will be possible over the offshore waters late tonight. This
period of strong offshore winds overnight could also produce some
extreme low water levels across the bays by tomorrow(Fri) morning.
A Low Water Advisory remains possible. These gale-force winds are
forecast to gradually weaken by tomorrow afternoon; but, Advisory
conditions could remain in place (mainly over the coastal waters)
through late Sat. Light to moderate onshore winds could return by
next Tues. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 13 27 18 37 / 0 0 0 0
Houston (IAH) 15 29 20 39 / 0 0 0 0
Galveston (GLS) 23 34 26 41 / 0 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Wind Advisory until midnight CST tonight for TXZ163-164-176>179-
195>200-210>214-226-227-235>238-300-313.
Hard Freeze Warning until noon CST Saturday for TXZ163-164-
176>179-195>200-210>214-226-227-235>238-300-313-335>338-
436>439.
Wind Chill Warning until noon CST Friday for TXZ163-164-176>179-
195>200-210>214-226-227-235>238-300-313-335>338-436-438-439.
Wind Advisory until noon CST Friday for TXZ335>338-436>439.
GM...Gale Warning until 3 PM CST Friday for GMZ330-335-350-355-370-
375.
&&
$$
SHORT TERM...03
LONG TERM....41
MARINE...41
Area Forecast Discussion
National Weather Service Lincoln IL
819 PM CST Thu Dec 22 2022
.SYNOPSIS...
Issued at 819 PM CST Thu Dec 22 2022
Dangerously cold weather will prevail across central Illinois tonight
into Friday...with wind-chill values hovering in the twenty five
to thirty five below zero range. In addition, the strong northwesterly
winds will create considerable drifting snow...especially across
rural roadways.
&&
.UPDATE...
Issued at 819 PM CST Thu Dec 22 2022
Snow has ended across the western KILX CWA this evening...with
02z/8pm radar imagery showing the back edge of the steady light
snow along a Pontiac to Taylorville line. Based on radar trends as
well as the latest HRRR guidance, it appears light snow will end
across east-central Illinois around midnight. Total snow
accumulations will be 1-3 inches across the area. Even though the
accumulating snowfall is about over, will be maintaining the
current Winter Storm Warning through the night due to drifting
snow and bitterly cold wind chills of 25 to 35 below zero. The
warning will likely be transitioned to a Wind Chill Warning
extending through Saturday morning with the next forecast package
in the morning.
&&
.SHORT TERM...(This evening through Friday)
ISSUED AT 315 PM CST Thu Dec 22 2022
A powerful cold front has swept across central Illinois with light
to at times moderate snow continuing across central Illinois.
Despite relatively light snow amounts, strong winds will result in
blowing and drifting, particularly in open/rural locations.
Expect widespread visibilities reduced to half to three quarters
of a mile and isolated whiteout condition. Expect whiteout
conditions to increase in coverage across the region this evening
and tonight as winds continue to pick up. Gusts will increase into
the 40 to 45 mph range this evening and overnight. As winds
increase and temps fall to between 5 and 10 below zero overnight,
wind chill values will dip to between 30 and 40 below.
Meanwhile, snowfall has likely peaked across the area within a
band of strong 850mb fgen. Latest RAP indicates this fgen band
will continue to shift east through the rest of the afternoon
entering Indiana early this evening, but weakening with eastward
extent. A second band of frontogenetical forcing currently over
Missouri will spread east this evening clipping our southern
forecast area south of I-70. Widespread accumulating snow should
end altogether across central Illinois by around midnight tonight.
By this time, expect most of central Illinois will have seen 2 to
3 inches of snow, though this may be hard to measure due to the
blowing. Some flurries will remain possible overnight as low level
cyclonic flow lingers over the region. Any falling snow, even if
just light flurries, could compound visibility issues from
blowing snow.
Friday will continue to experience very strong wind gusts peaking
between 40 and 50 mph much of the day. Blowing and drifting will
likely continue and remains the basis for the continued Winter
Storm Warning (in addition to the dangerously cold temps). It`s
important to note that conditions in town will likely be much
improved compared to open/rural areas including major instates
such as I-55 and I-57 which are perpendicular to the wind
direction. Flurries will also be possible through the day,
especially late afternoon into the evening. Accumulations will be
unlikely but any falling snow will compound visibility issues.
Friday night will remain gusty but should see a gradual
diminishing trend. Wind chill values are expected to bottom out 20
to 30 below.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 315 PM CST Thu Dec 22 2022
This weekend, a strong and expansive high will be in place across
the Great Plains while low pressure lifts north across Quebec.
Low level cyclonic flow will linger over portions of the Midwest
Saturday behind the departing low and a few additional flurries
will be possible as a result. Forecast soundings continue to show
strong winds within the well mixed boundary layer and gusts into
the 20 to 30 mph range remain possible through the afternoon. Any
flurries that do fall may contribute to lower visibility due to
blowing snow. Through the day Sunday, the ridge axis will spread
across the lower and mid Mississippi River Valley and then along
the Ohio River Valley. Winds will finally drop off as the ridge
axis moves across central Illinois and some breaks in the cloud
cover are possible. Temps will continue to run well below normal
through the weekend with highs in the single digits and teens each
day, Sunday being the warmer day by 2-4 degrees.
Guidance is starting to come into better agreement with a clipper
system impacting portions of the region late Sunday night through
Monday. QPF amounts look fairly light with this quick moving
system and there remains enough model spread that ensemble
guidance is a bit broad brushed. Still, NBM 90th percentile shows
potential for a couple inches of snow and expect the signal for
accumulations to increase as guidance locks onto a solution over
the next few days.
Another high will move across the region Tuesday with southwest
flow setting up as the high moves to the Atlantic Coast midweek.
Temperatures will turn warmer in response with widespread 40s
back in the forecast Wednesday and Thursday and a few sites may
tag 50s Thursday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 542 PM CST Thu Dec 22 2022
Back edge of the steady light snow has reached I-55 as of
2330z/530pm...with radar timing tools indicating an end to the
falling snow as far east as KCMI between 01z and 02z. Strong/gusty
northwesterly winds will continue through the remainder of the 00z
TAF period. Gusts will generally be in the 25-30kt range tonight,
then will increase to 30-40kt by Friday morning as low pressure
rapidly deepens over the eastern Great Lakes. This will blow the
light snow cover around quite efficiently, resulting in occasional
reduced visbys. With only 1-3 inches of snow on the ground,
limited the visby reductions to 5-6 miles. MVFR ceilings will
persist through Friday afternoon.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 6 AM CST Saturday for ILZ027>031-
036>038-040>057-061>063-066>068-071>073.
&&
$$
UPDATE...Barnes
SYNOPSIS...Barnes
SHORT TERM...Deubelbeiss
LONG TERM...Deubelbeiss
AVIATION...Barnes
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
954 PM EST Thu Dec 22 2022
.UPDATE...
Issued at 954 PM EST THU DEC 22 2022
The arctic air continues to push east this evening. The cold
front is pushing toward our western counties this hour and perhaps
a pre-frontal trough is noted with the precipitation moves east
ahead of the front. The temperature drop behind the front is still
lagging some and closer to the 925mb front. That said, we are in
the 40s in eastern Kentucky and western Kentucky is already in the
single digits. Did make some minor adjustments to bring in rain a
little quicker given the pre-frontal trough. Outside this only
minor edits were made to timing and temperatures as this seem to
be on track. Will send these updates out and continue to monitor
this unfolding winter storm.
UPDATE Issued at 740 PM EST THU DEC 22 2022
We are watching the arctic air filter into the western part of
the state this evening. The main surface boundary is coming
through central Kentucky right now and arctic air filters in with
the lagging 925mb front noted in the SPC mesoanalysis. The
guidance is in decent agreement on timing of the cold air and has
it in our western counties by around 10 to 11 PM and pushing east
through the night. The differences that remain are just how cold
we get and this has been lower in general from yesterdays forecast.
Still seems like the HRRR and RAP are the colder outliers at this
point. Either way we are talking about negative air temperatures
and wind chills in the -20 to -30 range by early Friday morning.
Overall the pace of this system and what we have in the grids are
verifying well at this point. Main concern will be if we see
colder temperatures sooner and how that would affect our snowfall
totals. However, seems like there would be some tapering of the
better moisture as it moves east leaving some uncertainty. This
will have to be monitored through the evening shift for any
possible need for upgrades.
&&
.SHORT TERM...(This evening through Friday night)
Issued at 524 PM EST THU DEC 22 2022
Late this afternoon an arctic cold front extended from MI south
through western KY and on to the lower Mississippi Valley. A wave
was traveling north along the front through IN. Ahead of the
front, our temperatures were mostly in the upper 40s and lower
50s. The front and developing low were supported by an anomalously
deep upper low dropping southeast from the north central CONUS.
The surface low will explosively deepen as it wraps under the
upper low tonight and Friday. The cold front will be propelled
eastward through the forecast area tonight, and with the upper
level support of the trough, bring precipitation. It will start
out as rain, but quickly change to snow after the frontal passage.
The snow may briefly come down heavy, especially if there are some
elevated convective elements. The intense low pressure system will
bring brisk winds, with gusts of 30-40 mph overnight into Friday.
This will carry in the arctic air, with temperatures plummeting
about 50 degrees, and much of this in drop occurring in just a
couple of hours after fropa. The resulting wind chills will be
dangerously cold, bottoming out at 25-35 below zero in most places
on Friday morning.
Flurries will continue at times on Friday and Friday night, but
the cold will continue to be the main story. By the end of Friday
night, the intense stacked low will still reside just north of the
Great Lakes, and its circulation dominating most of the eastern
half of North America. Temperatures will probably not warm out of
the single digits on Friday, and fall to near zero on Friday
night. Winds will ease a little, but still be strong enough to
make wind chill a concern going into the weekend. Even though the
Wind Chill Warning may be allow to expire on Friday, a Wind Chill
Advisory will likely need to be extended into the weekend.
.LONG TERM...(Saturday through Thursday)
Issued at 320 PM EST THU DEC 22 2022
Key Concerns:
1. Bitterly cold temperatures persist throughout Christmas weekend.
2. Nighttime lows in the single digits above and below zero for most
locations through Sunday night.
3. Wind chills of -10 to -20F (locally colder higher elevations) on
Saturday morning.
4. Generally dry weather persists for the remainder of the week.
5. Temperatures moderate back to above normal levels by New Year`s
weekend.
The 22/12z model suite analysis shows an ~495 dam low over Southern
Quebec at the start of period with an associated ~962 mb surface low
reflection. This is counterbalanced by a strong 589 dam high off the
Baja California coast and high amplitude ridging along/west of the
Rockies. A narrow axis of surface high pressure ridging spans the
High Plains of the US and Canada in the zone of subsidence ahead of
the upper level ridge axis.
Through the middle of the new workweek, the upper level pattern will
deamplify with the deep 500H trough/low generally shifting toward
Greenland while the subsiding 500H ridge moves out onto the Plains.
There is NWP support, though varying spatially/temporally from model
to model, for one last shortwave trough to rotate through the region
on Tuesday as the upper low pulls away. Otherwise, look for ridging
to increase over the Eastern CONUS later in the week while the next
seasonably deep upper level trough descends the Rockies. At the
surface, the pressure gradient will gradually weaken on Saturday and
Saturday night as the high pressure to our west and low pressure to
our north weakens. The high pressure shifts east to over the Ohio
Valley by Monday morning. By Tuesday, the upper level shortwave
drops through, but much of energy seems to split north and south
of the Ohio Valley with little fanfare for eastern Kentucky. In
fact, surface high pressure generally appears to remain over the
Ohio Valley Tuesday before gradually shifting east to the Atlantic
Seaboard on Wednesday through Friday. This will lead to a
pleasantly moderating southerly return flow for the remainder of
the week and year.
Sensible weather will feature bitterly cold temperatures and wind
chills lingering through the weekend. With 925 mb temperatures
moderating to between -12 and -16C, expect highs in the 15 to 20
degree range on Saturday. Lingering low cloudiness may yield a
few flurries through the day. Westerly wind gusts of 20 to 30 mph
continue through the day. The coldest wind chills in the long-term
period will be Saturday morning when they will flirt with 10 to
20 below zero at many locations. Saturday night lows will again be
in the single digits, though if significant clearing occurs,
sheltered valleys with snow cover could easily decouple and sink
below 0F. Wind will be much lighter on Sunday with increasing
sunshine and temperatures moderating into the upper teens north
to mid 20s south. Looking ahead to the new work week, ample
sunshine each day will be filtered by clouds at times.
Temperatures continue to moderate several degrees each day with
highs in the mid 20s to lower 30s on Monday, in the 30s (above
freezing) for most on Tuesday, in the 40s on Wednesday and rising
above 50 for most on Thursday. Nighttime lows will feature the
typical ridge-valley split on every night. It will still be cold
on Sunday night/Monday morning with upper single digits to lower
teens on the ridges while the valleys sink back into the single
digits to near 0F. That nocturnal ridge-valley temperature split
likely carries through the remainder of the period with teens to
lows 20s on Monday night, mid teens to mid 20s on Tuesday night
and low 20 to low 30s on Wednesday night.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
ISSUED AT 658 PM EST THU DEC 22 2022
We are starting the TAF period with the mix of VFR and MVFR. A
cold front continues to charge across the state this evening and
will bring conditions down through the night. We will see rain
showers initially with the surface front before quickly
transitioning to snow by around 4Z at SME and cold air quickly
moves east to transition to snow at SJS by around 7Z. Shortly
after the transition we will see the potential for a period of
heavy snow with LIFR conditions becoming probable at 90 to 100
percent chance based on the HREF during this time and probably in
the VLIFR range with probability of less than a half mile
visibility at 70 to 90 percent. The other issue will be strong
winds of 15 to 20 knots sustained and 30 to 35 knot gusts shifting
from south to west with the passage of the front. These snow
showers will then transition to flurries by Friday morning.
Overall after this, MVFR conditions will probably remain the
story and the winds remain elevated into the day Friday, with the
potential for continued blowing snow that could affect
visibilities at times.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 9 AM EST Friday for KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
Wind Chill Warning from 1 AM to 4 PM EST Friday for KYZ044-
050>052-058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...DJ
SHORT TERM...HAL
LONG TERM...GEERTSON
AVIATION...DJ
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
526 PM CST Thu Dec 22 2022
.UPDATE...
Issued at 517 PM CST Thu Dec 22 2022
Updated for 00Z aviation discussion below.
&&
.DISCUSSION...(This evening through Thursday)
Issued at 221 PM CST Thu Dec 22 2022
KEY MESSAGES:
- Life threatening conditions will arrive with increasing winds,
decreasing wind chills, and significantly reduced visibility
overnight. Stranded travelers could be susceptible to hypothermia
and frostbite within minutes.
- The worst conditions are expected Friday afternoon through Saturday
morning, with gusts peaking at 45-50mph. Please do not travel.
- A clipper system will bring light snow Sunday night into Monday
morning, causing slick conditions for the Monday morning commute.
- A pattern shift will warm temperatures significantly next week,
with highs by Wednesday in the low to mid 30s.
TONIGHT THROUGH SATURDAY MORNING...
Compared to the overnight forecast, there have been a few changes
but the overall weather picture has remained the same, in that unless
absolutely necessary we do not advise traveling anywhere tomorrow
through early Saturday. Conditions today have been proceeding as
expected, with areas of western and southern Minnesota having been at
or below 1 mile visibility for several hours already, with the
stronger winds making their way eastwards. The gusts will start to
pick up overnight especially, with the daylight hours tomorrow likely
being the worst of the conditions for much of the area.
Forecast soundings from CAMs have led to a small bump up in wind
speeds and gusts expected tomorrow and Saturday, which despite an
increase of only around 5mph has led to the Blizzard Warning being
expanded to include the counties within and around the I-94 corridor
in western Wisconsin. Momentum transfer winds of around 45-50kts are
present at the top of the channel within RAP soundings with the HRRR
only slightly lower, and while we likely won`t mix efficiently due to
the blowing snow inhibiting diurnal mixing and some mid level
clouds, we will still have plenty of wind to kick up the fresh snow.
The stronger winds have also led to a slight decrease in the coldest
wind chills, however this has not affected headline decisions as all
of the area was already in either wind chill warnings or advisories.
Conditions will slowly begin to improve on Saturday, but it will
likely be during the day on Sunday before we truly see the end of the
blowing snow concerns as winds above 15-20mph will be present through
at least Noon on Christmas Day. As we have been saying numerous times
throughout the last few days, this event has life threatening
implications should you choose to travel and end up getting stranded
due to both the difficulty of rescue operations and the dangerous
wind chills that could result in frostbite within less than 10
minutes. Even in areas that are not within a Blizzard Warning, they
are still going to be covered by a Winter Storm Warning, so do not
let your guard down at all during the day tomorrow no matter where
you are located.
SUNDAY THROUGH NEXT WEEK...
Christmas Day will see rapid improvement, especially during the
second half of the day, as winds decrease below 10mph with high
pressure beginning to more directly overhead. This will result in one
more cold morning with below zero low temperatures, however with much
weaker winds, our wind chills will only be in the teens below zero.
Another clipper system is looking probable late Sunday through early
Monday which could bring a hit of light snow for much of the area,
currently favoring western and southern Minnesota as the clipper
dives southeastwards. We could end up with a couple of inches of
light snow for the area, however at this point that just adds another
small amount to our currently generous snowpack.
Our pattern is going to shift significantly as
we head into next week, with temperatures slowly increasing such
that highs in the low to mid 30s are possible by Wednesday,
increasing further heading into next weekend. This pattern does look
to persist into the new year, with warmer than normal conditions
favored through the middle of the first week of January. Along with
the warmer temps, there does appear to be another potential system
moving towards the region later next week, and with temperatures
hovering near freezing at times could result in another sloppy event
with multiple precipitation types. For now, we have left that out of
the forecast as there are more immediate concerns than a day 7
freezing rain forecast, however as we get a bit closer expect more
details and discussion revolving around the mixed precipitation
potential.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 517 PM CST Thu Dec 22 2022
Northwest winds will continue to increase overnight, leading to
blowing snow through much of the period. Wind gusts will generally
range from 20-30 kts tonight, increasing to 30-40 kts overnight &
peaking near 40-45 kts during the day tomorrow.
Blowing snow will be a concern through the period, with IFR/MVFR
visibility tonight becoming predominately IFR tomorrow as the winds
increase. Several hours of visibility below 1SM is possible tomorrow,
especially across western and southern Minnesota.
KMSP...High confidence in the wind speeds forecast, but low
confidence on just how low visibility may drop with the blowing snow.
the trend has been towards pushing back the gusty winds & blowing
snow later and later, with MVFR/IFR vis now not expected until late
tonight. Several hours of IFR visibility is likely beginning tomorrow
morning, especially from mid-morning onwards as wind gusts peak up
to 45 kts at times. Visibility lower than 1SM can`t be ruled out if
the blowing snow potential is maximized.
/OUTLOOK FOR KMSP/
Sat...AM MVFR/IFR and BLSN. Wind NW 20G30 kts.
Sun...VFR. Wind SW 5-10 kts.
Mon...VFR. Wind NE 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Wind Chill Warning until noon CST Saturday for Brown-Chippewa-
Douglas-Kandiyohi-Lac Qui Parle-Martin-Pope-Redwood-Renville-
Stevens-Swift-Watonwan-Yellow Medicine.
Blizzard Warning until 6 AM CST Saturday for Carver-Dakota-Douglas-
Goodhue-Rice-Scott-Stearns-Todd-Wright.
Wind Chill Advisory until 6 PM CST this evening for Carver-Rice-
Scott-Stearns-Todd-Wright.
Wind Chill Warning until noon CST Saturday for Blue Earth-Carver-
Faribault-Freeborn-Le Sueur-McLeod-Meeker-Nicollet-Rice-Scott-
Sibley-Stearns-Steele-Todd-Waseca-Wright.
Wind Chill Advisory until noon CST Saturday for Anoka-Benton-
Chisago-Dakota-Goodhue-Hennepin-Isanti-Kanabec-Mille Lacs-
Morrison-Ramsey-Sherburne-Washington.
Winter Storm Warning until 6 AM CST Saturday for Anoka-Benton-
Chisago-Hennepin-Isanti-Kanabec-Mille Lacs-Morrison-Ramsey-
Sherburne-Washington.
Blizzard Warning until 6 AM CST Saturday for Blue Earth-Brown-
Chippewa-Faribault-Freeborn-Kandiyohi-Lac Qui Parle-Le Sueur-
Martin-McLeod-Meeker-Nicollet-Pope-Redwood-Renville-Sibley-
Steele-Stevens-Swift-Waseca-Watonwan-Yellow Medicine.
WI...Wind Chill Advisory until noon CST Saturday for Barron-Chippewa-
Dunn-Eau Claire-Pepin-Pierce-Polk-Rusk-St. Croix.
Winter Storm Warning until 6 AM CST Saturday for Barron-Polk-Rusk.
Winter Storm Warning until 6 AM CST Friday for Chippewa-Dunn-Eau
Claire-Pepin-Pierce-St. Croix.
Blizzard Warning from 6 AM Friday to 6 AM CST Saturday for Chippewa-
Dunn-Eau Claire-Pepin-Pierce-St. Croix.
&&
$$
DISCUSSION...TDH
AVIATION...ETA
Area Forecast Discussion
National Weather Service Springfield MO
613 PM CST Thu Dec 22 2022
Key Messages:
1. A band of moderate to heavy snow east of the Highway 65
corridor will continue to push through the area this afternoon,
reducing visibilities to a quarter mile at times. Patchy blowing
snow likely continues tonight.
2. Flurries/light lake effect snow possible tonight.
3. Historic and dangerously cold wind chills Thursday into
Saturday. Wind Chill Warning in effect areawide tonight into
Saturday morning.
4. Low-end light snow chances Sunday night into Monday with
passage of clipper system.
5. A sharp warming trend will rebound temperatures to near or
above normal early next week.
.SHORT TERM...(This evening through Friday)
Issued at 152 PM CST Thu Dec 22 2022
Radar returns currently show the band of heaviest snow east of
the Highway 65 corridor this afternoon. RAP data continues to
indicate 700 mb frontogenesis coinciding with strong omegas
aligned with this band, so intensity will likely be maintained at
least.
Snow will end from west to east throughout the afternoon. Reports
and observations received thus far show storm total snowfall
amounts of 1-3" areawide. Patchy blowing snow will be possible
intermittently behind the main band of snow this evening into the
overnight hours. The Winter Storm Warning will likely be trimmed
early as the accumulating snow ends.
Lake effect snow will also be possible near the larger lakes of
our CWA. With lake temperatures in the mid 30s, very cold air
above it, and strong unidirectional northwest winds over a
relatively large fetch will result in lake-induced cape values
above 500 J/kg according to Bufkit data. This could produce some
flurries or even snow showers this evening and tonight.
The primary hazard tonight, however, will be the dangerously cold
wind chills. Temperatures will continue to drop this evening in
the single digits below zero. With the persistent strong winds,
wind chills will fall into the -25F to -35F range areawide. The
Wind Chill Warning remains in effect until Saturday morning.
.LONG TERM...(Friday Night through Thursday)
Issued at 152 PM CST Thu Dec 22 2022
Friday - Saturday: Bitter cold temperatures will continue as the
Arctic air mass spreads southward across the central US. Most of
our area will likely see afternoon highs remaining below double
digits on Friday with wind chills around -20 to -30 as northwest
winds persist over the region. On Friday night, winds will gradually
weaken as the surface high settles over the southern Plains. With clear
skies and a snowpack over the area, we could see temperatures fall back
below 0, especially over our western counties.
Slightly warmer temperatures are expected on Saturday, but still
only rising to around 20 degrees and winds continuing to decrease.
Sunday - Monday: Surface winds will gradually shift to the southwest
on Sunday and help warm up the area but still expect highs to remain
below freezing. Upper level northwest flow may bring a clipper system
across the region Sunday night into Monday, which will bring increased
cloud cover and possibly some light snow/flurries.
Tuesday - Thursday: The upper level pattern will gradually shift to more
of a zonal, then southwesterly flow. This should give us a decent warm-up,
with a few locations rising into the 50s to near 60 degrees by Thursday
afternoon. WPC cluster analysis are pretty consistent with the
warming, but inconsistent with respect to timing. So we have
decent confidence on the warm-up, but lower confidence on the
timing.
We will also be watching forecast trends on a developing storm system
that could impact the region late next week and into the weekend. At this
time it looks like more of a thunderstorm/liquid precipitation event.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 552 PM CST Thu Dec 22 2022
With the exception of some flurries or light snow at the
Springfield terminal, due to lake effect snows off of Stockton
Lake, accumulating snow has ended. Ceilings should improve but
visibilities will be impacted by blowing snow with northwesterly
winds gusting from 25 to 40 mph at time. The strong gusty winds
will continue through the night and into Friday.
&&
.CLIMATE...
Issued at 245 AM CST Mon Dec 19 2022
(Vichy-Rolla had missing data in 1989)
***Thursday December 22nd***
Record Low Temperatures
Springfield -15 in 1989
Joplin -15 in 1989
West Plains -13 in 1989
Vichy -5 in 2000
***Friday December 23rd***
Record Low Temperatures
Springfield -16 in 1989
Joplin -15 in 1989
West Plains -12 in 1989
Vichy -4 in 1963
Record Lowest Maximum Temperatures
Springfield 5 in 1983
Joplin 3 in 1983
West Plains 10 in 1989
Vichy 12 in 1990
***Saturday December 24th***
Record Low Temperatures
Springfield -10 in 1983
Joplin -10 in 1983
West Plains -13 in 1989
Vichy -1 in 1990
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...Winter Storm Warning until midnight CST tonight for MOZ055-
066>068-071-077>079-082-083-088>090-094-097-098-106.
Wind Chill Warning until noon CST Saturday for MOZ055>058-
066>071-077>083-088>098-101>106.
KS...Winter Storm Warning until midnight CST tonight for KSZ073-097-
101.
Wind Chill Warning until noon CST Saturday for KSZ073-097-101.
&&
$$
SHORT TERM...Didio
LONG TERM...Terry
AVIATION...Hatch
CLIMATE...Perez