Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/23/20
Area Forecast Discussion
National Weather Service Cheyenne WY
455 PM MST Tue Dec 22 2020
.SHORT TERM...(This evening through Thursday night)
Issued at 230 PM MST Tue Dec 22 2020
Forecast challenges deal with strong winds through Wednesday.
Currently...cold front approaching from the west...currently
located from Cody to Riverton to just east of Evanston this
afternoon at 11AM on surface analysis. Radar showing area of
snow showers just west of Rawlins...moving east. Winds have been
slow to materialize...even in the wind prone areas. Right now in
WYZ 110 (Arlington)...gusts in the upper 40s are being reported
with 850/700mb Craig to Casper height gradients of 48 and 49 mtrs
respectively.
With the slow onset of winds...decided to delay onset of wind
warnings outside the wind prone areas until 5PM this afternoon.
This is when the front begins to push through the CWA and we get
the downward motions behind the front. Also upgraded the watches
we had out and started them at 8PM east of the Laramie Range and
southern Panhandle.
Snow squalls still look good as the front moves into Carbon and
Albany Counties this afternoon. HRRR simulated radar showing
pretty healthy line of snow showers pushing into eastern Carbon
and Albany County towards 00Z. NAM12 Snow Squall Parameter up
around 6-8 at this time as well. So evening shift will need to be
on the outlook for these bands.
Bora wind event behind the front for late tonight into Wednesday
as wind turn northwesterly. GFS showing 50+ knots from 700mbs down
to 850mbs from the Summit all the way into the Panhandle
beginning after 03Z tonight. These strong winds continue through
18Z.
.LONG TERM...(Friday through Tuesday)
Issued at 230 PM MST Tue Dec 22 2020
High pressure continues to dominate the Southeast through the Great
Lakes as a low pressure cell and it`s associated cold front digs
to the southeast. Mostly sunny and windy conditions expected as
we head into the weekend as a ridge of high pressure sets up over
the region, along with work heights indicating the Craig to Casper
gradients greater than 45 meters starting early Saturday and
lasting throughout the day. Next round of weather is expected
Saturday evening as a series of upper level troughs push through
the region, giving the chance for some light snow, primarily east
of LAR and along the Sierra Madres. Next chance for snow for
southeastern Wyoming and the Nebraska Panhandle appears to be next
Tuesday. Current model guidance has an area of low pressure
setting up on the southeastern corner of Colorado, which will
provide decent moisture from the south, wrap around snow, and
upslope flow. Current POPs are around 25 to 47 across the CWA.
However, will need to continually monitoring the tracking of this
system and determine the likelihood of it`s positioning, which
will greatly determine the system impacts across the Rockie
Mountain West through the Great Plains.
&&
.AVIATION...(For the 00Z TAFS through Wednesday afternoon)
Issued at 455 PM MST Tue Dec 22 2020
Strong cold front about to push through KCYS in the next hour. Brief
rainfall has changed to all snow with LIFR conditions for KRWL and
KLAR. Expect LIFR to IFR conditions to be brief this evening and
tonight with mainly a wind event through Wednesday for the high
valleys and eastern high plains into western Nebraska.
HAZARDS/WEATHER TRENDS: Weather trends will be very tricky over the
next 12 hours due to the brief nature of heavy snow showers, with
some additional light snow possible later tonight. For now, kept VFR
conditions prevailing with brief IFR/LIFR VIS due to locally heavy
snow showers through 02z for mainly the Wyoming terminals. Expect
strong winds to be the main threat, with gusts over 50 knots
expected across most terminals beginning shortly and continuing
through Wednesday morning. Winds may diminish a bit for KRWL and
KLAR after 08z, but this should be brief. MVFR CIGS, or lower, will
likely return across the eastern plains overnight.
&&
.FIRE WEATHER...
Issued at 349 AM MST Tue Dec 22 2020
Winds will be strong over the next few days as a strong cold front
passes through the region today, finally exiting midday Wednesday. A
High Wind Warning has been issued to cover the wind threat this
front will bring. Humidities will be in the 20s during this period.
Snow showers will accompany the front as well, but not expecting a
wetting liquid. A ridge of high pressure aloft will build into the
region Friday and Saturday - humidity will drop to near critical at
this time, though winds will decrease as well. Another chance for
winds and light precip again next week
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...High Wind Warning from 5 PM this afternoon to 2 PM MST Wednesday
for WYZ104-105-108-109-113-115-118-119.
High Wind Warning from 8 PM this evening to 2 PM MST Wednesday
for WYZ101-102-107.
High Wind Warning until 11 AM MST Friday for WYZ106-110-116-117.
Winter Weather Advisory until 11 AM MST Wednesday for WYZ110-112-
114.
NE...High Wind Warning from 5 PM this afternoon to 2 PM MST Wednesday
for NEZ002-095.
High Wind Warning from 8 PM this evening to 2 PM MST Wednesday
for NEZ003-019>021-054-055-096.
&&
$$
SHORT TERM...GCC
LONG TERM...MD
AVIATION...TJT
FIRE WEATHER...AB
Area Forecast Discussion
National Weather Service Dodge City KS
Issued by National Weather Service Goodland KS
410 PM CST Tue Dec 22 2020
...AVIATION section update...
.SHORT TERM...(This afternoon through Wednesday night)
Issued at 1201 PM CST Tue Dec 22 2020
Midlevel flow is in the process of becoming SWly at midday, in
response to a strong progressive trough digging into the northern
Rockies. In response to the approaching trough, lee cyclogenesis
will continue across the NE Colorado vicinity (down to 993 mb on
the latest HRRR iterations) this afternoon. South to southwest
winds will respond this afternoon, strongest across the eastern
zones, with gusts to near 40 mph. Unseasonably mild afternoon
temperatures will result, in the lower to mid 60s away from the
dwindling snowpack.
The initial cold frontal surge is expected this evening, as the
surface cyclone treks eastward across Nebraska. Surface winds will
shift abruptly NWly, and increase in strength. 12z NAM forecasts
winds at 850 mb/2000 ft AGL near 60 mph tonight, but feel
nocturnal timing/inversion issues will preclude full mixing
potential. Still, gusts up to 50 mph are certainly plausible all
night, especially on the higher terrain of the western zones.
Opted to begin the high wind warning at 6 AM Wednesday, but this
evening`s shift will need to reevaluate this potential, and
monitor the nocturnal inversion. With all the mixing going on,
temperatures tonight will again be well above normal for the time
of year, in the upper 20s and lower 30s.
Potent trough with a couple embedded shortwaves spreads over the
central Plains Wednesday, accompanied by intense NW winds and
much colder air. Kept all grids dry for all zones (pops < 15%).
Intense NW winds are expected, with the strongest winds from 10 am
through 3 pm Wednesday. Upgraded inherited high wind watch to a
high wind warning in zones where confidence is greatest on
reaching high wind criteria (sustained 40 mph, gusts 58 mph).
Collaborated with neighboring offices regarding their wind
headlines, but feel the highest damaging wind threat is along the
northern extent of the US 83 corridor (Scott City to Garden City)
during the late morning/midday hours. We are in the shortest days
of the year with the least mixing, so expect winds to begin
relaxing as soon as 4 pm. Models show strong cold/dry advection
daylight Wednesday, with the atmosphere getting progressively
colder and drier all day. With sunshine expected, allowed
temperatures to struggle upward through the 30s.
Wednesday night, it will be plenty cold, but not as cold as it
could be. The core of the coldest arctic airmass will bypass
SW KS to the east, and NW winds will remain elevated at 10-20 mph
all night. Even with these factors working against radiational
cooling, teens can be expected at many locations Thursday morning.
.LONG TERM...(Thursday through Tuesday)
Issued at 1247 PM CST Tue Dec 22 2020
A long stretch of dry weather is expected Thursday through Monday.
SW KS will be sandwiched between a cold 524 dm closed low over
Illinois Thursday, and expansive ridging across the Great Basin.
The resultant strong NW flow through the depth of the troposphere
will yield elevated NW winds again Thursday (stronger than NBM),
but temperatures will be allowed to moderate with sunshine, NWly
downslope, and very dry air.
Christmas Day will be spectacular, as ridging expands onto the
high plains, and afternoon temperatures warm to the upper 50s to
near 60 with light SW winds. Get outside Christmas afternoon!
12z ECMWF suggests Saturday will remain unseasonably mild with
near zonal flow aloft, followed by the next shortwave passing to
the north, with an attendant cold front ushering in cooler
temperatures Sunday. ECMWF is quite a bit colder than other
guidance Sunday night/Monday morning with a 1030+ surface ridge
over the central plains.
Medium range models agree on the next strong closed low digging to
the vicinity of Las Vegas by around Tuesday morning, with this
system subsequently moving out onto the plains around December
30th. This storm will be strong, and produce impacts somewhere on
the plains, but it is way too early to ascertain exact storm track
or details. For now accepted NBM pops for next Tuesday. Stay tuned
for this one.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 410 PM CST Tue Dec 22 2020
VFR conditions are expected at KDDC, KGCK, KHYS and KLBL.
Breezy south to southwest winds are expected at the terminals from
taf issuance through this evening then veering to the west and
northwest after midnight. For the day Wednesday northwest winds
gusting 45 to 55kts are expected. There is a threat of blowing
dust and sub vfr cigs/vis from around 17z-21z for all but KHYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 31 39 18 45 / 0 0 0 0
GCK 28 35 18 46 / 0 0 0 0
EHA 29 37 19 48 / 0 0 0 0
LBL 27 36 17 47 / 0 0 0 0
HYS 30 36 18 41 / 10 10 0 0
P28 37 44 23 43 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
High Wind Warning from 6 AM CST /5 AM MST/ to 6 PM CST /5 PM
MST/ Wednesday for KSZ030-031-043>045-061>064-074>078.
&&
$$
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...99
Area Forecast Discussion
National Weather Service Goodland KS
705 PM MST Tue Dec 22 2020
.UPDATE...
Issued at 700 PM MST Tue Dec 22 2020
Based on the obs upstream northwest of Akron CO, have decided to
update to increase sustained winds through 06z Wednesday. Gusts
are already 35 to 45 mph in Lima CO/Grover CO, and should reach
into portions of Yuma county in the next couple hours.
&&
.SHORT TERM...(This evening through Wednesday night)
Issued at 212 PM MST Tue Dec 22 2020
A High Wind Warning is in effect for the entire region from 11 PM
MST (Midnight CST) tonight to 5 PM MST (6 PM CST) Wednesday.
Water vapor imagery and 500mb RAP analysis showed southwest flow
aloft over the region today as a shortwave trough entered the
northern and central Rockies, pushing upper ridging to the east. At
2 PM MT this afternoon, a strong cold front associated with the
disturbance was located over central Wyoming and Utah. Skies were
mostly sunny across the Tri-State region, with south to southwest
winds at 15 to 20 mph, gusting up to 30 mph. Temperatures ranged in
the low 50s to low 60s.
The main story of the short term forecast is high winds. A cold
front is set to bring a taste of winter back to the region. The
front enters the region from the northwest this evening, bringing an
initial burst of strong winds overnight. Gusts of 50 to 60 mph will
be possible. Additionally, this disturbance brings a slight chance
of a rain/snow mix to the Nebraska-Kansas border region overnight.
A tight pressure gradient persists on Wednesday, and northwest winds
increase further through the morning as the mixing from winds aloft
deepens. At this point, it appears wind gusts of 50 to 65 mph will
occur across the region. With these winds comes a risk of blowing
dust that will be possible across the majority of the area from the
morning into the early afternoon hours. Those sensitive to air
quality may need to take precautions if the blowing dust becomes
dense enough to cause poor air quality. The winds should peak
midday and gradually decline from mid afternoon through the
evening.
As far as temperatures go, expect lows in the upper teens to upper
20s tonight. Highs are forecast in the mid 20s to low 30s on
Wednesday; however, with cooler air filtering into the region
behind the front, temperatures may hit their peak in the morning
before falling the remainder of the day. Otherwise, expect colder
lows on Wednesday night, in the teens.
.LONG TERM...(Thursday through Tuesday)
Issued at 1216 PM MST Tue Dec 22 2020
The main points of interest for the extended period include gusty
winds on Thursday, above normal temperatures for Christmas Day and
an unsettled weather pattern starting this weekend and lasting
through the remainder of the extended period.
Northwesterly flow is expected to start the extended period as the
trough moves off to the east. Gusty winds are expected (not as
strong as the previous days winds), the winds should taper off as
the evening goes on. A ridge then sets up over the plains on
Christmas Day that will usher in dry and above normal temperatures.
Dry weather will continue for the start of the weekend. The pattern
then becomes more unsettled starting Sunday as a cold front
associated with the development of cutoff low over the Great Lakes
region moves through the area, which will result in a cooling trend.
I am currently not expecting any precipitation with the system as
available moisture is low, cant rule out a few sprinkles or
flurries. Guidance then becomes more unclear with the development of
the next system. This next system is forecasted to move onshore from
the southwest Pacific coast. Once it gets on land guidance has a
hard time latching on to how it will evolve. The GFS eventually
has a closed low over the Tri-State area, whereas the ECMWF has
the low forming further to our east over the Kansas City area.
Ensembles are also hinting at breezy to gusty winds as well with
the passage of the system. Quite a bit of uncertainty still
exists with this system. It will continue to be monitored as it
appears it may be our next chance at measurable precipitation.
Temperatures at the start of the extended period are forecasted to
start in the 40s and warm into the 50s for Christmas Day for a good
majority of the CWA; a few locations may even hit 60 degrees. The
above normal temperatures are expected to remain for the start of
the weekend, then fall again with the passage of a cold front Sunday
morning. High temperatures really wont change much after that for
the latter portion of the extended as widespread 30s are expected.
Lows in the 20s are expected for the first half of the period,
before falling into the teens after the cold front on Sunday
morning.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 347 PM MST Tue Dec 22 2020
Vfr conditions are currently anticipated at KMCK and KGLD
terminals through the TAF period. A cold front is expected to
enter the region from the northwest tonight, abruptly shifting
winds to the northwest. Included a mention of LLWS at both
terminals after the initial passing of the front before surface
winds increase. Damaging winds will develop behind the front at
both terminals, persisting from late tonight through the day on
Wednesday. Blowing dust also looks to be a problem in the morning
to early afternoon. Otherwise, some cloud cover may develop
overnight tonight with the front`s passing, with a low potential
for some rain at KMCK. However, confidence was not high enough to
include a mention of precipitation in the TAF at this time.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...High Wind Warning from 11 PM MST /midnight CST/ this evening to
5 PM MST /6 PM CST/ Wednesday for KSZ001>004-013>016-
027>029-041-042.
CO...High Wind Warning from 11 PM this evening to 5 PM MST Wednesday
for COZ090>092.
NE...High Wind Warning from 11 PM MST /midnight CST/ this evening to
5 PM MST /6 PM CST/ Wednesday for NEZ079>081.
&&
$$
UPDATE...JN
SHORT TERM...JBH
LONG TERM...TT
AVIATION...JBH
Area Forecast Discussion...Updated
National Weather Service Hanford CA
439 PM PST Tue Dec 22 2020
Updated Air Quality Issues section
.SYNOPSIS...
High pressure over the region will keep the weather dry and
stable through Christmas Day. In the San Joaquin Valley trapped
low level moisture will allow for nighttime and morning patchy fog
to develop. A low pressure system will move into the area on
Friday night and Saturday bringing a chance of rain and mountain
snow. A second weather maker will arrive later on Monday with
another round of rain and mountain snow.
&&
.DISCUSSION...
Another round of widespread fog and drizzle overnight last night
with some clearing from the north as a mid level weather
disturbance is moving through the region. HRRR is not giving us
widespread fog tonight and we are a bit concerned about the mixing
with the short wave. The fog will be redeveloping again tonight,
but it will be patchy. Confidence is not high enough to issue a
dense fog advisory at this time for tonight. Cold temperatures
overnight will once again be below the freezing point in rural
parts of the valley tonight.
The fast moving trough will move east overnight with EPAC ridging
slowly building back into the area on Wednesday. Surface high of
around 1041mb will build into the Great Basin by Wednesday evening
and easterly winds are forecast to increase across Kern county.
The combination of low RH values and gusty winds will warrant
"Elevated Fire Danger" conditions across parts of Kern county
tomorrow afternoon and evening.
The models have been advertising a fast moving front forecast to
move across the CENCAL interior Friday night into Saturday
morning. The system is weakening as it moves through and qpf is
light associated with the front based on model data at this time.
Snowfall amounts are too light for any type of winter weather
statements for the Sierra. However since it is a holiday travel
weekend, we are encouraging you to take chains and emergency kit
if you decide to visit the Sierra this weekend for the holidays.
Another system is right on its heels and will be moving in here
early Monday. This system is a bit more robust with more QPF and
lower snow levels. We will be watching this system as it gets
closer to the time frame for potential statements for winter
weather. The storm is forecast to move east of the area by next
Tuesday with residual upslope clouds and even a few flurries
across the Sierra above 4000 feet early Tuesday morning as the
system moves out. Mid level ridging will build in behind the
system late Tuesday and into Wednesday with dry conditions and
cooler temps.
&&
.AVIATION...
IFR conditions in mist and haze in the San Joaquin Valley until
20z Wed. LIFR conditions in patchy dense fog in the San Joaquin
Valley after 10z tonight through 18z Wed. Elsewhere...VFR
conditions are expected above the fog and in the desert.
&&
.AIR QUALITY ISSUES...
On Wednesday, December 23rd, 2020, unhealthy for sensitive groups in
Fresno, Kern, and Tulare Counties. Fireplace/wood stove burning
status is: no burning unless registered in Kings, Madera, Merced,
and Tulare Counties. No burning for all in Fresno and Kern Counties.
Further information is available at Valleyair.org
&&
.CERTAINTY...
The level of certainty for days 1 and 2 is medium.
The level of certainty for days 3 through 7 is medium.
Certainty levels include low, medium, and high. Please visit
www.weather.gov/hnx/certainty.html for additional information and/or
to provide feedback.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
public...JDB
aviation....JDB
weather.gov/hanford
Area Forecast Discussion...UPDATED
National Weather Service Twin Cities/Chanhassen MN
844 PM CST Tue Dec 22 2020
.UPDATE...
Issued at 844 PM CST Tue Dec 22 2020
...HIGHLY IMPACTFUL HAZARDS EXPECTED WEDNESDAY AND WEDNESDAY
NIGHT...
Trends are evolving rapidly this evening. Confidence continues to
increase for a very impactful event Wednesday and Wednesday night
with strong, possibly damaging winds; heavy snow; and a dramatic
temperature drop, leading to a flash freeze and rapidly deteriorating
conditions in the afternoon.
Some finer details are beginning to come into focus. A sharpening 500
mb trough axis will increase southerly flow in advance of it to in
excess of 100 kts over Wisconsin by afternoon. Surface low pressure
will respond accordingly, deepening from the low 990s to the 980s as
it tries to become more neutrally tilted. Low level moisture will
increase late tonight and should allow light rain to develop by mid
morning across eastern Minnesota and snow across western Minnesota.
By 12Z, the cold front should be just east of the MN/SD state line,
and advance east to around I-35 by noon/18Z. Temperatures will
plummet behind the front from the 30s to the teens and single
digits. Precipitation will rapidly transition to snow, and as
temperatures fall through the 20s, a flash freeze is also expected.
Thus, travel will become extremely dangerous during the afternoon.
One of the biggest things to come into focus is a narrow band of
heavy snow along the 500 and 700 mb low tracks somewhere along I-35.
ECMWF, GEM, GFS as of 18Z, and NAM/ARW/NMM/NAMnest/NSSL-WRF as of
the new 00Z runs have shown this band very well. At MSP, the 18Z
GEFS increased its QPF mean to 0.8" from 0.4" with the 12Z run, and
0.2" from the 06Z run. The trend is very clear, so have the forecast
moving in that direction. If and when confidence increases more with
where this band will set up, snowfall totals will need to be
increased by another few inches in those locations. If not for
running out of time with this update, probably could justify the 00Z
guidance enough evidence to increase further right now. The current
forecast has the highest totals of 5 to 9 inches forecast from
Mankato to the Twin Cities and north along I-35.
Finally, the wind will be nothing less than impressive. In the
extreme CAA regime, very good mixing and an unstable boundary layer
could bring 50+ kt wind gusts down to the surface. All forecast
soundings from western Minnesota indicate 55-65 kt winds at the top
of the mixed layer. Looking at wind speed plots at 900 mb on a
plethora of models show a bubble of 50-55 kt isotachs plunging
southeast behind the strengthening surface low across western and
southern Minnesota during the afternoon and evening. This should be
when the strongest winds occur. In addition, convective snow showers
with a 15kft saturated DGZ should keep the light or moderate snow
going until the atmosphere cools past the DGZ late Wednesday evening
or overnight. Therefore, confidence is high enough blizzard
conditions will occur across most areas west of I-35 (except maybe
inside the core metro due to urban effects.) Upgraded the hazards to
a Blizzard Warning from Lake Mille Lacs to Waseca and west, including
the western Twin Cities suburbs, A Winter Storm Warning is now in
effect east of the Blizzard Warning to the Wisconsin border. Hazards
in Wisconsin were left alone for now due to lower confidence in
precip transition and totals.
&&
.SHORT TERM...(This evening through Wednesday night)
Issued at 307 PM CST Tue Dec 22 2020
There are many moving parts and still quite a bit of uncertainty
in the forecast through Wednesday night. What is known with high
confidence is that it will turn much colder, and it will be quite
windy Wednesday into Thursday, with winds peaking Wednesday afternoon
into Wednesday evening. The main uncertainty in the forecast is the
amount of snow that will occur across the area. Although the model
guidance is now in very good agreement on the overall development and
evolution of the upper wave and surface low as it moves out of the
Plains and through our area Wednesday into Wednesday night, there
remain differences on the amount of precipitation and where the
heaviest will occur. A blended forecast was used to account for the
differences, with a bit of additional weight toward the deterministic
ECMWF solution. This all resulted in an increase in forecast snow
amounts across the area, with at least 1 to 3 inches across the
entire area and some amounts of 4-6 inches north of Interstate 94.
Differences in the guidance are due to subtle differences in how much
of a TROWAL develops, the amount of moisture transport back into that
TROWAL, and the strength and duration of low to mid level
frontogenesis. Overall, the window of moderate to heavy precipitation
is fairly short, which should keep things from getting out of hand,
but precipitation amounts in excess of a half inch appear possible,
particularly from central into east central Minnesota (similar to
what the ECMWF and HRRR extension suggest).
Given the amount of wind that we`ll see Wednesday into Wednesday
night, there is the potential for significant blowing and drifting
snow. If we had the amount of snow cover we often have in place at
this time of year, there would be high confidence in blizzard
conditions in west central Minnesota. However, with nothing in place
the development of blizzard conditions hinges on the amount of
falling/new snow, which as discussed above is still somewhat
uncertain. Decided to go with a winter storm warning where there is
the greatest confidence in wind and at least a few inches of snow,
and put up a watch south/east of there, with an advisory south/east
of there (as confidence in the juxtaposition of high winds and snow
decrease going south/east). It is certainly possible that a portion
of the area may eventually need a blizzard warning if sufficient new
snow occurs for widespread near zero visibilities with blowing snow,
so forecasts should continue to be monitored. For the watch area, it
is likely that a portion will need a warning at some point, when
there is greater confidence in a sufficient combination of falling
snow, blowing snow, etc. Another concern Wednesday is the potential
for flash freezing of road surfaces as much colder air works in
behind the cold front given the possibility of some earlier rain and
mixed precipitation. Needless to say, travel should be postponed or
adjusted if possible given the adverse conditions that are expected.
Conditions will improve from west to east Wednesday night, but
fairly gusty winds will persist, so improvement may be a bit slow.
.LONG TERM...(Thursday through Tuesday)
Issued at 307 PM CST Tue Dec 22 2020
The highlights in the long term are the cold temperatures and
blustery winds on Thursday followed by a warming trend into the
weekend and a return to split flow and dry conditions.
With strong CAA in place and fresh snowfall on the ground
temperatures will not rise much from Thursdays morning lows
despite clearing skies progressing from west to east as Wednesdays
winter storm moves off to the east. As the pressure gradient starts
to weaken winds will relax some, but still be blustery Thursday with
northwest winds 10-20 MPH with gusts as high as 30 MPH. This will
lead to wind chills around -15F in our Wisconsin counties to as low
as -35F in our far northwestern counties. Highs on Thursday will top
out in the single digits above zero for most, with some locations in
the northwestern CWA remaining slightly below zero. Wind chills
Christmas Eve night will still be well below zero with readings of
-15 to -25F, but the winds will continue to relax overnight.
Christmas morning will be a few degrees colder in our eastern
forecast area and a couple degrees warmer in the western CWA as the
heart of the arctic air slides off to the east and moderating
temperatures move in from the west. The strong northerly flow will
become more northwesterly on Friday and temperatures will moderate
some as weak ridging approaches from the west. Christmas Day will see
sunny skies and high temperatures will be in the teens in west
central Wisconsin and mainly in the 20s for the Minnesota portion of
the forecast area. The warm up continues into the weekend with weak
ridging and sunny skies on Saturday getting back to a little above
average in the 20s to low 30s. Late in the weekend a system will take
shape somewhere around the Mid Mississippi Valley, but it looks like
this one will mostly miss us to the south and east, perhaps scraping
the far southern and eastern CWA with a bit of snow. A cold front
drops through on Sunday and lowers temperatures again, but nothing
too extreme for this time of year. Highs will fall back into the
teens and 20s with lows in the mainly in the single digits above
zero, but some single digit below zero readings in our northern
areas.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 844 PM CST Tue Dec 22 2020
VFR through most of the night, then low level moisture rapidly
increases early Wednesday morning ahead of the front, leading to
drizzle or light rain. The sharp arctic cold front will swing through
during the morning from west to east, leading to plunging
temperatures and intense northwest winds, likely gusting to 50 kts
across western Minnesota by afternoon. Blizzard conditions are
expected there with falling snow likely to continue. Flash freeze
across eastern MN and far western WI in the hour following the
transition to snow during the early afternoon, then steady snow,
possibly heavy, and winds increase also leading to blowing snow in
those areas.
KMSP...Rain will develop early Wednesday morning, then transition
very rapidly to snow around 19Z as temperatures plummet. Confidence
is increasing in a band of heavy snow will develop in the afternoon,
followed by blowing snow and the potential for 45-50 kt gusts.
/OUTLOOK FOR KMSP/
Thu...Cold. MVFR expected. Wind NW 15-25 kts.
Fri...VFR. Wind W around 10 kts becoming SW.
Sat...VFR. Wind light/variable.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Blizzard Warning from noon Wednesday to 6 AM CST Thursday for Blue
Earth-Brown-Carver-Faribault-Le Sueur-Martin-McLeod-Mille Lacs-
Nicollet-Sherburne-Sibley-Waseca-Watonwan-Wright.
Blizzard Warning from 6 AM Wednesday to 6 AM CST Thursday for
Chippewa-Douglas-Lac Qui Parle-Pope-Stevens-Swift-Yellow
Medicine.
Blizzard Warning from 10 AM Wednesday to 6 AM CST Thursday for
Benton-Kandiyohi-Meeker-Morrison-Redwood-Renville-Stearns-Todd.
Winter Storm Warning from 1 PM Wednesday to 6 AM CST Thursday for
Anoka-Chisago-Dakota-Hennepin-Isanti-Kanabec-Ramsey-Rice-Scott-
Washington.
Winter Weather Advisory from 3 PM Wednesday to midnight CST
Wednesday night for Freeborn-Goodhue-Steele.
WI...Winter Weather Advisory from 3 PM Wednesday to midnight CST
Wednesday night for Chippewa-Dunn-Eau Claire-Pepin-Pierce.
Winter Storm Watch from Wednesday afternoon through Wednesday
evening for Barron-Polk-Rusk-St. Croix.
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UPDATE...Borghoff
SHORT TERM...
LONG TERM...CEO
AVIATION...Borghoff