Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/07/23

Area Forecast Discussion

National Weather Service Des Moines IA

 536 PM CST Wed Dec 6 2023

...Updated for the 00z Aviation Discussion...

.DISCUSSION.../Tonight through Wednesday/
Issued at 341 PM CST Wed Dec 6 2023

Key Messages:
- Thursday will be warm with record highs being challenged in a few
  places assuming full sunshine.
- Rain chances remain Friday night into Saturday, particularly
  over southeastern Iowa. A bit of light snow is possible with an
  80-90% chance of accumulations remaining below an inch.
- Winds will be blustery on Saturday into Saturday night with gusts
  of 30 to 40 mph.
- More seasonal conditions this weekend into next week.

Details: Upper air analysis and water vapor imagery shows the
backside of the trough departing the state with the mid-level ridge
axis cresting over the Rockies. While some high clouds slowed
warming a bit, especially over eastern Iowa, these  have largely
exited the forecast area and temperatures have been lifted to around
forecast highs with breezy winds from the south or southwest. The
RAP 850mb analysis shows the strong low level warm air advection
with a change of 8 to 10C over the last 8 hours. Winds will lessen a
bit into tonight with perhaps some high clouds passing through
before exiting by sunrise Thursday.

The ridge axis passes over the state on Thursday with 850mb
temperatures similar to peak values today. Temperatures were again
bumped above initial National Blend of Models (NBM) guidance to the
75th percentile of NBM, which adds a few degrees in most places. One
thing to keep an eye on is the 12z HREF shows some low probabilities
(up to 30%) of high clouds passing through the day and this seems to
be tied to a vorticity lobe from the passing northern stream
shortwave trough. This cloud potential is also reflected in the NBM
sky cover, GFS cross section, and the RAP and HRRR showing some
saturation around 300mb in forecast soundings. This normally is not
a big concern, but if there is filtered sunshine this may cause our
current highs to be too high. If full sunshine does occur, which our
forecast leans towards, then record highs will be challenged with
NBM probabilities of tying or breaking a record most likely at Mason
City and Waterloo. Winds may not be quite as breezy on Thursday
(compared to today) as the elevated low level inversion will limit
the depth of mixing to between 1000 and 2000 feet and thus potential
for momentum transfer to the surface.

As mentioned above, the ridge moves off to the east and a shortwave
trough passes north of the state Thursday night into Friday. A cold
front will push through the state Friday and with lowering 850mb
temperatures and an increase in cloud cover, highs on Friday will be
several degrees lower than Thursday, but still mild for December.
During the same time, another trough will be moving over the western
US and digging into the southern Plains. This wave now looks to
remain more open, positively tilted through our longitude, and with
the energy not phasing as well as yesterday. Still, there continues
to be agreement of precipitation in the state, particularly over
southeastern Iowa where the chance is up to around 70 to 80% in the
Friday night timeframe. With the energy not phasing, much of the
precipitation will come from the low level QG convergence and
thermal lift Friday night tapering off Saturday morning. Forecast
soundings indicate that temperatures will largely be high enough to
support rain through a majority of the event. In the southeastern
forecast area, a few rumbles of thunder cannot be ruled out.
However, as the column cool, could see a brief changeover to light
snow as the column dries and precipitation ends. Ensemble snowfall
guidance has trended this way as well with an 80 to 90% chance that
snowfall will not exceed an inch. Winds will turn blustery as this
shortwave passes through and in its wake, but 0z ECMWF extreme
forecast index is not pinging on anything unusual or headline worthy
at this point.

The change from yesteday`s forecast is that there is a secondary
piece of energy passing over the state on Saturday as the first
shortwave lifts into the Great Lakes. This is generating some light
QPF - likely light snow - in some deterministic models, which seems
tied to mid/upper level forcing in the way of QG convergence and a
left exit region of a 250mb jet streak. Cross sections and soundings
show this lift above 500mb over northern Iowa as well as low level
saturation/clouds across central Iowa, but with dry air in between.
This depth looks too great for seeder feeder so some uncertainty
remains in how much of this will actually occur over northern Iowa.
Further examination of soundings reveals steepening low level lapse
rates generating elevated instability, which is into the
aforementioned low level saturation/clouds. It`s possible this could
generate convective snow showers if there enough saturation depth
and PoPs may need to be increased a bit on Saturday.

As this overall trough pulls away Saturday night through Sunday,
winds will decrease with northwesterly flow generally prevailing
into the middle of next week. This should favor dry conditions with
temperatures not straying far from seasonal levels.

&&

.AVIATION.../For the 00Z TAFS through 00Z Thursday evening/
Issued at 536 PM CST Wed Dec 6 2023

Widespread VFR conditions are expected for the duration of the
forecast with unrestricted visibilities. Any ceilings will be from
very high cirrus clouds with light south to southwest winds
tonight. Surface winds increase with mixing on Thursday to modest
levels by midday.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

DISCUSSION...Ansorge
AVIATION...Cogil



Area Forecast Discussion

National Weather Service Twin Cities/Chanhassen MN

 950 PM CST Wed Dec 6 2023

.KEY MESSAGES...

- December warmth continues Thursday, with record highs
  possible.

- Cooler air returns this weekend, along with the chance for
  wintry precipitation Saturday. Light snowfall accumulations
  appear possible.

&&

.DISCUSSION...
Issued at 204 PM CST Wed Dec 6 2023

Anomalous warming is well underway this afternoon, thanks in
part to clearing over southwestern Minnesota as well as breezy
southwest winds. The temperature forecast remains quite
favorable for overachievement, so we have continued to lean with
the 90th percentile NBM for highs. This output suggests upper
50s along the Buffalo Ridge, the upper 40s in and around the
Twin Cities Metro, and the upper 30s/low 40s for western
Wisconsin, where prolonged cloud cover will limit surface
heating. A mild night is ahead per early December standards, as
Thursday morning lows in the upper 20s and low 30s will be
closer to the normal high temperature (31) than the normal low
(19). A few areas of patchy fog may develop north of I-94.

On Thursday, surface low pressure will deepen as is moves east
across the Upper Great Plains. South/southwesterly 850mb flow will
continue to promote warm advection into MN/WI, and as a result the
warmest day of the work week across the area. Latest RAP forecast
soundings do appear a bit more favorable for mixing, thus have
continued to lean on the high end of NBM temperature guidance. It
appears likely that most locations along and south of I-94 will
climb above the 50 degree mark Thursday afternoon, with the
potential for low 60s along the Buffalo Ridge. We`ll be keeping a
close eye on observations through the day, as record high
temperatures appear possible at KMSP, KSTC, and KEAU. The current
records are listed below this discussion.

A cold front will move through early Friday, along with an increase
in wind speeds from the west. The latest guidance shows a period of
westerly gusts approaching speeds of 20-25 mph Friday afternoon. The
flow does not turn northwesterly until late Friday/early Saturday,
which will delay the arrival of colder air under the weekend.
Friday`s high temperatures will be slightly cooler when compared to
Thursday, however we`ll need to keep an eye on MSP, where the
record high of 50 (1990) may be achievable.

The eastward advance of a longwave upper-level trough will bring the
return of precipitation to the region on Saturday. Significant
changes have been noted across the deterministic suite in the last
24 hours, and as a result there is increased confidence in two
potential windows for wintry precipitation. The first will be across
western Wisconsin Saturday morning, as the southern stream of the
upper jet and associated surface low pivot northeast towards Lake
Michigan. Snow, and perhaps some mixed precipitation, may develop
across a deformation zone northwest of the surface low. We have
included chance PoPs in western WI to account for this potential,
however this scenario will be heavily track dependent and will
require fine tuning in the coming days.

A more likely chance for widespread light snow will arrive as the
northern stream of the upper jet advances across the region Saturday
morning and afternoon. Cyclonic flow and vorticity advection should
provide the lift necessary for snowflakes to fly and potentially
accumulate. Forecast soundings depict a short window of deep
saturation as a slug of moisture moves from west to east across
the area, despite limited QPF output across the global suite.
Putting the pieces together, it looks like a period of light
accumulating snow is in the cards for Saturday, so we have
collaborated with neighboring offices to raise PoPs across
Minnesota and western WI.

Looking ahead into early next week, northwest flow remains the key
player in what will be a cooler temperature forecast. Highs in the
30s will be the theme Sunday through Wednesday, with mainly dry
weather expected.


Record Highs Thursday 12/7
MSP: 54/1939
STC: 53/1939
EAU: 49/1916

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 946 PM CST Wed Dec 6 2023

FEW to SCT high clouds are present across the area and will
persist through the night and into tomorrow, with a gradual wind
shift from 200-240 at period start to 120-150 tomorrow, with a
lull in between with VRB03 tonight but mainly at 200-220 still.
Fog chances tonight appear to be present, but very weak with
only a few locations observing around 7sm visibility and fog as
of 04z. We likely remain VFR at all sites through the period,
with lowering clouds towards the very end of the period as fog
once again enters the forecast. For now, kept any cloud lowering
and fog mention to a minimum as it likely occurs after period
end after around 07z.

KMSP...There is a high likelihood of LLWS from roughly 02-08z
tomorrow night and into Friday morning. Other than this, we
could still see a fog mention depending on the extent of cloud
cover, with confidence still lacking to include in the TAF for
now.

/OUTLOOK FOR KMSP/
FRI...VFR. WIND NW 10-15G20-25KTS.
SAT...VFR, CHC MVFR/-SN. WIND NW 10-15KTS.
SUN...VFR. WIND NW 10-15KTS.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.

&&

$$

DISCUSSION...Strus
AVIATION...TDH



Area Forecast Discussion

National Weather Service Pocatello ID

 253 PM MST Wed Dec 6 2023

.SHORT TERM...Today and Thursday.
Looking at satellite imagery, high pressure ridging has moved east
of our area leaving our area in (warm) southwest flow aloft ahead
of a low pressure system located currently off the Washington and
Oregon coasts. Models continue to show moisture hitting the
western Central mountains starting early this evening and
progressing east through Thursday. Snow levels start high, around
7000 to 7500 ft for the western Central mountains before dropping
to all valley floors by Thursday morning. Still have a winter
weather advisory out for western Central mountains this evening
through Thursday morning for 1 to 5 inches below 7000 feet with 6
to 12 inches above 7000 ft with localized higher amounts across
the extreme western Sawtooths. Expect gusty winds up to around 30
to 40 mph. After midnight, snow reaches the Eastern Highlands.
Snow levels again start high, around 6500 ft before dropping
throughout the day. Have a winter weather advisory out for the
Eastern Highlands (Island Park area, Big Holes, Caribou range, and
the Wasatch mountains) for 6 to 12 inches with localized higher
amounts starting from midnight tonight and going through midnight
on Friday. Winds will gusts up to around 40 to 50 mph. Winds will
be breezy to strong across the Arco desert and the Snake plain as
well, expect gusts of around 35 to 50 mph. A wind advisory is in
place for these zones. Precipitation tonight though much of the
evening/early morning will start out as rain for all valleys. Snow
levels will drop to all valley floors by mid to late Thursday
morning. The second round of moisture will starting hitting our
western Central mountains early Thursday evening and continue
through Friday. Expect snow for all locations Thursday evening
through Friday. See below for more details on this second system.
TW

.LONG TERM...FRIDAY THROUGH NEXT WEDNESDAY...
Snow will be ongoing Fri AM, starting to taper off west to east and
focus into the ern highlands corridor with time. Colder air will
also deepen Fri as winds turn into the W-NW, with high temps
generally around freezing and below. Breezy conditions will also
continue through Fri eve, but more focused over the ern Magic Valley
and Raft River region/Cassia County compared to Thursday`s focus
over the Snake Plain corridor. We`ll again be close to Wind Advisory
criteria with gusts to 45 MPH, and we wouldn`t be surprised to see a
few downslope-enhanced gusts over 50 MPH along I-84 near
Idahome/Malta given the WNW trajectory, a cross-wind for drivers
there. Today`s 12z suite of deterministic models is looking even
more "solid" for a break between systems Sat, keeping things quiet
outside of lingering low stratus clouds. Longwave high pressure
builds over the Pacific, but will be centered too far south to block
our active storm track as multiple additional shortwaves ride over
the ridge and progress across our region from Sun through about Tue.
So far, snow and wind impacts during this period are looking more
tame compared to our main system prior to Saturday`s break, although
temps will continue to support snow to valley floors. Indeed, these
shortwaves are barely detectable in 500mb height cluster analysis
amid the ridge signature, and all clusters support strong influence
of the ridge by Wed, spelling out another break in our active
weather pattern.
01

&&

.AVIATION...
Complex aviation forecast with multiple hazards on the table as the
first in a series of shortwave troughs impinges on southeast Idaho
starting this eve. For each TAF site, we refined start times of both
VCSH (anywhere from 01z-07z/6pm-12am from west to east) and
impactful precip (05z-09z/10pm-2am west to east) based on the latest
HREF suite, resulting in a slight nudge toward a later start time by
1-3 hours at each site compared to the previous TAF package. Temps
will be very marginal, so while we lean snow with attendant IFR
vsbys at KSUN/KDIJ only (rain elsewhere), overall confidence is
moderate at best, and at least some brief mixing with snow cannot be
ruled out at KBYI/KPIH/KIDA which would bring vsbys lower than
currently forecast. Next, winds increase significantly out of the
WSW, but this will happen aloft first prior to really mixing down to
the sfc around 12z/5am Thu. A look at RAP, NAM, and HRRR forecast
soundings suggest most terminals should hold just shy of formal LLWS
criteria prior to this full mixing assuming sfc winds do start to
modestly trend up toward 10-13kts (supported by MOS and NBM), except
at KBYI where we have gone ahead and added LLWS to the TAF from 05z-
12z/10pm-5am as some models feature 40-45kts of westerly flow at
1,500-2,000ft AGL...the strongest regional values. Wind impacts may
be lowest at KSUN, where a non-diurnal up-valley SE flow is
sometimes favored during steady precip and is reflected in the TAF
(although low confidence there too). Finally, the full brunt of
strong sfc winds and continued precip coexist starting at 12z/5am,
but things quickly start to break up and take on a more "showery"
appearance on the CAMs, and we introduced an end time to the
predominant precip impacts and lowest cigs around 15z-16z/8am-9am at
KBYI/KPIH/KIDA, and 19z/noon at KSUN. Our overall confidence in the
worst impacts is highest for this 12z TAF group at each site. While
guidance suggests cigs should lift just slightly and even break up a
touch by late AM Thu, winds will remain strong into Thu afternoon
before slowly subsiding. Overall cig impacts for this event look
MVFR, highest at KBYI (borderline VFR) and lowest at KDIJ where
snowfall could drive vsbys close to closure criteria for the airport
Thu AM. More widespread snowfall impacts are possible heading into
Fri.
KSmith

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 7 AM to 5 PM MST Thursday for IDZ052>054.

Winter Weather Advisory from midnight tonight to 9 PM MST
Thursday for IDZ060-063-064-066.

Winter Weather Advisory from 6 PM this evening to 11 AM MST
Thursday for IDZ071>074.

&&

$$



Area Forecast Discussion

National Weather Service Raleigh NC

 920 PM EST Wed Dec 6 2023

.SYNOPSIS...
Surface high pressure over the lower Mississippi valley will build
into the southeastern United States tonight and Thursday, before
moving offshore Friday. A strong cold front will approach Saturday
and bring a period of rainy weather Saturday night through Sunday
night. Behind the front, cold high pressure will build in on Monday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 920 PM Wednesday...

Just a few small forecast adjustments this evening. Both satellite
imagery and UA analyses show the potent shortwave trough that vexed
our region over the last 36 hours has finally pushed E and offshore,
with a deep NW flow in its wake leading to a drying and stabilizing
column over NC. Hi-res GOES mesoscale imagery shows well the wave
clouds having partially breached the mountains and worked into the
Triad region. These have tended to dwindle in the last few hours but
scattered stratocu may linger through much of the night, based on
lingering moisture upstream in the 925-850 mb depth. Further
upstairs, streaks of high clouds extend well to our NW and should
persist through tonight. The vertical thermal structure noted on the
00z GSO sounding and RAP forecast soundings as well as the amount of
moisture here and upstream noted on UA analysis at around 300 mb
supports the potential for a few hours of orographically enhanced
cirrus overnight, spreading over the Triad and N into VA. Otherwise,
much of the area will be clear to mostly clear tonight. Made a few
tweaks to temps to reflect a slightly slower cooling pace thus far,
likely a function of continued light stirring as surface winds
remain in the 3-7 kt range in most places. Still expect lows in the
20s to around 30. -GIH

Earlier discussion from 140 PM: Satellite water vapor imagery
reveals the mid-level shortwave trough axis sits along the NC coast.
At the surface, 1030 mb high pressure was centered over the lower
Mississippi Valley, while a sub-1000 mb low was offshore over the
Atlantic. These opposing pressure centers are continuing to produce
gusty NNW winds in the 20-25 mph range. The highest gusts so far
have been to the mid 30s mph at FAY/MEB. These winds should diminish
by this evening as the surface high builds into the SE US overnight.

Low-level lapse rates are still fairly steep, between 7.5-8 degC/km
on the backside of the trough and departing offshore low. As such,
low-level stratocumulus continues to develop over the eastern
Piedmont/Sandhills, and Coastal Plain. Spotty light rain continues
to drift ESE with the steep lapse rates in place. A spotter reported
graupel near Roxboro early this afternoon, which is not a surprise
given the freezing levels between 2500 to 3500 ft from NE to SW.
Have left in a mention of spotty light rain into the late afternoon
over the eastern Piedmont/Coastal Plain given the aforementioned
forcing, but most areas with only see a trace to a few hundredths of
an inch at best.

Skies will clear tonight as ridging aloft builds into the Mid-
Mississippi Valley. A shortwave over the Great Lakes combined with a
NW jet streak could bring high clouds and orographic cirrus
overnight. Otherwise, partly cloudy to mostly clear skies is
forecast with lows colder in the mid 20s to low 30s.

&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
As of 140 PM Wednesday...

Mid-level ridging will build east into our area from the Midwest.
Meanwhile, surface high pressure over the SE US will slowly drift
offshore by the end of the period. This will favor a SSW wind in the
5-10 mph range. The airmass will start to moderate some from Wed but
still be a few degrees below seasonal normals in the low to mid 50s
from NE to SW. A shortwave over the northern Gulf Thu night is
forecast to reach southern GA by early Fri, which should increase
high clouds overnight. Lows will be closer to normal in the low to
mid 30s.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
As of 145 PM Wednesday...

Friday and Saturday will be quiet across
the region as  upper level ridge builds across the Mid-Atlantic.
Temperatures will be 5 to 10 degrees above average with highs on
Friday in the low 60s and Saturday in the mid 60s N to upper 60s S.
Surface low sitting offshore will influence light
south/southwesterly winds along with mostly clear skies Friday,
before mid to high clouds move in ahead of the next system on
Saturday.

Sunday will be the main focus for the long term period as a strong
trough moves across the TN and OH and into the Mid-Atlantic on
Sunday. PW values will surge from .50 inch Saturday to nearly 1.50
inches on Sunday ahead of a strong cold front. With precip chances
beginning in the NW Piedmont as early as late Saturday night, they
will quickly spread east across the region by Sunday morning and
continue through the day. Widespread precipitation is expected
Sunday with rain fall amounts for the event to fall between 1 inch
to 1.5 inch range. Models have been  in agreement with the passage
of a mid level shortwave, along with the cold front passage, for
more than a few runs and thus confidence remains high for widespread
rainfall Monday. What remains low confidence is the threat for
severe weather. While shear values (0-1km) of 40-60kts look
promising by Sunday afternoon, there could be a chance of
thunderstorms in the afternoon, especially along and east of the US1
corridor. Depending on where the frontal passage and the shortwave
cross each others paths this could cause a few short lived severe
storms. But confidence for severe is low at this time. For now will
keep with general thunderstorms across the region before the energy
degrades by the evening and the front moves off the coast by late
Sunday night early Monday morning. Subsidence behind the tough will
help things not only dry out rapidly but cool down quickly. Once the
rain moves out the cold dry air will move in bringing temperatures
down into the mid 30s by daybreak Monday morning. Wind gusts along
and behind the front will range from 20 to 30 mph, thus any outside
holiday decor should be secured.

Monday will be a chilly start with clear skies and temps in the mid
to upper 30s. Paired with some gusts, feels like temperatures will
be in the upper 20s to mid 30s early Monday, but by the afternoon
feeling like low 40s with an air temperature of around 50 degrees.
Exceptional radiational cooling Monday night with clear skies and
light NW wind will result in temperatures to fall into the mid/upper
20s for most of central NC with some areas hovering around 30
degrees south and east of Raleigh. Tuesday and Wednesday will return
to near normal with high pressure over  the region and high sin the
50s and lows in the 30s.


&&

.AVIATION /23Z WEDNESDAY THROUGH MONDAY/...
As of 610 PM Wednesday...

TAF period: VFR conditions are expected through the TAF period. A
few clouds will pass over INT/GSO/RDU overnight, mostly high clouds.
Northwest wind will decrease and back overnight, picking up again
out of the southwest late Thursday morning.

Outlook: VFR conditions are expected to dominate through Saturday. A
strong cold front crossing the region late Sun night will bring
widespread rain and possible storms, strong gusty winds and
associated sub-VFR restrictions to all of central NC Sunday. LLWS
may also be possible with strong low-level winds. VFR should return
Monday.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SYNOPSIS...Kren/Hartfield
NEAR TERM...Hartfield/Kren
SHORT TERM...Kren
LONG TERM...CA
AVIATION...Green/Kren



Area Forecast Discussion For Western SD and Northeastern WY

National Weather Service Rapid City SD

 946 PM MST Wed Dec 6 2023

.KEY MESSAGES...
251 PM MST Wed Dec 6 2023

- Gusty west to southwest winds expected south of I-90 tonight
through tomorrow, with strong downslope winds anticipated over the
southeastern Black Hills and foothills.

- Windy conditions continue across much of the area tomorrow night
through Friday behind a cold front.

- Occasional chances for light precipitation expected through the
weekend, but moisture will be limited.

&&

.DISCUSSION...(This Evening Through Wednesday)
Issued at 251 PM MST Wed Dec 6 2023

Satellite imagery this afternoon shows a corridor of
dense, topographically enhanced cirrus streaming across the region
from west to east atop broader ridging in place over the central
Rockies. Farther west, troughing is evident along the West Coast,
with attendant south-to-north oriented plumes of Pacific moisture
evident along its eastern periphery. Latest surface analysis shows
pressure falls over much of the central CONUS, with strengthening
lee troughing from near the Alberta/Montana border southeastward
toward the Front Range. Temperatures are a solid 15-25 F above
average for most of our area, though it appears we may fall just
short of record highs.

Lee trough will strengthen and shift eastward over the next 12
hours, with pressure falls of 3-4 mb/3 hr overspreading the western
and central SD plains by 09-12z. With time, a fairly strong/tight
pressure gradient is expected to develop across the Black Hills,
with the NAM depicting a 6 mb, southwest-to-northeast oriented
gradient by 12z. Such a gradient is comparable to those observed in
prior downslope windstorm events over the Black Hills. A roughly
west-to-east cross section over the Black Hills reveals that the
NAM/GFS are depicting potent downward motion along the
eastern/southeastern slopes of the Black Hills coincident with low-
level winds in excess of 50 kt. A potential failure mode here is
that the NAM shows a fairly shallow inversion--possibly below the
height of the Black Hills--which may favor flow around terrain
rather than downslope. GFS, RAP, and HRRR forecast soundings all
depict higher inversions, with flow exceeding 50 kt near and below
the inversion. HREF max gusts during the overnight period also
exceed 50 kt/60 mph, though mean gusts are a bit lower (closer to 55
mph). All told, warning-level (58 mph+) gusts are probable to likely
(60-80% likelihood) over portions of the central and southern Black
Hills and adjacent southeastern foothills; as such, have issued a
High Wind Warning here. Primary area of concern is east of Highway
385, west of Highway 79, and probably south of Highway 16. Many
members of the HREF maintain high winds or even strengthen them
after daybreak, likely aided by boundary layer mixing, with some
suggestions that warning-level winds could expand beyond just the
few zones currently in the warning area. Confidence is low on this
component of the forecast, but some gusts of at least 50-55 mph will
likely emerge over most of the area south of I-90 tomorrow morning
into the afternoon. Thus, have expanded the Wind Advisory to
encompass much of southwestern to south central SD.

As a cold front associated with the advancing trough crosses the
area tomorrow afternoon, gusty northwest winds are expected to
develop for locations north of I-90. Two separate low-level speed
maxima will likely cross the area from tomorrow afternoon through
Friday as the low-level cyclone strengthens and pivots over the far
north central CONUS and south central Canada, which will maintain
strong northwest flow through Friday afternoon. For now, opted to
not issue any headlines for this second bout with winds given
pressing near-term concerns, but suspect at least an advisory will
be needed for much of northwestern/west central SD sometime late
tomorrow through Friday.

Broad western trough with embedded shortwaves will gradually cross
the region through Saturday, with dirty northwest flow overhead
thereafter. As such, will likely see occasional chances for light
precipitation over the next several days, though particularly
impactful systems appear unlikely.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Thursday Night)
Issued At 943 PM MST Wed Dec 6 2023

VFR conditions will continue through the TAF period. Gusty
southwest winds will developing over parts of northeastern
Wyoming will spread into the Black Hills area and southwestern
South Dakota during the rest of the night. Low level wind shear
is expected over parts of northeastern Wyoming the Black Hills
area, including KRAP, and southwestern into south central South
Dakota during the rest of the night and into Thursday morning.

&&

.FIRE WEATHER...
Issued At 251 PM MST Wed Dec 6 2023

Poor relative humidity recovery is expected tonight, particularly
over portions of the central and southern Black Hills and adjacent
foothills where strong downslope winds will likely develop
tonight. Here, relative humidity values may remain in the 25 to 35
percent range overnight, with such relative humidity values likely
persisting through tomorrow afternoon. Combined with sustained
west to southwest winds of 25 to 40 mph and gusts of 50 to 60
mph, elevated to near-critical fire weather conditions are
anticipated. Strong winds and low relative humidities will expand
tomorrow afternoon, with elevated fire weather conditions and very
high to extreme grassland fire danger expected over much of
western and central SD from mid-morning through the afternoon.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory from 5 AM MST /6 AM CST/ to 5 PM MST /6 PM CST/
     Thursday for SDZ026-027-041-042-044-046-047-075>077.
     High Wind Warning until 11 AM MST Thursday for SDZ028-029-074.
     Wind Advisory until 5 PM MST Thursday for SDZ030.
WY...None.
&&

$$

DISCUSSION/KEY MESSAGES...Sherburn
AVIATION...10
FIRE WEATHER...Sherburn