Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/23/21

Area Forecast Discussion

National Weather Service La Crosse WI

 1000 PM CST Wed Dec 22 2021

.SHORT TERM...(Tonight through Thursday)
Issued at 230 PM CST Wed Dec 22 2021

A trough a day is keeping Santa away. Another shortwave trough is
heading toward the area, and is clearly visible in Goes water vapor
imagery in northeast MT at 19Z. This shortwave trough influences the
area Thursday morning with weak-moderate QVector
convergence...although water vapor imagery may suggest it is more
toward moderate forcing. Mid-level frontogenesis signals are mixed
with the latest RAP 22.18Z run indicating a bit stronger signal
across the northcentral WI. Raw model guidance consensus is about 40-
50% snow Thursday morning with the 22.12Z ECMWF one of the most
robust at 0.15". The challenge of this forecast is the dry sub-cloud
air mass in place when the wave moves through. Good forcing will
saturate the column in time for the driest air masses, but is it
enough in this case...obviously some model members say yes. Have
decided to continue or slightly increase the 30-50% chance of light
snow trend near/north of I-94. But, we will need to monitor the
trends on this as it could be a light cover of snow around the
morning commute Thursday.

.LONG TERM...(Friday through Wednesday)
Issued at 230 PM CST Wed Dec 22 2021

Busy weather pattern for the end of the year with quick moving,
mostly zonal flow ushering in bits of shortwave energy almost every
day. Pcpn chances with most and potential for a mix of pcpn types at
times.

FRIDAY: bits of shortwave energy look to ripple through the upper
level flow, although mostly focused across northern portions of
MN/WI. Decent isentropic upglide (290-295K) and 850 mb warming lead
the system through, focused on Fri morning. Some concern for
drizzle/freezing drizzle with the low level thermodynamics, but
saturation will be an issue. Bufkit soundings and time/height x-
sections point to a fairly shallow saturated layer moving in from
the south by mid/late morning. Whether or not this layer will be
deep enough to support drizzle production is uncertain, with higher
probabilities east of the local area. Some high cloud is expected to
ride over the lower cloud, but too deep of a dry layer between low
and high layers for seeder-feeder processes. Will go with some small
drizzle chances across the eastern 1/2 Fri morning.

HOLIDAY WEEKEND: models all in good agreement with shuffling bits of
shortwave energy across the region Christmas. A weak wave looks to
pass just south of the local area early in the day with another
stronger feature either north or right through the area later in the
day. The EC currently favors the northern track with the GFS/NAM
more south. Only small/if any chances via the EC with a better shot
in the GFS/NAM. Still, north is favored with these chances
(along/north of I-90). Temps would lean toward mostly snow where the
higher pcpn threat would lie and early signs point to some
accumulations for these areas. Christmas snow? A lot of spread in
the model outcomes right now, so how much could fall uncertain.
Could be some impacts to travel though - so keep an eye on forecasts
and plan accordingly.

Sunday another shortwave trough looks to lift northeast out of the
southern/central Plains and across the Upper Mississippi River
valley. Models are at odds with how developed/wound up this system
will be at this time, which lends uncertainty on potential
amounts/pcpn types. The GFS and EC do agree that some pcpn is likely
for at least part of the forecast area (especially Sun night).

NEXT WEEK: nearly daily chances for pcpn with a bit cooler temps
suggesting it should be (mainly) snow chances. The EC is a tad more
enthusiastic with the various shortwave development/strength as they
swing through. Confidence lower on the details for timing/possible
amounts at this time and will ride the model blends for chances.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1000 PM CST Wed Dec 22 2021

VFR conditions are expected with SE winds up to 10 kts shifting SW
for a time on Thursday as a weak trough of low pressure moves
through. Mid/high clouds will increase overnight, but precip
chances look to remain north and east of KLSE/KRST.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&

$$

SHORT TERM...Baumgardt
LONG TERM....Rieck
AVIATION...JM



Area Forecast Discussion

National Weather Service Goodland KS

 831 PM MST Wed Dec 22 2021

.SHORT TERM...(This evening through Saturday Morning)
Issued at 137 PM MST Wed Dec 22 2021

An overall quiet day has developed across the Tri-State area with
mainly clear skies and above normal temperatures along with light
winds. The main story for the short term is the above normal
temperatures over the area. Current RAP analysis indicates a low
amplitude ridge over the western CONUS along with a surface trough
extending from the Front Range into the Northern Plains. High
clouds are beginning to emanate off of the Front Range into
Western Kansas as the surface trough moves to the west. Into
tonight a mix of mid and high clouds remains over western portions
of the CWA whereas the eastern portions could see some high
clouds. Due to the lack of cloud cover have lowered temperatures a
few degrees to over the eastern CWA to account for stronger
radiational cooling. Overall the CWA can expect to see lows in the
20s overnight.

Thursday, will see temperatures fairly close to today, perhaps a
degree or two cooler with widespread 60s expected. Elevated to
near critical fire weather is expected along and west of Kansas
Highway 27. An hour or two critical fire weather is possible as
well. Winds will be out of the south at 10-20 mph with occasional
gusts of 25 mph especially across Kit Carson and Yuma counties.
Outdoor burning is not encouraged tomorrow as the finer fuels are
at the least modestly receptive to the spread of wildfires. Mid
level clouds will be on the increase during the overnight hours
resulting in low temperatures in the 30s, with some locations
potentially setting record highest low temperatures.

A surface low develops over SE Colorado/SW Kansas during the
afternoon resulting in warmer temperatures for Friday with 60s and
and perhaps some low 70s over the southern counties for afternoon
highs. Winds will become breezy mainly over southeastern portions
of the CWA with the eastward progression of the low with wind
gusts of 30-35 mph possible. It is worth noting that the GFS is
further north with the low which if verifies would creating gusty
to windy conditions mainly along and south of Interstate 70.
Christmas morning lows will fall into the upper 20s to low 30s
over the area.

.LONG TERM...(Saturday through Wednesday)
Issued at 122 PM MST Wed Dec 22 2021

The lack of precipitation across much of the Tri-State area for
the last month or so continues to bring fire weather concerns to
the forefront. Continue to monitor conditions and heed any burn
bans put in place.

The forecast starts out with a weak ridge crossing the plains on
Saturday and southwest flow commencing on Sunday. Sunday poses the
best chance for fire weather conditions with a warm front draped
from northwest to southeast across the Tri-State area.
Temperatures in the southern part of the area may rise into the
mid-60s with a few models hinting at potential upper 60s. Minimum
relative humidity values will be in the mid to upper teens for
areas south of Hwy 36 and west of a line from St. Francis to
Goodland to Russell Springs. Winds gusting to 25-35mph will be
possible in these areas increasing the potential fire concerns in
the afternoon. With conditions as dry as they are and forecasted
winds, any fires that ignite will have the potential to grow
rapidly.

Sunday, a low develops in the vicinity of the Black Hills and
Bighorns region, pushing east on Monday. An attendant cold front
is expected to slip south into the region Sunday night/Monday
morning. Forecast high temperatures are expected to be 10 to 15
degrees cooler, ranging from the mid-40s to low 50s. Cooler
temperatures remain through the end of the forecast with highs
down to the mid- 30s to low 40s by Wednesday and lows in the
single digits and teens.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 815 PM MST Wed Dec 22 2021

VFR conditions will rule through the TAF period, with ceilings
confined to cirrus AOA 20-25 kft. 6-12 knot SW-WSW winds will
prevail overnight.. becoming variable AOA sunrise. Winds will
shift to the S and increase to 10-20 knots by mid-late afternoon..
10-15 kt at MCK.. 15-20 kt at GLD.

&&

.FIRE WEATHER...
Issued at 137 PM MST Wed Dec 22 2021

Fire weather concerns will be present over the next several days
due to low relative humidity values and the potential for gusty
winds. RH values for Thursday look to be in the mid teens, however
with dry downslope winds being present (which has lowered
dewpoints lower than expected for today) would not be surprised if
the same scenario presents itself tomorrow. Southerly winds of
10-20 knots are expected with gusts of 25 knots possible. Friday,
RH values will be a little higher in the lower 20s with gusts of
20-30 knots possible. The GFS has a surface low tracking further
north over the CWA, which if verifies would create stronger wind
gusts potentially reaching the surface. With many traveling for
the holidays, make sure to try to avoid creating sparks as fuels
are very supportive for the spread of wildfires and be aware of
any local burn bans that may be in place.

&&

.CLIMATE...
Issued at 137 PM MST Wed Dec 22 2021

==================================================
December 24th Maximum Temperature Records:
==================================================

Hill City
64 degrees in 1955 (Current Forecast: 68 degrees)

==================================================
December 24th Warmest Low Temperatures Records:
==================================================

Goodland
32 degrees in 1940 (Current Forecast: 35 degrees)

Burlington
28 degrees in 2016 (Current Forecast: 35 degrees)

Hill City
34 degrees in 1940 (Current Forecast: 34 degrees)

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&

$$

SHORT TERM...TT
LONG TERM...AW
AVIATION...VINCENT
FIRE WEATHER...TT
CLIMATE...TT