Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/18/20

Area Forecast Discussion

National Weather Service La Crosse WI

 450 PM CST Tue Nov 17 2020

.SHORT TERM...(Tonight through Wednesday)
Issued at 230 PM CST Tue Nov 17 2020

Forecast concerns in the short term will be increased cloud
cover, how long they last, impact on temperatures tonight,
strengthening south winds for Wednesday, and temperatures
Wednesday. Farther out, we`ll want to see how the storm system
Friday and Saturday evolves.

GOES satellite imagery showed a band of mid-level warm advection
clouds...which at 18Z had pushed into the KRST to KDEH. The OAX
12Z sounding had a moisture layer from 8K-11K AGL. The RAP
appeared underdone with the clouds and was too slow with their
arrival. The back edge extended from eastern South Dakota toward
Des Moines, IA. At the surface, high pressure extended across the
Upper and Middle Mississippi Valley. Afternoon temperatures were
in the 30s to lower 40s with dewpoints in the teens and 20s and
light and variable winds.

Through Wednesday, the mid-level ridge over the Rockies will
build in to the Great Lakes with rising heights. Surface low
pressure developing across southern Canada will induce south flow
across a large portion of the nation`s mid-section.

The mid clouds will continue to spread eastward and if they
continue east at the same speed...should be east of the area
after 01Z at KRST and after 03Z at KLSE. Light and variable winds
tonight should help some cool spot locations in WI under the
ridge drop down into the teens to around 20. Farther to the west,
the south winds increase aloft and should hinder temperatures from
bottoming out. Sunshine for Wednesday will help local readings
warm through the 40s into the 50s. Boosted the south winds with
gusts 30 to 40 mph. KRST may gust higher. At this time, winds look
to remain below wind advisory criteria. Farther west, records are
threatened for parts of the Central Plains where highs are
forecast to be in the 70s.

Local maximum records for LSE are 68 for Wed (set in 1999, 1953,
and 1941). For RST the record for Wed is 69 set in 1939.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 230 PM CST Tue Nov 17 2020

Not as cold Wednesday night with lows in the 30s/40s. The ridge
begins to flatten with a cold front pushing into MPX`s area by
morning. the front slows down and the real cold push comes in more
during the evening. Forecast soundings and timesections show that
the front comes through dry and although there will be cirrus,
the lower clouds lag. The NAEFs Ensemble had h850 temperatures in
the 99th or greater percentile. Highs are expected to be in the
50s to mid 60s. Did boost highs, but currently do not have records
forecast. Partly due to the recent wetness and cold ground. The
record for LSE is 73 set in 1930 Thu. For RST the record for Thu
is 68 set in 1930.

Cold high pressure across Canada builds southward across the
northern U.S. Thursday night through Saturday. A shortwave trough
over Nevada and Utah will trace into the Plains with overrunning
precipitation north of the front. There are still some differences
as to how far north the precipitation will make it and what the
thermal structure will be. The EC is farther south; move over
Missouri, compared to the GFS which has a stronger front farther
north and significant snow for the forecast area this weekend. The
GEFs members are clustered around an inch or less with a few
members around 3 inches and a couple much higher. The EC ensemble
is also around an inch or less with a couple of members in the 6
to 12 inch range. The probabilistic forecasts initially have us
in the 10-30% for .25 water equivalent or more. Our NBM blended
forecast mirrors the farther south track. The EC EPS seems to have
less variability in temperatures from FRI/SAT/SUN. The wave takes
shape Friday into Friday night, so we`ll want to keep an eye on
this. A reinforcing front comes through Sunday. Could see some
light snow with this too.

Temperatures remain above normal with 40s and 50s for Friday and
30s and 40s Saturday through Tuesday.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 450 PM CST Tue Nov 17 2020

VFR conditions expected through this TAF cycle. Mid-level warm
advection cloud shield will pass east through the evening with
only some occasional high clouds at times through the rest of the
period. A period of LLWS is expected late tonight into Wednesday
morning as winds just off the surface increase to over 50 kt,
particularly at KLSE where surface winds may remain a bit lighter.
S/SE winds will increase to 15-25 kts with gusts 25-35 kts during
the morning on Wednesday before slowly subsiding late in the
afternoon.

&&

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

$$

SHORT TERM...Zapotocny
LONG TERM...Zapotocny
AVIATION...JM



Area Forecast Discussion

National Weather Service Goodland KS

 624 PM MST Tue Nov 17 2020

.UPDATE...
Issued at 621 PM MST Tue Nov 17 2020

No major updates the forecast based on latest guidance. Current
forecast trend looks good but will continue to monitor, especially
for lows tonight.

&&

.SHORT TERM...(This evening through Wednesday)
Issued at 1239 PM MST Tue Nov 17 2020

19Z UTC Water Vapor Imagery and RAP analysis indicated large,
fairly high amplitude ridge entering western CWA with area of high
clouds not making it very far from the ridge axis. At the surface,
lee trough continues to deepen with temperatures climbing into the
70s at many locations.

Aforementioned H5 ridge will remain in control of the weather
pattern across the area through Wednesday maintaining warm and dry
conditions. The main concern through Wednesday will be the
magnitude of fire weather threat.

Mostly clear skies and diminishing winds will lead to similar
overnight conditions as yesterday. With lower spots radiating out
quite well and temperatures holding up on relative high spots, but
otherwise little sensible weather impacts are expected.

On Wednesday, H5 ridge axis shifts to the east and flattens
somewhat with flow aloft becoming more zonal and perpendicular to
the Rockies. At first glance, record breaking highs look likely as
locations near 80. The aforementioned height pattern however, has
me a bit concern for potential mountain wave cirrus that would
persist across the area in the afternoon. While not likely, if it
does occur could easily hold temperatures back 3-5 degrees.

This uncertainty with respect to heating further complicates
potential fire danger forecast. Assuming the warmest solutions,
will see much of the northwest CWA have several hours of relative
humidity below 15 percent. Meanwhile the stronger winds will be
out of phase with this area, mainly south of Interstate 70. While
I was leaning towards a fire weather watch, uncertainty just to
high at this point to warrant one.

.LONG TERM...(Thursday through Tuesday)
Issued at 1233 PM MST Tue Nov 17 2020

The main points of interest for the extended period include a
cool down along with precipitation chances for weekend .

Semi-zonal flow over the region for Thursday will lead to dry
conditions. A cold front then moves through during the day that is
expected to cap highs slightly cooler than previous days, albeit
still above normal. Friday during the day still has the advancing
trough from the SW migrating towards the plains. The majority of
Friday will remain dry. However gulf moisture advection
overspreads the plains. Precipitation chances start to increase
during the evening into the overnight hours. Guidance still varies
on the start of the precipitation, so confidence remains low on
that aspect but still confident that much needed precipitation
will occur, with mainly rain but snow may try to mix in due to the
cooler temperatures. Rain chances will persist throughout the day
Saturday. Precipitation chances continue Saturday night into
Sunday morning. Guidance currently is trending toward slightly
lower temperatures for Sunday, so a rain/snow mix overnight
Saturday may change to all snow for a period of time during the
Sunday morning hours. I have been noticing that guidance ensembles
are trending towards some gustier winds during the time period of
the potential all snow, some blowing snow may be of concern
during that time frame. I will not make any significant changes to
the wind forecast at this time due to a lack of certainty but
this will continue to be monitored. The pattern then shifts back
to a northwesterly flow during the Sunday afternoon hours which
leads to a dry start for the latter portion of the extended
forecast period.

Above normal temperatures are still expected for Thursday but not
nearly as warm as previous days as highs in the NW portion of the
CWA may only reach the mid 60`s while other areas will be in the
70`s. Starting Friday, a cool down is expected to more normal like
temperatures for mid-November as widespread highs in the 50`s are
expected. The majority of the weekend highs will struggle to make it
out of the 40`s before a slight warm up back into the 50`s looks
possible for the beginning of next week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 426 PM MST Tue Nov 17 2020

A trough of low pressure that remained over eastern Colorado for
most of the day, is expected to transition a bit northeast from
its current location into southwest Nebraska before repositioning
over the Front Range/eastern Colorado for the afternoon hours on
Wednesday.

No precipitation is expected and VFR conditions will ensue during
the forecast period, with wind shift being the only wx issue/
concern.

Winds for KGLD, south southwest 10-15kts through 10z Wednesday,
then west southwest around 10kts. By 19z, a shift back to the
southwest around 10-15kts.

Winds for KMCK, south around 10kts through 11z Wednesday, then
west southwest less than 10kts. By 20z, a return to a southerly
flow around 10kts, with a shift towards southeast by 23z.


&&

.CLIMATE...
Issued at 215 AM MST Mon Nov 16 2020

Record/near record high temperatures are expected Wednesday
November 18 at the following locations:

Goodland..........77 degrees set in 2008 and previous years
Hill City.........80 degrees set in 1908
McCook............76 degrees set in 1933
Burlington........76 degrees set in 2008
Colby.............76 degrees set in 1981
Tribune...........78 degrees set in 1999
Yuma..............76 degrees set in 1999

&&

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

$$

UPDATE...JN/KAK
SHORT TERM...JRM
LONG TERM...TT
AVIATION...JN
CLIMATE...DDT