Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/03/22
Area Forecast Discussion
National Weather Service Cheyenne WY
849 PM MST Wed Mar 2 2022
Issued at 820 PM MST Wed Mar 2 2022
Cold frontal boundary zone has slipped south through Chadron this
evening and will continue to slowly ooze southward across the
central NE Panhandle and should then orient more NW to SE overnight.
Confidence is low the boundary reaches Sidney but could barely reach
there by 6am Thursday morning. With the cooler airmass comes greater
chances of lower ceilings and patchy fog filtering in across the
Nebraska Panhandle late tonight and especially Thursday morning from
5am-10am. Can already see lower ceilings building west behind the
cooler airmass per nighttime microphysics satellite imagery. HRRR
and NAM suggest this trend to continue west as low-level saturation
occurs. Confidence is increasing in patchy to areas of fog for
Chadron and Alliance with moderate confidence at Sidney and
Scottsbluff Thursday morning. Have expanded on day shifts` fog
inclusion of patchy and areas of fog farther south across the NE
Panhandle and slightly farther west. No precipitation expected but
can`t rule out some brief mist in the most foggy/saturated areas.
Temperatures will fall near freezing most locations overnight but
not too cold with values in the 30s/20s. Another warm day tomorrow
with solid rebound into the 50s and 60s. 70s may also be possible
in a few select spots in NE Panhandle but clouds could hamper that
possibility. Still, an above normal temperature day expected.
Updated zone forecast has been sent.
.SHORT TERM...(This evening through Saturday)
Issued at 115 PM MST Wed Mar 2 2022
Forecast concerns deal with snow and amounts Friday night into
Saturday in the Short Term. Nice warm temperatures the rest of the
week...before the bottom drops out Friday night.
Currently...Frontal boundary lays across northeastern Nebraska
into western South Dakota into southern Montana this afternoon.
1026mb surface high over western Wyoming into northwestern
Colorado. Leeside surface trough lays along the east slopes of
the Laramie Range with some mid and high clouds over the south
Laramie Range. Current 700mb temperatures right around +4C over
the Laramie Range...yielding 1PM temperatures in the 50s west of
the Laramie Range and near or above 60 east. Very nice day
Did add some patchy fog across the northern Nebraska Panhandle as
we see a slight surge in the northern front into maybe Lusk to
Alliance. Surface winds shift to the northeast which is an upslope
flow for that area up against the Pine Ridge. GFS showing
favorable fog profiles at Chadron and Alliance tonight from rough
08Z to 14Z Thursday.
Similar temperatures for Thursday...though more widespread
cloudiness may damper afternoon highs some. Most of Friday looks
to be warm and dry as well as a low pressure system tracks into
the 4 Corners area and moisture begins to increase from southwest
to northeast Friday evening. At the same time...the front to our
north continues to drop south into the northern Panhandle and
Converse/Niobrara Counties in east central Wyoming.
May be a brief time Friday evening that precip falls as rain...but
my thinking is that we should quickly wet bulb down as forecast
dewpoints are in the 20s and low 30s...so by midnight...precip
should be all snow. Definitely all snow by 07 or 08Z Saturday as
northern front gets pulled south to near Laramie.
Looking like we will need some winter storm watches in the next 24
hours for the mountains out west...maybe the northern Panhandle
into Niobrara County as well as the south Laramie Range as current
snow totals well above warning levels, Did tweak the qpf amounts
over the Pine Ridge in the northern Nebraska Panhandle as
guidance usually does not handle the Pine Ridge very well. Will
give the night crew a chance to look at another model run before
issuing any winter headlines.
.LONG TERM...(Saturday night through Wednesday)
Issued at 115 PM MST Wed Mar 2 2022
Latter half of the weekend will continue to see light to moderate
snowfall across the region with colder temperatures Sunday. Wide
upper level troughing across the western CONUS will continue as the
leading closed low with the initial round of snowfall Saturday will
continue to push off to the northeast while a second closed low will
drop into the four corners region.
Latest ensemble cluster analysis for Sunday shows little variation
in the 500mb pattern all suggesting anomalously low heights. This
will result in cold air sitting over the region as 700mb temps drop
around -15C through much of the extended. Nudged temperatures
slightly below NBM guidance with high temperatures in the low 20s
Sunday. Snowfall will mainly continue along and west of the Laramie
Range Sunday as a secondary front passes south aiding in additional
upslope flow. However, additional accumulations should be light as
the better dynamics with this second low appear to remain farther
south as the shortwave looks to progress more eastward from the four
This upper level troughing over the western CONUS looks to breakdown
late Monday with northwesterly low returning to the area with
multiple passing progressive shortwaves. This could lead to a brief
period of elevated to high winds across southeast Wyoming Monday
night into Tuesday and again later in the week. However, parameters
do not look all to impressive outside of the wind-prone areas.
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 843 PM MST Wed Mar 2 2022
Wyoming TAFS...VFR. Wind gusts to 23 knots from 15Z to 01Z.
Nebraska TAFS...VFR at Chadron and Alliance until 07Z, then MVFR
until 09Z, then IFR until 14Z, then MVFR until 17Z, then VFR.
Wind gusts to 22 knots until 08Z.
VFR at Scottsbluff until 09Z, then IFR until 15Z, then VFR. Wind
gusts to 22 knots from 09Z to 15Z.
VFR at Sidney until 10Z, then MVFR until 15Z, then VFR. Wind gusts
to 23 knots from 09Z to 10Z.
Issued at 200 AM MST Wed Mar 2 2022
A upper level ridge of high pressure will dominate the districts
through Friday. A backdoor cold front will briefly slip southward
into far northwest Nebraska Thursday morning, then lift northward
Thursday night. Unseasonably mild temperatures will continue for
the next few days. Minimum relative humidities of 15 to 25 percent
and gusty winds will result in elevated fire weather conditions,
however ground fuels are not susceptible for rapid fire growth.
A return to colder temperatures, higher humidities and chances
for measurable precipitation in the form of rain and snow is
expected late Friday through the weekend. Significant snow
accumulations are possible, especially for the higher terrain.
Area Forecast Discussion
National Weather Service Goodland KS
544 PM MST Wed Mar 2 2022
.SHORT TERM...(This evening through Friday)
Issued at 145 PM MST Wed Mar 2 2022
Upper ridge remains in control through Friday. The ridge axis will
move across the area tomorrow and transition to a southwest flow
aloft on Friday ahead of the next system digging into the Four
Corners. Main concerns in the short term will be elevated fire
weather conditions and a back door cold front which will approach
the area Thursday morning with low clouds and areas of fog.
The aforementioned front will enter the McCook area around 12z
Thursday morning and then stall out near the Colorado/Kansas
border area around 18z. HRRR and RAP suggest that there will be a
narrow corridor about a county wide of fog immediately on the cool
side of the front and low clouds extending well behind the front.
RAP is slightly further west with the fog, straddling the
Colorado and Kansas border, and more widespread. So, will have
areas of fog in that area for Thursday morning. Saturated layer
appears very shallow, so will not mention drizzle at this time.
Morning lows will be in the lower 30s, so cannot totally discount
freezing fog, but clouds may keep temperatures slightly above
freezing. Those clouds will gradually burn off by 18z, but more
clouds will be moving in from the west in the afternoon. Therefore
expecting temperatures to be cooler compared today, with coolest
temperatures in southwest Nebraska behind the front where may only
see upper 50s. Elevated fire weather threat for Thursday will be
confined to southwest part of the area, generally south of
Interstate 70, where relative humidity will fall below 20 percent
for a few hours.
Front will lift out as a warm front on Friday with the warmer
temperatures returning. Surface flow will parallel upper winds,
and with the added downslope component temperatures should have
no problem reaching the upper 70s to lower 80s. Afternoon humidity
will fall below 20 percent everywhere and below 15 percent in
western areas, resulting in elevated fire weather conditions, but
wind speeds for now remain a tad below critical threshold.
.LONG TERM...(Friday night through Wednesday)
Issued at 202 PM MST Wed Mar 2 2022
For this long-term forecast period, the weather pattern becomes
active with several disturbances expected to move through the
region. Overall though, confidence is low regarding the threat of
high-impact weather from the lead system, mainly because the track
is not climatologically favored for a significant winter weather
event. The following systems are lower in magnitude and currently
do not appear to bring a threat for significant weather.
Beginning with the lead system, changes to the overall weather
should begin to be observed early Saturday morning as a surface
low pressure deepens over the High Plains. In fact, the low should
be centered more or less directly over the region. With that in
mind, it is currently hard to see the previous day`s weather set
up, particularly in the form of placement of the fronts, changing
too much until later in the day Saturday as the low moves
northeast and swings the cold front southeast. So, on Saturday, it
is possible there is a brief period of low relative humidity and
gusty southwest winds during the late morning hours. Then, the
cold front should move through and cause a shift in the wind
direction, which would be problematic for any fires that are able
to begin. That being said, this fire weather threat on Saturday is
quite conditions as it depends on the exact positioning and
timing of the low pressure and front movements.
The other weather threat that may come out of this initial system
is the chance for wintry precipitation. On the backside of this
system, there will be an opportunity for a band of precipitation
to develop. Temperature profiles from forecast soundings indicate
that behind the cold front, atmospheric profiles are cold enough
for snow to be the main precipitation type. That being said, other
portions of forecast guidance indicate that the column may not be
saturated in the snow growth zone, which could lead to
precipitation type issues...as in precipitation may fall in the
form of freezing drizzle or freezing rain. Again, the wintry
threat depends on the movement and exact locations of both the low
pressure and surface cold front, as well as any lingering warm
layer aloft. This is quite the complicated forecast, but given an
evaluation of the overall weather pattern and movement of the
upper level low, this system does not currently have the potential
to be a significant wintry weather event for the High Plains. Any
potential significant snowfall would be well to the north,
removed from our forecast area. In addition, forecast
probabilities also highlight the same message...there is only a 15
percent chance for QPF to be over 0.25", so the likelihood of
significant precipitation in general is quite low. Finally, the
temperature forecast is in doubt, mainly as a result of the
timing. Once precipitation changes to the wintry variety behind
the cold front, I don`t see it changing back due to a warming from
daytime heating. Cold air advection should dictate that once the
cold front comes through, temperatures drop through the rest of
Attention then turns to the next weather system, this one in
rapid succession and moving through the region Sunday into Sunday
night. However, with this system moving well behind the initial
cold front, cold air should prevail and precipitation type issues,
or mixed signals on what type of precipitation will fall, are not
expected. Therefore, any precipitation with this system should
fall in the form of snow due to cold temperatures throughout the
atmospheric profile. For this event, there are also no strong
signals for substantial lift that would produce any substantial
snow bands as we`ve seen. Therefore, am anticipating a broad
precipitation field consisting of light snow. Snow amounts should
be quite light, only amounting to a dusting for most locations.
Finally, another disturbance could move over the Plains on
Wednesday. However, model guidance is not in strong agreement,
differing drastically on the timing of and somewhat the strength
of this system. Therefore, it`s difficult to confidently predict
what will happen with this one. A cold front does look to appear
to move through, so a return of colder air can be expected. Any
precipitation has the possibility of falling as snow, especially
if strong cold air advection occurs behind the front. For now,
will not highlight this system in any product as uncertainty is
quite high at this juncture.
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 500 PM MST Wed Mar 2 2022
GLD: VFR conditions will prevail this evening and overnight. A
period of IFR stratus and/or fog may develop around, or shortly
after, sunrise (12-15Z) -- as a cooler airmass /effective cold
front/ progresses southwestward from Nebraska into northwest
Kansas. With the GLD terminal situated on, or very near, the
western-most periphery of the frontal zone.. considerable
uncertainty exists with regard to whether or not low ceilings
and/or fog will develop.. and, if so.. the extent/duration
thereof. Light and variable winds will prevail this evening
through late Thu morning.. shifting to the S and increasing to
10-20 knots by early afternoon.
MCK: VFR conditions will prevail through the evening and most of
tonight. MVFR-IFR ceilings are anticipated to develop around
sunrise (11-14Z).. as a cooler airmass /effective cold front/
progresses southwestward from Nebraska into northwest Kansas.
Low ceilings may persist for several hours thereafter. Conditions
are anticipated to improve during the late morning and early
afternoon. Light/variable or light ENE winds will prevail this
evening.. veering to the E and increasing to 12-17 knots shortly
before sunrise (10-12Z). Winds will veer to the ESE-SE and
decrease to 8-13 knots during the late morning and afternoon.