149
FXUS63 KGLD 071010
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
310 AM MST Thu Nov 7 2024

.KEY MESSAGES...

- Rain and snow showers are forecast to continue today, though
  lessen in coverage from east to west as the day goes on.
  Additional rain accumulations of a tenth to half an inch and
  snow accumulations (Eastern Colorado) of 2 to 7 inches are
  possible. The Winter Storm Warning remains in effect.

- After a brief reprieve Thursday night, the system is forecast
  to move back over the area Friday, producing heavy amounts of
  precipitation. Additional rain accumulations between 3/4 and
  3 inches are possible. Additional snow accumulations of 6 to
  12 inches are possible in Eastern Colorado depending on where
  the rain/snow line sets up.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 307 AM MST Thu Nov 7 2024

Current observations show the upper low shifting slowly south
through Arizona with rain and snow showers moving in from the
southwest. Meanwhile, higher surface pressure continues to push in
from the north.

For today, conditions are forecast to be somewhat similar to
yesterday with persistent cloud cover across most of the area, rain
showers in NW Kansas and SW Nebraska, and snow showers in Eastern
Colorado and adjacent counties. The bigger difference for today is
that the surface low and forcing is going to be well south of the
area. This will limit the chance for longer lived bands of heavy
precipitation. We`ll still see bands of precipitation rotate into
the area, but they will favor the southwestern portions of the area.
Chances for rain are forecast to lower to 10% or less by late
morning for locales along and east of Highway 25 as the saturated
area pulls west and drier air begins moving in from the east. This
may even allow for some breaks in the clouds and sunshine for
eastern portions of the area. As for as precip totals go, most of NW
Kansas and SW Nebraska are forecast to see around a tenth or less of
precip during the daytime hours as the drier air moves in. For
Eastern Colorado and adjacent counties, it`ll vary a bit on how far
west the dry air can move in, but a quarter to half an inch of
liquid is currently forecast with snow amounts ranging from 1 inch
in far Western Kansas, to 7 inches in far western Kit Carson and
Cheyenne counties where moisture is forecast to linger through the
day. Highs will range from 30`s for counties along the Colorado
border, to 40`s and 50`s for the rest of the area.

Tonight, the upper low is forecast to begin moving east and a bit
north. However, the Tri-state area is forecast to remain under high
surface pressure, so any precipitation will result from saturated
air and likely just lead to low accumulations through the night (2
inches or less of snow, quarter of an inch of rain or less). With
the persistent cloud cover, temperatures are forecast to only lower
into the 20`s and 30`s.

Tomorrow is forecast to be a bit more active and interesting as the
upper low is forecast to pull northeast across the area, with the
surface low pulled just south of the area. With this, the area will
likely see wrap around precipitation through much of the day. With
moisture feeding in around the low, the area should see some hefty
precip totals with 3/4 quarters of an inch to 3 inches of
rain/liquid equivalent through Saturday morning. Given the long
duration of the rainfall, flooding is not expected. Even if heavy
rain bands develop, the current forecast speed of the upper and
surface low should keep the bands moving and not allow them to
remain over one spot for long. On top of the rain, will have to
watch for more snow in Eastern Colorado and adjacent areas with the
moisture moving in. With the forecast QPF, if snow remains the main
precip type, 6 to 12 inches of snow on Friday would be feasible. The
main questions is how much warmer air gets pulled in from the east
along with the moisture that would pull temperatures and dew points
above freezing. If the rain/snow line is pushed back into our
Eastern Colorado counties, then Snow Liquid Ratios (SLRs) will
remain too low and the slushy snow would likely melt with rain
mixing in. Otherwise, accumulating snow would be possible again. A
Winter Storm Watch has been issued for Eastern Colorado on Friday.
Will also have to watch for stronger wind gusts above 30 mph mixing
with the snow as the surface low increases the pressure gradient
over the area. Visibility may be reduced and, in a worst case,
blizzard conditions may be possible for parts of Eastern Colorado.
highs are forecast to be in the 30`s and 40`s with the widespread
precipitation.

Tomorrow night, the lows are forecast to continue shifting
northeast. While precipitation will be likely through the night,
will have to watch for a dry slot as the surface low is pulled over
the area. The low moving over the area is also forecast to weaken
the winds. Lows are forecast to again remain in the 20`s and 30`s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Issued at 100 AM MST Thu Nov 7 2024

Saturday...a 550mb upper level low pressure area is forecast to be
on top of the Tri-State area in the morning, continuing a northeast
movement into eastern Nebraska by late in the day then toward
Minnesota overnight. Similar to 24 hours ago, the best chance for
additional moisture (mainly rain) will be in the morning as we`re
under wraparound precipitation. The overnight hours will be dry with
decreasing cloudiness. High temperatures are currently forecast to
be in the upper 30s to lower 50s, coldest across far eastern
Colorado where considerable snow cover is likely. Low temperatures
are forecast to be in the lower 20s to lower 30s.

Sunday...near zonal flow is forecast across the area. Moisture
availability for precipitation is nearly nil so we`ll continue with
a dry forecast. High temperatures remain challenging given some
expected snow cover along and west of the CO/KS border so
adjustments are likely going forward. Presently, highs will range
from the 40s and 50s in far eastern Colorado to the lower to middle
60s elsewhere. Low temperatures fall into the lower 20s to
middle 30s.

Monday...a pattern change remains in the forecast as a large upper
moves onshore of the west coast overnight with downstream ridging
over the northern and central plains. With a continued lack of
moisture for precipitation, we`ll continue with a dry forecast. High
temperatures are forecast to be in the 40s and 50s in snow covered
areas of far eastern Colorado with 60 to 65 elsewhere. Low
temperatures are forecast to be in the middle 20s to middle 30s.

Tuesday...there is a bit more agreement between the GFS/ECMWF/GEFS
models in bringing Mondays upper trough into our area. The ECMWF
models is most bullish in moisture availability for light
precipitation which is what the NBM model has overnight...a 20%
chance for light rain showers in far eastern Colorado. High
temperatures remain similar to Monday with readings in the 40s and
50s in far eastern Colorado, likely dependent on any snow cover
with lower 60s elsewhere. Low temperatures again in the middle
20s to middle 30s.

Wednesday...as the upper trough moves away from the area, we`ll have
increasing northwesterly winds. Locally developed blowing dust
parameters such as 0.5-1km wind speeds of at least 44kts are met
while 0-2km lapse rates up to 7C/km arent the greatest. If the GFS
were to verify, the blowing dust threat would be east of the CO/KS
border in the afternoon. GEM/ECMWF models arent as strong on the 0.5-
1km wind speeds and timing of the whole synoptic system are in
question so confidence in any one solution is rather low. High
temperatures are forecast to be in the 40s and 50s with low
temperatures in the 20s.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1026 PM MST Wed Nov 6 2024

At KGLD...light snow and low ceilings will continue to impact
flight categories through the entire TAF period. The main upper
low will move over the area tomorrow which will continue to
provide lift for mainly snow, though there may be occasional
changeovers to rain, particularly Thursday afternoon as
temperatures warm into the mid to upper 30s.

At KMCK...precipitation chances more uncertain at McCook. Best
chances will be during the overnight and morning hours when
occasional rain showers will be possible, but with only minor,
if any, reductions in visibility. Ceilings will be very close
to the VFR/MVFR threshold, but expect mostly MVFR through
tonight and tomorrow morning, with a tendency to go more VFR by
Thursday afternoon. The next round of precipitation coming up
from the south tomorrow will mostly impact areas further west,
but still might see some showery type activity through the
afternoon, mainly as rain.

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...Winter Storm Warning until 5 PM MST this afternoon for KSZ013.
     Winter Weather Advisory until 6 AM CST early this morning for
     KSZ001.
CO...Winter Storm Warning until 5 PM MST this afternoon for
     COZ090>092.
     Winter Storm Watch from late tonight through late Friday night
     for COZ090>092.
NE...Winter Weather Advisory until 5 AM MST early this morning for
     NEZ079.

&&

$$

SHORT TERM...KAK
LONG TERM...99
AVIATION...024