710
FXUS63 KGLD 191653
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
953 AM MST Sun Jan 19 2025

.KEY MESSAGES...

- Extreme Cold Watch continues for the entire area this evening
  through Tuesday morning as the potential remains for -15 to -30
  below wind chills.

- Light powdery snowfall returns to the area late tonight,
  continuing through the day Monday with accumulations
  generally under one inch.

&&

.UPDATE...
Issued at 857 AM MST Sun Jan 19 2025

The Cold Weather Advisory has been allowed to expire on time as
temperatures are warming and will continue to warm into the
upper teens to low 20s through the remainder of the day. The
Extreme Cold Watch through Tuesday morning remains unchanged at
this time.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 300 AM MST Sun Jan 19 2025

Today-tonight...we should see some sunshine today, ahead of another
weather disturbance that will move into the area by mid evening,
continuing overnight. There is a 20%-50% chance of light powdery
snow as this system moves through, mainly for those south of the
KS/NE border. Snowfall accumulations ranging from a trace to a few
tenths of an inch are forecast.

High temperatures are expected to be in the lower to middle 20s. Low
temperatures are currently forecast to be in the single digits above
and below zero. Overnight wind chill readings are forecast to range
from 10 below to 27 below zero, coldest across eastern Colorado.
Day shift will evaluate the need for Cold Weather Advisories
and potential Extreme Cold Warnings.

Monday-Monday night...there will continue to be a chance of light
powdery snow during the day (20%-60%) with decreasing chances from
north to south as Sundays nights weather system moves through.
Additional snowfall accumulations of a trace to perhaps one inch are
forecast with the highest values across Greeley and Wichita counties.

Northwest winds gusting up to 30 mph develop behind the departing
precipitation area during the day.

High temperatures are forecast to be in the in the single digits
across eastern Colorado with 10 to 15 degrees east of the CO/KS
border as the final shot of arctic air moves in. Low temperatures
are currently forecast to be in the single digits below zero.

Daytime wind chill readings may not get above zero and
highlights may be needed across eastern Colorado where Flagler
is hovering around 15 below zero. Overnight, wind chill readings
are forecast to be in the 10 below to 25 below zero range,
coldest across eastern Colorado. An Extreme Cold Watch remains
in effect.

Tuesday-Tuesday night...it looks like we`ll break out of the extreme
cold as warm above freezing with high temperatures currently
forecast to be in the lower 30s to around 40. However, with NBM
model showing a 7 to 11 degree spread in high temperatures, they
could be lower, similar to the NAM/SREF highs several degrees
cooler. Low temperatures are forecast to be in the teens.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Issued at 122 AM MST Sun Jan 19 2025

The period will begin with an Alberta Clipper moving into the Great
Plains. While this Clipper will not make a direct impact on the Tri-
State area, we can expect a northwesterly 850 mb LLJ to form remain
in place until Thursday afternoon. Friday, a ridge will push into
the western CONUS, weakening the farther east it moves by another
trough that follows closely behind. The GFS, ECMWF, and CMC-NH are
all finally agreeing that the cutoff low that`s been sitting off the
west coast for about a week will be ingested into this weekend
trough, to what extent is still up for debate.

Down at 850 mb, a high will be extending from the Great Basin/Four
Corners area into northwestern Texas. This will move some warmer air
into the Southern Plains, potentially getting into the CWA. However,
Wednesday morning, a Colorado low forms and moves southeast, helping
drag cooler air into the CWA. NBM and diagnostic guidance is pretty
confident with high temperatures Wednesday being the mid 30s to low
40s and the dry air preventing precipitation. The 850 mb LLJ looks
to be around 30 kts, with little to no inversion preventing mixing.
This would allow gusts around 30 kts to occur at the surface.

Thursday looks to be copy of Wednesday, except with less confidence
in temperatures. If the low stays farther west, temperatures will be
in the upper 20s to mid 30s, but if the low moves east Wednesday
night, highs will be in the upper 30s to mid 40s. There is no strong
indication what the low will do yet, but we`ll keep an eye on it.
Lows Wednesday and Thursday nights will be in the teens across the
area. Some of the western portions of the CWA could drop into the
upper single digits if skies remain clear.

Friday morning, all the guidance I am seeing (GFS, GEFS, ECMWF, &
CMC-NH) is showing the 850 mb high moves into Texas and extends a
pronounced ridge into the the Great Plains. At some point between
12Z Friday and 6Z Saturday, a southwesterly LLJ of 30-45 kts forms,
pumping warm, moist air into the region. If all of this comes to
fruition, temperatures will warm into the 50s Friday. However, if
this ridge is weaker than currently shown, the LLJ will be slower
and temperatures will be in the 40s.

A trough will be moving in around the Friday-Sunday timeframe from
the Pacific Northwest. There is large range of possibilities in what
this trough will bring, so confidence is very low. A couple of
scenarios include the additional moisture from the southwesterly LLJ
would allow the trough and associated low to produce precipitation
across the area. What kind of precipitation will entirely depend on
the PBL temperatures, but snow, rain, and wintry mix are all
possible. Conversely, the low could stop the southwesterly LLJ
before it moves moisture into the area and keep temperatures below
freezing over the weekend with little/no precipitation.

List of acronyms
NBM - National Blend of Models
GFS - Global Forecast System
GEFS - GFS Ensemble Forecast System
ECMWF - European Centre for Medium-range Weather Forecasts
CMC-NH - Canadian Meteorological Centre-Northern Hemisphere
CAA - Cold Air Advection
WAA - Warm Air Advection
PoP - Probability Of Precipitation
PBL - Planetary Boundary Layer
LLJ - Low Level Jet
RH  - Relative Humidity
F/C - Fahrenheit/Celsius
mb - Millibar
kts - Knots
Z - Zulu time (UTC)
CWA - County Warning Area
CONUS - CONtiguous United States

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 950 AM MST Sun Jan 19 2025

VFR conditions are currently forecast at each terminal for the
majority of this TAF period. The exception may be at KGLD where
a PROB30 exists as some powdery snow may try to develop between
the 05 and 09Z time frame. I do have some concerns about to much
dry air being in place which is the reasoning for the lesser
confidence versus the prior VCSH mention. A cold front will then
push through the area leading to breezy winds and being more
from the NNW direction through the end of the period. Behind
this much drier air will push in bringing an end to any cloud
cover.

&&

.FIRE WEATHER...
Issued at 300 AM MST Sun Jan 19 2025

Elevated fire weather conditions are possible Monday afternoon north of
Interstate 70 and east of Highway 25. In this area, relative humidity
falls to around 20 percent with northwest winds gusting up to 30 mph.

For Tuesday afternoon, relative humidity values fall into the 15 to 20
percent range along and north of Interstate 70 and along and east of
Highway 27. Surface winds are currently forecast to be below thresholds,
generally from the west-southwest at 10 to 15 mph with gusts up to 20
mph.

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...Extreme Cold Watch from 5 PM MST /6 PM CST/ this afternoon
     through Tuesday morning for KSZ001>004-013>016-027>029-
     041-042.
CO...Extreme Cold Watch from 5 PM MST this afternoon through
     Tuesday morning for COZ090>092.
NE...Extreme Cold Watch from 5 PM MST /6 PM CST/ this afternoon
     through Tuesday morning for NEZ079>081.

&&

$$

UPDATE...Trigg
SHORT TERM...99
LONG TERM...CA
AVIATION...Trigg
FIRE WEATHER...99