607
FXUS63 KGLD 292020
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
220 PM MDT Mon Apr 29 2024

.KEY MESSAGES...

- A marginal to slight risk for severe thunderstorms continues
  for areas east of Highway 25 on Wednesday afternoon and
  evening. However, confidence is low at this time due to
  uncertainty on the location of a warm front which will
  determine where storms will develop.

&&

.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 220 PM MDT Mon Apr 29 2024

Latest surface analysis shows a warm front from the Nebraska
panhandle into northwest Kansas and a new lee trough developing
in northeast Colorado. At 500 mb, seeing zonal flow with some
weak embedded waves. Visible satellite imagery shows some
scattered CU across the area with strong surface heating.
However bases are at around 10kft so only the occasional virga
on radar. Tonight, expecting mostly clear skies with surface
winds turning towards the southeast and gradually increasing.
Low temperatures will be in the 40s to lower 50s.

Tuesday, shortwave trough rotating around the base of an upper
low in the northern Rockies will force a surface cold front
through the area in the morning. Winds will shift to the
northwest behind the front with gusts up to 35 mph in northwest
corner of the area (Yuma County) and 20-30 mph across the
remainder of the area. Afternoon relative humidity values of
less than 15% have a fairly high probability of occurring for
areas south of Interstate 70, but probabilities for wind gusts
of greater than 25 mph are very low, as most of the wind is in
the morning behind the front. So, not expecting any fire weather
concerns due to the lack of wind in the afternoon. Despite the
frontal passage, expecting high temperatures in the 70s to
around 80. Tuesday night may see an isolated shower or two in
the post frontal upslope regime into the higher terrain, but
not much forcing otherwise. Low temperatures will be in the 40s.

Wednesday, will start the day cloudy and cool with east to
northeast surface winds. May be some fog as well. Old frontal
boundary will start to return north as a warm front into south
central Kansas during the afternoon. Models not in very good
agreement on how far north the front will retreat. NAM in
particular keeps the front south of the area with cloudy, cool
conditions through the entire day. GFS a little further north
but most of the area still capped, particularly north of the
Interstate. All of this casts some doubt on severe potential
Wednesday afternoon. Nonetheless, SPC keeps the eastern area
outlooked with marginal to slight risks, assuming the warm front
is further north. Deep layer shear will be sufficient for severe
storms should that happen. Synoptic scale forcing will also be
rather nebulous in the afternoon, with a broad southwesterly
flow aloft ahead of a shortwave trough axis still over the
central Rockies. As that wave comes out Wednesday evening,
showers and isolated thunderstorms will increase in coverage,
with the associated surface cold front serving as a focus.
Models again are not in particularly good agreement for
Wednesday night either. ECMWF is much wetter compared to the GFS
with a swath of near 1" precipitation amounts along the front,
while the GFS shows up to a half inch, mainly in southwest
Nebraska. Either way, with the upper dynamics and front moving
through Wednesday night should see the best chance for rain in
the area. Temperatures on Wednesday will be highly dependent on
what happens with the warm front, but for now NBM shows 70s and
80s across the area, but the NAM is notably cooler, especially
north of Interstate 70 in Kansas and Nebraska, showing only 50s
and 60s for highs. Low temperatures Wednesday night will be
mostly in the 40s.

Upper trough axis will be moving through Thursday morning with
gusty northwest winds behind it. Both GFS and ECMWF show gusts
to around 40 mph in the morning, gradually diminishing through
the afternoon. Best chance for lingering showers will be in the
morning. Highs will be in the 60s. A bit skeptical of the NBM
shower chances Thursday night with lack of forcing and surface
winds remaining downslope. Both the GFS and ECMWF are dry
Thursday night. Low temperatures will range from the middle 30s
in western areas to the lower 40s in eastern areas. Some patchy
frost possible in eastern areas where vegetation is
susceptible, but about a week early for frost/freeze concerns in
western areas where typical last freeze dates are around May 7-
May 10.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Issued at 220 PM MDT Mon Apr 29 2024

Another shortwave trough will be moving across the central CONUS
on Friday in the fast zonal flow aloft. Thunderstorm chances
will be limited by weak low level moisture return and
instability forecasts of only a few hundred j/kg. So expecting
scattered showers and only isolated thunderstorms as it moves
through Friday afternoon and Friday night. Highs will be in the
lower 70s and lows Friday night ranging from the middle 30s in
Colorado to the middle 40s in north central Kansas.

Over the weekend, will be between systems with shortwave ridging
on Saturday transitioning to southwest flow on Sunday ahead of
the next system digging into the southwest CONUS. Saturday will
see temperatures in the upper 60s to lower 70s with a big warm
up on Sunday to the upper 70s to lower 80s. Cannot rule out a
stray shower or thunderstorm either day, but with the lack of
forcing and almost no instability, think it will be mainly dry.

On Monday, the next system starts to move towards the plains out
of the southwest. There are some rather large discrepancies in
the models in the track of the upper low at this point, such
that by Monday afternoon the GFS has it over eastern Colorado
but the ECMWF has it over North Dakota. Blended model keeps it
dry for now with temperatures warming into the 80s. May also
have fire weather concerns by Monday, but low confidence give
the model discrepancies.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1136 AM MDT Mon Apr 29 2024

VFR expected to prevail at both KGLD and KMCK through the TAF
period. Surface winds will back from northwesterly this
afternoon to southeasterly by tonight. A cold front will move
through the terminals Tuesday morning with surface winds
shifting back to northwest and becoming gusty.

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...None.
NE...None.

&&

$$

SHORT TERM...024
LONG TERM...024
AVIATION...024