-- Discussion containing changed information from previous version are highlighted. --
780
FXUS63 KGLD 271104
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
504 AM MDT Mon May 27 2024

.KEY MESSAGES...

- Relatively mild conditions with highs around 80 and winds
  generally below 10-15 mph are forecast for Memorial Day and
  Tuesday. A few non-severe, showers and storms are possible
  during the evening hours both days.

- Warm and active pattern is expected next week, with chances
  for storms bringing an associated flooding risk.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 255 AM MDT Mon May 27 2024

For Memorial Day, a pleasant day is in store for the area. With an
upper ridge beginning to build into the area and relatively weak
flow, mild temperatures in the upper 70`s and light winds generally
below 10 mph are forecast for today. There could be a few sprinkles
and shower tonight with some mid-level moisture moving over the
area. The question is if there is too much dry air at the surface
for anything to hit the ground. Lows tonight will drop into the 40`s
with mostly calm winds.

Tomorrow, the upper ridge axis is forecast to move further east into
the Rockies with a little more influence over the area. Winds are
forecast to shift to out of the southeast during the day and begin
bringing in moisture into the area. With the mid level moisture
remaining over the area, the daytime hours are forecast to see
partly cloud skies and maybe a few sprinkles. Highs are forecast to
reach the low 80`s. Showers and storms become more likely in the
late afternoon and evening hours as moisture continues to advect
into the area and a small disturbance possibly moves through the
flow. At best, it looks like a cluster of storms could form in
Eastern Colorado and move east, along and south of I-70. Severe
weather isn`t expected and the storms may move through a small
portion of the area if they form at all. Winds will calm going into
the night and skies clear with lows dropping to around 50.

Wednesday, the upper ridge axis is forecast to be over the area.
While this would generally favor temperatures warming to the mid to
upper 80`s, cloud cover may prevent heating to potential as guidance
suggests a fair amount of low level moisture may be present by
Wednesday. With the moisture over the area and broad low pressure
forecast to form along the Front Range, storms could fire up in
Eastern Colorado during the afternoon and evening hours. These
storms would have the potential to be marginally severe with
forecasted CAPE around 1000-1500 J/KG and effective shear around 40
kts. However, instability would be lacking a bit if cloud cover does
linger across most of the region during the day. The storms would
also struggle to enter NW Kansas and SW Nebraska with low
instability and no synoptic forcing as you go east. Wed night would
then see a mix of clouds and clear skies with storm chances
dropping. Winds may remain a bit more elevated around 15 to 20 kts
with the low pressure to the west of the area.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Issued at 306 AM MDT Mon May 27 2024

Thursday, an upper-level low pressure system is showing up near the
Great Basin region. Ensembles and diagnostic models are still
showing this feature, which could bring our next chances of
organized, potentially severe, convection. The broad strokes of the
forecast have stayed the same and now some of the "finer" details
are showing. Ahead of the convection, starting some time Wednesday
evening, the LLJ looks to start kicking up and will start shoveling
moisture into the region. The LLJ looks to continue for about 48-60
hours, until the low level low pressure system, and corresponding
cold front, moves through. This increased moisture is expected to
increase PWATS to over an inch by Thursday through potentially
remain until Saturday. As the forecast currently stands, Thursday
will be a heavy rain day, Friday could see more severe weather, and
Saturday`s storms will be "whatever`s left" situation.

Thursday is looking to have the highest PWATS, ranging from 1.15-1.4
inches, EBWD shear around 25-30 kts, and up/downshear speeds <30/20
kts, and the 0C line being around 14,000 feet. These parameters
suggest storms that form will produce heavy rain and will be moving
at a slower pace than recent storms. However, instability in the
environment could easily turn heavy rain storms into large hail
storms. MUCAPE from the GFS is 3,000-4,000 J/kg. The most likely
hazards Thursday will be heavy rain leading to localized flooding,
hail, and strong winds.

Friday`s severe convective parameters suggest the threat for hail
and wind is greater than the heavy rain threat. A tornado or two
cannot be ruled out for Friday either. PWATS come down slightly, to
around 1-1.15 inches, but EBWD increases to around 40 kts, and LCLs
drop to around 1 km. Instability will be decreased from the
persistent cloud cover and cooler temperatures versus Thursday.
MUCAPE looks to be around 1,000-1,500 J/kg, so a low CAPE high shear
day my be in order. A major note about Friday is that heavy rain may
still happen, and combined with Thursday`s rain, flooding will still
be a concern Friday. Storm speeds are expected to be a bit fast on
Friday, with downshear speeds over 30 kts.

Saturday and beyond are a bit of a question still. Around this time
the models start getting dissonant about what will happen, but we
are seeing guidance suggesting Saturday will see the final low
pressure system and cold front move through the area. This is
expected to cause more storms to form, but severe weather looks less
likely as instability will be fairly limited by then. The risk for
flooding will still continue on Saturday as any location that
receives heavy rainfall the previous two days will be prone to
flooding if additional rain occurs.

There is a chance (~15%) that we will only see some showers or weak
storms throughout the period and severe weather won`t occur. This
would occur if the increased cloud cover kept temperatures cooler
than forecast, which would greatly reduce our instability. This
would also lower the flood risk to near 0.

Temperatures will be in the mid 70s to mid 80s Thursday and cool off
behind the first wave of storms. Friday and Saturday, most locations
won`t warm out of the 70s. Sunday, after most of the moisture has
cleared out, temperatures will return to the upper 70s and 80s for
most of the CWA. Low temperatures will have less variance are are
expected to remain in the 50s throughout the period.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
-- Changed Discussion --
Issued at 501 AM MDT Mon May 27 2024

For KGLD & KMCK... VFR conditions are expected through the day
with light near surface winds, generally below 10 kts. The only
thing worth note is the potential for sprinkles and showers
between 03-12Z, but chances are around 10% or less that they
would form.
-- End Changed Discussion --

&&

.HYDROLOGY...
Issued at 306 AM MDT Mon May 27 2024

Highly efficient moisture return looks to begin late Tuesday night
and continue into the end of the workweek via the 850 mb LLJ. This
moist conveyor belt will cause PWATS to increase above 1 inch
starting Wednesday afternoon and potentially remain that way until
Saturday. The highest values will be in the eastern CWA, but the
majority of the Tri-State area will have a good chance (60%+) at
seeing PWATS above 1 inch. Throughout this active pattern, a high
melting layer is also expected, generally 11,000-15,000 feet agl.

Thursday is currently the best day for storms to create heavy
rainfall that could lead to rate-driven flash flooding. However,
Friday and Saturday are also at risk for flooding potential due to a
combination of efficient rain producing storms and potentially
multiple days of heavy rain saturating the soil.

Current confidence in localized flooding occurring in the latter
half of the week is around 10%.

&&

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

&&

$$

SHORT TERM...KAK
LONG TERM...CA
AVIATION...KAK
HYDROLOGY...