-- Discussion containing changed information from previous version are highlighted. --
098
FXUS63 KGLD 251755
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
1155 AM MDT Sat May 25 2024

.KEY MESSAGES...

- A Red Flag Warning has been issued for Cheyenne county in
  Colorado this afternoon.

- Severe storms are possible for most of Northwestern Kansas and
  Southwestern Nebraska this afternoon and evening. Yuma county
  could also see a severe storm or two. Large to very large
  hail, damaging wind gusts, and a tornado or two are possible.

- Warm and active pattern is expected next week.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 336 AM MDT Sat May 25 2024

Another active day is in store for the area as an upper trough
swings through the Northern Rockies and a surface low move east into
the area off the Front Range. For the daytime hours, the biggest
question is how much upper level cloud cover will be present over
the area. Current satellite observations show high clouds moving off
the mountains into the area along with some high clouds over the
eastern parts of the area from sprinkles. If the cloud cover spreads
over the area and maintains, temperatures could be a few degrees
cooler than forecast. The biggest impact would be to the critical
fire conditions in East Central Colorado as RH may not drop below
15% or for a much more limited time period. Otherwise, temperatures
should warm into the mid to upper 80`s with mostly sunny skies
through the day. Did issue a Red Flag Warning for Cheyenne county in
Colorado as the afternoon hours should see critical conditions, even
if the increased cloud cover occurs (it would just lower the number
of hours closer to 3).

For the severe weather chances, still looking at two potential
rounds of storms today. The first would be during the mid afternoon
hours around 2-4pm CDT along the dryline and a small area of surface
convergence near the center of the low. This line would mainly
impact Northwest Kansas, but could extend far enough north into
Southwestern Nebraska. This round would likely feature very large
hail as the main threat, but damaging wind gusts and a tornado or
two would be possible (especially going into a more moist air mass
as you go east). However, chances have decreased that this line
would occur (around 30%) due to both generally weak forcing and a
potential for not enough moisture. Most guidance still keeps the mid
levels dry which would require good saturation within the lowest few
kilometers. For the second round, storms are forecast to form along
the advancing cold front around 5pm to 8pm MT and move east,
generally along and north of Highway 36. There could be some help
for initiation along the higher terrain in Eastern Colorado that
could allow severe storms to start in Yuma county. Otherwise, storms
that form should move east with all hazards possible. Likely, hail
would be the initial threat with damaging winds the main threat
after Highway 25. A tornado or two would be possible at any point
similar to thursday. This batch has around a 50-60% chance of
occurring as the main limitation would be if dry air moved far
enough north to cut off any development or keep it weak. The evening
and overnight hours would then see the winds abruptly shift to out
of the northwest with gusts up to 40 mph behind the front (shouldn`t
be as windy as Thursday night due to lesser pressure changes with
the low being more broad).

Tomorrow, the upper trough swings through the area while the surface
low moves off to the east. The pressure gradient will remain a bit
strong with winds around 20 to 25 mph with gusts up to 35 mph. Highs
should generally be in the 70`s with partly cloudy skies. There
could be a few showers or thunderstorms in the late afternoon for
eastern parts of the area with some moisture forecast to linger over
those areas. Severe weather is unlikely with fairly low instability
and effective shear below 20 kts.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Issued at 321 AM MDT Sat May 25 2024

Monday, an upper-level ridge will move in to the region from the
west and push out the remaining trough to the east. This ridge will
dominate the period through early Thursday, bringing warmer
temperatures and diurnal pop-up showers and storms Tuesday and
Wednesday. The showers and storms during this period are generally
expected to be scattered in nature, although severe weather cannot
be ruled out due to fairly strong shear. PoPs range around 20-40 in
the eastern and northern CWA, tapering off in the southwest.

Thursday, an upper-level low pressure system is showing up near the
Great Basin/Four Corners region. Ensembles and diagnostic models are
all showing this feature, which could bring our next chances of
organized, potentially severe, convection. Ahead of the convection,
starting some time Wednesday, the LLJ looks to start kicking up and
will start shoveling moisture into the region. The LLJ looks to
continue for about 48 hours, until the low level system moves
through. This increased moisture is expected to increase PWATS to
well over an inch. Combined with effective shear of 35-50 kts,
1,500+ J/kg CAPE, low LCLs and moderately slow storm motions, all
hazards are possible including flooding. Confidence at this point is
low (~10-15%) that severe weather will occur, but pinpointing a time
and place for severe weather is impossible this far out. Thursday
and Friday evenings will both have chances at severe weather.

There is a chance (~20%) that we will only see some showers or weak
storms on Thursday and Friday. This would occur if the increased
cloud cover kept temperatures cooler than forecast, which would
greatly reduce our instability.

Temperatures will generally range from the mid 70s to upper 80s
throughout the period and lows will cool into the upper 40s and
50s.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
-- Changed Discussion --
Issued at 1154 AM MDT Sat May 25 2024

For KGLD... VFR conditions prevail through the 18Z TAF period.
Southerly winds gusting to around 40 knots are anticipated to
continue through much of the afternoon. A cold front is then
forecast to move through the area around 00-02Z, shifting winds to
become out of the northwest. Storms are forecast to move into
the area with the cold front; however, confidence in impact to
the GLD terminal is low, so have omitted from this TAF issuance.


For KMCK... VFR conditions (to briefly MVFR possible in
thunderstorms) prevail through the 18Z TAF period. Southerly winds
gusting to around 30 knots are anticipated to continue through much
of the afternoon. A cold front is then forecast to move through the
area around 00-02Z, shifting winds to become out of the northwest.
Storms, possibly severe, are forecast to move into the area with the
cold front (~40-50% chance of occurrence) - have included TSRA for
the terminal beginning around 00Z. If severe storms were to occur,
all hazards including large hail, damaging winds, and a tornado
would be possible.
-- End Changed Discussion --

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
KS...None.
CO...Red Flag Warning until 6 PM MDT this evening for COZ254.
NE...None.
-- End Changed Discussion --

&&

$$

SHORT TERM...KAK
LONG TERM...CA
AVIATION...CC